RE: [CAD_CAM_EDM_DRO] Small Problem

Weyland:

I'd strongly suggest that you dig into your pockets a little deeper and go
with the bipolar drivers. Years back, I used some of the unipolar drives in
an industrial application. In order to get any performance from the motors,
we needed a relatively high voltage power supply and some really large power
dissipation resistors which were put in series with each of the motor
windings. The resistors ran really hot.

Contrast that with some projects I've worked on more recently that were
implemented with bipolar drivers. First, no series resistors were required
so the entire system ran cooler. And, the motors were really "stiff." That
is, they really ran well and did not want to stall or drop steps (important
in CNC where you are essentially "counting steps" to know where you are).

I just went through the same exercise that you are going through and decided
on the Camtronics 2 amp board. My decision was made based on a couple of
things: First, the motor current requirements matched the driver's
capabilities. Second, I don't mind building a kit and adding the "extras"
required to make a "stand alone" controller. Third, both Gecko and
Camtronics have received several favorable comments on this list and no
negatives. I have already received the Camtronics toys and assembled them,
but have not tested them because I'm still waiting on delivery of the motors
and mechanical coupling to the Sherline mill. If I didn't want to build the
circuit board, I'd have gone with the Geckos (again based on favorable
comments here and their being capable of driving the motors). But, even with
the Geckos, you still have to mount them, add fuses and switches, etc. so
that's not even a "done deal."

Hope this clears a little mud from the waters.

-- Jerry Jankura
Strongsville, Ohio
So many toys, so little time....


| -----Original Message-----
| From: Weyland [mailto:weyland@...]
| Sent: Thursday, August 02, 2001 5:14 PM
| To: CAD_CAM_EDM_DRO@yahoogroups.com
| Subject: Re: [CAD_CAM_EDM_DRO] Small Problem
|
|
| From: "Alan Marconett KM6VV" <KM6VV@...>
|
| > I have a friend who just got a router from him, so everything should be
| > ok. If you just want a driver, why not go to Camtronics? or Gecko's?
| > The Rigotti driver I'm familiar with is Unipolar. What motors to you
| > have? Can they be connected bipolar? MaxNC "Motion control kit" would
| > be another option, if you need motors/driver/software (unipolar again).
|
| Hey Alan~!
|
| Thanks for the reply.
| I looked at Gecko's, but they're a little outta my price range for this
| first go-around.
| (3 Geckos @ $120 or so, each + motors)
| My *plan* was to buy Dave's driver board kit ($49), and then
| buy the 125 oz/in steppers ($30 ea.) from him.
| This would've come out to around $145 + shipping for everything.
|
| The Camtronics kit for 3 axis is $229 - without any motors.
| (or am I looking at the wrong one?)
| There's another one down the page (3 axis, 2A) that goes for $150.
|
| Yes, everything I've been learning from you guys (thank you)
| says bipolar is better, but I really haven't seen anything in my budget to
| allow it.
|
| The MaxNC kit (the one most affordable to me) is $295 *AND*
| comes with software,but is only 70 oz/in motors, so I'm a little wary on
| that.
| (can't tell if they're bipolar or not)
|
| All in all, I'm back to being in information overload again.
| I need to keep this affordable, but if a driver I buy because of price
| is going to hang me up later, I'd rather flip my pockets out looking for
| more change.
|
| I'm getting dizzy.
| You guys seem to have a more electronics oriented background,
| which I envy, but mine is more machining, welding, sheetmetal oriented.
| To be honest, I wouldn't have a clue which was better for me.
| I can make just about anything, but don't have the slightest idea
| of which motors it would take to run it.
|
| HELP~!
|
| Weyland
|
|
|
|
| Addresses:
| FAQ: http://www.ktmarketing.com/faq.html
| FILES: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/
|
| Post messages: CAD_CAM_EDM_DRO@yahoogroups.com
| Subscribe: CAD_CAM_EDM_DRO-subscribe@yahoogroups.com
| Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@yahoogroups.com
| List owner: CAD_CAM_EDM_DRO-owner@yahoogroups.com, wanliker@...
| Moderator: jmelson@... timg@... [Moderator]
| URL to this page: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO
| bill,
| List Manager
|
|
|
| Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
|
|
|