Howdy, gang.

For the MOEPED 6 (remember the MOEPED?) I need some control cables
routed over 1-1/8 inch tubing so I bought an aluminum two-piece shaft
collar and placed some 3/32 holes in it. As expected, they wandered
from the face drilled, coming out the back a bit off location. Then I
got a couple of same-size same-type shaft collars in lightweight
Delrin and used a 1-1/8 hole saw as a guide, clamping the aluminum jig
collar over the Delrin work collar. I learned two things for my next
try:

1) The holes are placed right on the drilled side of the jig collar,
so THAT side should face the drilled side of the workpiece. Also, the
second feature should go on that side of the work.

2) Drills dig in Delrin. I am nursing a tiny thumb cut proving this.
Next time, I'll clamp the collars and holesaw up in a six-inch three-
jaw chuck that will resist lifting. I'd thought of a hold down the
Super Shop has on it, but now that I've botched a part, the heavy
chuck is clearly the way to go. It'll let the part float to follow the
small hole; a hold-down wouldn't allow that. Yes, I know about
blunting the edge. I think I should do that, too, next time

You know, it's a bitch to get this kind of **** right the first time.
There goes about $38 worth of Delrin, but then again, here comes $38
plus worth of knowledge. If I didn't believe that, there'd be no
freakin' way I could soldier on through this kind of disappointment.
As is, I've pretty much seen it all before and am largely immune to
the upset..

When finished, the collars will be around 9 inches apart on the tubing
and the control cables will enter one collar, the sheaths will stop
there, the cables will continue, and the sheaths will pick up on the
other side. So the feature I am trying to make (eight times correctly
the first time through) is a 3/32 through hole 1/2 inch long and a 6
mm stopped hole around 3/8 deep. It's not that hard. I could serial-
ream the features and there'd be no digging. When finished, some
cables will trip switches or measure control pressure with a strain
gage and others will interact with each other to lock out
overshifting. The OEM cable routing sucks; it's a bracket applied with
fiberglass tape.

I sure am enjoying the Super Shop! It does everything well.

It's hard translating what you know into what you do the first time
through.

Why is that?

Doug Goncz
Replikon Research
Seven Corners, VA 22044-0394

On Mon, 18 Feb 2008 01:16:10 -0800 (PST), The Dougster 22044
wrote:


You know, it's a bitch to get this kind of **** right the first time.
There goes about $38 worth of Delrin, but then again, here comes $38
plus worth of knowledge. If I didn't believe that, there'd be no
freakin' way I could soldier on through this kind of disappointment.
As is, I've pretty much seen it all before and am largely immune to
the upset..


You need Delrin? What size?

Gunner



"Pax Americana is a philosophy. Hardly an empire.
Making sure other people play nice and dont kill each other (and us)
off in job lots is hardly empire building, particularly when you give
them self determination under "play nice" rules.

Think of it as having your older brother knock the **** out of you
for torturing the cat." Gunner

On Feb 18, 7:10*am, Gunner Asch wrote:
On Mon, 18 Feb 2008 01:16:10 -0800 (PST), The Dougster 22044

wrote:

You know, it's a bitch to get this kind of **** right the first time.
There goes about $38 worth of Delrin, but then again, here comes $38
plus worth of knowledge. If I didn't believe that, there'd be no
freakin' way I could soldier on through this kind of disappointment.
As is, I've pretty much seen it all before and am largely immune to
the upset..

You need Delrin? *What size?

Gunner

"Pax Americana is a philosophy. Hardly an empire.
Making sure other people play nice and dont *kill each other (and us)
off in job lots is hardly empire building, particularly when you give
them self determination under "play nice" rules.

Think of it as having your older brother knock the **** out of you
for torturing the cat." *Gunner

Hey, Gunner!

Sorry, I don't need any stock. I am working with Delrin shaft collars.
They're light, and strong enough. Each collar is around $19 with
shipping; $38 ensures.

Doug

Keywords:
On Mon, 18 Feb 2008 01:16:10 -0800 (PST), The Dougster 22044
wrote:


You know, it's a bitch to get this kind of **** right the first time.
There goes about $38 worth of Delrin, but then again, here comes $38
plus worth of knowledge. If I didn't believe that, there'd be no
freakin' way I could soldier on through this kind of disappointment.
As is, I've pretty much seen it all before and am largely immune to
the upset..

You can also assuage your frustration by using it as an excuse to buy new
tools. I have to drill in soft plastics & brass enough that I bought a
set of slow twist drills, and when those didn't behave, a set of half
round drill bits. The slow twist bits have been a great help. The
half-round bits don't get used very often at all, and probably aren't
worth the investment unless you do a lot of materials where the slow
twists are still too grabby. They work very well on thin materials, but
I've largely switched to using step drills for that.

Doug White

Hey Doug;

If it's a full 'nominal' size you're drilling, try a 'spade' type
wood drill. They work well on plastics. Mostly come in 1/8" increments
though.

Pete
--
Pete Snell
Department of Physics
Royal Military College

---------------------------------------------------------------------
It is not the critic who counts: not the man who points out how the
strong man stumbles or where the doer of deeds could have done better.
The credit belongs to the man who is actually in the arena.

Theodore Roosevelt (1858-1919)
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Hey Doug,

Well, if the drill bit size had been 3/16 or more, I'd suggest trying
a "spur bit". But I doubt they are available in 3/32. Try a bit
sharpened at 130 degrees instead of 118, and low rake, but mostly very
high speed RPM.

One thing that may help small holes go "straight" is to start with a
centre drill, even if it is oversize (I think a Number 0 is close
though), and then have both the work and the drill bit spinning. That
usually means something mounted in the lathe, which inherently gives
you good feed-rate control.

........and Doug!!!! Cursing on RCM!! Not like you. Try to clean up
your act a bit, or you'll be just like the rest of us!!!!! VBG

Take care. Nice to hear from you once in a while.

Brian Lawson,
Bothwell, Ontario.
XXXXXXXXXXXXXXXXXXX


On Mon, 18 Feb 2008 01:16:10 -0800 (PST), The Dougster 22044
wrote:

Howdy, gang.

For the MOEPED 6 (remember the MOEPED?) I need some control cables
routed over 1-1/8 inch tubing so I bought an aluminum two-piece shaft
collar and placed some 3/32 holes in it. As expected, they wandered
from the face drilled, coming out the back a bit off location. Then I
got a couple of same-size same-type shaft collars in lightweight
Delrin and used a 1-1/8 hole saw as a guide, clamping the aluminum jig
collar over the Delrin work collar. I learned two things for my next
try:

1) The holes are placed right on the drilled side of the jig collar,
so THAT side should face the drilled side of the workpiece. Also, the
second feature should go on that side of the work.

2) Drills dig in Delrin. I am nursing a tiny thumb cut proving this.
Next time, I'll clamp the collars and holesaw up in a six-inch three-
jaw chuck that will resist lifting. I'd thought of a hold down the
Super Shop has on it, but now that I've botched a part, the heavy
chuck is clearly the way to go. It'll let the part float to follow the
small hole; a hold-down wouldn't allow that. Yes, I know about
blunting the edge. I think I should do that, too, next time

You know, it's a bitch to get this kind of **** right the first time.
There goes about $38 worth of Delrin, but then again, here comes $38
plus worth of knowledge. If I didn't believe that, there'd be no
freakin' way I could soldier on through this kind of disappointment.
As is, I've pretty much seen it all before and am largely immune to
the upset..

When finished, the collars will be around 9 inches apart on the tubing
and the control cables will enter one collar, the sheaths will stop
there, the cables will continue, and the sheaths will pick up on the
other side. So the feature I am trying to make (eight times correctly
the first time through) is a 3/32 through hole 1/2 inch long and a 6
mm stopped hole around 3/8 deep. It's not that hard. I could serial-
ream the features and there'd be no digging. When finished, some
cables will trip switches or measure control pressure with a strain
gage and others will interact with each other to lock out
overshifting. The OEM cable routing sucks; it's a bracket applied with
fiberglass tape.

I sure am enjoying the Super Shop! It does everything well.

It's hard translating what you know into what you do the first time
through.

Why is that?

Doug Goncz
Replikon Research
Seven Corners, VA 22044-0394

Hi Doug,

Not sure why you are having so much trouble drilling Delrin. We use a
lot of it in some of our products and it behaves very well. We drill
holes for M4 to M10 and never have any digging in. I am not sure of
the exact rpm but when I am in the shop later today I will put a tach
on the drill-press we use. The work must be held firmly and rpm
(guess) is low in the 1200-1500 range and feed is fast. We also
machine and drill it in the CNC machines and I just looked at one
GCode file and it calls for 1600-rpm and 20-ipm feed.

We do not square the edge of the drills as for brass, they are normal
screw length 135deg with relief.

It sounds like your collars maybe Nylon and not Delrin as I don't
recall every seeing Delrin dig in when drilling UNLESS being held by
hand or not clamped properly.

Happy to help more if you need it.

Dave

On Mon, 18 Feb 2008 05:20:48 -0800 (PST), The Dougster 22044
wrote:

On Feb 18, 7:10*am, Gunner Asch wrote:
On Mon, 18 Feb 2008 01:16:10 -0800 (PST), The Dougster 22044

wrote:

You know, it's a bitch to get this kind of **** right the first time.
There goes about $38 worth of Delrin, but then again, here comes $38
plus worth of knowledge. If I didn't believe that, there'd be no
freakin' way I could soldier on through this kind of disappointment.
As is, I've pretty much seen it all before and am largely immune to
the upset..

You need Delrin? *What size?

Gunner

"Pax Americana is a philosophy. Hardly an empire.
Making sure other people play nice and dont *kill each other (and us)
off in job lots is hardly empire building, particularly when you give
them self determination under "play nice" rules.

Think of it as having your older brother knock the **** out of you
for torturing the cat." *Gunner

Hey, Gunner!

Sorry, I don't need any stock. I am working with Delrin shaft collars.
They're light, and strong enough. Each collar is around $19 with
shipping; $38 ensures.

Doug

Ive got access to delrin drops, both square and round. If you have a
lathe, you can make your own shaft collars a lot cheaper.

Gunner



"Pax Americana is a philosophy. Hardly an empire.
Making sure other people play nice and dont kill each other (and us)
off in job lots is hardly empire building, particularly when you give
them self determination under "play nice" rules.

Think of it as having your older brother knock the **** out of you
for torturing the cat." Gunner

On Mon, 18 Feb 2008 10:13:18 -0500, Pete Snell wrote:

Hey Doug;

If it's a full 'nominal' size you're drilling, try a 'spade' type
wood drill. They work well on plastics. Mostly come in 1/8" increments
though.

Pete


And it works well on delrin. Been there, done that.

Gunner



"Pax Americana is a philosophy. Hardly an empire.
Making sure other people play nice and dont kill each other (and us)
off in job lots is hardly empire building, particularly when you give
them self determination under "play nice" rules.

Think of it as having your older brother knock the **** out of you
for torturing the cat." Gunner

On Feb 18, 1:20*pm, Gunner Asch wrote:
On Mon, 18 Feb 2008 10:13:18 -0500, Pete Snell wrote:
Hey Doug;

* If it's a full 'nominal' size you're drilling, try a 'spade' type
wood drill. They work well on plastics. Mostly come in 1/8" increments
though.

Pete

And it works well on delrin. Been there, done that.

Gunner

"Pax Americana is a philosophy. Hardly an empire.
Making sure other people play nice and dont *kill each other (and us)
off in job lots is hardly empire building, particularly when you give
them self determination under "play nice" rules.

Think of it as having your older brother knock the **** out of you
for torturing the cat." *Gunner

What a delight to be back in the RCM saddle, to turn a phrase, and
yes, I will see too my potty-mouth. (grin)

I admit I was not holding the work right. Thus, the thumb cut. So,
live and learn.

In general it is interesting that there is a break (in me, and in
you?) between what I know and what I do. I KNOW it'll dig in, but
unless I remember WHY, I don't modify my behavior to make it NOT dig
in. Now I remember why, too much rake in a soft material makes a tool
dig in. And so next time, should be good results.

Doug

Gunner Asch writes:

Ive got access to delrin drops, both square and round.

I have an ongoing need for *black* Delrin rounds in roughly 2.5 inch
diameter by 5.25 inches long or more, either solid or up to 1.375 core. I
currently pay $28 delivered from Enco for a 12-inch length of 2.5 dia black
Delrin that makes two of these blanks.

[I tried to email you but earthlink.net
sez, "550 account is overquota"]

Hi Doug,

I checked the drill press and it is 505-rpm! Even slower than I
thought. The idea is to keep SF/M as low as possible.

Dave

On Mon, 18 Feb 2008 15:18:22 -0600, Richard J Kinch
wrote:

Gunner Asch writes:

Ive got access to delrin drops, both square and round.

I have an ongoing need for *black* Delrin rounds in roughly 2.5 inch
diameter by 5.25 inches long or more, either solid or up to 1.375 core. I
currently pay $28 delivered from Enco for a 12-inch length of 2.5 dia black
Delrin that makes two of these blanks.

Ill see what I can do. Straight delrin or graphite impregnated?

Gunner


[I tried to email you but earthlink.net
sez, "550 account is overquota"]



"Pax Americana is a philosophy. Hardly an empire.
Making sure other people play nice and dont kill each other (and us)
off in job lots is hardly empire building, particularly when you give
them self determination under "play nice" rules.

Think of it as having your older brother knock the **** out of you
for torturing the cat." Gunner

Gunner Asch writes:

Ill see what I can do. Straight delrin or graphite impregnated?

Straight. Gets made into an optical assembly for medical and scientific
instrumentation.

On Mon, 18 Feb 2008 01:16:10 -0800 (PST), The Dougster 22044
wrote:

Howdy, gang.

For the MOEPED 6 (remember the MOEPED?) I need some control cables
routed over 1-1/8 inch tubing so I bought an aluminum two-piece shaft
collar and placed some 3/32 holes in it. As expected, they wandered
from the face drilled, coming out the back a bit off location. Then I
got a couple of same-size same-type shaft collars in lightweight
Delrin and used a 1-1/8 hole saw as a guide, clamping the aluminum jig
collar over the Delrin work collar. I learned two things for my next
try:

1) The holes are placed right on the drilled side of the jig collar,
so THAT side should face the drilled side of the workpiece. Also, the
second feature should go on that side of the work.

2) Drills dig in Delrin. I am nursing a tiny thumb cut proving this.
Next time, I'll clamp the collars and holesaw up in a six-inch three-
jaw chuck that will resist lifting. I'd thought of a hold down the
Super Shop has on it, but now that I've botched a part, the heavy
chuck is clearly the way to go. It'll let the part float to follow the
small hole; a hold-down wouldn't allow that. Yes, I know about
blunting the edge. I think I should do that, too, next time

You know, it's a bitch to get this kind of **** right the first time.
There goes about $38 worth of Delrin, but then again, here comes $38
plus worth of knowledge. If I didn't believe that, there'd be no
freakin' way I could soldier on through this kind of disappointment.
As is, I've pretty much seen it all before and am largely immune to
the upset..

When finished, the collars will be around 9 inches apart on the tubing
and the control cables will enter one collar, the sheaths will stop
there, the cables will continue, and the sheaths will pick up on the
other side. So the feature I am trying to make (eight times correctly
the first time through) is a 3/32 through hole 1/2 inch long and a 6
mm stopped hole around 3/8 deep. It's not that hard. I could serial-
ream the features and there'd be no digging. When finished, some
cables will trip switches or measure control pressure with a strain
gage and others will interact with each other to lock out
overshifting. The OEM cable routing sucks; it's a bracket applied with
fiberglass tape.

I sure am enjoying the Super Shop! It does everything well.

It's hard translating what you know into what you do the first time
through.

Why is that?

It's merely a matter of reconciling what you thought you knew before
doing to what you really know after trying.

Delrin actually is easy stuff to machine, it's just a bit different
than metal. Start your holes with a center drill. Then keep the
speed down so things don't get warm, don't advance too fast and back
out to clear the curly chip fairly often. A sharp drill will dig only
if the setup allows it to. Provide light clamping drag on your
tailstock or quill or whatever to resist that.

On Mon, 18 Feb 2008 05:20:48 -0800 (PST), The Dougster 22044
wrote:


Sorry, I don't need any stock. I am working with Delrin shaft collars.
They're light, and strong enough. Each collar is around $19 with
shipping; $38 ensures.

I'd say you need some stock!

On Mon, 18 Feb 2008 10:13:18 -0500, Pete Snell wrote:

Hey Doug;

If it's a full 'nominal' size you're drilling, try a 'spade' type
wood drill. They work well on plastics. Mostly come in 1/8" increments
though.

Pete

3/32" spade drills?

Ordinary twist drills work just fine in delrin. My most-used
rod-stock materials are 12Lxx steel, brass, ally and delrin.

Delrin tends to hug a drill so holes tend to be a bit undersize, but
other than that I've had no problems drilling delrin.

On Mon, 18 Feb 2008 10:16:55 -0500, Brian Lawson
wrote:

Hey Doug,

Well, if the drill bit size had been 3/16 or more, I'd suggest trying
a "spur bit". But I doubt they are available in 3/32. Try a bit
sharpened at 130 degrees instead of 118, and low rake, but mostly very
high speed RPM.

Nooooo! Slow speed and aggressive feed is what works with delrin.
You want long clean curly chips climbing the flutes of your drill. Try
it! You could use a bit of ethylene glycol (AKA antifreeze) as
coolant, but I never do. It's not necessary if you get your speed and
feed right.

Try it!

Even spit-sizzle warm is too hot for delrin.

As Brian notes, a center drill is your friend with delrin. Use it.
Every time! If the follow drill starts straight, it'll run straight.
The converse is also true.

On Mon, 18 Feb 2008 17:21:27 -0600, Richard J Kinch
wrote:

Gunner Asch writes:

Ill see what I can do. Straight delrin or graphite impregnated?

Straight. Gets made into an optical assembly for medical and scientific
instrumentation.

Ok, Ill check with my sources. It comes feast or famine.

Gunner



"Pax Americana is a philosophy. Hardly an empire.
Making sure other people play nice and dont kill each other (and us)
off in job lots is hardly empire building, particularly when you give
them self determination under "play nice" rules.

Think of it as having your older brother knock the **** out of you
for torturing the cat." Gunner

Keywords:
In article , Don Foreman wrote:
On Mon, 18 Feb 2008 10:16:55 -0500, Brian Lawson
wrote:

Hey Doug,

Well, if the drill bit size had been 3/16 or more, I'd suggest trying
a "spur bit". But I doubt they are available in 3/32. Try a bit
sharpened at 130 degrees instead of 118, and low rake, but mostly very
high speed RPM.

Nooooo! Slow speed and aggressive feed is what works with delrin.
You want long clean curly chips climbing the flutes of your drill. Try
it! You could use a bit of ethylene glycol (AKA antifreeze) as
coolant, but I never do. It's not necessary if you get your speed and
feed right.

Try it!

Even spit-sizzle warm is too hot for delrin.

I'm sure this is old news to many folks, but one of the biggest problems
with drilling in plastics is their high coefficient of thermal expansion,
combined with poor thermal conductivity.

When the plastic around a hole being drilled heats up, it wants to
expand. But because the plastic around it hasn't bothered getting warm
yet, the only place it can go is to squeeze into the hole you are making.
The exciting part is when this causes more friction against the drill,
which causes more heat, which causes more expansion which means BANG!
Suddenly the part siezes onto the drill bit & something (usually
expensive and/or painful) gets trashed.

Depending on what you are doing, a little cooling can go a long ways.
I've used soapy water, soluble oil & almost any other liquid I have
handy. Just be sure to check that any solvents won't do nasty things to
the plastic short or long term. I have cans of compressed freon gas
(electronics "dusters") that make good spot coolers when inverted. If I
have to drill a hole and things start getting a little warm, I'll back
out the drill & frost it up before continuing.

Doug White

On 2008-02-18, Doug White wrote:
Keywords:
On Mon, 18 Feb 2008 01:16:10 -0800 (PST), The Dougster 22044
wrote:


You know, it's a bitch to get this kind of **** right the first time.
There goes about $38 worth of Delrin, but then again, here comes $38
plus worth of knowledge. If I didn't believe that, there'd be no
freakin' way I could soldier on through this kind of disappointment.
As is, I've pretty much seen it all before and am largely immune to
the upset..

You can also assuage your frustration by using it as an excuse to buy new
tools. I have to drill in soft plastics & brass enough that I bought a
set of slow twist drills, and when those didn't behave, a set of half
round drill bits. The slow twist bits have been a great help.

Or -- you can "dub" the drill bits which you use for Delrin
and/or Brass. ("Dub" means to grind a flat on the edge of the end flute
parallel to the axis of the bit so it does not dig in. Sort of the
ultimate slow twist drill, but a lot cheaper. Keep the dull bits from
other work and dub them to make what you need for brass and plastics.

Enjoy,
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:
..."Dub" means to grind a flat on the edge of the end flute
parallel to the axis of the bit so it does not dig in. ...

"parallel" to the axis? IOW, the outer/circumferential edge? I thought
it was the cutting edge that was "flattened". I.e., lessening the
relief angle. Not that I've ever done this.

But I like to learn,
Bob

On 2008-02-20, Bob Engelhardt wrote:
DoN. Nichols wrote:
..."Dub" means to grind a flat on the edge of the end flute
parallel to the axis of the bit so it does not dig in. ...

"parallel" to the axis? IOW, the outer/circumferential edge?

No -- the radial cutting edge on the end of the drill bit. But
it is the rake angle produced by the spiral flutes which is removed for
a short distance -- perhaps something like 1/4 the diameter or so --
just enough to keep it from digging in.

I thought
it was the cutting edge that was "flattened". I.e., lessening the
relief angle. Not that I've ever done this.

Hmm ... not enough angles in the available characters to do an
ASCII drawing, unfortunately. But you look at the angle formed by the
relief on the end of the bit and the rake formed by the angle of twist,
and grind off the sharp point producing a surface parallel to the axis
of the bit.

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:
... But you look at the angle formed by the
relief on the end of the bit and the rake formed by the angle of twist,
and grind off the sharp point producing a surface parallel to the axis
of the bit.

I got it. You're reducing the rake, not the relief. Although, having
experienced negative relief, I can tell you that it should prevent
digging in also.

Bob

Bob Engelhardt wrote:
I got it. You're reducing the rake, not the relief. Although, having
experienced negative relief, I can tell you that it should prevent
digging in also.

Bob

That should have a smiley I think. :-)
...lew...