stepper construction

[Jon Kirwan]

I'm interested in the idea of actually building a stepper and
I'd like to know if anyone knows of companies selling
hobbyist quantities of parts for doing that. Laminations,
stators, rotors, etc. I found one in Switzerland, but it's
not a complete supplier of parts and I'm not sure about their
ability to sell hobbyist qtys.

I'm mostly interested in doing this to learn, though I may
use the results as well. I would like to try building
unipolar PM and hydrid types. I'm interested in prediction of
performance, given a physical design, too. So details on that
would be intriguing, but not necessary. I can play and just
find out what I get as a result. Most steppers are prebuilt
units, for hobbyists. I'd like to actually assemble and wind
some by hand.

It's a "highly technical sale" and I'm sure there are very
few companies that want to step into this mire of horrible
after sale customer support, for no decent profits. So I know
why there would be few, or none, doing this. So any supplier
names would be very much appreciated as I expect them to be
as rare as hens' teeth.

Perhaps there is a club doing this kind of thing where I
could piggy back on purchase orders?

Thanks,
Jon

 

[Bob Masta]

On Sun, 17 Mar 2013 14:33:30 -0700, Jon Kirwan
<jonk@infinitefactors.org> wrote:

I'm interested in the idea of actually building a stepper and
I'd like to know if anyone knows of companies selling
hobbyist quantities of parts for doing that. Laminations,
stators, rotors, etc. I found one in Switzerland, but it's
not a complete supplier of parts and I'm not sure about their
ability to sell hobbyist qtys.

I'm mostly interested in doing this to learn, though I may
use the results as well. I would like to try building
unipolar PM and hydrid types. I'm interested in prediction of
performance, given a physical design, too. So details on that
would be intriguing, but not necessary. I can play and just
find out what I get as a result. Most steppers are prebuilt
units, for hobbyists. I'd like to actually assemble and wind
some by hand.

It's a "highly technical sale" and I'm sure there are very
few companies that want to step into this mire of horrible
after sale customer support, for no decent profits. So I know
why there would be few, or none, doing this. So any supplier
names would be very much appreciated as I expect them to be
as rare as hens' teeth.

Perhaps there is a club doing this kind of thing where I
could piggy back on purchase orders?

Thanks,
Jon

As an alternative, how about tearing down old steppers for
parts? Old 5.25" floppy drives are one place to find them.
The driver circuitry is right there as well, which might
simplify some of your experimenting. There used to be (and
probably still is) info on the Web about how to tap into it.

Some years ago I built a simple robot from a couple of old
drives, as a project to work on with my then-young nephew.
Mounted the steppers from both drives on one chassis, axles
sticking out on either side, installed wheels on them,
mounted the second controller board atop the first, and
wired both to a long cable with a printer port connector on
the other end. (Plus an old PSU.) Simple commands in BASIC
operated the steppers independently or together for
steering, etc.

The nephew had a blast, but is going into automotive
technology instead of robots or programming... oh, well!

Best regards,


Bob Masta

DAQARTA v7.21
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Scope, Spectrum, Spectrogram, Sound Level Meter
Frequency Counter, Pitch Track, Pitch-to-MIDI
FREE Signal Generator, DaqMusic generator
Science with your sound card!

 

[Jon Kirwan]

On Mon, 18 Mar 2013 13:17:35 GMT, N0Spam@daqarta.com (Bob
Masta) wrote:

As an alternative, how about tearing down old steppers for
parts? Old 5.25" floppy drives are one place to find them.
The driver circuitry is right there as well, which might
simplify some of your experimenting. There used to be (and
probably still is) info on the Web about how to tap into it.

I only have a couple of 5.25" floppies and I want them to
keep working. I suppose I could go to a computer junking
place and see what I could come up with. But eventually, I'd
like to build up some Nema 42 frames for some practical
applications. So that is where I'm headed in the end. And I
won't be doing that with floppy motors. So eventually, I'd
need a supplier. Though certainly I can do a lot of learning
before that time.

I could also just buy steppers and tear them down. But I'd
really like to find a supplier. That's my big goal, right
now. But I just can't seem to find more than the one is
Switzerland. And they don't supply all the needed parts, so
they provide the kingdom that fails for want of a nail, so to
speak.

Some years ago I built a simple robot from a couple of old
drives, as a project to work on with my then-young nephew.
Mounted the steppers from both drives on one chassis, axles
sticking out on either side, installed wheels on them,
mounted the second controller board atop the first, and
wired both to a long cable with a printer port connector on
the other end. (Plus an old PSU.) Simple commands in BASIC
operated the steppers independently or together for
steering, etc.

The nephew had a blast, but is going into automotive
technology instead of robots or programming... oh, well!

Hehe. Maybe he decided he couldn't compete with you and ever
feel good enough about himself?

Anyway, still looking for a supplier. And thanks for any
comments, though. Certainly, worth considering until I do
find a few. (I can hope I will find them, perhaps.) Someone
has to supply the parts that are used by these stepper
manufacturers....

Jon

 

[Michael Black]

On Mon, 18 Mar 2013, Bob Masta wrote:

Some years ago I built a simple robot from a couple of old
drives, as a project to work on with my then-young nephew.
Mounted the steppers from both drives on one chassis, axles
sticking out on either side, installed wheels on them,
mounted the second controller board atop the first, and
wired both to a long cable with a printer port connector on
the other end. (Plus an old PSU.) Simple commands in BASIC
operated the steppers independently or together for
steering, etc.

I wsa thinking of doing something like that, only more like the "space

crawler" from Major Matt Mason. It didn't have wheels, it had four arms
coming out of the shaft, on each side of the vehicle, supposed to be
better for climbing over things. I imagined it might make sense to have
each side on its own stepping motor, so if stuck one could wiggle via the
other one.

Somewhat related, the regional science fair is happening here this week,
and as always, it gets no publicity ahead of time. By the time the news
covers it, it's too late to go and take in the event.

Michael

 

[Tim Wescott]

On Mon, 18 Mar 2013 19:25:48 -0400, Michael Black wrote:

On Mon, 18 Mar 2013, Bob Masta wrote:



Some years ago I built a simple robot from a couple of old drives, as a
project to work on with my then-young nephew. Mounted the steppers from
both drives on one chassis, axles sticking out on either side,
installed wheels on them, mounted the second controller board atop the
first, and wired both to a long cable with a printer port connector on
the other end. (Plus an old PSU.) Simple commands in BASIC operated
the steppers independently or together for steering, etc.

I wsa thinking of doing something like that, only more like the "space
crawler" from Major Matt Mason. It didn't have wheels, it had four arms
coming out of the shaft, on each side of the vehicle, supposed to be
better for climbing over things. I imagined it might make sense to have
each side on its own stepping motor, so if stuck one could wiggle via
the other one.

Gearmotors would give you a lot more torque for the size of the package
than steppers.

(grain-o-salt: I dislike steppers for all but the uses where they are
shoo-ins).

--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?

Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com

 

[Jim Thompson]

On Mon, 18 Mar 2013 19:16:47 -0500, Tim Wescott <tim@seemywebsite.com>
wrote:

On Mon, 18 Mar 2013 19:25:48 -0400, Michael Black wrote:

On Mon, 18 Mar 2013, Bob Masta wrote:



Some years ago I built a simple robot from a couple of old drives, as a
project to work on with my then-young nephew. Mounted the steppers from
both drives on one chassis, axles sticking out on either side,
installed wheels on them, mounted the second controller board atop the
first, and wired both to a long cable with a printer port connector on
the other end. (Plus an old PSU.) Simple commands in BASIC operated
the steppers independently or together for steering, etc.

I wsa thinking of doing something like that, only more like the "space
crawler" from Major Matt Mason. It didn't have wheels, it had four arms
coming out of the shaft, on each side of the vehicle, supposed to be
better for climbing over things. I imagined it might make sense to have
each side on its own stepping motor, so if stuck one could wiggle via
the other one.

Gearmotors would give you a lot more torque for the size of the package
than steppers.

(grain-o-salt: I dislike steppers for all but the uses where they are
shoo-ins).

I'm not at all a motor person, other than simple-minded applications
like my Bosch motor driver chip... so maybe a dumb-ass question...

Could you use a gear-motor for a _fast_ (12"/sec, one axis)
positioner, with loose positioning accuracy, like 0.02" ??

...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

 

[Jon Kirwan]

On Mon, 18 Mar 2013 19:16:47 -0500, Tim Wescott
<tim@seemywebsite.com> wrote:

On Mon, 18 Mar 2013 19:25:48 -0400, Michael Black wrote:

On Mon, 18 Mar 2013, Bob Masta wrote:



Some years ago I built a simple robot from a couple of old drives, as a
project to work on with my then-young nephew. Mounted the steppers from
both drives on one chassis, axles sticking out on either side,
installed wheels on them, mounted the second controller board atop the
first, and wired both to a long cable with a printer port connector on
the other end. (Plus an old PSU.) Simple commands in BASIC operated
the steppers independently or together for steering, etc.

I wsa thinking of doing something like that, only more like the "space
crawler" from Major Matt Mason. It didn't have wheels, it had four arms
coming out of the shaft, on each side of the vehicle, supposed to be
better for climbing over things. I imagined it might make sense to have
each side on its own stepping motor, so if stuck one could wiggle via
the other one.

Gearmotors would give you a lot more torque for the size of the package
than steppers.

(grain-o-salt: I dislike steppers for all but the uses where they are
shoo-ins).

I can use a DC motor, of course, _IF_ I add feedback
(optical, for example.)

As I understand it, open loop driving steppers works okay for
positioning (my application) with the money going into better
and better lead screws and backlash nuts. Up to a point where
the lead screws are costing LOTS of money to get the
increasing precision out of them. Then it's back to using
cheaper motors and expensive precision optical feedback
ruling for position control. Something like that, anyway.

Torque is great of course. But I'm positioning, as well. Open
loop with steppers, given enough torque for the job. Closed
loop won't require them, I suppose. But it adds another whole
element to the system.

(Shorter term I'm targeting a 12" x 18" x-y platform motion
with 10 micron positioning resolution, ą2 micron variation,
and perhaps a few kg mass. Longer term will depend on
successes there.)

I'd like to learn, though, if there are better ways to see
this.

Jon

 

[Michael Black]

On Mon, 18 Mar 2013, Tim Wescott wrote:

On Mon, 18 Mar 2013 19:25:48 -0400, Michael Black wrote:

On Mon, 18 Mar 2013, Bob Masta wrote:



Some years ago I built a simple robot from a couple of old drives, as a
project to work on with my then-young nephew. Mounted the steppers from
both drives on one chassis, axles sticking out on either side,
installed wheels on them, mounted the second controller board atop the
first, and wired both to a long cable with a printer port connector on
the other end. (Plus an old PSU.) Simple commands in BASIC operated
the steppers independently or together for steering, etc.

I wsa thinking of doing something like that, only more like the "space
crawler" from Major Matt Mason. It didn't have wheels, it had four arms
coming out of the shaft, on each side of the vehicle, supposed to be
better for climbing over things. I imagined it might make sense to have
each side on its own stepping motor, so if stuck one could wiggle via
the other one.

Gearmotors would give you a lot more torque for the size of the package
than steppers.

(grain-o-salt: I dislike steppers for all but the uses where they are
shoo-ins).

Except I wasn't interested in real results, just the notion of using some

of the stepping motors I have lying around.

I remember the Steve Ciarcia column in Byte where he uses a cordless drill
for the source of propulsion.

Michael

 

[Tim Wescott]

On Mon, 18 Mar 2013 17:23:18 -0700, Jim Thompson wrote:

On Mon, 18 Mar 2013 19:16:47 -0500, Tim Wescott <tim@seemywebsite.com
wrote:

On Mon, 18 Mar 2013 19:25:48 -0400, Michael Black wrote:

On Mon, 18 Mar 2013, Bob Masta wrote:



Some years ago I built a simple robot from a couple of old drives, as
a project to work on with my then-young nephew. Mounted the steppers
from both drives on one chassis, axles sticking out on either side,
installed wheels on them, mounted the second controller board atop
the first, and wired both to a long cable with a printer port
connector on the other end. (Plus an old PSU.) Simple commands in
BASIC operated the steppers independently or together for steering,
etc.

I wsa thinking of doing something like that, only more like the "space
crawler" from Major Matt Mason. It didn't have wheels, it had four
arms coming out of the shaft, on each side of the vehicle, supposed to
be better for climbing over things. I imagined it might make sense to
have each side on its own stepping motor, so if stuck one could wiggle
via the other one.

Gearmotors would give you a lot more torque for the size of the package
than steppers.

(grain-o-salt: I dislike steppers for all but the uses where they are
shoo-ins).

I'm not at all a motor person, other than simple-minded applications
like my Bosch motor driver chip... so maybe a dumb-ass question...

Could you use a gear-motor for a _fast_ (12"/sec, one axis) positioner,
with loose positioning accuracy, like 0.02" ??

Well, a motor could. Depending on how much money you have, how fast you
need it to settle to position, how heavy a load, how much friction, and
all those other anal-retentive enginering-ish questions, you could maybe
go that fast and get better accuracy than that to boot.

12"/sec is a challenging requirement, but think about how fast the
carriage on an inkjet printer traverses -- in most cases I'm pretty sure
that's not only a DC motor, but a fairly cheap one. (Of course, I'm also
pretty sure that the printing is driven off of the carriage position, not
the other way around).

As far as a _gear_ motor -- if you drive the process with a lead screw
with a 1/10 inch pitch (which is pretty common), that implies 7200 RPM at
the screw. You wouldn't be using any gears beyond the lead screw in that
case.

You may need to gear things down going from a motor to a belt or to a
rack and pinion -- but probably not by much.

--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?

Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com

 

[Tim Wescott]

On Mon, 18 Mar 2013 22:52:16 -0400, Michael Black wrote:

On Mon, 18 Mar 2013, Tim Wescott wrote:

On Mon, 18 Mar 2013 19:25:48 -0400, Michael Black wrote:

On Mon, 18 Mar 2013, Bob Masta wrote:



Some years ago I built a simple robot from a couple of old drives, as
a project to work on with my then-young nephew. Mounted the steppers
from both drives on one chassis, axles sticking out on either side,
installed wheels on them, mounted the second controller board atop
the first, and wired both to a long cable with a printer port
connector on the other end. (Plus an old PSU.) Simple commands in
BASIC operated the steppers independently or together for steering,
etc.

I wsa thinking of doing something like that, only more like the "space
crawler" from Major Matt Mason. It didn't have wheels, it had four
arms coming out of the shaft, on each side of the vehicle, supposed to
be better for climbing over things. I imagined it might make sense to
have each side on its own stepping motor, so if stuck one could wiggle
via the other one.

Gearmotors would give you a lot more torque for the size of the package
than steppers.

(grain-o-salt: I dislike steppers for all but the uses where they are
shoo-ins).

Except I wasn't interested in real results, just the notion of using
some of the stepping motors I have lying around.

Well, there is that. If you already have the steppers then the urge to
use them gets strong.

You'd still end up with a lighter, smaller, and probably more efficient
assembly with gearmotors, though.

I remember the Steve Ciarcia column in Byte where he uses a cordless
drill for the source of propulsion.

A cordless drill _is_ a gearmotor, that's been optimized for a specific
use. Take away some of the use-specific stuff, and you still have a
really nice rugged gear motor.

--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?

Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com

 

[Tim Wescott]

On Mon, 18 Mar 2013 19:12:11 -0700, Jon Kirwan wrote:

On Mon, 18 Mar 2013 19:16:47 -0500, Tim Wescott <tim@seemywebsite.com
wrote:

On Mon, 18 Mar 2013 19:25:48 -0400, Michael Black wrote:

On Mon, 18 Mar 2013, Bob Masta wrote:



Some years ago I built a simple robot from a couple of old drives, as
a project to work on with my then-young nephew. Mounted the steppers
from both drives on one chassis, axles sticking out on either side,
installed wheels on them, mounted the second controller board atop
the first, and wired both to a long cable with a printer port
connector on the other end. (Plus an old PSU.) Simple commands in
BASIC operated the steppers independently or together for steering,
etc.

I wsa thinking of doing something like that, only more like the "space
crawler" from Major Matt Mason. It didn't have wheels, it had four
arms coming out of the shaft, on each side of the vehicle, supposed to
be better for climbing over things. I imagined it might make sense to
have each side on its own stepping motor, so if stuck one could wiggle
via the other one.

Gearmotors would give you a lot more torque for the size of the package
than steppers.

(grain-o-salt: I dislike steppers for all but the uses where they are
shoo-ins).

I can use a DC motor, of course, _IF_ I add feedback (optical, for
example.)

As I understand it, open loop driving steppers works okay for
positioning (my application) with the money going into better and better
lead screws and backlash nuts. Up to a point where the lead screws are
costing LOTS of money to get the increasing precision out of them. Then
it's back to using cheaper motors and expensive precision optical
feedback ruling for position control. Something like that, anyway.

Torque is great of course. But I'm positioning, as well. Open loop with
steppers, given enough torque for the job. Closed loop won't require
them, I suppose. But it adds another whole element to the system.

(Shorter term I'm targeting a 12" x 18" x-y platform motion with 10
micron positioning resolution, Âą2 micron variation, and perhaps a few kg
mass. Longer term will depend on successes there.)

I'd like to learn, though, if there are better ways to see this.

I was mostly commenting on Michael's notion of using steppers for
propulsion -- that's kinda counter-indicated for a stepper.

For medium-precision positioning where speed, size, and power are not the
most important variables to optimize, steppers are a good candidate.
They're certainly easy to use as long as you never challenge them past
the torque that they can deliver.

In your case you're asking for a rangerecision ratio of a bit over
70000. That's going to be a challenge no matter what you do, and you may
find that nothing that you can do with a single-stage unit and no
feedback will work. I leave that as an exercise to the user, however.

The problems that I have run into with steppers have been associated with
trying to use them where speed was important, and they were being
challenged to deliver lots of torque (mostly for acceleration to meet
speed goals). As soon as you apply more torque to a stepper than it can
resist, it slips. When it slips, it's average torque goes down almost to
the friction of the mechanical assembly (or lower, because it's being
rattled electrically). If all you have is a stepper and a precision
stop, then at that point you are screwed.

--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?

Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com

 

[Baron]

Jon Kirwan Inscribed thus:

On Mon, 18 Mar 2013 13:17:35 GMT, N0Spam@daqarta.com (Bob
Masta) wrote:

As an alternative, how about tearing down old steppers for
parts? Old 5.25" floppy drives are one place to find them.

Just about every printer has one or more stepper motors, though the HP
ink jets tend to use brush motors and encoders. If you want really
powerful steppers grab an old photo copier.

Anyway, still looking for a supplier. And thanks for any
comments, though. Certainly, worth considering until I do
find a few. (I can hope I will find them, perhaps.) Someone
has to supply the parts that are used by these stepper
manufacturers....

Jon

--
Best Regards:
Baron.

 

[Tim Wescott]

On Sun, 17 Mar 2013 14:33:30 -0700, Jon Kirwan wrote:

I'm interested in the idea of actually building a stepper and I'd like
to know if anyone knows of companies selling hobbyist quantities of
parts for doing that. Laminations, stators, rotors, etc. I found one in
Switzerland, but it's not a complete supplier of parts and I'm not sure
about their ability to sell hobbyist qtys.

I'm mostly interested in doing this to learn, though I may use the
results as well. I would like to try building unipolar PM and hydrid
types. I'm interested in prediction of performance, given a physical
design, too. So details on that would be intriguing, but not necessary.
I can play and just find out what I get as a result. Most steppers are
prebuilt units, for hobbyists. I'd like to actually assemble and wind
some by hand.

It's a "highly technical sale" and I'm sure there are very few companies
that want to step into this mire of horrible after sale customer
support, for no decent profits. So I know why there would be few, or
none, doing this. So any supplier names would be very much appreciated
as I expect them to be as rare as hens' teeth.

Perhaps there is a club doing this kind of thing where I could piggy
back on purchase orders?

To build a stepper for educational purposes, I'd suggest you get some tin
cans and some magnets, and get cracking.

To build your own custom stepper -- I think you're on your own. What do
you want out of a stepper motor that you can't get from an off-the-shelf
one?

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com

 

[Tim Wescott]

On Tue, 19 Mar 2013 19:30:08 +0000, Baron wrote:

Jon Kirwan Inscribed thus:

On Mon, 18 Mar 2013 13:17:35 GMT, N0Spam@daqarta.com (Bob Masta) wrote:

As an alternative, how about tearing down old steppers for parts? Old
5.25" floppy drives are one place to find them.

Just about every printer has one or more stepper motors, though the HP
ink jets tend to use brush motors and encoders. If you want really
powerful steppers grab an old photo copier.

Or, if you're lazy, look to the surplus places. There always seem to be
steppers available (probably 'cause they were replaced by gear motors .

My favorites, although there may be better ones out there:

http://www.mpja.com
http://www.allelectronics.com
http://www.herbach.com

--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?

Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com

 

[Jon Kirwan]

On Tue, 19 Mar 2013 14:58:17 -0500, Tim Wescott
<tim@seemywebsite.com> wrote:

On Tue, 19 Mar 2013 19:30:08 +0000, Baron wrote:

Jon Kirwan Inscribed thus:

On Mon, 18 Mar 2013 13:17:35 GMT, N0Spam@daqarta.com (Bob Masta) wrote:

As an alternative, how about tearing down old steppers for parts? Old
5.25" floppy drives are one place to find them.

Just about every printer has one or more stepper motors, though the HP
ink jets tend to use brush motors and encoders. If you want really
powerful steppers grab an old photo copier.

Or, if you're lazy, look to the surplus places. There always seem to be
steppers available (probably 'cause they were replaced by gear motors .

My favorites, although there may be better ones out there:

http://www.mpja.com
http://www.allelectronics.com
http://www.herbach.com

I'm gradually gathering that assembling your own stepper
"isn't done at the hobbyist level" anymore.

I definitely remember watching some club members building
their own DC motors for model aircraft -- magnet wire,
stators, etc., all laying on a table about the dozen or so
people sitting around trying their hand FOR THE FIRST TIME
making their own motors to whatever size they wanted. It was
very pleasant to watch. At the time, I wasn't involved and
didn't care so much. Now I do and now I'd like to be doing
that, as well, but with steppers.

Dismantling different motors will probably yield me parts
that won't go together right in the end. (Different frames,
etc.) And, at my level of ignorance right now, I'm not even
sure if I selected all of them with the same frame that I
would find I could make up a larger body without some want of
a "nail" that wouldn't be there. I suppose I could just go do
it. But a supplier of parts would be nice to know about just
the same.

But I'm getting the message. No one here knows of a supplier
for hobbyist qtys. Which, together with my google
difficulties finding one, I suppose says something. It's not
done by hobbyists now.

Jon

 

[Jon Kirwan]

On Tue, 19 Mar 2013 14:33:11 -0500, Tim Wescott
<tim@seemywebsite.please> wrote:

On Sun, 17 Mar 2013 14:33:30 -0700, Jon Kirwan wrote:

I'm interested in the idea of actually building a stepper and I'd like
to know if anyone knows of companies selling hobbyist quantities of
parts for doing that. Laminations, stators, rotors, etc. I found one in
Switzerland, but it's not a complete supplier of parts and I'm not sure
about their ability to sell hobbyist qtys.

I'm mostly interested in doing this to learn, though I may use the
results as well. I would like to try building unipolar PM and hydrid
types. I'm interested in prediction of performance, given a physical
design, too. So details on that would be intriguing, but not necessary.
I can play and just find out what I get as a result. Most steppers are
prebuilt units, for hobbyists. I'd like to actually assemble and wind
some by hand.

It's a "highly technical sale" and I'm sure there are very few companies
that want to step into this mire of horrible after sale customer
support, for no decent profits. So I know why there would be few, or
none, doing this. So any supplier names would be very much appreciated
as I expect them to be as rare as hens' teeth.

Perhaps there is a club doing this kind of thing where I could piggy
back on purchase orders?

To build a stepper for educational purposes, I'd suggest you get some tin
cans and some magnets, and get cracking.

To build your own custom stepper -- I think you're on your own. What do
you want out of a stepper motor that you can't get from an off-the-shelf
one?

Education and the ability to build a stepper that is
precisely designed for a specific application, no larger and
no smaller than exactly needed, once I learn enough to do
that.

Jon

 

[Jon Kirwan]

On Tue, 19 Mar 2013 13:58:19 -0700, Jon Kirwan
<jonk@infinitefactors.org> wrote:

snip
Education and the ability to build a stepper that is
precisely designed for a specific application, no larger and
no smaller than exactly needed, once I learn enough to do
that.

The goal is the process of doing, and then doing better, and
then feeling a sense of accomplishment when finally able to
both apply theory and test the final result for conformance
to that theory and to feel a sense of "closure" about it.
It's a very nice feeling.

Jon

 

[Michael Black]

On Tue, 19 Mar 2013, Baron wrote:

Jon Kirwan Inscribed thus:

On Mon, 18 Mar 2013 13:17:35 GMT, N0Spam@daqarta.com (Bob
Masta) wrote:

As an alternative, how about tearing down old steppers for
parts? Old 5.25" floppy drives are one place to find them.

Just about every printer has one or more stepper motors, though the HP
ink jets tend to use brush motors and encoders. If you want really
powerful steppers grab an old photo copier.

And you get the power supply too (which are often in the 20 to 30v range).

I'd also argue that the driver circuitry is more accessible than from a
floppy drive.

There used to be projects in the hobby magazines for using printers (I
guess theyw ere dot-matrix at the time) as the foundation of things like
plotters. Mostly leave the printer intact. Of course, there was also
that gadget for the Apple Imagewriter that looked like a ribbon cartridge,
but was a a scanner sensor, so you'd put the paper to be scanned into the
printer just like any other sheet of paper, and scan it simply by issuing
commands to the printer (I guess something like spaces to advance the
"scanner head" then carriage returns at the end of each line).

Michael

Anyway, still looking for a supplier. And thanks for any
comments, though. Certainly, worth considering until I do
find a few. (I can hope I will find them, perhaps.) Someone
has to supply the parts that are used by these stepper
manufacturers....

Jon

--
Best Regards:
Baron.

 

[Michael Black]

On Tue, 19 Mar 2013, Jon Kirwan wrote:

I'm gradually gathering that assembling your own stepper
"isn't done at the hobbyist level" anymore.

I've never heard of anyone making their own stepper motors.

Maybe way off in that direction, but never a mainstream thing if
it was ever done. Stepper motors were never a real mainstream
hobby thing, so there's less reason to build your own.

I definitely remember watching some club members building
their own DC motors for model aircraft -- magnet wire,
stators, etc., all laying on a table about the dozen or so
people sitting around trying their hand FOR THE FIRST TIME
making their own motors to whatever size they wanted. It was
very pleasant to watch. At the time, I wasn't involved and
didn't care so much. Now I do and now I'd like to be doing
that, as well, but with steppers.

Need may have been a requirement there. Making tiny motors that were

otherwise unavailable. Model building has been like that, the first
model airplane that wsa radio controlled was done with a ham license,
since there was nothing else, until the hobby became so mainstream that
a special radio service/license was created. That goes way back to the
thirties, and since it started early as a hobby, it wsa hobbyists who
built up the equipment. Likely the commerical manufacturers that
eventually came along were started by hobbyists who had the background and
saw a wider interest than just the ones who were building everything.

Of course, at one point, motor building was a hobby thing. I remember one
article in one of the hobby magazines were someone built endlessly small
motors in his home workshop. IN part to show he could.

Dismantling different motors will probably yield me parts
that won't go together right in the end. (Different frames,
etc.) And, at my level of ignorance right now, I'm not even
sure if I selected all of them with the same frame that I
would find I could make up a larger body without some want of
a "nail" that wouldn't be there. I suppose I could just go do
it. But a supplier of parts would be nice to know about just
the same.

But I'm getting the message. No one here knows of a supplier
for hobbyist qtys. Which, together with my google
difficulties finding one, I suppose says something. It's not
done by hobbyists now.

I don't think there were ever "parts to build stepper motors for

hobbyists". People tended to use surplus (which is the same thing as
taking apart floppy drives and printers), hoping to find something useful,
and if not, then they are buying off the shelf and paying the price.

There was a time when hobbyists were looking to hobby shops, I can
remember some articles in Byte about using servo motors from radio
controlled modelling for various things. They were trying for off the
shelf solutions.

Michael

 

[Jon Kirwan]

On Tue, 19 Mar 2013 22:52:44 -0400, Michael Black
<et472@ncf.ca> wrote:

On Tue, 19 Mar 2013, Jon Kirwan wrote:

I'm gradually gathering that assembling your own stepper
"isn't done at the hobbyist level" anymore.

I've never heard of anyone making their own stepper motors.
Maybe way off in that direction, but never a mainstream thing if
it was ever done. Stepper motors were never a real mainstream
hobby thing, so there's less reason to build your own.

I'm not looking for "main stream." Back in the day, I built
three telecopes. It took me about 1-2 thousand hours each,
grinding and figuring the mirrors and some other work, too.
Not a lot of people were doing that, then. But enough that
there were hobbyist qtys of glass of various kinds AND
suppliers of same for hobbyists.

I don't think this is much different than that. Probably, the
market would be even bigger than it was for people making
telescopes. For one thing, the world's population was about
40% then what it is today, so you've already got a 2.5 factor
there. For another, I have to believe that NEMA 42's costing
$200 each would be a motivation and there are more people
interested in steppers than in telescope mirror grinding -- I
think.

I'm not arguing the market is big. But you used the phrase
"mainstream." Neither telecope making, nor stepper making,
would be mainstream. But that doesn't mean there cannot be
suppliers. There may be. There may not be. I was asking.

By the way, I do have ONE company doing it. Not for
hobbyists, looking at the web site. But doing it, at least. I
can, if they will sell to me, actually build up my own
steppers from stacks of parts, wire, and their prefabbed
magnet structures.

I definitely remember watching some club members building
their own DC motors for model aircraft -- magnet wire,
stators, etc., all laying on a table about the dozen or so
people sitting around trying their hand FOR THE FIRST TIME
making their own motors to whatever size they wanted. It was
very pleasant to watch. At the time, I wasn't involved and
didn't care so much. Now I do and now I'd like to be doing
that, as well, but with steppers.

Need may have been a requirement there. Making tiny motors that were
otherwise unavailable. Model building has been like that, the first
model airplane that wsa radio controlled was done with a ham license,
since there was nothing else, until the hobby became so mainstream that
a special radio service/license was created. That goes way back to the
thirties, and since it started early as a hobby, it wsa hobbyists who
built up the equipment. Likely the commerical manufacturers that
eventually came along were started by hobbyists who had the background and
saw a wider interest than just the ones who were building everything.

I was there. It was about learning, mostly. These were first
time builders there, not because they couldn't buy such a
motor as they were building, but there because they thought
this was fun. I can assure you it was about nothing else.

Of course, at one point, motor building was a hobby thing. I remember one
article in one of the hobby magazines were someone built endlessly small
motors in his home workshop. IN part to show he could.

hehe. Well, I'm still looking. And I won't be discouraged for
at least another few months, yet. I will contact the Swiss
company, too, and ask them about buying as well as if they
can point me to some other companies who may be willing to
cater to me. Might get a helpful reply. Can no more than ask.

Dismantling different motors will probably yield me parts
that won't go together right in the end. (Different frames,
etc.) And, at my level of ignorance right now, I'm not even
sure if I selected all of them with the same frame that I
would find I could make up a larger body without some want of
a "nail" that wouldn't be there. I suppose I could just go do
it. But a supplier of parts would be nice to know about just
the same.

But I'm getting the message. No one here knows of a supplier
for hobbyist qtys. Which, together with my google
difficulties finding one, I suppose says something. It's not
done by hobbyists now.

I don't think there were ever "parts to build stepper motors for
hobbyists". People tended to use surplus (which is the same thing as
taking apart floppy drives and printers), hoping to find something useful,
and if not, then they are buying off the shelf and paying the price.

There was a time when hobbyists were looking to hobby shops, I can
remember some articles in Byte about using servo motors from radio
controlled modelling for various things. They were trying for off the
shelf solutions.

I've seen the parts for DC motors being used in a hobby
class. (As mentioned.) So I KNOW for certain that someone was
able to get such parts for that purpose. I see no reason why
it's such a stretch from there to a stepper. Of course, I'm
not even sure I can find out who they used as a suppler for
the DC motors, either. But they stacked up as many stator
laminations as they wanted to. Like the following:

http://www.made-in-china.com/showroom/rainbowzyp/product-detailxopnAtEKuskP/China-Stator-Lamination-for-Shade-Pole-Motor.html

Which brings me to the point. These DO exist. People DO build
steppers. They may do them as a commercial business, of
course. But they DO get parts from SOMEWHERE. The issue may
be that I have to buy in bulk. But that often can be
finessed. I just need to find out WHO is doing this, who
their competition is, what their selling policies are, etc. I
can then work through the mail, phone calls, arguments, and
so on to achieve my goals. But I have to have someone to talk
to, to start.

Anyway, I'll keep looking for a bit. I was mostly curious if
anyone here had tried their hand and had some success at
this. Seems not. Which is fine. The only sure way of finding
out is asking.

Thanks,
Jon