Re: Spindle Relay Question

Do you have a part number for that? I have ordered the 1.5HP 110VDC
motor and 115VAC/130VDC controller for it. It there a different
controller to use to make this interface MACH2 easier. I was just
going to use a relay to switch the AC to the controller on/off and
set speed by hand.

Thanks,
Rod
--- In CAD_CAM_EDM_DRO@yahoogroups.com, "turbulatordude"
<dave_mucha@y...> wrote:

>
> >
> > DPDT relays are readily available on eBay - you need only

choose one

> > with contact ratings 50% over the typical current draw of your

motor,

> > and a coil suitable for the drive output of your computer.
>
> DPDT solid state relays are something I have never seen.
>
> Mechanical relays that are DPDT are a dime a dozen, well a couiple
> bux anyway.
>
> I am not sure how you propose to run the motor. PWM out of the PC

and

> PWM the SSR ?
>
> For a few $$ you can buy a SCR driver for the motor (surplus

center)

> and that can accept your PWM as the speed source.
>
> A single DPDT mechanical relay could be used to then reverse

direction.

>
> As was mentioned, the current and voltage must be zero when you

open

> the relay.
>
> Some of the more elaborate SCR drivers for treadmill motors have a
> tachometer, either a encoder type wheel or a single magnet as a
> feedback device.
>
> The ones I have seen have been seperate boards that accept your
> setting for speed, look at the RPM and then adjust the output to

the

> controller as needed.
>
> From the few units I've seen, they are labeled controllers and not
> drivers. different than we are accustomed to for stepper and servo
> drivers.
>
> From my limited experiance, the controller needs a circuit

breaker.

> I've had mine trip a dozen times in an after noon. no fuses there.
>
> And, I am very confidant in saying that unless you do have RPM
> feedback of some sort, you will have wildly varying speeds.
>
> Also, the ones I've pulled from treadmills have a matched inductor

for

> the motor. Not totally sure what part that plays in the control

scheme.

>
> If you check out the DART site about controllers, they have decent
> manuals and describe the features of the common controller.
>
>
>
>
>
> Dave