Re: [CAD_CAM_EDM_DRO] Enco XY Table

Hi Jaredts,

I'm not sure you've got enough torque to move it! You might try to make
a quick-and-dirty coupler from the 1/4" stepper shaft of the stepper to
one of the shafts of the table, and see if your stepper can move it.
Maybe a 3:1 pulley ratio would give you a enough torque. If you don't
need speed, and you can move the ways, then sure, have some fun with it!

A spring scale or a pail with sand at an appropriate distance away from
the shaft of one of the leadscrews (a 1' lever arm, for example) can be
used to roughly determine starting torque to move that axis.

Yeah, Gecko's driving steppers will give you more power, and higher
speeds. But it's the "switching" feature of the drivers that get all
the speed and torque out of the motors for you. They allow you to use
20X voltage, whereas a typical unipolar driver needs BIG L/R resistors
to allow the voltage to be only a few times higher.

If your motors are 6 or 8 leads, then they can be driven (usually) with
a bipolar driver as well. So you can "upgrade" later!

Try to use all the voltage you can with your stepperworld drivers, that
will help. You don't mention which one you're considering, but if it is
a "chopper" or has "PWM Current Control", then you you should get quite
a bit out of the driver. No, the SP-2 looks like it just uses UDN-2003
drivers, and that wouldn't do it. The MS-1 on the other hand runs 1.5A
and up to 50V, which if matched to a motor (bipolar), CAN give you quite
a bit of torque. Enough for the table? Maybe with 3:1 pulleys,
otherwise fine for a Sherline sized mill.

HTH

Alan KM6VV
(back from U.K.)


JAREDTS wrote:

>
> I'm dying to put together a cnc for routing, milling, or at least
> engraving, so I bought an Enco mill drill table. This thing must
> wiegh over 50 lbs. I hope to put the fet-3 controller + 150 ozin
> motors from stepperworld on it as my first step. I realize its a
> unipolar package, but would it really be that bad (if I get
> everything else right)?
>