Re: [CAD_CAM_EDM_DRO] Re: max. Servo motor voltage ??

Tom Murray wrote:

>Jon,
>
>I am glad I saw your post before I went ahead and spent > $50 for a
>new transformer.
>
>I wonder if you or someone else on this group could help me evaluate
>the suitability of a transformer that I have on hand.
>
>The transformer that I have outputs 30 volts. I don't have an exact
>figure for amperage, but I am confident that it can supply enough
>current for my application. I was planning to use it to power some
>servos using Gecko 320 amps.
>
>The motors that I will use are rated at 24 volts, 1000 rpm max.
>Continuous torque is 50 oz-in, peak is 100 oz-in at 6 amps. No Kv
>listed (would it be 24 V?)
>

Could be, if the rating is 24 V AT 1000 RPM. But, it might be at some
different RPM, too.

>, but the torque constant is 17.6 oz-in-
>amps. Terminal resistance is 3.3 ohms. I know these motors seem
>small, but they will be used on a Taig mill with 10 TPI lead screws.
>
>

Hmm, these motors might be fine, given the 100 Oz-In peak at 6 A.

>I was going to scrap the idea of using this transformer and was about
>to purchase one at a lower voltage. With my limited understanding of
>what you wrote, I realized that perhaps my transformer would be
>alright to use, after all.
>
>

Actually, the 30 V might be a little low, too. If you can do 1000 RPM,
that will give 100 IPM,
assuming direct drive. 6 A x 3.3 Ohms is 19.8 V. 24 + 19.8 = 43.8
Your transformer will
give roughly 1.414 * 30 = 42.2 V, but that is not leaving an allowance
for the servo drive.
Well, you'll just have to find out what speed it runs out of gas at, and
set a velocity limit
a little below that speed. Likely, it will be fine with a Taig-size
machine.

Jon