130 IPM on 1/2 amp!

[jemmyell]

Hi, after a couple of emails from Mariss and much studying I have arrived at a stable configuration for my router table retrofit that simply flies!

I am using a G540, a Keling 48V PS and the original motors. These are Vexta PK268-01A, a bad match for the G540 due to the inductance. I now have them wired 1/2 winding (instead of series) and I reduced the current to 1/2 amp (500 ohm current set resistor). This combination is reliably producing 130 IPM rapids with no sign of a stall after prolonged testing.

I am so pleased with the G540, what a wonderful piece of hardware!

The table is 29" x 28" with 5 TPI ballscrews.

-James Leonard

[Mariss Freimanis]

What I going to tell you will make it even better.:-) Set the drives to 1A (use a 1K resistor) and double your low speed torque. You kind of got it backwards; that motor should be set to 1A in half-winding, 0.5A in full-winding. Reason:

Torque equals ampere-turns. In full-winding current passes through twice as many turns of wire so current must be 1/2 the motor's rating (use 0.5A). In half-winding, use the motor's rated current (1A).

Mariss

[jemmyell]

Hi Mariss,

I will definitely give that a try. I set the current to 1/2 amp based on what I read in yiour step motor guide about setting the current to 1/2 the unipolar rating which is 1 Amp for these motors. I previously had them set to .71 ampsm but after reading about micro step bunching I reduced the current.

-James

[Mariss Freimanis]

The current rating for a 6-wire motor is the one you want to use when running the motor half-winding. It also gives the smoothest possible motion.

Mariss

[jemmyell]

Lol, now I can run 200 IPM on 1 amp. THAT is fast enough. On these small tables and with the soft acceleraion I need for small router bits it is only up to speed for 1/3 of the max 19" X axis travel.

I put my last 1K resistor in my test cable, so back to Orvac...

These motors may be a bad match for G540, but OMG they are working GREAT for me!

Thanks Mariss!

-James Leonard