Howdy,

I am building a half-rack squat rack for weightlifting. For a conceptual
reference, here is a picture of one particular commercially available unit:
http://i42.tinypic.com/2e3rcdc.jpg

For my version, I am using 3"x3" square steel tubing with an 11 gauge
(~1/8") wall thickness. The vertical members will be drilled through in a
couple dozen locations (for mounting the bar holders and safeties to), each
to a diameter of one inch.

And therein lies my issue.

My drill press is a small bench mount Delta, with a 1/4hp motor, two inch
plunge depth, and a 1/2 inch chuck. My first thought is to use a Silver and
Demming (reduced shank) drill bit, 1/2" shank, 1" drill.

The plan is to set it up outside, build a sturdy dowelled jig for locating
purposes, and use water as coolant. I will drill through one side, then flip
it over to drill the other side.

I come to you here today for a reality check. While I realize that this it
will take awhile, this being a one-off project means I am okay with it
taking several days to complete the drilling cycle.

My main concern, then, is this: am I out of my tree to consider drilling one
inch holes in 1/8" material with a 1/4 horsepower drill press?

Thank you for any and all perspectives you would be so kind as to convey to
me,

Jon

"Jon Danniken" wrote in message
...
Howdy,
snip.

My main concern, then, is this: am I out of my tree to consider drilling
one inch holes in 1/8" material with a 1/4 horsepower drill press?

You'd have more than one problem. Even with decent fixturing, it's entirely
possible that your drilled holes, assuming you had success, would not line
up. Part of the problem would be the condition of the material, which most
likely is not uniform in size, nor square.

The big problem you'd have isn't just power. Small drill presses are
expected to turn small drills, so they are geared accordingly. In order
to run a 1" drill without damage, it would have to be turned down around 475
RPM. If you can't run that slowly, you're likely to damage the drill from
heating.

One more thing to consider. Drilling large holes in thin material generally
results in three sided holes (holes that will not accept a pin the same size
as the drill used to drill the hole). I expect you won't enjoy much
success with your plan. A mill would really help.
Alternately, if you can run slow enough and can step drill, you could use a
reamer to size the holes. Overall, you would be best served if you could
drill through both sides at the same time.

Harold

DON"T do it that way - you will be VERY unhappy - get yourself a decent
bimetal hole saw of the proper diameter and use that - it will take less
power, it will make round holes, and you will not kill yourself - use some
cutting fluid

"Jon Danniken" wrote in message
...
Howdy,

I am building a half-rack squat rack for weightlifting. For a conceptual
reference, here is a picture of one particular commercially available
unit: http://i42.tinypic.com/2e3rcdc.jpg

For my version, I am using 3"x3" square steel tubing with an 11 gauge
(~1/8") wall thickness. The vertical members will be drilled through in a
couple dozen locations (for mounting the bar holders and safeties to),
each to a diameter of one inch.

And therein lies my issue.

My drill press is a small bench mount Delta, with a 1/4hp motor, two inch
plunge depth, and a 1/2 inch chuck. My first thought is to use a Silver
and Demming (reduced shank) drill bit, 1/2" shank, 1" drill.

The plan is to set it up outside, build a sturdy dowelled jig for locating
purposes, and use water as coolant. I will drill through one side, then
flip it over to drill the other side.

I come to you here today for a reality check. While I realize that this it
will take awhile, this being a one-off project means I am okay with it
taking several days to complete the drilling cycle.

My main concern, then, is this: am I out of my tree to consider drilling
one inch holes in 1/8" material with a 1/4 horsepower drill press?

Thank you for any and all perspectives you would be so kind as to convey
to me,

Jon

Bill Noble wrote:
DON"T do it that way - you will be VERY unhappy - get yourself a
decent bimetal hole saw of the proper diameter and use that - it will
take less power, it will make round holes, and you will not kill
yourself - use some cutting fluid

Ah, thanks Bill, I hadn't considered using a bimetal hole saw.

Do you think my 1/4 horsepower drill press has enough horse to turn a one
inch bimetal hole saw through 1/8" mild steel?

Thanks again,

Jon

Harold & Susan Vordos wrote:
You'd have more than one problem. Even with decent fixturing, it's
entirely possible that your drilled holes, assuming you had success,
would not line up. Part of the problem would be the condition of
the material, which most likely is not uniform in size, nor square.

Thanks, Harold. Fortunately one of the benefits of a half-rack is that
there is less of a need for precision - there are no back tube holes to
match to the front tube holes as in a four-corner rack.

The holes themselves on my rack receive a one inch diameter steel peg, and
are only used to prevent vertical motion of the barbell hook once it is
attached to the upright. To prevent movement in the horizontal direction,
the barbell hook uses a wrap-around metal strap. You might be able to get
an idea of this with this image, on the off chance that you haven't come
across such an animal in the past: http://i41.tinypic.com/2mgw787.jpg

The big problem you'd have isn't just power. Small drill presses are
expected to turn small drills, so they are geared accordingly. In
order to run a 1" drill without damage, it would have to be turned
down around 475 RPM. If you can't run that slowly, you're likely
to damage the drill from heating.

Thanks Harold, I hadn't calculated the feed rate yet, and I appreciate you
doing that for me. My drill press only goes down to 620 RPM.

As for damaging by heating, wouldn't the cutting fluid (in this case water)
keep the bit from burning out if it were run at 620 RPM? (I am not
experienced enough to know this).

One more thing to consider. Drilling large holes in thin material
generally results in three sided holes (holes that will not accept a
pin the same size as the drill used to drill the hole). I expect
you won't enjoy much success with your plan. A mill would really
help.

Aye, I may likely have to ream the holes out, depending upon the diameter of
the one-inch steel pegs to be inserted into them; thanks.

Alternately, if you can run slow enough and can step drill, you could
use a reamer to size the holes. Overall, you would be best served
if you could drill through both sides at the same time.

Indeed, that would save half of the work. One solution I am considering is
to incorporate my jig with a dowel inline with the spindle, underneath the
tube which has already had one side drilled. Using this method, the tube
would lock into place on the dowel, locating the upright drill with an
accuracy based on how well I can set up the jig in relation to the spindle.

Thanks again Harold,

Jon

On Fri, 23 Apr 2010 21:58:43 -0700, "Jon Danniken"
wrote:

Howdy,

I am building a half-rack squat rack for weightlifting. For a conceptual
reference, here is a picture of one particular commercially available unit:
http://i42.tinypic.com/2e3rcdc.jpg

For my version, I am using 3"x3" square steel tubing with an 11 gauge
(~1/8") wall thickness. The vertical members will be drilled through in a
couple dozen locations (for mounting the bar holders and safeties to), each
to a diameter of one inch.

And therein lies my issue.

My drill press is a small bench mount Delta, with a 1/4hp motor, two inch
plunge depth, and a 1/2 inch chuck. My first thought is to use a Silver and
Demming (reduced shank) drill bit, 1/2" shank, 1" drill.

The plan is to set it up outside, build a sturdy dowelled jig for locating
purposes, and use water as coolant. I will drill through one side, then flip
it over to drill the other side.

I come to you here today for a reality check. While I realize that this it
will take awhile, this being a one-off project means I am okay with it
taking several days to complete the drilling cycle.

My main concern, then, is this: am I out of my tree to consider drilling one
inch holes in 1/8" material with a 1/4 horsepower drill press?

Thank you for any and all perspectives you would be so kind as to convey to
me,

Jon

Frankly Jon..you would be better served if you made up templates to mark
your holes, center punch them..and then use a 1/2" drill motor.

While you could perhaps(not likely) drill them with a 1/4hp drill
press..you will have to work very slowly, and probably increasingly
bigger holes first.

A 1" drill isnt magic..but it takes some OOMPH to actually drill with
one.

You can make templates out of file folder cardboard every easily.

And Id at least use a 3/16" drill for a pilot drill.

The other option..would be to use a UniBit, with a 1/2" drill.

You might even get by with a 3/8" DECENT drill
motor...but...cringe....I personally would rather not.

Gunner


"First Law of Leftist Debate
The more you present a leftist with factual evidence
that is counter to his preconceived world view and the
more difficult it becomes for him to refute it without
losing face the chance of him calling you a racist, bigot,
homophobe approaches infinity.

This is despite the thread you are in having not mentioned
race or sexual preference in any way that is relevant to
the subject." Grey Ghost

On Sat, 24 Apr 2010 00:23:28 -0700, "Jon Danniken"
wrote:

Bill Noble wrote:
DON"T do it that way - you will be VERY unhappy - get yourself a
decent bimetal hole saw of the proper diameter and use that - it will
take less power, it will make round holes, and you will not kill
yourself - use some cutting fluid

Ah, thanks Bill, I hadn't considered using a bimetal hole saw.

Do you think my 1/4 horsepower drill press has enough horse to turn a one
inch bimetal hole saw through 1/8" mild steel?

Thanks again,

Jon

Thats not a bad suggestion at all.. And you MIGHT have enough power.
Maybe. Could be.

Dont have a hand drill??

Gunner


"First Law of Leftist Debate
The more you present a leftist with factual evidence
that is counter to his preconceived world view and the
more difficult it becomes for him to refute it without
losing face the chance of him calling you a racist, bigot,
homophobe approaches infinity.

This is despite the thread you are in having not mentioned
race or sexual preference in any way that is relevant to
the subject." Grey Ghost

On Sat, 24 Apr 2010 00:23:28 -0700, "Jon Danniken"
wrote:

Bill Noble wrote:
DON"T do it that way - you will be VERY unhappy - get yourself a
decent bimetal hole saw of the proper diameter and use that - it will
take less power, it will make round holes, and you will not kill
yourself - use some cutting fluid

Ah, thanks Bill, I hadn't considered using a bimetal hole saw.

Do you think my 1/4 horsepower drill press has enough horse to turn a one
inch bimetal hole saw through 1/8" mild steel?

Thanks again,

Jon


I've got a drill press, probably the same size as you, although I
built second set of belt sheaves to reduce the speed but I have cut 2
inch holes in aluminum plate with no problems. Takes a while but gets
it done.

The secret is a sharp hole saw and light feed pressure. and a lot of
oil :-)


John B. Slocomb
(johnbslocombatgmaildotcom)

On Sat, 24 Apr 2010 00:23:28 -0700, the infamous "Jon Danniken"
scrawled the following:

Bill Noble wrote:
DON"T do it that way - you will be VERY unhappy - get yourself a
decent bimetal hole saw of the proper diameter and use that - it will
take less power, it will make round holes, and you will not kill
yourself - use some cutting fluid

Ah, thanks Bill, I hadn't considered using a bimetal hole saw.

Do you think my 1/4 horsepower drill press has enough horse to turn a one
inch bimetal hole saw through 1/8" mild steel?

With prayer, patience, and plenty of cutting oil, yes.

--
....in order that a man may be happy, it is necessary that he should
not only be capable of his work, but a good judge of his work.
-- John Ruskin

Gunner Asch wrote:

Frankly Jon..you would be better served if you made up templates to
mark your holes, center punch them..and then use a 1/2" drill motor.

Heya Gunner, good to see ya, mate! Hope everything is well in Gunnerville.
Thanks for the suggestion, but I just don't have the precision with a hand
motor to get anywhere near straight. I have seen the little holders for
hand motors, but I don't know how precise I could be with one of those.

While you could perhaps(not likely) drill them with a 1/4hp drill
press..you will have to work very slowly, and probably increasingly
bigger holes first.

Okay, now that brings up a question I have. If you had an adequately rated
drill press, and needed to drill a number of one inch diameter holes in 1/8"
mild steel, would you use a hole saw or a twist bit? What would you
consider to be the minimum horsepower for either type of bit?

Also, would you consider a S/D bit suitable for a one inch hole if your
chuck was only 1/2"?

Thanks Gunner,

Jon

On Fri, 23 Apr 2010 21:58:43 -0700, "Jon Danniken"
wrote:

Howdy,

I am building a half-rack squat rack for weightlifting. For a conceptual
reference, here is a picture of one particular commercially available unit:
http://i42.tinypic.com/2e3rcdc.jpg

For my version, I am using 3"x3" square steel tubing with an 11 gauge
(~1/8") wall thickness. The vertical members will be drilled through in a
couple dozen locations (for mounting the bar holders and safeties to), each
to a diameter of one inch.

Unless you're using existing fittings that require the 1" holes, I'd
reduce their diameter. As a point of reference, I recently had to look
at #80 roller chain for lifting service. The chain pins are 5/16"
diameter; its minimum tensile strength is 12,500 lbs. The pins are in
double shear (two shear planes) and made of alloy steel, but you get
the picture.

If you're stuck with 1" holes, I second the hole saw.

--
Ned Simmons

Ned Simmons wrote:

Unless you're using existing fittings that require the 1" holes, I'd
reduce their diameter. As a point of reference, I recently had to look
at #80 roller chain for lifting service. The chain pins are 5/16"
diameter; its minimum tensile strength is 12,500 lbs. The pins are in
double shear (two shear planes) and made of alloy steel, but you get
the picture.

If you're stuck with 1" holes, I second the hole saw.

Hi Ned, and thank you for your reply. I actually noticed the same thing the
other day when I looked at the pin on my ball mount (it's a 5/8" pin in a
2"x2" piece of square tubing).

The difference, however, is that the ball mount tubing is 3/32" thickness,
instead of the 1/8" thickness of the 3x3 I will be working with. While I
would likely agree with you that it would be sturdy enough for my intended
usage, I will still be using one-inch holes in 3x3 tubing, for no other
reason than to give myself a little extra cushion for the pushin (and to
help compensate for my lack of perfect weldments, et cetera).

Also, thanks for the suggestion about the hole saw.

Jon

On Sat, 24 Apr 2010 06:51:38 -0700, "Jon Danniken"
wrote:

Gunner Asch wrote:

Frankly Jon..you would be better served if you made up templates to
mark your holes, center punch them..and then use a 1/2" drill motor.

Heya Gunner, good to see ya, mate! Hope everything is well in Gunnerville.
Thanks for the suggestion, but I just don't have the precision with a hand
motor to get anywhere near straight. I have seen the little holders for
hand motors, but I don't know how precise I could be with one of those.

While you could perhaps(not likely) drill them with a 1/4hp drill
press..you will have to work very slowly, and probably increasingly
bigger holes first.

Okay, now that brings up a question I have. If you had an adequately rated
drill press, and needed to drill a number of one inch diameter holes in 1/8"
mild steel, would you use a hole saw or a twist bit? What would you
consider to be the minimum horsepower for either type of bit?

Also, would you consider a S/D bit suitable for a one inch hole if your
chuck was only 1/2"?

Thanks Gunner,

Jon

A hole saw with plenty of cutting fluid will be the lowest-torque
approach. Next would be a step bit, last choice would be a 1" dia
twist drill. The twist drill would be better for production rate in
heavier material with suitable machinery driving it, but hole saws and
step drills (unibit) work much better when the dia of the hole is
considerably larger than the thickness of the material.

1/4 hp at 620 RPM is 25.4 in-lbf of torque. That might drive a good
holesaw if nothing binds up due to deflection. It would help a lot if
you could change pulleys to get the speed down. That would increase
your torque and decrease heating.

At 620 RPM a 1" hole saw will have a tooth speed of 162 SFPM, which is
on the high side of the range for bimetal cutting mild steel but not
absurdly out of the ball park. The range generally goes from 80 to
200 SFPM. Use lots of juice. Slower would be better.

On Sat, 24 Apr 2010 06:51:38 -0700, "Jon Danniken"
wrote:

Gunner Asch wrote:

Frankly Jon..you would be better served if you made up templates to
mark your holes, center punch them..and then use a 1/2" drill motor.

Heya Gunner, good to see ya, mate! Hope everything is well in Gunnerville.
Thanks for the suggestion, but I just don't have the precision with a hand
motor to get anywhere near straight. I have seen the little holders for
hand motors, but I don't know how precise I could be with one of those.

While you could perhaps(not likely) drill them with a 1/4hp drill
press..you will have to work very slowly, and probably increasingly
bigger holes first.

Okay, now that brings up a question I have. If you had an adequately rated
drill press, and needed to drill a number of one inch diameter holes in 1/8"
mild steel, would you use a hole saw or a twist bit? What would you
consider to be the minimum horsepower for either type of bit?

Also, would you consider a S/D bit suitable for a one inch hole if your
chuck was only 1/2"?

Thanks Gunner,

Jon

Id consider a 1/3hp drill press to be the minimum with a drill bit and
perhaps a 1/4 hp a minimum with a hole saw. If as everyone suggested,
you gear it down and use lots of oil G

How many holes do you actually need to drill? Up to say..15 or so..if
you took your time and used oil and didnt try to force em....Id say you
would be ok with a 1" hole saw. A good quality one like a Lenox. The
other option is to use a unibit/step drill of some sort..and take your
time. 1/4 hp..really isnt very much for a largish cutter of any sort.

Shrug

Gunner




"First Law of Leftist Debate
The more you present a leftist with factual evidence
that is counter to his preconceived world view and the
more difficult it becomes for him to refute it without
losing face the chance of him calling you a racist, bigot,
homophobe approaches infinity.

This is despite the thread you are in having not mentioned
race or sexual preference in any way that is relevant to
the subject." Grey Ghost

How many holes do you actually need to drill? Up to say..15 or so..if
you took your time and used oil and didnt try to force em....Id say you
would be ok with a 1" hole saw. A good quality one like a Lenox. The
other option is to use a unibit/step drill of some sort..and take your
time. 1/4 hp..really isnt very much for a largish cutter of any sort.


One thing I've not seen mentioned. Holes saws tend to give you quite a bit
overisze hole with 25 thou over not uncommon. The uni bit will give you very
close to 1.00

Karl

Don Foreman wrote:

A hole saw with plenty of cutting fluid will be the lowest-torque
approach. Next would be a step bit, last choice would be a 1" dia
twist drill. The twist drill would be better for production rate in
heavier material with suitable machinery driving it, but hole saws and
step drills (unibit) work much better when the dia of the hole is
considerably larger than the thickness of the material.

1/4 hp at 620 RPM is 25.4 in-lbf of torque. That might drive a good
holesaw if nothing binds up due to deflection. It would help a lot if
you could change pulleys to get the speed down. That would increase
your torque and decrease heating.

At 620 RPM a 1" hole saw will have a tooth speed of 162 SFPM, which is
on the high side of the range for bimetal cutting mild steel but not
absurdly out of the ball park. The range generally goes from 80 to
200 SFPM. Use lots of juice. Slower would be better.

Thanks Don, I appreciate it. Right now 620RPM is the slowest speed the
drillpress will go down to, with 3 7/8" OD pulley on the quill and 1 1/2" OD
pulley on the motor shaft.

BUT: I dug around in the shop and found my old compressor, with the 1hp
motor (not compressor duty) motor still attached to it. If I can make an
adaptor plate between the 1hp motor and the drill press mount, it *will*
fit.

The only rub is that it has a 5/8" shaft (3/16" keyway), and the smallest
single pulley with those dimensions from McmasterCarr has an OD of 1 3/4".
I'm guessing that extra 1/4" inch will multiply the RPM by 1.75/1.5 (if that
is the correct formula), and I will end up with about 725RPM at 1hp.

That's a fair bit faster, but with the extra torque perhaps I could then use
the 1" silver/demming drill bit with coolant and crank it hard through the
workpiece.

Hmmm....

Jon

Gunner Asch wrote:
Id consider a 1/3hp drill press to be the minimum with a drill bit and
perhaps a 1/4 hp a minimum with a hole saw. If as everyone suggested,
you gear it down and use lots of oil G

How many holes do you actually need to drill? Up to say..15 or so..if
you took your time and used oil and didnt try to force em....Id say
you would be ok with a 1" hole saw. A good quality one like a Lenox.
The other option is to use a unibit/step drill of some sort..and take
your time. 1/4 hp..really isnt very much for a largish cutter of any
sort.

Thanks again, Gunner, I appreciate it. The number of holes will depend upon
how closely I can space the holes without weakening the uprights (which are
3x3 square tube @ 1/8" wall thickness). If I go with 2" vertical spacing,
I'm looking at about 80 holes; with 3" spacing I'm looking at about 54 holes
(this assumes holes from 28" high to 68" high, which may increase slightly
if I discover I need holes up higher).

That'd mean going through a lot of hole cutters!

(copied from the reply I just sent to Don
BUT: I dug around in the shop and found my old compressor, with the 1hp
motor (not compressor duty) motor still attached to it. If I make an
adaptor plate between the 1hp motor and the drill press mount, it *will*
fit.

The only rub is that it has a 5/8" shaft (3/16" keyway), and the smallest
single pulley with those dimensions from McmasterCarr has an OD of 1 3/4".
I'm guessing that extra 1/4" inch will multiply the RPM by 1.75/1.5 (if that
is the correct formula), and I will end up with about 725RPM at 1hp.

That's a fair bit faster, but with the extra torque perhaps I could then use
the 1" silver/demming drill bit with coolant and crank it hard and fast
through the
workpiece (unless I can get a smaller single pulley for a 5/8" motor shaft
with a 3/16" keyway).

Hmmm....

Jon

Jon Danniken wrote:


Step drill like a Unibit. Easy to power because your only cutting a
small amount each time.

--
Steve W.
(\___/)
(='.'=)
(")_(")

On 2010-04-24, JR North wrote:
Forget the S/D drills and hole saw ideas. You need this:

http://www.harborfreight.com/cpi/cta...emnumber=96275

Might even get to 1" if you drill slow.

Perhaps -- though I'm not sure whether these are made from a
real HSS (as claimed) or one of the Chinese alloys which are not as
good. TiN is good for wear on a good strong steel, but on a poorer
quality steel is just gilding. I would be more likely to trust the
ones by Klien which I posted some pointers to in a previous (but recent)
response to this thread. Yes, it costs significantly more for the one
bit which I suggested, but that one bit is likely to last through all of
the (80+) holes you need to drill, while these may not.

Still -- use the high sulfur pipe threading oil as
coolant/lubricant. Paint it on the cutter before each cut since you
don't have flood coolant.

Good luck,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

DoN. Nichols wrote:

Maybe -- maybe not. What is the nameplate RPM for that motor vs
the one currently in the drill press? If it is a 4-pole motor (a bit
below 1800 RPM) and the original was a 2-pole motor (a bit below 3600
RPM) you would gain slower operation as well. (Same for other
possible ratios of pole counts on the motors.

Hi Don, thanks for your response; they are both 1725s.

You're forgetting the tri-lobed holes from a standard drill bit
in thin metal which was mentioned earlier.

If I go with a twist bit, I will finish it up with a reamer, a tool which I
have always been eager to play with.

But if you insist on running one -- check whether the shank has
three partial flats on it. Without those, the bit is likely to bind
and the shank slip in the chuck.

Oh man tell me about it! This Delta of mine spins a 3/8" shiny finish when
it catches at the end of a hole, and drives me NUTS!

Unfortunate, too, because there is a S/D bit in my size for under $10 from
Amazon (the flatted one is a Milwaukee at fifty bucks and it got a bad
review). I might just try a round shank, and see if I can pound the key
enough to lock it in place.

You've already had one suggestion to use a Unibit, and I second
that. In case you don't know what they are -- they are a stepped
drill bit with a single flute which is self-guiding in the metal.
They come in various size ranges and step height. How thick is your
steel?

The steel is 11 gauge (0.12). I do know what a step-drill is, and actually
have one of the DrillMaster units from HF. I have always considered it to
be a bit for drilling out thin sheet metal; I originally purchased it for
making knob holes in a chassis.

That I have had more than a couple of suggestions to use one has garenerd my
attention, although I must admit a bit of skepticism as to whether or not it
is the right tool considering the number of holes (60 to 80) and the
thickness of material which I am looking to bore (1/8").

In any case -- instead of using water, I would suggest Rigid
high-sulfur thread cutting oil.

You won't have to remove as much metal at a pass as you would
with the Silver & Demming bit, so there is a greater chance that your
drill press will have sufficient torque -- with the above-mentioned
cutting oil refreshed for each hole. (Paint it on the unibit with an
acid brush or something similar.

Thanks for the suggestion, Don. I must admit that I really like water
because it is cheap and is easy to flow at a volume sufficient to cool the
bit and workpiece. I have used it before with good results in cooling, but
perhaps it is the lubrication ability of the bona fide product which makes
it shine.

Yes -- using the dowel pin to locate the already-drilled hole on
the other side makes sense.

Thanks, it seemed to be the logical solution. I appreciate the input.

Jon

Note: apologies if this is a dupe; eternal september is living up to it's
name....

DoN. Nichols wrote:

Maybe -- maybe not. What is the nameplate RPM for that motor vs
the one currently in the drill press? If it is a 4-pole motor (a bit
below 1800 RPM) and the original was a 2-pole motor (a bit below 3600
RPM) you would gain slower operation as well. (Same for other
possible ratios of pole counts on the motors.

Hi Don, thanks for your response; they are both 1725s.

You're forgetting the tri-lobed holes from a standard drill bit
in thin metal which was mentioned earlier.

If I go with a twist bit, I will finish it up with a reamer, a tool which I
have always been eager to play with.

But if you insist on running one -- check whether the shank has
three partial flats on it. Without those, the bit is likely to bind
and the shank slip in the chuck.

Oh man tell me about it! This Delta of mine spins a 3/8" shiny finish when
it catches at the end of a hole, and drives me NUTS!

Unfortunate, too, because there is a S/D bit in my size for under $10 from
Amazon (the flatted one is a Milwaukee at fifty bucks and it got a bad
review). I might just try a round shank, and see if I can pound the key
enough to lock it in place.

You've already had one suggestion to use a Unibit, and I second
that. In case you don't know what they are -- they are a stepped
drill bit with a single flute which is self-guiding in the metal.
They come in various size ranges and step height. How thick is your
steel?

The steel is 11 gauge (0.12). I do know what a step-drill is, and actually
have one of the DrillMaster units from HF. I have always considered it to
be a bit for drilling out thin sheet metal; I originally purchased it for
making knob holes in a chassis.

That I have had more than a couple of suggestions to use one has garenerd my
attention, although I must admit a bit of skepticism as to whether or not it
is the right tool considering the number of holes (60 to 80) and the
thickness of material which I am looking to bore (1/8").

In any case -- instead of using water, I would suggest Rigid
high-sulfur thread cutting oil.

You won't have to remove as much metal at a pass as you would
with the Silver & Demming bit, so there is a greater chance that your
drill press will have sufficient torque -- with the above-mentioned
cutting oil refreshed for each hole. (Paint it on the unibit with an
acid brush or something similar.

Thanks for the suggestion, Don. I must admit that I really like water
because it is cheap and is easy to flow at a volume sufficient to cool the
bit and workpiece. I have used it before with good results in cooling, but
perhaps it is the lubrication ability of the bona fide product which makes
it shine.

Yes -- using the dowel pin to locate the already-drilled hole on
the other side makes sense.

Thanks, it seemed to be the logical solution. I appreciate the input.

Jon

Note: apologies if this is a dupe; eternal september is living up to it's
name....

DoN. Nichols wrote:

Maybe -- maybe not. What is the nameplate RPM for that motor vs
the one currently in the drill press? If it is a 4-pole motor (a bit
below 1800 RPM) and the original was a 2-pole motor (a bit below 3600
RPM) you would gain slower operation as well. (Same for other
possible ratios of pole counts on the motors.

Hi Don, thanks for your response; they are both 1725s.

You're forgetting the tri-lobed holes from a standard drill bit
in thin metal which was mentioned earlier.

If I go with a twist bit, I will finish it up with a reamer, a tool which I
have always been eager to play with.

But if you insist on running one -- check whether the shank has
three partial flats on it. Without those, the bit is likely to bind
and the shank slip in the chuck.

Oh man tell me about it! This Delta of mine spins a 3/8" shiny finish when
it catches at the end of a hole, and drives me NUTS!

Unfortunate, too, because there is a S/D bit in my size for under $10 from
Amazon (the flatted one is a Milwaukee at fifty bucks and it got a bad
review). I might just try a round shank, and see if I can pound the key
enough to lock it in place.

You've already had one suggestion to use a Unibit, and I second
that. In case you don't know what they are -- they are a stepped
drill bit with a single flute which is self-guiding in the metal.
They come in various size ranges and step height. How thick is your
steel?

The steel is 11 gauge (0.12). I do know what a step-drill is, and actually
have one of the DrillMaster units from HF. I have always considered it to
be a bit for drilling out thin sheet metal; I originally purchased it for
making knob holes in a chassis.

That I have had more than a couple of suggestions to use one has garenerd my
attention, although I must admit a bit of skepticism as to whether or not it
is the right tool considering the number of holes (60 to 80) and the
thickness of material which I am looking to bore (1/8").

In any case -- instead of using water, I would suggest Rigid
high-sulfur thread cutting oil.

You won't have to remove as much metal at a pass as you would
with the Silver & Demming bit, so there is a greater chance that your
drill press will have sufficient torque -- with the above-mentioned
cutting oil refreshed for each hole. (Paint it on the unibit with an
acid brush or something similar.

Thanks for the suggestion, Don. I must admit that I really like water
because it is cheap and is easy to flow at a volume sufficient to cool the
bit and workpiece. I have used it before with good results in cooling, but
perhaps it is the lubrication ability of the bona fide product which makes
it shine.

Yes -- using the dowel pin to locate the already-drilled hole on
the other side makes sense.

Thanks, it seemed to be the logical solution. I appreciate the input.

Jon

On Sat, 24 Apr 2010 13:16:58 -0700, "Jon Danniken"
wrote:

Don Foreman wrote:

A hole saw with plenty of cutting fluid will be the lowest-torque
approach. Next would be a step bit, last choice would be a 1" dia
twist drill. The twist drill would be better for production rate in
heavier material with suitable machinery driving it, but hole saws and
step drills (unibit) work much better when the dia of the hole is
considerably larger than the thickness of the material.

1/4 hp at 620 RPM is 25.4 in-lbf of torque. That might drive a good
holesaw if nothing binds up due to deflection. It would help a lot if
you could change pulleys to get the speed down. That would increase
your torque and decrease heating.

At 620 RPM a 1" hole saw will have a tooth speed of 162 SFPM, which is
on the high side of the range for bimetal cutting mild steel but not
absurdly out of the ball park. The range generally goes from 80 to
200 SFPM. Use lots of juice. Slower would be better.

Thanks Don, I appreciate it. Right now 620RPM is the slowest speed the
drillpress will go down to, with 3 7/8" OD pulley on the quill and 1 1/2" OD
pulley on the motor shaft.

BUT: I dug around in the shop and found my old compressor, with the 1hp
motor (not compressor duty) motor still attached to it. If I can make an
adaptor plate between the 1hp motor and the drill press mount, it *will*
fit.

The only rub is that it has a 5/8" shaft (3/16" keyway), and the smallest
single pulley with those dimensions from McmasterCarr has an OD of 1 3/4".
I'm guessing that extra 1/4" inch will multiply the RPM by 1.75/1.5 (if that
is the correct formula), and I will end up with about 725RPM at 1hp.

That's a fair bit faster, but with the extra torque perhaps I could then use
the 1" silver/demming drill bit with coolant and crank it hard through the
workpiece.

Hmmm....

Please re-read guidance several have offered, then do as you will.

A 1" drill bit, silver demming or otherwise, is not a good choice for
11 gage steel, and it's a particularly bad choice in a lightweight
drillpress.

I have a Bridgeport mill and I have a 1" silver-deming drillbit with
1/2" shank. If I were drilling 11 gage, I'd use a holesaw or a step
drill whether in a drillpress or in the mill.

Harbor Freight offers a pair of stepdrills for $14.99.
http://www.harborfreight.com/cpi/cta...emnumber=96275

These work quite well in a hand-held drillmotor. Drill 1/2" pilot
holes on your DP, then enlarge them to suit with a step drill in a
handheld that has the low-speed high-torque to get it done.

In article ,
"Jon Danniken" wrote:

Note: apologies if this is a dupe; eternal september is living up to it's
name....

DoN. Nichols wrote:
[snip]
If I go with a twist bit, I will finish it up with a reamer, a tool which I
have always been eager to play with.

But if you insist on running one -- check whether the shank has
three partial flats on it. Without those, the bit is likely to bind
and the shank slip in the chuck.

Oh man tell me about it! This Delta of mine spins a 3/8" shiny finish when
it catches at the end of a hole, and drives me NUTS!

I have a Delta DP-350, and the chuck it came with is useless. I had to replace
the chuck with a Jacobs. I've heard that Rohm chucks are good too.


Unfortunate, too, because there is a S/D bit in my size for under $10 from
Amazon (the flatted one is a Milwaukee at fifty bucks and it got a bad
review). I might just try a round shank, and see if I can pound the key
enough to lock it in place.

Tighten using all three key holes one after another. But it will still likely
spin free. I never could get the OEM chuck to grip firmly enough.


You've already had one suggestion to use a Unibit, and I second
that. In case you don't know what they are -- they are a stepped
drill bit with a single flute which is self-guiding in the metal.
They come in various size ranges and step height. How thick is your
steel?

The steel is 11 gauge (0.12). I do know what a step-drill is, and actually
have one of the DrillMaster units from HF. I have always considered it to
be a bit for drilling out thin sheet metal; I originally purchased it for
making knob holes in a chassis.

That I have had more than a couple of suggestions to use one has garenerd my
attention, although I must admit a bit of skepticism as to whether or not it
is the right tool considering the number of holes (60 to 80) and the
thickness of material which I am looking to bore (1/8").

I have used Irwin Unibits in thick steel sheet. They work just fine. But you
do need lubrication. I typically use black sulfur oil for steel and stainlesss
steel, and denatured alcohol for aluminum. Or water-soluble oil for all metals
listed.

I would not attempt to use a 1" twist drill in such a small machine, even if
slipping could be prevented. And in a big enough machine, when the bit caught,
it would swing the tubing and smack you, hard. The workpiece must be somehow
clamped to the drillpress table.

Even with a unibit, the workpiece must be clamped somehow.


In any case -- instead of using water, I would suggest Rigid
high-sulfur thread cutting oil.

You won't have to remove as much metal at a pass as you would
with the Silver & Demming bit, so there is a greater chance that your
drill press will have sufficient torque -- with the above-mentioned
cutting oil refreshed for each hole. (Paint it on the unibit with an
acid brush or something similar.

Thanks for the suggestion, Don. I must admit that I really like water
because it is cheap and is easy to flow at a volume sufficient to cool the
bit and workpiece. I have used it before with good results in cooling, but
perhaps it is the lubrication ability of the bona fide product which makes
it shine.

While water is certainly convenient, I would not use water for this.

DoN is right. Use black sulfur oil, which is made for exactly this purpose, and
is cheap and widely available. Lubrication is the issue, plus chemistry. The
sulfur is there for a reason. Cooling is less of an issue with HSS tools.

Many hardware stores carry black sulfur cutting oil, as does Home Despot (may be
in plumbing, may be in hardware), and all plumbing supply houses. There are
many brands. You will also want a small brush for applying the oil. The
traditional approach is to use a seamless steel tuna can and an acid brush.
Seamless is good because the oil will seep through the seals in some kinds of
tin can. Steel is good because the sulfur in the oil will stain non-ferrous
alloys.


Given the number of large holes to made, I have to ask why you don't just get a
larger and stronger drill press.


Joe Gwinn

"Don Foreman" wrote in message
...
snip
A hole saw with plenty of cutting fluid will be the lowest-torque
approach. Next would be a step bit, last choice would be a 1" dia
twist drill. The twist drill would be better for production rate in
heavier material with suitable machinery driving it, but hole saws and
step drills (unibit) work much better when the dia of the hole is
considerably larger than the thickness of the material.

Exactly.

In spite of my suggestion, earlier, to follow the drilled hole with a
reamer, I would use a hole saw, assuming I could get one that created a hole
in keeping with my needs. They tend to cut a ragged hole until they self
pilot.

In answer to the concept of water allowing a greater surface speed, while
coolant keeps temperature under control, it has little effect of the cutting
edge. If you run too fast, the cutting edge overheats and burns, in spite
of being cooled. Surface speed must be reduced, or tools that can
withstand greater surface speed would be required.

Harold

I'll throw in a vote for using a hole saw. And add that they are good
to have around, even if they are not used that much.

As far as using a hole saw, there is something very important to know:
the teeth will become clogged with chips VERY quickly - maybe in 1/2
revolution, if you're actually feeding & not just rubbing the teeth G.
You can "peck" to clean the teeth, but better is to pre-drill a couple
of small clearance holes just inside the circumference of the hole saw.
For your 1" holes, I'd drill 2, 1/4" clearance holes 180 degrees
apart. Makes a BIG difference.

Bob

My drill press is a small bench mount Delta, with a 1/4hp motor, two inch
plunge depth, and a 1/2 inch chuck. My first thought is to use a Silver and
Demming (reduced shank) drill bit, 1/2" shank, 1" drill.

Others have addressed the bit, and there has been passing reference to
gearing down the drill press.

Here's how I did that for mine:
http://home.comcast.net/~glyford/js/js.htm

This old article did something similar:
http://www.projectsplans.com/downloa...rill_press.pdf

I also second the recommendation for either a vise or clamps. If not
using a vise, a block or piece of angle clamped to the table may help
keep your distance in from the edge of the 3x3 consistent, only
requiring you to slide it axially for each hole to line up your next
mark under the bit--as long as your table doesn't swing around the
column on you, such as might happen if the bit jams.

--Glenn Lyford

What's that Lassie? You say that Harold & Susan Vordos fell down the
old rec.crafts.metalworking mine and will die if we don't mount a
rescue by Sun, 25 Apr 2010 21:25:46 GMT:

I would use a hole saw, assuming I could get one that created a hole
in keeping with my needs. They tend to cut a ragged hole until they self
pilot.

When I use hole saws, I replace the pilot drill with a solid round
bar. Helps a lot with thinner stock that the pilot drill wouldn't
make a round hole in.
--

Dan H.
northshore MA.

Use a step drill for sheet. It outperforms twist drills.

Martin

Don Foreman wrote:
On Sat, 24 Apr 2010 13:16:58 -0700, "Jon Danniken"
wrote:

Don Foreman wrote:
A hole saw with plenty of cutting fluid will be the lowest-torque
approach. Next would be a step bit, last choice would be a 1" dia
twist drill. The twist drill would be better for production rate in
heavier material with suitable machinery driving it, but hole saws and
step drills (unibit) work much better when the dia of the hole is
considerably larger than the thickness of the material.

1/4 hp at 620 RPM is 25.4 in-lbf of torque. That might drive a good
holesaw if nothing binds up due to deflection. It would help a lot if
you could change pulleys to get the speed down. That would increase
your torque and decrease heating.

At 620 RPM a 1" hole saw will have a tooth speed of 162 SFPM, which is
on the high side of the range for bimetal cutting mild steel but not
absurdly out of the ball park. The range generally goes from 80 to
200 SFPM. Use lots of juice. Slower would be better.
Thanks Don, I appreciate it. Right now 620RPM is the slowest speed the
drillpress will go down to, with 3 7/8" OD pulley on the quill and 1 1/2" OD
pulley on the motor shaft.

BUT: I dug around in the shop and found my old compressor, with the 1hp
motor (not compressor duty) motor still attached to it. If I can make an
adaptor plate between the 1hp motor and the drill press mount, it *will*
fit.

The only rub is that it has a 5/8" shaft (3/16" keyway), and the smallest
single pulley with those dimensions from McmasterCarr has an OD of 1 3/4".
I'm guessing that extra 1/4" inch will multiply the RPM by 1.75/1.5 (if that
is the correct formula), and I will end up with about 725RPM at 1hp.

That's a fair bit faster, but with the extra torque perhaps I could then use
the 1" silver/demming drill bit with coolant and crank it hard through the
workpiece.

Hmmm....

Please re-read guidance several have offered, then do as you will.

A 1" drill bit, silver demming or otherwise, is not a good choice for
11 gage steel, and it's a particularly bad choice in a lightweight
drillpress.

I have a Bridgeport mill and I have a 1" silver-deming drillbit with
1/2" shank. If I were drilling 11 gage, I'd use a holesaw or a step
drill whether in a drillpress or in the mill.

Harbor Freight offers a pair of stepdrills for $14.99.
http://www.harborfreight.com/cpi/cta...emnumber=96275

These work quite well in a hand-held drillmotor. Drill 1/2" pilot
holes on your DP, then enlarge them to suit with a step drill in a
handheld that has the low-speed high-torque to get it done.

On 2010-04-25, Jon Danniken wrote:
DoN. Nichols wrote:

Maybe -- maybe not. What is the nameplate RPM for that motor vs
the one currently in the drill press? If it is a 4-pole motor (a bit
below 1800 RPM) and the original was a 2-pole motor (a bit below 3600
RPM) you would gain slower operation as well. (Same for other
possible ratios of pole counts on the motors.

Hi Don, thanks for your response; they are both 1725s.

So much for that possible benefit. :-)

You're forgetting the tri-lobed holes from a standard drill bit
in thin metal which was mentioned earlier.

If I go with a twist bit, I will finish it up with a reamer, a tool which I
have always been eager to play with.

Hmm ... what kind of reamer? Single size reamers are really
designed to remove very little metal from a slightly undersized hole to
produce a precise hole size. I don't think that one would work well in
a tri-lobed hole.

Or -- if you are talking about a tapered reamer, that (under
manual power) might do reasonably well. The one I'm most familiar with
goes from perhaps 3/16" to 1/2" with a T-handle. There are larger ones
designed to ream the ID of pipes to remove burrs. These are fitted with
the square shank which fits a brace (drill holder for wood bits). That,
with a brace might work well, as long as you had a way to make sure that
you stop before the hole gets too large.

But if you insist on running one -- check whether the shank has
three partial flats on it. Without those, the bit is likely to bind
and the shank slip in the chuck.

Oh man tell me about it! This Delta of mine spins a 3/8" shiny finish when
it catches at the end of a hole, and drives me NUTS!

:-)

Do you use the chuck key in all three positions? This makes for
a somewhat better grip.

Unfortunate, too, because there is a S/D bit in my size for under $10 from
Amazon (the flatted one is a Milwaukee at fifty bucks and it got a bad
review).

Perhaps the bad review is because of the relative price?

A quick plunge into MSC's online catalog search for "Cutting
Tools"/drills/Reduced shank drills" and limiting to 1/2" shank 1"
diameter, and Cobalt steel (gets you better wear life) finds six of
them, ranging from $67.70 to $121.07. None of them state whether they
have flats on the shank.

HSS has 9 bits. Price range from $31.97 to $75.79.

Looking at the illustration for MSC #00649616 (Triumph Twist
Drill) I see that this one has a split point, which would mean less
force needed to drill directly without a pilot hole. The price on this
one is $52.26.

I might just try a round shank, and see if I can pound the key
enough to lock it in place.

Try tightening it in all three key positions. That will help a
bit -- though probably not enough.

If you have a milling machine and a spin indexer, you could
machine your own flats on the shank if it turns out to not have them.

FWIW -- the flute length on these is 3" -- but if your drill
press's stroke is shorter than that, you would not want that.

Given the price range found there, the price on your Milwaukee
seems to be reasonable. What did the test report complain about?
Performance, or price compared to import bits?

You've already had one suggestion to use a Unibit, and I second
that. In case you don't know what they are -- they are a stepped
drill bit with a single flute which is self-guiding in the metal.
They come in various size ranges and step height. How thick is your
steel?

The steel is 11 gauge (0.12). I do know what a step-drill is, and actually
have one of the DrillMaster units from HF. I have always considered it to
be a bit for drilling out thin sheet metal; I originally purchased it for
making knob holes in a chassis.

It is good for material thickness up to the step length on the
particular Unibit which you have. The one which I found appears to have
a long enough step to handle your 1/8" steel.

That I have had more than a couple of suggestions to use one has garenerd my
attention, although I must admit a bit of skepticism as to whether or not it
is the right tool considering the number of holes (60 to 80) and the
thickness of material which I am looking to bore (1/8").

Try it -- you'll be surprised. Just for a test, try the
smaller one which you already have and see how it performs producing
holes up to 1/2" (or whatever its maximum is).

In any case -- instead of using water, I would suggest Rigid
high-sulfur thread cutting oil.

You won't have to remove as much metal at a pass as you would
with the Silver & Demming bit, so there is a greater chance that your
drill press will have sufficient torque -- with the above-mentioned
cutting oil refreshed for each hole. (Paint it on the unibit with an
acid brush or something similar.

Thanks for the suggestion, Don. I must admit that I really like water
because it is cheap and is easy to flow at a volume sufficient to cool the
bit and workpiece.

You use it outdoors? Indoors makes a real mess since you don't
have a way to capture and recycle the coolant. If you did, I would
suggest you use it with a soluble oil in the water -- made for steel
cutting.

I have used it before with good results in cooling, but
perhaps it is the lubrication ability of the bona fide product which makes
it shine.

The sulfur in the high sulfur cutting oil both lubricates the
chips (a high pressure lubricant) and reduces the strength of the metal
in shear where you are cutting.

Good Luck,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

Glenn Lyford wrote:
My drill press is a small bench mount Delta, with a 1/4hp motor, two
inch plunge depth, and a 1/2 inch chuck. My first thought is to use
a Silver and Demming (reduced shank) drill bit, 1/2" shank, 1" drill.

Others have addressed the bit, and there has been passing reference to
gearing down the drill press.

Here's how I did that for mine:
http://home.comcast.net/~glyford/js/js.htm

This old article did something similar:
http://www.projectsplans.com/downloa...rill_press.pdf

I also second the recommendation for either a vise or clamps. If not
using a vise, a block or piece of angle clamped to the table may help
keep your distance in from the edge of the 3x3 consistent, only
requiring you to slide it axially for each hole to line up your next
mark under the bit--as long as your table doesn't swing around the
column on you, such as might happen if the bit jams.

Wow, thanks Glen, those are two very ingenious solutions! I really like the
way yours turned out.

I will definitely be making a secure jig for this operation; I don't want to
get caught up in an eight-foot rotor!

Jon

DoN. Nichols wrote:

Hmm ... what kind of reamer? Single size reamers are really
designed to remove very little metal from a slightly undersized hole
to produce a precise hole size. I don't think that one would work
well in a tri-lobed hole.

Or -- if you are talking about a tapered reamer, that (under
manual power) might do reasonably well. The one I'm most familiar
with goes from perhaps 3/16" to 1/2" with a T-handle. There are
larger ones designed to ream the ID of pipes to remove burrs. These
are fitted with the square shank which fits a brace (drill holder for
wood bits). That, with a brace might work well, as long as you had a
way to make sure that you stop before the hole gets too large.

Well, I hadn't exactly completely throught through that part of the process.
I also have no experience in actually using a reamer, so you could say I am
eager to get my hands on one to learn from it.

But if you insist on running one -- check whether the shank has
three partial flats on it. Without those, the bit is likely to bind
and the shank slip in the chuck.

Oh man tell me about it! This Delta of mine spins a 3/8" shiny
finish when it catches at the end of a hole, and drives me NUTS!

:-)

Do you use the chuck key in all three positions? This makes for
a somewhat better grip.

Until today, I had never come across that pearl. Whatever I take away from
my recent expeditions, this will remain the most valuable.

If you have a milling machine and a spin indexer, you could
machine your own flats on the shank if it turns out to not have them.

A few years ago I tried to "roll my own" flats on a spade bit without using
the above mentioned tools. You can probably guess as to how that experiment
worked out.

Thanks for the suggestion, Don. I must admit that I really like
water because it is cheap and is easy to flow at a volume sufficient
to cool the bit and workpiece.

You use it outdoors? Indoors makes a real mess since you don't
have a way to capture and recycle the coolant. If you did, I would
suggest you use it with a soluble oil in the water -- made for steel
cutting.

I used it indoors at the sink for drilling 1/8" holes through the center of
1.5" long sections of 3/8" threaded rod. I had to go pretty slow once I got
in, and also had to pull the bit out frequently to clear the debris, but it
did work (ignoring the half-dozen mulligans). Mess was contained by setting
the drill press into a plastic-sheet lined basin near the sink, so the water
flowed into the drain.

Here is a picture of one of the completed units in it's assembly for you to
guess out the
purpose: http://img15.imageshack.us/img15/7540/jonpart.jpg

The sulfur in the high sulfur cutting oil both lubricates the
chips (a high pressure lubricant) and reduces the strength of the
metal in shear where you are cutting.

Thanks Don, I will be picking up some proper cutting fluid for this job; big
drill bits aren't cheap!

Jon

Jon, I thought you might be interested in how I did similar. Here's
links to some old dropbox posts. Issues with the bench in use: my son
isn't fond of the bench, wants something with a better pad; the
elevation toggle is a real pinch point; The threaded pins, while hell
for stout and very secure, are slow. But it damn sure don't wiggle or
flex.
http://metalworking.com/dropbox/HoleJig.txt
http://metalworking.com/dropbox/HoleJig01.JPG
http://metalworking.com/dropbox/HoleJig02.JPG
http://metalworking.com/dropbox/HoleJig03.JPG
http://metalworking.com/dropbox/HoleJig04.JPG
http://metalworking.com/dropbox/HoleJig05.JPG
http://metalworking.com/dropbox/HoleJig06.JPG
http://metalworking.com/dropbox/HoleJig07.JPG

http://metalworking.com/dropbox/WeightBench.txt
http://metalworking.com/dropbox/WeightBench02.jpg
http://metalworking.com/dropbox/WeightBench08.jpg
http://metalworking.com/dropbox/WeightBench09.jpg
http://metalworking.com/dropbox/WeightBench12.jpg
http://metalworking.com/dropbox/WeightBench13.jpg
http://metalworking.com/dropbox/WeightBench16.jpg
http://metalworking.com/dropbox/WeightBench17.jpg

Good luck,

Pete Keillor

On 2010-04-28, Jon Danniken wrote:
DoN. Nichols wrote:

Hmm ... what kind of reamer? Single size reamers are really

[ ... ]

Or -- if you are talking about a tapered reamer, that (under

[ ... ]

Well, I hadn't exactly completely throught through that part of the process.
I also have no experience in actually using a reamer, so you could say I am
eager to get my hands on one to learn from it.

The first rule with any reamer is *never* turn it backwards. It
chips the hardened cutting edge.

I think that the step drill would still be the best bet for
this, if you are going to pilot drill through. It will make smooth
round holes.

For the straight reamers, there are two styles -- the ones with
the square on the end for a tap wrench which are made for hand use.
They have along chamfer on the end to help getting it started cutting,
assuming that your pilot hole is close to size.

The other has a long round shank and is called a "chucking
reamer", intended to be used under power -- often in a turret in a lathe
for taking a hole to finish size just after the previous station drilled
it a little undersized. It has a very short chamfer and is pretty
useless under hand power. And often a bad idea in a drill press too.

[ ... ]

Do you use the chuck key in all three positions? This makes for
a somewhat better grip.

Until today, I had never come across that pearl. Whatever I take away from
my recent expeditions, this will remain the most valuable.

Something which I learned as a teen, back in the late 1950s.

If you have a milling machine and a spin indexer, you could
machine your own flats on the shank if it turns out to not have them.

A few years ago I tried to "roll my own" flats on a spade bit without using
the above mentioned tools. You can probably guess as to how that experiment
worked out.

Well -- you could do it with a file while holding the shank in a
vise, but the trick is getting the three flats equally spaced around the
shank.

Thanks for the suggestion, Don. I must admit that I really like
water because it is cheap and is easy to flow at a volume sufficient
to cool the bit and workpiece.

You use it outdoors? Indoors makes a real mess since you don't
have a way to capture and recycle the coolant. If you did, I would
suggest you use it with a soluble oil in the water -- made for steel
cutting.

I used it indoors at the sink for drilling 1/8" holes through the center of
1.5" long sections of 3/8" threaded rod. I had to go pretty slow once I got
in, and also had to pull the bit out frequently to clear the debris, but it
did work (ignoring the half-dozen mulligans). Mess was contained by setting
the drill press into a plastic-sheet lined basin near the sink, so the water
flowed into the drain.

O.K. I hope that your drill press frame was well grounded
through the power cord -- or that the outlet was equipped with a ground
fault interrupter. Otherwise, you are in serious danger.

Here is a picture of one of the completed units in it's assembly for you to
guess out the
purpose: http://img15.imageshack.us/img15/7540/jonpart.jpg

Hmmm ... mounted in a piece of plexiglass with a curved edge
which looks as though it may form a complete circle.

3/8" rod -- the hole you say is only 1/8". It might be the size
of the center insulation of a coax cable just a bit smaller than RG-58.
I think that I see the impressions of the braid in the OD. It is not
precisely enough made to be a proper gas-tight seal. It looks as
though you have flats filed near the end for a wrench which suggests
that you are trying to adjust the extension. Perhaps some kind of spark
gap, sparking against something not visible in this view.

If there were metal extending beyond the insulation I would
consider it an electrical feedthrough, especially since I seem to see a
ghostly image of the same projection on the other side.

Hmm ... perhaps the Plexiglas is a full circle, and the whole
device is intended to carry a spark between electrodes spaced on either
side of the Plexiglas as it rotates?

BTW -- this (drilling though the center) is the kind of task which a
lathe with the bit in a tailstock chuck would have been better at. Yes,
keep backing the bit out (peck drilling) to clear the chips.

The sulfur in the high sulfur cutting oil both lubricates the
chips (a high pressure lubricant) and reduces the strength of the
metal in shear where you are cutting.

Thanks Don, I will be picking up some proper cutting fluid for this job; big
drill bits aren't cheap!

Indeed so.

Good Luck,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

DoN. Nichols wrote:

The first rule with any reamer is *never* turn it backwards. It
chips the hardened cutting edge.

I think that the step drill would still be the best bet for
this, if you are going to pilot drill through. It will make smooth
round holes.

For the straight reamers, there are two styles -- the ones with
the square on the end for a tap wrench which are made for hand use.
They have along chamfer on the end to help getting it started cutting,
assuming that your pilot hole is close to size.

The other has a long round shank and is called a "chucking
reamer", intended to be used under power -- often in a turret in a
lathe for taking a hole to finish size just after the previous
station drilled it a little undersized. It has a very short chamfer
and is pretty useless under hand power. And often a bad idea in a
drill press too.

Rats, well I'll get to play with a reamer one of these days. I guess now I
have another excuse to have to get a lathe.

O.K. I hope that your drill press frame was well grounded
through the power cord -- or that the outlet was equipped with a
ground fault interrupter. Otherwise, you are in serious danger.

It was, but don't forsee utilizing that setup again. It did work at the
time, though.

Here is a picture of one of the completed units in it's assembly for
you to guess out the
purpose: http://img15.imageshack.us/img15/7540/jonpart.jpg

Hmmm ... mounted in a piece of plexiglass with a curved edge
which looks as though it may form a complete circle.

3/8" rod -- the hole you say is only 1/8". It might be the size
of the center insulation of a coax cable just a bit smaller than
RG-58. I think that I see the impressions of the braid in the OD. It
is not precisely enough made to be a proper gas-tight seal. It looks
as though you have flats filed near the end for a wrench which
suggests that you are trying to adjust the extension. Perhaps some
kind of spark gap, sparking against something not visible in this
view.

If there were metal extending beyond the insulation I would
consider it an electrical feedthrough, especially since I seem to see
a ghostly image of the same projection on the other side.

Hmm ... perhaps the Plexiglas is a full circle, and the whole
device is intended to carry a spark between electrodes spaced on
either side of the Plexiglas as it rotates?

Yep, it's a spark gap, you get the cigar. This one is used for a tesla coil
(they don't like you building them for transmitters anymore).

http://img580.imageshack.us/img580/8080/gap04.jpg

BTW -- this (drilling though the center) is the kind of task which a
lathe with the bit in a tailstock chuck would have been better at.
Yes, keep backing the bit out (peck drilling) to clear the chips.

Indeed, and thanks!

Jon

Pete Keillor wrote:
Jon, I thought you might be interested in how I did similar. Here's
links to some old dropbox posts. Issues with the bench in use: my son
isn't fond of the bench, wants something with a better pad; the
elevation toggle is a real pinch point; The threaded pins, while hell
for stout and very secure, are slow. But it damn sure don't wiggle or
flex.
http://metalworking.com/dropbox/HoleJig.txt
http://metalworking.com/dropbox/HoleJig01.JPG
http://metalworking.com/dropbox/HoleJig02.JPG
http://metalworking.com/dropbox/HoleJig03.JPG
http://metalworking.com/dropbox/HoleJig04.JPG
http://metalworking.com/dropbox/HoleJig05.JPG
http://metalworking.com/dropbox/HoleJig06.JPG
http://metalworking.com/dropbox/HoleJig07.JPG

http://metalworking.com/dropbox/WeightBench.txt
http://metalworking.com/dropbox/WeightBench02.jpg
http://metalworking.com/dropbox/WeightBench08.jpg
http://metalworking.com/dropbox/WeightBench09.jpg
http://metalworking.com/dropbox/WeightBench12.jpg
http://metalworking.com/dropbox/WeightBench13.jpg
http://metalworking.com/dropbox/WeightBench16.jpg
http://metalworking.com/dropbox/WeightBench17.jpg

Wow, thank you Pete, you did a phenomenal job on that. There will come a
day, not too far off in the future, when it dawns on your son that there is
no other bench he would rather work at.

I really like how you tackled the flat bench to incline bench transition,
your solution is both elegant and simple by using the nested tubing. I have
been struggling to come up with an acceptable solution, and I think I'm
going to steal your idea.

Thanks!

Jon

Cutting some flats on drill shanks can be aided with a spare chuck and/or a
big hex nut on the opposite end for indexing the 3 positions.

A magnetic pointer made from wire, and attached to the vise or other
drill-holding part, can be used for a reference point.

One could choose a feature on the drill chuck that appears in 3 positions,
or the points of a big hex fastener coupled to the drill to index each
position.

A relatively simple fixture consisting of an adjustable slide could simplify
the 3 flats grinding task with the flats being a more precisely uniform
depth.
Making the flats the same depth is also practical, otherwise the drill point
may orbit around the drillpress spindle's axis.

The commonly available stones for rotary tools such a Dremel have abrasive
that's so fine, that it's not likely one would accidentally grind off too
much material.
Checking the flats' depths with a caliper or micrometer would gage
uniformity.

--
WB
..........


"DoN. Nichols" wrote in message
...

A few years ago I tried to "roll my own" flats on a spade bit without
using
the above mentioned tools. You can probably guess as to how that
experiment
worked out.

Well -- you could do it with a file while holding the shank in a
vise, but the trick is getting the three flats equally spaced around the
shank.