RE: [CAD_CAM_EDM_DRO] driver wiring questions

> -----Original Message-----
> Hi
>
> I'm fairly new to all this and I have a few questions. I thought I'd ask
> here rather than pestering Dan/Mariss at Camtronics/Gecko and there might
> be other beginners here who would appreciate the answers. I'm using
> G201A's to power a Taig mill (still waiting for the mill to show
> up). I've
> managed to round up a 24V 10A transformer.
>
> According to the instructions from Gecko I will need a minimum of about
> 24,000 microfarad cap.
>
> 80,000*10/33.6=23809
>
> How critical is this, I have a 20,000 75v cap on the bench and
> would just
> as soon use that.

Just use the one you have on hand. It will likely work just fine. You may
want to add a 1000 uf cap right at the drive. I think my first power supply
for a Camtronics 5 amp drive with some 250 in/oz motors used a 15000 uf cap.
My guess is that your ripple will not be that big as you will not be drawing
all that much current from the transformer.

> The steppers I'm using are p/n 1523-025, 210 oz.in., from
> Camtronics. They
> can obviously be wired for series (2A) or parallel (4A). I'm planning on
> series, the thought being that if things go well I may put on a
> fourth axis
> and the 10A power supply may not be enough for 4 axis at 4A. Comments?

Do either half winding or parallel. Half winding is easier and only a few
percent less torque than parallel. Don't do series. you will be giving up
some of your rapid speed and gaining torque at low speeds. With the motors
you have you don't need the additional low end torque. I would not worry too
much about the power supply. Funny thing about a chopper type stepper drive
is that they don't seem to draw as much current as the amperage rating you
are running the output at. Guess it has to do with them working as a switch
type power supply.

> Regarding the 5V power that according to an email from Mariss has to come
> from the computer (I'm planning on getting it from either the
> keyboard port
> of a laptop or gameport of a desktop). However I see that at
> http://24.12.163.105/mill/servomotor.htm he just put a 5v
> regulator on the
> power supply of the drive (see second last paragraph). I plan on
> sticking
> with the instructions from Mariss but would like any comments.

Just go with the power from the PC. Unless you are using optoisolators and
powering them from the separate 5 V circuit you still have to tie the 5V
transformer to the PC at some point or the signals from the parallel port
will not do anything.

> What type of cable do you suggest I look for to run the 4 leads to the
> motors? Most of the cables I've seen seem like to small a gauge for this
> purpose.

I used 16 (was on some 5 amp steppers) or 18 ga stranded wire in 4 colors
and just used some electrical tape every 8" or so to keep it neat.

> I plan on getting cncpro eventually but would like to wait till I
> have the
> system finished. What software would you recommend for just testing the
> drives/motors once I get them wired?

You could use the CNCPro Demo. The only freeware program I know of would be
DanCAD. It will get the motors turning, but takes a little studying to
understand.

Tim
[Denver, CO]

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