David Billington prodded the keyboard

On 29/01/15 14:46, Baron wrote:
Terry Coombs prodded the keyboard

Got any stepper motors for cheep? I think nema 34's will work
, I want to
power the X axis and maybe the Y on my benchtop mill . I have (or
have components to build) controllers and power supplies , can
fabricate mounts
and the rest in house . I actually had an 18v HF drill motor all
but mounted , using a PWM controller and a 13.5 volt supply . At
the speeds I need it didn't have enough torque - though I may
revisit that setup now that I can cut gears .
And speaking of cutting gears , how about cutting pulleys for
cogged belts
, anybody got experience doing that that they'd like to share ?
--
Snag
As if I didn't have enough in the works ... but a powered X
on the mill will make some of that a LOT easier!
Have you considered car wiper motors ?

See my build log :-
http://www.homemodelenginemachinist.com/showthread.php?t=23130
You will need to register to see the pictures.

One issue with typical wiper motors is they're only intended to
rotate in one direction and in my experience don't run as well in
the reverse direction. The few I have taken apart only have thrust
provision for the intended direction. I have used them to run in
both direction and it worked OK. Window winder motors are
bidirectional and have thrust pads at both end of the shaft on the
ones I've dismantled.

Yes that's true ! Which is one reason that I used a tumbler gear
mechanism to reverse the table direction. Limit switches take care
of running into the ends of the table.

As far as servoing is concerned, isn't that what the DRO is for. Set
zero and run to value "X" then stop.


--
Best Regards:
Baron.

Baron fired this volley in news:magspv$c8r$1@dont-
email.me:

isn't that what the DRO is for.

Yup. The term "feedback" covers a lot of ground.

Lloyd

On Fri, 30 Jan 2015 08:07:40 -0600, Ignoramus8636
wrote:

On 2015-01-30, Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote:
Um... I didn't say they were. They can be made INTO servos quite easily,
and if you have an application that won't mind the inherent backlash in the
geartrain, they're quite powerful and quite inexpensive for the torque
they'll put out.

My own thinking is, if you are smart enought to make a servo out of a
wiper motor and adapt it to a milling machine, you should be able to
make enough money in less time to simply buy proper equipment.

i
+2 on that. Decent low cost steppers af reasonable power are readily
available at reasonable cost, and stepper drivers are likewize easily
available. When you are done you have something that works properly
and looks like it will.

To put a decent decoder on a wiper motor takes some hacking. Do you
put the encoder on the motor shaft, or on the output gear? On the
motor shaft gives much higher resolution, but requires a lot more
hacking (physically) to get to the motor shaft. - and then it is all
exposed unless you build a housing for it. Or are you talking about a
circuit to determine the revolutions by reading the waveform from
commutation? If so, even the big manufacturers can't seem to make THAT
work reliably..

On Fri, 30 Jan 2015 11:43:57 -0600, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Ed Huntress fired this volley in
:

Those of
us who take the "recreational" part seriously should have an easy
answer: if you find it pleasurable to do so, then make it. If it's a
chore and if the option to buy is reasonable, then buy it.


Yeah, I'll go along with that.

Lloyd
I've often made something and ended up replacing it with something
purchased , even though what I made "worked". Generally I'd have been
farther ahead buying the right parts in the first place. Buying
"parts" does not preclude building the machine.

On Fri, 30 Jan 2015 15:37:54 -0600, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Baron fired this volley in news:magspv$c8r$1@dont-
email.me:

isn't that what the DRO is for.

Yup. The term "feedback" covers a lot of ground.

Lloyd
If you are using it for "full stroke" milling I guess a wiper motor
is useable. Certainly not if you are going to try to set it up as CNC
- which is more what I was thinking of when you mentioned power
driving the feed.

fired this volley in
:

Certainly not if you are going to try to set it up as CNC
- which is more what I was thinking of when you mentioned power
driving the feed.


The original post never smelled of CNC, or I'd not have suggested that a
wiper motor could be "servo'd".

For the sort of app he seemed to be asking for, the "feedback" could be a
simple as a limit switch. As I wrote earlier, "feedback" covers a lot of
ground.

Lloyd

prodded the keyboard

On Fri, 30 Jan 2015 15:37:54 -0600, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Baron fired this volley in
news:magspv$c8r$1@dont- email.me:

isn't that what the DRO is for.

Yup. The term "feedback" covers a lot of ground.

Lloyd
If you are using it for "full stroke" milling I guess a wiper motor
is useable. Certainly not if you are going to try to set it up as
CNC - which is more what I was thinking of when you mentioned power
driving the feed.

I wouldn't say CNC. Certainly the wiper motor stops dead when the
power is removed, well maybe not the armature, but the table does. I
can cut a slot within a tenth of a given distance. A caveat is to
take the backlash out before cutting or you end up cutting short.

--
Best Regards:
Baron.

prodded the keyboard

On Fri, 30 Jan 2015 08:07:40 -0600, Ignoramus8636
wrote:

On 2015-01-30, Lloyd E. Sponenburgh lloydspinsidemindspring.com
wrote:
Um... I didn't say they were. They can be made INTO servos quite
easily, and if you have an application that won't mind the
inherent backlash in the geartrain, they're quite powerful and
quite inexpensive for the torque they'll put out.

My own thinking is, if you are smart enought to make a servo out of
a wiper motor and adapt it to a milling machine, you should be able
to make enough money in less time to simply buy proper equipment.

i
+2 on that. Decent low cost steppers af reasonable power are
readily available at reasonable cost, and stepper drivers are
likewize easily available. When you are done you have something that
works properly and looks like it will.

To put a decent decoder on a wiper motor takes some hacking. Do you
put the encoder on the motor shaft, or on the output gear? On the
motor shaft gives much higher resolution, but requires a lot more
hacking (physically) to get to the motor shaft.

No just take the output from the DRO scale.

--
Best Regards:
Baron.

On Sat, 31 Jan 2015 11:23:40 +0000, Baron
wrote:

prodded the keyboard

On Fri, 30 Jan 2015 15:37:54 -0600, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Baron fired this volley in
news:magspv$c8r$1@dont- email.me:

isn't that what the DRO is for.

Yup. The term "feedback" covers a lot of ground.

Lloyd
If you are using it for "full stroke" milling I guess a wiper motor
is useable. Certainly not if you are going to try to set it up as
CNC - which is more what I was thinking of when you mentioned power
driving the feed.

I wouldn't say CNC. Certainly the wiper motor stops dead when the
power is removed, well maybe not the armature, but the table does. I
can cut a slot within a tenth of a given distance. A caveat is to
take the backlash out before cutting or you end up cutting short.

Cutting short isn't as bad as cutting long!! You know the old saw -
"I cut it again and it's STILL too short"

On Sat, 31 Jan 2015 11:27:52 +0000, Baron
wrote:

prodded the keyboard

On Fri, 30 Jan 2015 08:07:40 -0600, Ignoramus8636
wrote:

On 2015-01-30, Lloyd E. Sponenburgh lloydspinsidemindspring.com
wrote:
Um... I didn't say they were. They can be made INTO servos quite
easily, and if you have an application that won't mind the
inherent backlash in the geartrain, they're quite powerful and
quite inexpensive for the torque they'll put out.

My own thinking is, if you are smart enought to make a servo out of
a wiper motor and adapt it to a milling machine, you should be able
to make enough money in less time to simply buy proper equipment.

i
+2 on that. Decent low cost steppers af reasonable power are
readily available at reasonable cost, and stepper drivers are
likewize easily available. When you are done you have something that
works properly and looks like it will.

To put a decent decoder on a wiper motor takes some hacking. Do you
put the encoder on the motor shaft, or on the output gear? On the
motor shaft gives much higher resolution, but requires a lot more
hacking (physically) to get to the motor shaft.

No just take the output from the DRO scale.

I'd rather just punch in a number - from this point go 100,231 counts,
knowing 10 counts is 1 thou, or whatever, and the control does the
rest. And you can program the feed speed by adding a delay loop
between steps on the stepper. Just using a PWM the motor slows dwn
under load so you could get a variable speed feed, which could affect
the look of the finish.

On 2015-01-31, wrote:
On Sat, 31 Jan 2015 11:27:52 +0000, Baron
wrote:

prodded the keyboard

[ ... ]

To put a decent decoder on a wiper motor takes some hacking. Do you
put the encoder on the motor shaft, or on the output gear? On the
motor shaft gives much higher resolution, but requires a lot more
hacking (physically) to get to the motor shaft.

No just take the output from the DRO scale.

I'd rather just punch in a number - from this point go 100,231 counts,
knowing 10 counts is 1 thou, or whatever, and the control does the
rest. And you can program the feed speed by adding a delay loop
between steps on the stepper. Just using a PWM the motor slows dwn
under load so you could get a variable speed feed, which could affect
the look of the finish.

Depends. If you make it a *real* servo, there should be some
form of speed feedback, so the PWM is automatically adjusted to maintain
the desired speed.

A *real* servo motor has a tach generator on the shaft as well,
so this is easy to do.

If you've just got an encoder, you need to integrate the pulse
rate from the encoder to derive a speed value, and tuning it is a bit
trickier.

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | (KV4PH) 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 1 Feb 2015 03:31:17 GMT, "DoN. Nichols"
wrote:

On 2015-01-31, wrote:
On Sat, 31 Jan 2015 11:27:52 +0000, Baron
wrote:

prodded the keyboard

[ ... ]

To put a decent decoder on a wiper motor takes some hacking. Do you
put the encoder on the motor shaft, or on the output gear? On the
motor shaft gives much higher resolution, but requires a lot more
hacking (physically) to get to the motor shaft.

No just take the output from the DRO scale.

I'd rather just punch in a number - from this point go 100,231 counts,
knowing 10 counts is 1 thou, or whatever, and the control does the
rest. And you can program the feed speed by adding a delay loop
between steps on the stepper. Just using a PWM the motor slows dwn
under load so you could get a variable speed feed, which could affect
the look of the finish.

Depends. If you make it a *real* servo, there should be some
form of speed feedback, so the PWM is automatically adjusted to maintain
the desired speed.

A *real* servo motor has a tach generator on the shaft as well,
so this is easy to do.

If you've just got an encoder, you need to integrate the pulse
rate from the encoder to derive a speed value, and tuning it is a bit
trickier.

Standard modern found that out, in spades, on their NC lathes. They
attempted to use integrators to control the "servos" for the X and Y
axis, and repeatability was terrible.
After Standard Modern gave up on the lathe I spent hours on it
getting it useable (sort of, anyway)- we changed grounds and
sheilding, and put the PC on a dual conversion UPS (separately derived
power source) and got the failure rate down from over 30% to less than
3% on production runs of 600 parts.
It was the most useless damned piece of equipment I ever had the
msfortune of running across, My buddy Steve lost his shirt on it -
this was back at the time that Standard Modern failed and before
LeBlond took it over.
Enjoy,
DoN.

Larry Jaques wrote:
On Wed, 28 Jan 2015 22:58:41 -0600, "Terry Coombs"
wrote:

Got any stepper motors for cheep? I think nema 34's will work , I
want to

From $12.99 w/ f/s on eBay http://tinyurl.com/of8584m
How much torque do you need?


Those cheaper ones are all nema 17's , I already have 2 of those . I have
the power supply here now that I intended to power those with , I'll be
looking at some reduction for torque increase . I can get either 9:1 or 16:1
in a fairly small package using 20dp gears . I never expected the responses
this thread generated ... I just wanted a uniform speed for the X , and if I
can work it out the Z .

--
Snag

On Sat, 31 Jan 2015 23:51:59 -0600, "Terry Coombs"
wrote:

Larry Jaques wrote:
On Wed, 28 Jan 2015 22:58:41 -0600, "Terry Coombs"
wrote:

Got any stepper motors for cheep? I think nema 34's will work , I
want to

From $12.99 w/ f/s on eBay http://tinyurl.com/of8584m
How much torque do you need?


Those cheaper ones are all nema 17's , I already have 2 of those . I have
the power supply here now that I intended to power those with , I'll be
looking at some reduction for torque increase . I can get either 9:1 or 16:1
in a fairly small package using 20dp gears . I never expected the responses
this thread generated ... I just wanted a uniform speed for the X , and if I
can work it out the Z .
With steppers on x and y you can program for angle cuts too.

On Sun, 01 Feb 2015 01:08:48 -0500, wrote:

On Sat, 31 Jan 2015 23:51:59 -0600, "Terry Coombs"
wrote:

Larry Jaques wrote:
On Wed, 28 Jan 2015 22:58:41 -0600, "Terry Coombs"
wrote:

Got any stepper motors for cheep? I think nema 34's will work , I
want to

From $12.99 w/ f/s on eBay http://tinyurl.com/of8584m
How much torque do you need?


Those cheaper ones are all nema 17's , I already have 2 of those . I have
the power supply here now that I intended to power those with , I'll be
looking at some reduction for torque increase . I can get either 9:1 or 16:1
in a fairly small package using 20dp gears . I never expected the responses
this thread generated ... I just wanted a uniform speed for the X , and if I
can work it out the Z .
With steppers on x and y you can program for angle cuts too.

The price of servos has fallen and they are readily available in the
used market. Why not simply use servos rather than jitterbugs?

Gunner

"At the core of liberalism is the spoiled child,
miserable, as all spoiled children are, unsatisfied,
demanding, ill-disciplined, despotic and useless.
Liberalism is a philosophy of sniveling brats."
PJ O'Rourke

On Sat, 31 Jan 2015 23:51:59 -0600, "Terry Coombs"
wrote:

Larry Jaques wrote:
On Wed, 28 Jan 2015 22:58:41 -0600, "Terry Coombs"
wrote:

Got any stepper motors for cheep? I think nema 34's will work , I
want to

From $12.99 w/ f/s on eBay http://tinyurl.com/of8584m
How much torque do you need?


Those cheaper ones are all nema 17's , I already have 2 of those . I have

I noticed that a minute after sending the URL. Vendors put "NEMA 17
23 34" in the titles and it screws up searches. I saw one listing for
a boresnake which stated that it worked on bores from .17 to 12ga.


the power supply here now that I intended to power those with , I'll be
looking at some reduction for torque increase . I can get either 9:1 or 16:1
in a fairly small package using 20dp gears . I never expected the responses
this thread generated ... I just wanted a uniform speed for the X , and if I
can work it out the Z .

Also, don't forget Burden Surplus www.surpluscenter.com for all sorts
of gearhead drives at different RPMs for cheap prices.

--
Self-development is a higher duty than self-sacrifice.
-- Elizabeth Cady Stanton

On Sun, 01 Feb 2015 00:01:33 -0800, Gunner Asch
wrote:

On Sun, 01 Feb 2015 01:08:48 -0500, wrote:

On Sat, 31 Jan 2015 23:51:59 -0600, "Terry Coombs"
wrote:

Larry Jaques wrote:
On Wed, 28 Jan 2015 22:58:41 -0600, "Terry Coombs"
wrote:

Got any stepper motors for cheep? I think nema 34's will work , I
want to

From $12.99 w/ f/s on eBay http://tinyurl.com/of8584m
How much torque do you need?


Those cheaper ones are all nema 17's , I already have 2 of those . I have
the power supply here now that I intended to power those with , I'll be
looking at some reduction for torque increase . I can get either 9:1 or 16:1
in a fairly small package using 20dp gears . I never expected the responses
this thread generated ... I just wanted a uniform speed for the X , and if I
can work it out the Z .
With steppers on x and y you can program for angle cuts too.

The price of servos has fallen and they are readily available in the
used market. Why not simply use servos rather than jitterbugs?

It's my impression that for the DIYer, stepper controls are easier and
cheaper to source - but if good surplus servo controls are available
at reasonable price, of coarse use them. I've got several rather large
and clunky servos around, but no drive circuitry. Definitely too big
to put on my Myford lathe - - - - . Then there are the servoed motors
out of inkjet computers - too small for the job.
Steppers out of old LaserJets are a dime a dozen and about the right
size.....

Gunner

"At the core of liberalism is the spoiled child,
miserable, as all spoiled children are, unsatisfied,
demanding, ill-disciplined, despotic and useless.
Liberalism is a philosophy of sniveling brats."
PJ O'Rourke

On Sun, 01 Feb 2015 05:59:21 -0800, Larry Jaques
wrote:

On Sat, 31 Jan 2015 23:51:59 -0600, "Terry Coombs"
wrote:

Larry Jaques wrote:
On Wed, 28 Jan 2015 22:58:41 -0600, "Terry Coombs"
wrote:

Got any stepper motors for cheep? I think nema 34's will work , I
want to

From $12.99 w/ f/s on eBay http://tinyurl.com/of8584m
How much torque do you need?


Those cheaper ones are all nema 17's , I already have 2 of those . I have

I noticed that a minute after sending the URL. Vendors put "NEMA 17
23 34" in the titles and it screws up searches. I saw one listing for
a boresnake which stated that it worked on bores from .17 to 12ga.


the power supply here now that I intended to power those with , I'll be
looking at some reduction for torque increase . I can get either 9:1 or 16:1
in a fairly small package using 20dp gears . I never expected the responses
this thread generated ... I just wanted a uniform speed for the X , and if I
can work it out the Z .

Also, don't forget Burden Surplus www.surpluscenter.com for all sorts
of gearhead drives at different RPMs for cheap prices.


I've got a couple Nema 23s I have considered putting on the Myford.

On 2/1/2015 3:25 PM, wrote:
On Sun, 01 Feb 2015 00:01:33 -0800, Gunner Asch
wrote:

On Sun, 01 Feb 2015 01:08:48 -0500, wrote:

On Sat, 31 Jan 2015 23:51:59 -0600, "Terry Coombs"
wrote:

Larry Jaques wrote:
On Wed, 28 Jan 2015 22:58:41 -0600, "Terry Coombs"
wrote:

Got any stepper motors for cheep? I think nema 34's will work , I
want to

From $12.99 w/ f/s on eBay http://tinyurl.com/of8584m
How much torque do you need?


Those cheaper ones are all nema 17's , I already have 2 of those . I have
the power supply here now that I intended to power those with , I'll be
looking at some reduction for torque increase . I can get either 9:1 or 16:1
in a fairly small package using 20dp gears . I never expected the responses
this thread generated ... I just wanted a uniform speed for the X , and if I
can work it out the Z .
With steppers on x and y you can program for angle cuts too.

The price of servos has fallen and they are readily available in the
used market. Why not simply use servos rather than jitterbugs?

It's my impression that for the DIYer, stepper controls are easier and
cheaper to source - but if good surplus servo controls are available
at reasonable price, of coarse use them. I've got several rather large
and clunky servos around, but no drive circuitry. Definitely too big
to put on my Myford lathe - - - - . Then there are the servoed motors
out of inkjet computers - too small for the job.
Steppers out of old LaserJets are a dime a dozen and about the right
size.....

Gunner

"At the core of liberalism is the spoiled child,
miserable, as all spoiled children are, unsatisfied,
demanding, ill-disciplined, despotic and useless.
Liberalism is a philosophy of sniveling brats."
PJ O'Rourke

Coffee can (2 pound) sized servo's are used on CNC CAD/CAM plasma
tables. Might find one for sell and have two X/Y nice ones with
internal glass. Mine does - and has a third smaller one for Z.
So I can cut wavy sheet metal following he metal up and down while
cutting.

Martin