Making of encoder mounting plates requires several accurately drilled
holes. I already made one plate and it seems to work, but I had some
problems/issues with placing holes precisely.

The material is brass (it was a great idea to use brass).

I calulated all hole positions using a spreadsheet. See "Encoder
Mounts" sheet he

http://spreadsheets.google.com/pub?k...en&output=html

To fit it over a 17mm motor shaft, I had to drill a 43/64
hole. (17.065mm).

I do not know of any way how I could drill that hole precisely, with a
huge (comparatively) MT3 drill bit, as any drill bit would wander away
at least somewhat, I think.

So what I did was, I drilled the 17mm hole aproximately where it
should be. Then, with DRO, I located the center of the hole and then
moved to what should be a point (0,0), based on the calculated
position of the center of the hole. (kind of a backwards thinking
process).

For smaller holes, all I did was start them with a center drill and
then drill with a drill bit.

It actually seems to have worked, as the encoder works just fine.

When making that mounting plate, I realized that there is a lot to
precision drilling, and want to ask now if anyone knows tricks for
drilling precise holes. I have two more plates to make.

The required precision for locating encoder base is 0.01". (which is
not that bad).

On a related note: to bolt the base to the motor, I had to drill four
holes for the mounting bolts. How can I precisely measure the distance
between holes. I tried using a caliper and it worked, obviously, but I
can not be totally sure how accurate I was. I would measure the
distance between two points in holes closest to one another, then
farthest, and average the two. But it felt that there was a lot of
wiggle room in those measurements. SEM has a manual for the motors in
question and it specifies the distance, but based on what I drilled,
the distance is slightly wrong. (the motors were made 20 years ago).,
I was lucky that I drilled the holes slightly oversize. For the next
pair of plates, I would really like to drill to-size holes in the
right place.

i

i

This is where autocad is a great tool. Draw it and print full scale. check
paper against part.

From there, you have all your holes centers and diameters. use a center
drill or spot drill (my favorite) then drill each point. A CNC machine is
best Grin, but a DRO works too. Do your milling at the same time.

Karl

P.S. Find me a deal on a Leblond servo shift and I'll make the parts for
you.

Ignoramus3537 wrote:

Making of encoder mounting plates requires several accurately drilled
holes. I already made one plate and it seems to work, but I had some
problems/issues with placing holes precisely.

The material is brass (it was a great idea to use brass).

I calulated all hole positions using a spreadsheet. See "Encoder
Mounts" sheet he

http://spreadsheets.google.com/pub?k...en&output=html

To fit it over a 17mm motor shaft, I had to drill a 43/64
hole. (17.065mm).

I do not know of any way how I could drill that hole precisely, with a
huge (comparatively) MT3 drill bit, as any drill bit would wander away
at least somewhat, I think.

So what I did was, I drilled the 17mm hole aproximately where it
should be. Then, with DRO, I located the center of the hole and then
moved to what should be a point (0,0), based on the calculated
position of the center of the hole. (kind of a backwards thinking
process).

For smaller holes, all I did was start them with a center drill and
then drill with a drill bit.

It actually seems to have worked, as the encoder works just fine.

When making that mounting plate, I realized that there is a lot to
precision drilling, and want to ask now if anyone knows tricks for
drilling precise holes. I have two more plates to make.

The required precision for locating encoder base is 0.01". (which is
not that bad).

On a related note: to bolt the base to the motor, I had to drill four
holes for the mounting bolts. How can I precisely measure the distance
between holes. I tried using a caliper and it worked, obviously, but I
can not be totally sure how accurate I was. I would measure the
distance between two points in holes closest to one another, then
farthest, and average the two. But it felt that there was a lot of
wiggle room in those measurements. SEM has a manual for the motors in
question and it specifies the distance, but based on what I drilled,
the distance is slightly wrong. (the motors were made 20 years ago).,
I was lucky that I drilled the holes slightly oversize. For the next
pair of plates, I would really like to drill to-size holes in the
right place.

i

i

For all of the holes, you should be spotting them with the short
flex-free center drill to get started on center without wander. You also
need to plunge the center drill down solidly to start which also helps
ensure it doesn't wander. After center drilling switch to regular drill
bits, but work your way up to the final hole size in a few steps if it's
a larger hole. If you really want a good hole, you drill up to a size a
few thou short of the final size and then ream to final size.

DRO ??

Bob Swinney


"Ignoramus3537" wrote in message
...
Making of encoder mounting plates requires several accurately drilled
holes. I already made one plate and it seems to work, but I had some
problems/issues with placing holes precisely.

The material is brass (it was a great idea to use brass).

I calulated all hole positions using a spreadsheet. See "Encoder
Mounts" sheet he

http://spreadsheets.google.com/pub?k...en&output=html

To fit it over a 17mm motor shaft, I had to drill a 43/64
hole. (17.065mm).

I do not know of any way how I could drill that hole precisely, with a
huge (comparatively) MT3 drill bit, as any drill bit would wander away
at least somewhat, I think.

So what I did was, I drilled the 17mm hole aproximately where it
should be. Then, with DRO, I located the center of the hole and then
moved to what should be a point (0,0), based on the calculated
position of the center of the hole. (kind of a backwards thinking
process).

For smaller holes, all I did was start them with a center drill and
then drill with a drill bit.

It actually seems to have worked, as the encoder works just fine.

When making that mounting plate, I realized that there is a lot to
precision drilling, and want to ask now if anyone knows tricks for
drilling precise holes. I have two more plates to make.

The required precision for locating encoder base is 0.01". (which is
not that bad).

On a related note: to bolt the base to the motor, I had to drill four
holes for the mounting bolts. How can I precisely measure the distance
between holes. I tried using a caliper and it worked, obviously, but I
can not be totally sure how accurate I was. I would measure the
distance between two points in holes closest to one another, then
farthest, and average the two. But it felt that there was a lot of
wiggle room in those measurements. SEM has a manual for the motors in
question and it specifies the distance, but based on what I drilled,
the distance is slightly wrong. (the motors were made 20 years ago).,
I was lucky that I drilled the holes slightly oversize. For the next
pair of plates, I would really like to drill to-size holes in the
right place.

i

i

"Robert Swinney" fired this volley in
:

DRO ??

Bob Swinney

Drill relocation option.

Special tool on his mill.

(Digital Read-Out) G

LLoyd

On 2010-07-13, Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote:
"Robert Swinney" fired this volley in
:

DRO ??

Bob Swinney

Drill relocation option.

Special tool on his mill.

(Digital Read-Out) G

I have a DRO. The issue is, if I move to point (1.2345, 6.5432), and
plung the drill down, will the hole really be in thast point or
somewhere close due to drill wandering.

i

Ignoramus3537 wrote:

On 2010-07-13, Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote:
"Robert Swinney" fired this volley in
:

DRO ??

Bob Swinney

Drill relocation option.

Special tool on his mill.

(Digital Read-Out) G

I have a DRO. The issue is, if I move to point (1.2345, 6.5432), and
plung the drill down, will the hole really be in thast point or
somewhere close due to drill wandering.

The hole will be at that point it you use a suitable center or spotting
drill (short and stiff), and plunge fast enough that it bites properly
before having and opportunity to wander. You should also be using a
fairly high spindle speed for the small drills.

"Ignoramus3537" wrote in message
...
On 2010-07-13, Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote:
"Robert Swinney" fired this volley in
:

DRO ??

Bob Swinney

Drill relocation option.

Special tool on his mill.

(Digital Read-Out) G

I have a DRO. The issue is, if I move to point (1.2345, 6.5432), and
plung the drill down, will the hole really be in thast point or
somewhere close due to drill wandering.

Please just drill them close to size and then bore them.
You must have a boring head.

JC

Ignoramus3537 fired this volley in
:

I have a DRO. The issue is, if I move to point (1.2345, 6.5432), and
plung the drill down, will the hole really be in thast point or
somewhere close due to drill wandering.

Iggy, you understand he doesn't mean plunge the 43/64" drill. He was
talking about a short, rigid spotting drill.

Unless you've got lost motion in your system, it should be close enough;
WAY tighter than your spec on those mounts.

It cannot hurt, after dialing to your location, to lock both ways and
just barely gently snug up the quill lock. Re-check that the way locks
didn't move the table, and that the quill lock didn't push the quill out
of line. Unless your machine is quite worn, it shouldn't.

I personally wouldn't drill such a hole in that thin stock. I'd
drill/ream or bore it to finished size. A trick I'm partial to is to
mount a boring head in the tailstock, and use the head's vernier to
adjust the hole size. There's no difference in the finished job between
doing that or just using a boring tool on the post, but it is faster and
more convenient for me to do it that way if I don't already have a boring
tool holder in the toolpost. (I have a homebrew indexable post that is
anything BUT "quick-change").


LLoyd

"Lloyd E. Sponenburgh" lloydspinsidemindspring.com fired this volley in
. 3.70:

A trick I'm partial to is to
mount a boring head in the tailstock, and use the head's vernier to
adjust the hole size.

It might have been appropriate to say, "when I'm drilling in the lathe..."

Duh!

LLoyd

"Karl Townsend" wrote in message
anews.com...
This is where autocad is a great tool. Draw it and print full scale. check
paper against part.

From there, you have all your holes centers and diameters. use a center
drill or spot drill (my favorite) then drill each point. A CNC machine is
best Grin, but a DRO works too. Do your milling at the same time.

Karl

Karl,

I disagree. If he has the money for the CNC, then he should buy a
multi-spindle drilling head from those AutoDrill guys and do it in one
stroke. That way, the head manufacturer is 100% liable if the pattern comes
out wrong. A drill bushing plate could help with the oversized issue too...
But to create that plate is more work than the single part I presume he
needed.

grinning wildly at the misapplication of technology I have just suggested
--


Regards,
Joe Agro, Jr.
(800) 871-5022
01.908.542.0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com
Production Tapping: http://Production-Tapping-Equipment.com/
Flagship Site: http://www.Drill-N-Tap.com
VIDEOS: http://www.youtube.com/user/AutoDrill
TWITTER: http://twitter.com/AutoDrill
FACEBOOK: http://tinyurl.com/AutoDrill-Facebook

V8013-R

"Ignoramus3537" wrote in message
...
Making of encoder mounting plates requires several accurately drilled
holes. I already made one plate and it seems to work, but I had some
problems/issues with placing holes precisely.

The material is brass (it was a great idea to use brass).

I calulated all hole positions using a spreadsheet. See "Encoder
Mounts" sheet he

http://spreadsheets.google.com/pub?k...en&output=html

To fit it over a 17mm motor shaft, I had to drill a 43/64
hole. (17.065mm).

I do not know of any way how I could drill that hole precisely, with a
huge (comparatively) MT3 drill bit, as any drill bit would wander away
at least somewhat, I think.

As John said, the way that accurately-located and -sized holes are made is
to drill, then bore. You won't get accurate location or size with a drill
bit -- depending on what you mean by "accurate."

You can drill and then ream for good size and roundness, but that won't give
you location. Or drill close to location and then bore for size, roundness,
*and* location.

This is what toolmaker's buttons were all about, and the basic idea has been
the way to produce accurate holes for over 100 years.

--
Ed Huntress

On Jul 13, 9:13*am, Ignoramus3537
wrote:
...
When making that mounting plate, I realized that there is a lot to
precision drilling, and want to ask now if anyone knows tricks for
drilling precise holes. I have two more plates to make.
...
i

I lock the table and drill mostly to size with cheap or resharpened
drill bits, which are more fast than accurate, then swap to the boring
head and take a light cut for concentricity. Finally, since my mill
doesn't have much headroom, I drill to size with a good S&D bit in a
collet. So far hole size and location has been good to 0.002" or
better.

These are better than I expected:
http://brutelli.com/g/grippcsu481.html

They are only 3" long beyond the collet so you can mill and drill at
the same head or table height setting. I bought them locally, that
site is the first one that Google returned.

I once worked for a very nice, but very large, guy named Vito who
inspired a lot of similar comments.

jsw

Ignoramus3537 wrote:

When making that mounting plate, I realized that there is a lot to
precision drilling, and want to ask now if anyone knows tricks for
drilling precise holes. I have two more plates to make.

The required precision for locating encoder base is 0.01". (which is
not that bad).
Well, you need a CNC machine to do that! The problem is that without
accurate measuring of table travel, it is hard to do. You can use a
boring head to bore the central hole, and any centering boss or recess
at your (0,0) coordinate. but, then you need to spot and drill 4 holes
at the corners. A machine with worn Acme screws and no DRO will give
you fits as there is differential wear on the screws, so even relative
movements are wrong. (My old manual Bridgeport had this disease,
nothing would ever fit no matter how careful I was.)

Yoiu can try scribing marks with calipers, or even surface plates and
height gauges, but it all comes down to how accurate you can dial in the
drill bit over the mark. I was never very good at this.

Jon

Karl Townsend wrote:
This is where autocad is a great tool. Draw it and print full scale. check
paper against part.

laser printers have gotten a LOT better since the early ones, but they
are still very inaccurate. If you can get .050" accuracy over the whole
sheet of paper, I'd be amazed. I'd NEVER try to do precision work this
way. print a document twice, once with mirror printing on, and hold the
two up to a light to see how well they align.

Jon

Ignoramus3537 wrote:

I have a DRO. The issue is, if I move to point (1.2345, 6.5432), and
plung the drill down, will the hole really be in thast point or
somewhere close due to drill wandering.
OK. With the DRO, it is doable to get well-centered holes.
For the central hole and any locating bosses, use a boring head and
boring tools. You can set the exact diameter needed, the hole will be
aligned very accurately. For the bolt holes that will likely have a
little slop anyway, use a center drill first, then change to the
jobber's length drill and drill to size. it will be quite well
centered, probably within .003" or better of the table's position.
The bored hole will be within .001".

Jon

On 2010-07-13, Jon Elson wrote:
Ignoramus3537 wrote:

I have a DRO. The issue is, if I move to point (1.2345, 6.5432), and
plung the drill down, will the hole really be in thast point or
somewhere close due to drill wandering.
OK. With the DRO, it is doable to get well-centered holes.
For the central hole and any locating bosses, use a boring head and
boring tools. You can set the exact diameter needed, the hole will be
aligned very accurately. For the bolt holes that will likely have a
little slop anyway, use a center drill first, then change to the
jobber's length drill and drill to size. it will be quite well
centered, probably within .003" or better of the table's position.
The bored hole will be within .001".

Yes, I think that I will bore the next two large holes. Good idea.

While we are at it, an unrelated question: can EMC be configured with
just one axis? (for testing). I want to test as much as possible with
one axis (limits, estop, homing etc), so that things are well
debugged. Then I would move to the remaining two axes. The question is
does EMC work with only one axis?

thanks

i

On Tue, 13 Jul 2010 08:13:59 -0500, Ignoramus3537
wrote:

Making of encoder mounting plates requires several accurately drilled
holes. I already made one plate and it seems to work, but I had some
problems/issues with placing holes precisely.

The material is brass (it was a great idea to use brass).

I calulated all hole positions using a spreadsheet. See "Encoder
Mounts" sheet he

http://spreadsheets.google.com/pub?k...en&output=html

To fit it over a 17mm motor shaft, I had to drill a 43/64
hole. (17.065mm).

I do not know of any way how I could drill that hole precisely, with a
huge (comparatively) MT3 drill bit, as any drill bit would wander away
at least somewhat, I think.

So what I did was, I drilled the 17mm hole aproximately where it
should be. Then, with DRO, I located the center of the hole and then
moved to what should be a point (0,0), based on the calculated
position of the center of the hole. (kind of a backwards thinking
process).

For smaller holes, all I did was start them with a center drill and
then drill with a drill bit.

It actually seems to have worked, as the encoder works just fine.

When making that mounting plate, I realized that there is a lot to
precision drilling, and want to ask now if anyone knows tricks for
drilling precise holes. I have two more plates to make.

The required precision for locating encoder base is 0.01". (which is
not that bad).

On a related note: to bolt the base to the motor, I had to drill four
holes for the mounting bolts. How can I precisely measure the distance
between holes. I tried using a caliper and it worked, obviously, but I
can not be totally sure how accurate I was. I would measure the
distance between two points in holes closest to one another, then
farthest, and average the two. But it felt that there was a lot of
wiggle room in those measurements. SEM has a manual for the motors in
question and it specifies the distance, but based on what I drilled,
the distance is slightly wrong. (the motors were made 20 years ago).,
I was lucky that I drilled the holes slightly oversize. For the next
pair of plates, I would really like to drill to-size holes in the
right place.

i

i

Something that may make life a bit easier for you are "helical couplers"

This is one of my clients..and the source for my helical couplers used
between motor and ballscrews, encoder and shafts and whatnot.

http://www.rocomcorp.com/

Tell em the OmniTurn guy recommened them.

Gunner

One could not be a successful Leftwinger without realizing that,
in contrast to the popular conception supported by newspapers
and mothers of Leftwingers, a goodly number of Leftwingers are
not only narrow-minded and dull, but also just stupid.
Gunner Asch

On 7/13/2010 3:18 PM, Jon Elson wrote:

Well, you need a CNC machine to do that! The problem is that without
accurate measuring of table travel, it is hard to do. You can use a
boring head to bore the central hole, and any centering boss or recess
at your (0,0) coordinate. but, then you need to spot and drill 4 holes
at the corners. A machine with worn Acme screws and no DRO will give you
fits as there is differential wear on the screws, so even relative
movements are wrong. (My old manual Bridgeport had this disease, nothing
would ever fit no matter how careful I was.)

Yoiu can try scribing marks with calipers, or even surface plates and
height gauges, but it all comes down to how accurate you can dial in the
drill bit over the mark. I was never very good at this.

Jon

With some indicators set up you should be able to figure out what your
backlash is like and get to within .01 easy enough. Might be a pain in
the ass moving the indicator every time your close to travel limits, but
it would at least get you there.

Ignoramus3537 fired this volley in
:

The question is
does EMC work with only one axis?


The snide answer is, "It'll work with anything you compile it for."

I haven't started on my EMC^2 conversion of my BOSS, so I don't know for
sure, but I think you can "kill" any axis independently as the package is
currently configured. Don't you have to re-compile for a specific custom
hardware setup, anyway?

LLoyd

On 2010-07-13, Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote:
Ignoramus3537 fired this volley in
:

The question is
does EMC work with only one axis?


The snide answer is, "It'll work with anything you compile it for."

I haven't started on my EMC^2 conversion of my BOSS, so I don't know for
sure, but I think you can "kill" any axis independently as the package is
currently configured. Don't you have to re-compile for a specific custom
hardware setup, anyway?

I do not think so, all configuration is done via config files. I just
get EMC as a ubuntu package.

i

Gunner Asch wrote:

On Tue, 13 Jul 2010 08:13:59 -0500, Ignoramus3537
wrote:

Making of encoder mounting plates requires several accurately drilled
holes. I already made one plate and it seems to work, but I had some
problems/issues with placing holes precisely.

The material is brass (it was a great idea to use brass).

I calulated all hole positions using a spreadsheet. See "Encoder
Mounts" sheet he

http://spreadsheets.google.com/pub?k...en&output=html

To fit it over a 17mm motor shaft, I had to drill a 43/64
hole. (17.065mm).

I do not know of any way how I could drill that hole precisely, with a
huge (comparatively) MT3 drill bit, as any drill bit would wander away
at least somewhat, I think.

So what I did was, I drilled the 17mm hole aproximately where it
should be. Then, with DRO, I located the center of the hole and then
moved to what should be a point (0,0), based on the calculated
position of the center of the hole. (kind of a backwards thinking
process).

For smaller holes, all I did was start them with a center drill and
then drill with a drill bit.

It actually seems to have worked, as the encoder works just fine.

When making that mounting plate, I realized that there is a lot to
precision drilling, and want to ask now if anyone knows tricks for
drilling precise holes. I have two more plates to make.

The required precision for locating encoder base is 0.01". (which is
not that bad).

On a related note: to bolt the base to the motor, I had to drill four
holes for the mounting bolts. How can I precisely measure the distance
between holes. I tried using a caliper and it worked, obviously, but I
can not be totally sure how accurate I was. I would measure the
distance between two points in holes closest to one another, then
farthest, and average the two. But it felt that there was a lot of
wiggle room in those measurements. SEM has a manual for the motors in
question and it specifies the distance, but based on what I drilled,
the distance is slightly wrong. (the motors were made 20 years ago).,
I was lucky that I drilled the holes slightly oversize. For the next
pair of plates, I would really like to drill to-size holes in the
right place.

i

i

Something that may make life a bit easier for you are "helical couplers"

This is one of my clients..and the source for my helical couplers used
between motor and ballscrews, encoder and shafts and whatnot.

http://www.rocomcorp.com/

Tell em the OmniTurn guy recommened them.

Except for the fact that his encoders have no shaft to couple and no
bearings. His code wheel will automatically be centered on the motor
shaft, he just needs to mount the reader head within tolerance around
the code wheel.

The center hole he is drilling is just clearance for the motor shaft and
definitely does not need to be precision bored, it just has to not rub
on the motor shaft.

The mounting holes for the reader head, and the holes to mount the
adapter plate to the motor are the important ones, and all of those are
small holes that don't need to be bored either. With the tapered
centering tool that he'll either buy from US Dig or make, he can readily
center the reader head around the motor shaft and then secure the head
and mounting plate.

"Jon Elson" wrote in message
...
Karl Townsend wrote:
This is where autocad is a great tool. Draw it and print full scale.
check paper against part.

laser printers have gotten a LOT better since the early ones, but they are
still very inaccurate. If you can get .050" accuracy over the whole sheet
of paper, I'd be amazed. I'd NEVER try to do precision work this way.
print a document twice, once with mirror printing on, and hold the two up
to a light to see how well they align.

Jon

You misunderstand me. this is not for tolerance, its for finding your gross
measuring errors. I agree, the printer isn't exact, but it will quickly spot
a measurement error.

Karl

On 2010-07-13, Pete C. wrote:
Except for the fact that his encoders have no shaft to couple and no
bearings. His code wheel will automatically be centered on the motor
shaft, he just needs to mount the reader head within tolerance around
the code wheel.

Correct.

The center hole he is drilling is just clearance for the motor shaft
and definitely does not need to be precision bored, it just has to
not rub on the motor shaft.

The reason I want to locate all holes precisely is to align
everything.

Thus the hole for the motor shaft is very close (0.06mm) to the motor
shaft diameter and I want all other holes to be located precisely,
with minimal slop.

The first plate seems to have worked out well.

The mounting holes for the reader head, and the holes to mount the
adapter plate to the motor are the important ones, and all of those are
small holes that don't need to be bored either. With the tapered
centering tool that he'll either buy from US Dig or make, he can readily
center the reader head around the motor shaft and then secure the head
and mounting plate.

I am afraid that if I allow slop in mounting of the reader head, then
if I accidentally knock the encoder, it will become misaligned. The
mount that I already made and used, has no "play" in head mounting, so
an accidental bump would not change any alignment.

i

On 2010-07-13, Karl Townsend wrote:

"Jon Elson" wrote in message
...
Karl Townsend wrote:
This is where autocad is a great tool. Draw it and print full scale.
check paper against part.

laser printers have gotten a LOT better since the early ones, but they are
still very inaccurate. If you can get .050" accuracy over the whole sheet
of paper, I'd be amazed. I'd NEVER try to do precision work this way.
print a document twice, once with mirror printing on, and hold the two up
to a light to see how well they align.

Jon

You misunderstand me. this is not for tolerance, its for finding your gross
measuring errors. I agree, the printer isn't exact, but it will quickly spot
a measurement error.

I did some sanity checks in the spreadsheet.

i

On Jul 13, 4:47*pm, Ignoramus3537
wrote:
....
I am afraid that if I allow slop in mounting of the reader head, then
if I accidentally knock the encoder, it will become misaligned. The
mount that I already made and used, has no "play" in head mounting, so
an accidental bump would not change any alignment.
i

Have you heard of toolmakers' buttons? I haven't seen new ones for
sale but they aren't hard to make, drill the center of some ground
drill rod and part off a few rings.

To use them drill your mounting pattern to scribed or worn-leadscrew
accuracy for an undersized tap, attach the rings with screws and
washers and knock them into position as measured with calipers or a
micrometer. Center each one under the spindle with an indicator and
bore out the threads, then drill/bore/ream to finished size.

This means you have to buy a small enough boring bar. The standard tap
was #5-40, which is 1/8" OD, and my B&S buttons are 0.200 in diameter.

I put a ground rod in the drill chuck and measure from it to a plug in
other holes.

I haven't tried this but if you have X and Y zero references like a
vise stop and the back vise jaw or a protruding parallel maybe you
could locate the spindle with an edge finder and the depth rod of
calipers. This would be a good use for vernier calipers that lie flat
face down.

jsw

Jim Wilkins wrote:
On Jul 13, 4:47 pm,
wrote:
....
I am afraid that if I allow slop in mounting of the reader head, then
if I accidentally knock the encoder, it will become misaligned. The
mount that I already made and used, has no "play" in head mounting, so
an accidental bump would not change any alignment.
i

Have you heard of toolmakers' buttons? I haven't seen new ones for
sale but they aren't hard to make, drill the center of some ground
drill rod and part off a few rings.

To use them drill your mounting pattern to scribed or worn-leadscrew
accuracy for an undersized tap, attach the rings with screws and
washers and knock them into position as measured with calipers or a
micrometer. Center each one under the spindle with an indicator and
bore out the threads, then drill/bore/ream to finished size.

This means you have to buy a small enough boring bar. The standard tap
was #5-40, which is 1/8" OD, and my B&S buttons are 0.200 in diameter.

I put a ground rod in the drill chuck and measure from it to a plug in
other holes.

I haven't tried this but if you have X and Y zero references like a
vise stop and the back vise jaw or a protruding parallel maybe you
could locate the spindle with an edge finder and the depth rod of
calipers. This would be a good use for vernier calipers that lie flat
face down.

Somewhere in my dusty library, I have a book that
takes your procedure one step further. It described
methods for making tooling fixtures for manufacturing
timepieces. X and Y were located by stacking Jo-blocks
between stops and the tooling fixture.

The old guys were pretty clever.

Jon Elson wrote:
Karl Townsend wrote:
This is where autocad is a great tool. Draw it and print full scale.
check paper against part.

laser printers have gotten a LOT better since the early ones, but they
are still very inaccurate. If you can get .050" accuracy over the whole
sheet of paper, I'd be amazed. I'd NEVER try to do precision work this
way. print a document twice, once with mirror printing on, and hold the
two up to a light to see how well they align.

Jon


I printed some CD labels a while back that the foreground image was
not printing. But the circle of the CD outline did - about .010 wide.

Four passes on a cheap Lexmark X2550 - Four paper reloads on the same page.

Absolutely beautiful registration.

Perfectly round with no widening of the line anywhere.


But I'm not mirroring anything.

Why would I want to???

--

Richard Lamb

"Jim Stewart" wrote in message
...
Jim Wilkins wrote:
On Jul 13, 4:47 pm,
wrote:
....
I am afraid that if I allow slop in mounting of the reader head, then
if I accidentally knock the encoder, it will become misaligned. The
mount that I already made and used, has no "play" in head mounting, so
an accidental bump would not change any alignment.
i

Have you heard of toolmakers' buttons? I haven't seen new ones for
sale but they aren't hard to make, drill the center of some ground
drill rod and part off a few rings.

To use them drill your mounting pattern to scribed or worn-leadscrew
accuracy for an undersized tap, attach the rings with screws and
washers and knock them into position as measured with calipers or a
micrometer. Center each one under the spindle with an indicator and
bore out the threads, then drill/bore/ream to finished size.

This means you have to buy a small enough boring bar. The standard tap
was #5-40, which is 1/8" OD, and my B&S buttons are 0.200 in diameter.

I put a ground rod in the drill chuck and measure from it to a plug in
other holes.

I haven't tried this but if you have X and Y zero references like a
vise stop and the back vise jaw or a protruding parallel maybe you
could locate the spindle with an edge finder and the depth rod of
calipers. This would be a good use for vernier calipers that lie flat
face down.

Somewhere in my dusty library, I have a book that
takes your procedure one step further. It described
methods for making tooling fixtures for manufacturing
timepieces. X and Y were located by stacking Jo-blocks
between stops and the tooling fixture.

The old guys were pretty clever.

It may be one of Dick Moore's early books, which I think covered the
subject. When I first inherited my lathe, I spent the first three or four
months learning old toolmaking techniques, especially the use of the
faceplate and toolmaker's buttons (I have four faceplates and two sets of
Starrett toolmaker's buttons.) I even learned how to crush diamond bort and
make my own internal grinding tools. It's interesting to learn but I don't
recommend doing it. g

I still find it to be the most interesting part of old-time machining.
Around 1900, they could make master watch and clock plates (the ultimate
drill jigs) to +/- 50 millionths accuracy -- in plain-bearing lathes.

Moore's Jig Borer was the next step in the process of applying technology to
this fundamental problem. (NC milling was the next.) At that time (1900 -
1940), the dominant product of toolmaking was drill jigs.

--
Ed Huntress

Ignoramus3537 fired this volley in
:

I do not think so, all configuration is done via config files. I just
get EMC as a ubuntu package.

So did I. But I perceived that the "config files" were designed for
certain specific types of hardware, and one might have to re-compile at
least the hardware interfaces if you were doing something full-custom.

I don't know if you're designing your own hardware, or using off-the-shelf
stuff.

LLoyd

On Jul 13, 6:13*pm, Jim Stewart wrote:
Jim Wilkins wrote:
...

Somewhere in my dusty library, I have a book that
takes your procedure one step further. *It described
methods for making tooling fixtures for manufacturing
timepieces. *X and Y were located by stacking Jo-blocks
between stops and the tooling fixture.

The old guys were pretty clever.

That's more work. You have to clamp two bars to the mill table or
lathe faceplate and set them square to each other, then locate the
hole nearest the corner under the spindle axis somehow. Maybe you
center drill it and hold it in place with the mill or tailstock
spindle while you clamp on the bars. Subsequent holes will be spaced
by the accuracy of the Jo blocks, minus any user error or clamping
distortion.

The blocks in my set aren't really long enough to guarantee that the
work piece won't tilt.

I've used the watchmakers' disk method to drill locating pin holes for
the wedges for a pie chuck. The method worked well enough but it's
very difficult and tedious, involving turning three identical disks to
better than 0.001" diameter accuracy and identifying when they barely
make contact with one on a locating dowel pin in a previous hole and
the other on a pin in the drill chuck. Of course I had to drill the
hole without the disk in place to preserve its ID. The chuck locating
pins they had to fit onto are 0.125" diameter and 1-5/32 (1.15625)
apart. The three spacing disks I made measure 0.5814", 0.5815", and
0.5813".

jsw

On Tue, 13 Jul 2010 15:28:39 -0500, "Pete C."
wrote:


Gunner Asch wrote:

On Tue, 13 Jul 2010 08:13:59 -0500, Ignoramus3537
wrote:

Making of encoder mounting plates requires several accurately drilled
holes. I already made one plate and it seems to work, but I had some
problems/issues with placing holes precisely.

The material is brass (it was a great idea to use brass).

I calulated all hole positions using a spreadsheet. See "Encoder
Mounts" sheet he

http://spreadsheets.google.com/pub?k...en&output=html

To fit it over a 17mm motor shaft, I had to drill a 43/64
hole. (17.065mm).

I do not know of any way how I could drill that hole precisely, with a
huge (comparatively) MT3 drill bit, as any drill bit would wander away
at least somewhat, I think.

So what I did was, I drilled the 17mm hole aproximately where it
should be. Then, with DRO, I located the center of the hole and then
moved to what should be a point (0,0), based on the calculated
position of the center of the hole. (kind of a backwards thinking
process).

For smaller holes, all I did was start them with a center drill and
then drill with a drill bit.

It actually seems to have worked, as the encoder works just fine.

When making that mounting plate, I realized that there is a lot to
precision drilling, and want to ask now if anyone knows tricks for
drilling precise holes. I have two more plates to make.

The required precision for locating encoder base is 0.01". (which is
not that bad).

On a related note: to bolt the base to the motor, I had to drill four
holes for the mounting bolts. How can I precisely measure the distance
between holes. I tried using a caliper and it worked, obviously, but I
can not be totally sure how accurate I was. I would measure the
distance between two points in holes closest to one another, then
farthest, and average the two. But it felt that there was a lot of
wiggle room in those measurements. SEM has a manual for the motors in
question and it specifies the distance, but based on what I drilled,
the distance is slightly wrong. (the motors were made 20 years ago).,
I was lucky that I drilled the holes slightly oversize. For the next
pair of plates, I would really like to drill to-size holes in the
right place.

i

i

Something that may make life a bit easier for you are "helical couplers"

This is one of my clients..and the source for my helical couplers used
between motor and ballscrews, encoder and shafts and whatnot.

http://www.rocomcorp.com/

Tell em the OmniTurn guy recommened them.

Except for the fact that his encoders have no shaft to couple and no
bearings. His code wheel will automatically be centered on the motor
shaft, he just needs to mount the reader head within tolerance around
the code wheel.

The center hole he is drilling is just clearance for the motor shaft and
definitely does not need to be precision bored, it just has to not rub
on the motor shaft.

The mounting holes for the reader head, and the holes to mount the
adapter plate to the motor are the important ones, and all of those are
small holes that don't need to be bored either. With the tapered
centering tool that he'll either buy from US Dig or make, he can readily
center the reader head around the motor shaft and then secure the head
and mounting plate.

Encoders without a shaft?????? Blink blink.....blink.....

Gunner

One could not be a successful Leftwinger without realizing that,
in contrast to the popular conception supported by newspapers
and mothers of Leftwingers, a goodly number of Leftwingers are
not only narrow-minded and dull, but also just stupid.
Gunner Asch

On 2010-07-13, Ignoramus3537 wrote:
Making of encoder mounting plates requires several accurately drilled
holes. I already made one plate and it seems to work, but I had some
problems/issues with placing holes precisely.

The material is brass (it was a great idea to use brass).

I calulated all hole positions using a spreadsheet. See "Encoder
Mounts" sheet he

http://spreadsheets.google.com/pub?k...en&output=html

To fit it over a 17mm motor shaft, I had to drill a 43/64
hole. (17.065mm).

I do not know of any way how I could drill that hole precisely, with a
huge (comparatively) MT3 drill bit, as any drill bit would wander away
at least somewhat, I think.

So what I did was, I drilled the 17mm hole aproximately where it
should be. Then, with DRO, I located the center of the hole and then
moved to what should be a point (0,0), based on the calculated
position of the center of the hole. (kind of a backwards thinking
process).

With a mill, I would more likely have used a 2-flute center
cutting end mill and plunged through somewhat undersized (e.g. 5/8")
then used a boring head to take it out to the desired diameter.

But does the hole actually have to be that precise a fit? All
it needs to do is clear the shaft, I thought. Bore it a little
oversized, and turn something to be a sliding fit over the shaft and
with the right OD to center the encoder properly. You were talking
about getting a centering bushing from the encoder vendors, but why not
*make* one?

However -- if you want a drill which does not walk the way a
normal chisel-point drill bit does -- get one which has a split point --
which does a much better job following a staring hole made with a center
punch of appropriate size or a center drill.

For smaller holes, all I did was start them with a center drill and
then drill with a drill bit.

Again -- go for split point drills -- less wandering.

It actually seems to have worked, as the encoder works just fine.

When making that mounting plate, I realized that there is a lot to
precision drilling, and want to ask now if anyone knows tricks for
drilling precise holes. I have two more plates to make.

The required precision for locating encoder base is 0.01". (which is
not that bad).

Especially if you make your own centering bushing using the
lathe.

On a related note: to bolt the base to the motor, I had to drill four
holes for the mounting bolts. How can I precisely measure the distance
between holes. I tried using a caliper and it worked, obviously, but I
can not be totally sure how accurate I was. I would measure the
distance between two points in holes closest to one another, then
farthest, and average the two.

How precisely did you take the measurements? Assuming a digital
caliper and clean untapped holes all the same size, take the spurs on the
back of the caliper, place them in a single hole, and zero the caliper.
Then move one spur to the next hole, and expand so you are measuring
between two points as far apart as possible (the calipers will naturally
seek this position). This will directly read the center distance quite
accurately. Yes, the zero setting of the diameter of a single hole will
be a little undersized, because the spurs don't have a fully sharp edge,
so the chord takes up a bit -- but you have the same thing happening
when measuring between two holes so the errors cancel.

But it felt that there was a lot of
wiggle room in those measurements. SEM has a manual for the motors in
question and it specifies the distance, but based on what I drilled,
the distance is slightly wrong. (the motors were made 20 years ago).,
I was lucky that I drilled the holes slightly oversize. For the next
pair of plates, I would really like to drill to-size holes in the
right place.

Slightly oversized, with a centering bushing (again, made on
your lathe) allows you to get the encoder properly centered.

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 ---

On 2010-07-13, Jon Elson wrote:
Karl Townsend wrote:
This is where autocad is a great tool. Draw it and print full scale. check
paper against part.

laser printers have gotten a LOT better since the early ones, but they
are still very inaccurate. If you can get .050" accuracy over the whole
sheet of paper, I'd be amazed. I'd NEVER try to do precision work this
way. print a document twice, once with mirror printing on, and hold the
two up to a light to see how well they align.

In particular -- the linear dimensions across the short
dimension of the paper tend to be more non-linear because they are drawn
with a rotating mirror and the laser -- trying to convert angular motion
to linear motion -- (with optics which attempt to correct the linearity
-- but are not perfect). The other axis is defined by the paper being
advanced by stepping switches, and might actually be more accurate if
the advance rollers do not slip. (Some plotters actually have grit on
the advance rollers which form a track in the back of the paper, so it
moves the same distance for all the passes back and forth to draw the
whole image. Overall, a good plotter is more accurate (at least to
start with) though the paper can shrink or swell with humidity changes,
so use it as soon after plotting as possible.

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 ---

On Tue, 13 Jul 2010 16:35:24 -0700, Jim Wilkins wrote:
....
I've used the watchmakers' disk method to drill locating pin holes for
the wedges for a pie chuck. The method worked well enough but it's very
difficult and tedious, involving turning three identical disks to better
than 0.001" diameter accuracy and identifying when [...] The
three spacing disks I made measure 0.5814", 0.5815", and 0.5813".

Well, if they were supposed to be identical, why'd you make
them with so much slop?

--
jiw

On 2010-07-13, Ignoramus3537 wrote:
On 2010-07-13, Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote:
"Robert Swinney" fired this volley in
:

DRO ??

Bob Swinney

Drill relocation option.

Special tool on his mill.

(Digital Read-Out) G

I have a DRO. The issue is, if I move to point (1.2345, 6.5432), and
plung the drill down, will the hole really be in thast point or
somewhere close due to drill wandering.

Better if you start with a spotting drill -- or even a center
drill -- which are not long enough to flex much. But if you use a split
point, you will still have very good centering compared to a standard
chisel-point jobber's drill. Using screw-machine length drills
(shorter) will also provide less flex room.

I keep a set of split-point screw machine length drills for
frequent use, and a 1/2" split point drill (jobber's length) in the
stand by the lathe for starting holes for boring. I've also got a set
of 1/16th to 1/2" jobbers length drills with split points.

To show how little walking there is, I used the 1/16" bit to
hand held electric drill in place a cross hole in a 1/4" shaft for a
cotter key (to keep the track roller for the garage door from walking
out of its brackets), and the hole was close enough to straight
diametrical so I would not be ashamed to show it to anyone.

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 ---

"James Waldby" wrote in message
...
On Tue, 13 Jul 2010 16:35:24 -0700, Jim Wilkins wrote:
...
I've used the watchmakers' disk method to drill locating pin holes for
the wedges for a pie chuck. The method worked well enough but it's very
difficult and tedious, involving turning three identical disks to better
than 0.001" diameter accuracy and identifying when [...] The
three spacing disks I made measure 0.5814", 0.5815", and 0.5813".

Well, if they were supposed to be identical, why'd you make
them with so much slop?

--
jiw

They have to be more accurate than the resolution of your gage, or they're
confusing. I put mine on an electronic gage at Wasino and they were within
25 millionths of each other.

--
Ed Huntress

On Jul 13, 8:37*pm, James Waldby wrote:
On Tue, 13 Jul 2010 16:35:24 -0700, Jim Wilkins wrote:

...

I've used the watchmakers' disk method to drill locating pin holes for
the wedges for a pie chuck. The method worked well enough but it's very
difficult and tedious, involving turning three identical disks to better
than 0.001" diameter accuracy and identifying when [...] The
three spacing disks I made measure 0.5814", 0.5815", and 0.5813".

Well, if they were supposed to be identical, why'd you make
them with so much slop?

--
jiw * *

The dealer warned me not to grind or lap on the hardened-bed lathe.

jsw

On 2010-07-13, Jon Elson wrote:
Ignoramus3537 wrote:

When making that mounting plate, I realized that there is a lot to
precision drilling, and want to ask now if anyone knows tricks for
drilling precise holes. I have two more plates to make.

The required precision for locating encoder base is 0.01". (which is
not that bad).

[ ... ]

Yoiu can try scribing marks with calipers, or even surface plates and
height gauges, but it all comes down to how accurate you can dial in the
drill bit over the mark. I was never very good at this.

A sharp-pointed wiggler can help to get you centered on the
scribe marks. Then swap it out for the drill bit.

Or -- an optical centering microscope, if you have (or make)
one.

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 ---

"Jim Wilkins" wrote in message
...
On Jul 13, 8:37 pm, James Waldby wrote:
On Tue, 13 Jul 2010 16:35:24 -0700, Jim Wilkins wrote:

...

I've used the watchmakers' disk method to drill locating pin holes for
the wedges for a pie chuck. The method worked well enough but it's very
difficult and tedious, involving turning three identical disks to better
than 0.001" diameter accuracy and identifying when [...] The
three spacing disks I made measure 0.5814", 0.5815", and 0.5813".

Well, if they were supposed to be identical, why'd you make
them with so much slop?

--
jiw

The dealer warned me not to grind or lap on the hardened-bed lathe.

jsw

Why not lap? All of the old-time lapping methods contain the grit pretty
well. And you can cover the ways with aluminum foiled or oiled newspaper if
you're edgy about it.

If you're hand-lapping, it doesn't get in the way of anything.

--
Ed Huntress