I have a large AstroWorks Fork mount.
It has a 315 tooth Mathis worm Wheel driven by a 0.5 rpm synchronious ac motor
with 400 oz./in. torque ,but 2 of the internal gears are stripped.
The motor has a 25 tooth spur gear on the 3/16" motor shaft that drives a 57
tooth gear which drives the worm.
I can't find a sutible replacement motor anywhere.
Does anyone know what I can do?
I put a Losmandy STEPPER motor from a G-11 mount, but it runs way too SLOW.
Thanks
John

John,
   Hurst makes a 1/2 rpm 200in/oz motor. Herbach and Redmann carries them. Here
is a link.
http://www.herbach.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=HAR&Product_\
Code=H2-241&Category_Code=HURST

      All the Best,
        - Dave

--- In atm_free@yahoogroups.com, "majorobs14" <majorobs14@...> wrote:
>
> I have a large AstroWorks Fork mount.
> It has a 315 tooth Mathis worm Wheel driven by a 0.5 rpm synchronious ac motor
with 400 oz./in. torque ,but 2 of the internal gears are stripped.
> The motor has a 25 tooth spur gear on the 3/16" motor shaft that drives a 57
tooth gear which drives the worm.
> I can't find a sutible replacement motor anywhere.
> Does anyone know what I can do?
> I put a Losmandy STEPPER motor from a G-11 mount, but it runs way too SLOW.
> Thanks
> John
>

John,

You might try McMaster-Carr for a coupler but since the motor shaft is 1/8 and
the gear bore is 3/16 all you really need is a short piece of brass tubing from
a hardware store or hobby shop (K&B has a display you'll find at a lot of Ace
hardwares and HobbyTowns). 1/8 ID and 3/16 OD is a very common size. Just cut a
short piece with a fine tooth hack saw (such as an Exacto or other modeling
saw), put a tiny drop of epoxy cement (or a suitable Loctite adhesive)into the
open end of the tubing slide it on the motor shaft being careful not to get the
glue into the motor and let it set up overnight. The epoxy plus the 'squeeze'
from the mounting set screw of the motor should provide adequate resistance to
slipping between the shaft and the gear.

Of course, I'm assuming the motor shaft is long enough. If it is not then you
need to go to McMaster-Carr or find a friend with a small lathe.

Good luck!

Mark Christensen

--- In atm_free@yahoogroups.com, John <majorobs14@...> wrote:
>
> Hello Dave, I checked out there site.
> At $171 for the Hurst motor you suggest, it is out of reach for me.
> They also have an AC motor at the right speed fo $19, but the shaft is only
1/8" so my 25 tooth gear won't fit It is 3/16" dia. shaft bore.
> Unless I can get a insert or coupler to go from 1/8 to 3/16.
> Thanks for your help.
> Regards
> John
>
> From: David <David.M.Groski@...>
> >To: atm_free@yahoogroups.com
> >Sent: Wednesday, April 20, 2011 2:37 PM
> >Subject: Re: [atm_free] Re: Need Help (suggestions) for a Drive Problem???
> >
> >
> > 
> >John,
> >Hurst makes a 1/2 rpm 200in/oz motor. Herbach and Redmann carries them. Here
is a link.
>
>http://www.herbach.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=HAR&Product\
_Code=H2-241&Category_Code=HURST
> >
> >All the Best,
> >- Dave
> >
> >--- In atm_free@yahoogroups.com, "majorobs14" <majorobs14@> wrote:
> >>
> >> I have a large AstroWorks Fork mount.
> >> It has a 315 tooth Mathis worm Wheel driven by a 0.5 rpm synchronious ac
motor with 400 oz./in. torque ,but 2 of the internal gears are stripped.
> >> The motor has a 25 tooth spur gear on the 3/16" motor shaft that drives a
57 tooth gear which drives the worm.
> >> I can't find a sutible replacement motor anywhere.
> >> Does anyone know what I can do?
> >> I put a Losmandy STEPPER motor from a G-11 mount, but it runs way too SLOW.
> >> Thanks
> >> John
> >>
> >
> >
> >
> >
> >
>

I actually do have experience with tempered PYREX (or its equivalent).

I received a 16.5" diameter, 7/8" thick blank for very little $ and began
working on it and didn't test it correctly for strain. Wasn't sure what it was
made out of.
After a lot fo work, I found that I could not get rid of astigmatism and other
problems, and did a better strain test (a la zambuto cd). Found lots of strain,
and that explained the little marks where it appeared that the maker of the
porthole had held the glass while it was being tempered.

So I sent it to have it annealed, which meant going back to 80 grit because the
entire shape changed.

In any case, the glass did NOT shatter when I was originally grinding it.

  Guy Brandenburg, Washington, DC
http://gfbrandenburg.wordpress.com/
http://home.earthlink.net/~gfbranden/GFB_Home_Page.html
============================

Guy,

Thanks much for relating the experience. I had a lead on some cheap (about
$50-60 with shipping) porthole glasses of 12.5 inch size and was tempted to buy
a few. The seller only knows that they are marked "Heat Treated" which could
mean any of a number of things, from tempering (4X stronger but more likely to
shatter or warp), to heat strengthened (2X stronger). The only data point on
this type of glass seems to be the posting on the San Fran Sidewalk Astronomers
site, which says they have been successful with "heat treated porthole" glass,
which is what these are advertised to be.

Given the small price difference (about $25), it is just as cheap to get
annealed plate in the same size and play it safe. I might get one or two of the
portholes to experiment with or to use as a tool just for the heck of it.

Thanks again.

Mark C.

--- In atm_free@yahoogroups.com, Guy Brandenburg <gfbrandenburg@...> wrote:
>
> I actually do have experience with tempered PYREX (or its equivalent).
>
> I received a 16.5" diameter, 7/8" thick blank for very little $ and began
> working on it and didn't test it correctly for strain. Wasn't sure what it was
> made out of.
> After a lot fo work, I found that I could not get rid of astigmatism and other
> problems, and did a better strain test (a la zambuto cd). Found lots of
strain,
> and that explained the little marks where it appeared that the maker of the
> porthole had held the glass while it was being tempered.
>
> So I sent it to have it annealed, which meant going back to 80 grit because
the
> entire shape changed.
>
> In any case, the glass did NOT shatter when I was originally grinding it.
>
>  Guy Brandenburg, Washington, DC
> http://gfbrandenburg.wordpress.com/
> http://home.earthlink.net/~gfbranden/GFB_Home_Page.html
> ============================
>

John,

Good luck, I'm sure you'll be successful.

To correct myself, it is K&S metal, not K&B.
You'd think I'd know since there here around
Chicago.

Mark

--- In atm_free@yahoogroups.com, John <majorobs14@...> wrote:
>
> Mark,
> Thanks for the info.
> I will do that.
> I didn't think I would find such small items stock.
> Regards
> John
>
> From: Mark C <mjcw500@...>
> >To: atm_free@yahoogroups.com
> >Sent: Wednesday, April 20, 2011 3:36 PM
> >Subject: Re: [atm_free] Re: Need Help (suggestions) for a Drive Problem???
> >
> >
> > 
> >John,
> >
> >You might try McMaster-Carr for a coupler but since the motor shaft is 1/8
and the gear bore is 3/16 all you really need is a short piece of brass tubing
from a hardware store or hobby shop (K&B has a display you'll find at a lot of
Ace hardwares and HobbyTowns). 1/8 ID and 3/16 OD is a very common size. Just
cut a short piece with a fine tooth hack saw (such as an Exacto or other
modeling saw), put a tiny drop of epoxy cement (or a suitable Loctite
adhesive)into the open end of the tubing slide it on the motor shaft being
careful not to get the glue into the motor and let it set up overnight. The
epoxy plus the 'squeeze' from the mounting set screw of the motor should provide
adequate resistance to slipping between the shaft and the gear.
> >
> >Of course, I'm assuming the motor shaft is long enough. If it is not then you
need to go to McMaster-Carr or find a friend with a small lathe.
> >
> >Good luck!
> >
> >Mark Christensen
> >
> >--- In atm_free@yahoogroups.com, John <majorobs14@> wrote:
> >>
> >> Hello Dave, I checked out there site.
> >> At $171 for the Hurst motor you suggest, it is out of reach for me.
> >> They also have an AC motor at the right speed fo $19, but the shaft is only
1/8" so my 25 tooth gear won't fit It is 3/16" dia. shaft bore.
> >> Unless I can get a insert or coupler to go from 1/8 to 3/16.
> >> Thanks for your help.
> >> Regards
> >> John
> >>
> >> From: David <David.M.Groski@>
> >> >To: atm_free@yahoogroups.com
> >> >Sent: Wednesday, April 20, 2011 2:37 PM
> >> >Subject: Re: [atm_free] Re: Need Help (suggestions) for a Drive Problem???
> >> >
> >> >
> >> > 
> >> >John,
> >> >Hurst makes a 1/2 rpm 200in/oz motor. Herbach and Redmann carries them.
Here is a link.
> >>
>http://www.herbach.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=HAR&Product\
_Code=H2-241&Category_Code=HURST
> >> >
> >> >All the Best,
> >> >- Dave
> >> >
> >> >--- In atm_free@yahoogroups.com, "majorobs14" <majorobs14@> wrote:
> >> >>
> >> >> I have a large AstroWorks Fork mount.
> >> >> It has a 315 tooth Mathis worm Wheel driven by a 0.5 rpm synchronious ac
motor with 400 oz./in. torque ,but 2 of the internal gears are stripped.
> >> >> The motor has a 25 tooth spur gear on the 3/16" motor shaft that drives
a 57 tooth gear which drives the worm.
> >> >> I can't find a sutible replacement motor anywhere.
> >> >> Does anyone know what I can do?
> >> >> I put a Losmandy STEPPER motor from a G-11 mount, but it runs way too
SLOW.
> >> >> Thanks
> >> >> John
> >> >>
> >> >
> >> >
> >> >
> >> >
> >> >
> >>
> >
> >
> >
> >
> >
>

I am looking to build a very simple alt azm mount for my copy scope.  Anyone
have any plans, pic etc the want to share?

There are many good ways to make an alt azm mount.  I'm not sure what a copy
scope is however.

One source of pictures is this group's photo section for starters.  The
Dobsonian mount is one of the most popular and easiest to make of the alt az
variety.

Dale Eason

--- In atm_free@yahoogroups.com, "bgnirrep" <blgnir@...> wrote:
>
> I am looking to build a very simple alt azm mount for my copy scope.  Anyone
have any plans, pic etc the want to share?
>

What's a "copy scope"?

About very simple and tiny Altaz mounts, I built a mount for a green
laser pointer instead of telescope. Directly on stepper's axes,
without reductions, using 200 steps/rev step motors. The stepper's
bearings are stiff and precise, and it works very well.

Powered by SoundStepper.

Maciel


2011/4/21 bgnirrep <blgnir@...>:
> I am looking to build a very simple alt azm mount for my copy scope.  Anyone
have any plans, pic etc the want to share?
>

Are you sure those rings are below the surface and not *on* the
surface?. The photo looks like a concave depression has been ground
through four thin layers. I thought BVC was black, so how can you see
below the surface?

Richard
UK

----- Original Message -----
From: "Peter"

I discovered that BVC glass exhibited strange looking air
spaces between the top layer to the 2nd.

Yes below.

BVC is black but translucent. You can shine a light through the bottom or
side and see the layers.

-----Original Message-----
From: Richard [mailto:richard@...]
Sent: Friday, April 22, 2011 1:09 PM
To: Peter; atm@...; atm_free@yahoogroups.com
Subject: Re: [ATM] Project Update - 24" F/3.37 BVC

Are you sure those rings are below the surface and not *on* the surface?.
The photo looks like a concave depression has been ground through four thin
layers. I thought BVC was black, so how can you see below the surface?

Richard
UK

----- Original Message -----
From: "Peter"

I discovered that BVC glass exhibited strange looking air spaces between the
top layer to the 2nd.

----- Original Message -----

From: Maciel Bassani Sparrenberger

To: atm_free@yahoogroups.com

Sent: Friday, April 22, 2011 10:05 AM

Subject: Re: [atm_free] simple alt azamuth mount

 

What's a "copy scope"?

About very simple and tiny Altaz mounts, I built a mount for a green
laser pointer instead of telescope. Directly on stepper's axes,
without reductions, using 200 steps/rev step motors. The stepper's
bearings are stiff and precise, and it works very well.

Powered by SoundStepper.

Maciel

2011/4/21 bgnirrep <blgnir@...>:
> I am looking to build a very simple alt azm mount for my copy scope.  Anyone have any plans, pic etc the want to share?
>

Hi Peter-
I have a similarly sized BVC blank which I polished out and discovered
astigmatism during the testing. Have you performed a simple Ronchi test with 1
fringe surrounded by a circle on the figure? If it exhibits an S-shape then you
have more grinding to do to fix this.
The back of my blank was not flat enough and it caused problems for me. The
owner was not grinding the backs flat enough-I learned the hard way. I also have
a partial light colored area on the glass (air?). Hope this helps.

   John A


--- In atm_free@yahoogroups.com, "Peter" <peter@...> wrote:
>
> Hi,
>
>
>
> For those interested I have a short update on my 24" fast focal ratio BVC
> mirror.
>
>
>
> Recall previously that my objective was to make an f/3.3 mirror out of a BVC
> blank. The challenge was to ensure that I did not penetrate the ½" thick top
> optical layer because my sagitta was close the full thickness of the top
> layer. After careful grinding and estimating the thickness to the next layer
> I managed to get the mirror to f/3.37 with an estimated 2 mm of clearance
> between layers. I discovered that BVC glass exhibited strange looking air
> spaces between the top layer to the 2nd. There are two circular air space
> rings, one around the 45% zone and the second around the 70% zone. After
> communicating with another individual who has a 16" BVC it turns out that
> his blank also exhibits similar rings. I have to assume during the fusing
> process the blanks had a small amount of sag in the center of the glass
> causing concentric circles of air to be trapped between layers. Here's a
> photo of the polished surface showing the air gaps:
>
>
>
> https://lh5.googleusercontent.com/_NU_o65fcJxs/TbGnTQ2-VHI/AAAAAAAAAjU/iqgGn
> -wy87k/s640/IMG-20110416-00118.jpg
>
>
>
> Under the Foucault and Ronchi tests the air space regions do not show any
> visible defects in the figure so I believe that I'm good to go. It took 10.5
> hrs to machine polish out this glass and thankfully the surface turned out
> defect free from any scratches or pits and the mirror has a good edge. We're
> about 6 hrs into the figuring process and still only 40% corrected.
>
>
>
> I plan to use the Foucault test as much as I can before moving on to a more
> sensitive test. I noticed the contrast between zones is much higher than any
> other mirror my friends or I have ever figured. We decided to incorporate
> zonal  blinking as part of the Foucault test to hopefully add some extra
> accuracy. The outer 70% zones need to be better than 0.001" accuracy to
> obtain ¼ wavefront. I now understand why Mel and others say the Foucault is
> not sensitive enough for super-fast mirrors.
>
>
>
> My plan is to get the mirror as close as I can using Foucault then switch to
> the Caustic then star testing.
>
>
>
> I searched  the Internet and could not find much information on the Caustic
> test. I would appreciate it if anyone out there has links or information how
> to make the tester and interpret the results? I did search the ATM Archives
> and found lots of discussion about it but I did not find instructions on the
> testing itself.
>
>
>
> Thanks and Happy Easter to everyone!
>
>
>
>
>
> Peter
>

maybe you can help this group to follow  SST
http://groups.yahoo.com/group/ISStracking/

whit a soundstepper

do you think it is possible

jack 47'n7 1'W



What's a "copy scope"?

About very simple and tiny Altaz mounts, I built a mount for a green
laser pointer instead of telescope. Directly on stepper's axes,
without reductions, using 200 steps/rev step motors. The stepper's
bearings are stiff and precise, and it works very well.

Powered by SoundStepper.

Maciel


2011/4/21 bgnirrep <blgnir@...>:
> I am looking to build a very simple alt azm mount for my copy scope.
> Anyone have any plans, pic etc the want to share?
>


------------------------------------

Yahoo! Groups Links

You need to be more specific.  Almost of all the newtonian telescopes use a
Parabolic Reflector that is a mirror with a parabolic curve.
If that is all you mean then yes.  Radio telescopes use a parabolic reflector as
well.

Dale Eason

--- In atm_free@yahoogroups.com, John Luich <jluich@...> wrote:
>
>
>
> Has anyone built or used Parabolic Reflectors in their telescopes ?
>

I've managed to find what appears to be a fully assembled stepper controller for a good price. $17.00  delivered.

The features listed appear to be appropriate to my needs but I am not well versed in steppers and need the opinions of those of you who are familiar with this techology.

I am attempting to motorize the polar shaft with a circuit that has provisions for tweaking stepper's speed so it matches the Sidereal Rate.

Mounting the unit and gearing it are not an issue.

I was looking for someting with a potentiometer for adjusting the frequency but this might do. It also saves the PWM setting when the system is shut off,  if the jumper is in place.

What do you think?

Stepper Motor Speed Pulse Controller & Dribver Board 

Thanks

Art

I've managed to find what appears to be a fully assembled stepper controller for a good price. $17.00  delivered.

The features listed appear to be appropriate to my needs but I am not well versed in steppers and need the opinions of those of you who are familiar with this techology.

I am attempting to motorize the polar shaft with a circuit that has provisions for tweaking stepper's speed so it matches the Sidereal Rate.

Mounting the unit and gearing it are not an issue.

I was looking for someting with a potentiometer for adjusting the frequency but this might do. It also saves the PWM setting when the system is shut off,  if the jumper is in place.

What do you think?

Stepper Motor Speed Pulse Controller & Dribver Board 

Thanks

Art

 

 

The main problem with steppers controlling telescopes that I have found is that
they can cause vibration and noise related to their step rate.  That rate can
cause large vibrations in the telescope assembly if it can excite natural
vibration modes of the system.  So don't be surprised that you may need to
address that issue.

To get an idea of the problem think about the noise you hear comming from
printers and scanners.  That is all stepper motor generated noise. Very little
of it is from the other mechanics in those devices.

Dale Eason

--- In atm_free@yahoogroups.com, "art.bianconi" <artbianconi@...> wrote:
>
>
> I've managed to find what appears to be a fully assembled stepper
> controller for a good price. $17.00  delivered.
>
> The features listed appear to be appropriate to my needs but I am not
> well versed in steppers and need the opinions of those of you who are
> familiar with this techology.
>
> I am attempting to motorize the polar shaft with a circuit that has
> provisions for tweaking stepper's speed so it matches the Sidereal Rate.
>
> Mounting the unit and gearing it are not an issue.
>
> I was looking for someting with a potentiometer for adjusting the
> frequency but this might do. It also saves the PWM setting when the
> system is shut off,  if the jumper is in place.
>
> What do you think?
>
> Stepper Motor Speed Pulse Controller & Dribver Board
> <http://cgi.ebay.com/Stepper-Motor-Speed-Pulse-Controller-Driver-Board-/\
> 330528895509?pt=LH_DefaultDomain_0&hash=item4cf50eb215>
>
> Thanks
>
> Art
>

IT IS
why  I used and some of us  used
SOUNDSTEPPER  system

be able to have  diect current  dc  to stop position

and no microstep or noise mouvment

jack 47'N 71'W



> The main problem with steppers controlling telescopes that I have found is
> that they can cause vibration and noise related to their step rate.  That
> rate can cause large vibrations in the telescope assembly if it can excite
> natural vibration modes of the system.  So don't be surprised that you may
> need to address that issue.
>
> To get an idea of the problem think about the noise you hear comming from
> printers and scanners.  That is all stepper motor generated noise. Very
> little of it is from the other mechanics in those devices.
>
> Dale Eason
>
> --- In atm_free@yahoogroups.com, "art.bianconi" <artbianconi@...> wrote:
>>
>>
>> I've managed to find what appears to be a fully assembled stepper
>> controller for a good price. $17.00  delivered.
>>
>> The features listed appear to be appropriate to my needs but I am not
>> well versed in steppers and need the opinions of those of you who are
>> familiar with this techology.
>>
>> I am attempting to motorize the polar shaft with a circuit that has
>> provisions for tweaking stepper's speed so it matches the Sidereal Rate.
>>
>> Mounting the unit and gearing it are not an issue.
>>
>> I was looking for someting with a potentiometer for adjusting the
>> frequency but this might do. It also saves the PWM setting when the
>> system is shut off,  if the jumper is in place.
>>
>> What do you think?
>>
>> Stepper Motor Speed Pulse Controller & Dribver Board
>> <http://cgi.ebay.com/Stepper-Motor-Speed-Pulse-Controller-Driver-Board-/\
>> 330528895509?pt=LH_DefaultDomain_0&hash=item4cf50eb215>
>>
>> Thanks
>>
>> Art
>>
>
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>

I apologize Jack.

I should have mentioned that this set up must be simple and a standalone.

No PC inputs are needed or wanted. I simply want a scope that stays on target as the earth turns. 

The only control needed is a method for tweaking the frequency so that the Sidereal Rate can by locked in and it appears this board provides that..

Thanks for the support.

Art

--- In atm_free@yahoogroups.com, jacot <jacquessavard@...> wrote:
>
> you can have the equivalent whit a 5 inch floppy drive board
>
> easy to control by parall port whit 3 wire
>
> jack 47'N 71'w
>
>
>
>
>
>
> I've managed to find what appears to be a fully assembled stepper controller for a good price. $17.00 delivered.
>
> The features listed appear to be appropriate to my needs but I am not well versed in steppers and need the opinions of those of you who are familiar with this techology.
>
> I am attempting to motorize the polar shaft with a circuit that has provisions for tweaking stepper's speed so it matches the Sidereal Rate.
>
> Mounting the unit and gearing it are not an issue.
>
> I was looking for someting with a potentiometer for adjusting the frequency but this might do. It also saves the PWM setting when the system is shut off, if the jumper is in place.
>
> What do you think?
>
> Stepper Motor Speed Pulse Controller & Dribver Board
>
> Thanks
>
> Art
>

Hi Dale!

I've a signal generator and transducer that will help me identify the natural frequency of the system. I hadn't considered that. Thanks for the heads up.

This scope is for a friend; a replicated antique of one her father built in 1948.  

It's a 6" F8 and I seriously doubt she will be pushing the magnification to anywhere near the 50X  theoretical limits but I'll look to see how to mount the stepper so I can insulate it from the system.

What was your opinion of the driver board?

Thanks

Art

--- In atm_free@yahoogroups.com, "atmpob" <atmpob@...> wrote:
>
> The main problem with steppers controlling telescopes that I have found is that they can cause vibration and noise related to their step rate. That rate can cause large vibrations in the telescope assembly if it can excite natural vibration modes of the system. So don't be surprised that you may need to address that issue.
>
> To get an idea of the problem think about the noise you hear comming from printers and scanners. That is all stepper motor generated noise. Very little of it is from the other mechanics in those devices.
>
> Dale Eason
>
> --- In atm_free@yahoogroups.com, "art.bianconi" artbianconi@ wrote:
> >
> >
> > I've managed to find what appears to be a fully assembled stepper
> > controller for a good price. $17.00 delivered.
> >
> > The features listed appear to be appropriate to my needs but I am not
> > well versed in steppers and need the opinions of those of you who are
> > familiar with this techology.
> >
> > I am attempting to motorize the polar shaft with a circuit that has
> > provisions for tweaking stepper's speed so it matches the Sidereal Rate.
> >
> > Mounting the unit and gearing it are not an issue.
> >
> > I was looking for someting with a potentiometer for adjusting the
> > frequency but this might do. It also saves the PWM setting when the
> > system is shut off, if the jumper is in place.
> >
> > What do you think?
> >
> > Stepper Motor Speed Pulse Controller & Dribver Board
> > <http://cgi.ebay.com/Stepper-Motor-Speed-Pulse-Controller-Driver-Board-/\
> > 330528895509?pt=LH_DefaultDomain_0&hash=item4cf50eb215>
> >
> > Thanks
> >
> > Art
> >
>

Jack, isn't the SOUNDSTEPPER system dependent on a PC?

I need to keep this system simple for a Newbie to use.

Art


--- In atm_free@yahoogroups.com, jacot <jacquessavard@...> wrote:
>
> IT IS
> why I used and some of us used
> SOUNDSTEPPER system
>
> be able to have diect current dc to stop position
>
> and no microstep or noise mouvment
>
> jack 47'N 71'W
>
>
>
> > The main problem with steppers controlling telescopes that I have
found is
> > that they can cause vibration and noise related to their step rate.
That
> > rate can cause large vibrations in the telescope assembly if it can
excite
> > natural vibration modes of the system. So don't be surprised that
you may
> > need to address that issue.
> >
> > To get an idea of the problem think about the noise you hear comming
from
> > printers and scanners. That is all stepper motor generated noise.
Very
> > little of it is from the other mechanics in those devices.
> >
> > Dale Eason
> >
> > --- In atm_free@yahoogroups.com, "art.bianconi" artbianconi@ wrote:
> >>
> >>
> >> I've managed to find what appears to be a fully assembled stepper
> >> controller for a good price. $17.00 delivered.
> >>
> >> The features listed appear to be appropriate to my needs but I am
not
> >> well versed in steppers and need the opinions of those of you who
are
> >> familiar with this techology.
> >>
> >> I am attempting to motorize the polar shaft with a circuit that has
> >> provisions for tweaking stepper's speed so it matches the Sidereal
Rate.
> >>
> >> Mounting the unit and gearing it are not an issue.
> >>
> >> I was looking for someting with a potentiometer for adjusting the
> >> frequency but this might do. It also saves the PWM setting when the
> >> system is shut off, if the jumper is in place.
> >>
> >> What do you think?
> >>
> >> Stepper Motor Speed Pulse Controller & Dribver Board
> >>
<http://cgi.ebay.com/Stepper-Motor-Speed-Pulse-Controller-Driver-Board-/\
\
> >> 330528895509?pt=LH_DefaultDomain_0&hash=item4cf50eb215>
> >>
> >> Thanks
> >>
> >> Art
> >>
> >
> >
> >
> >
> > ------------------------------------
> >
> > Yahoo! Groups Links
> >
> >
> >
>