Hello all. I just upgraded my mid 90's pr shopbot to a 4vg control with gecko drives. I didn't mess with changing the gecko drive settings for more power, because I saw a post warning against doing this for pr machines.

usb connection to windows 7 instead of serial port is nice. In order to get the new control card to work, I needed to change out my electric motor on z axis to a pk 268m-03a. My old one was a pk 268-02a.

When I use the "default settings", my unit values for all axis need to be changed to a negative number to get them oriented properly. So default settings for a prt. My machine is a pr, but default settings not offered for a pr in instructions for 4vg upgrade.

Instructions for v4g say that the correct unit values for a prt with 3.6 motors and 25 tooth pinions are......

1833.465 on x and y
2291.831 on z And I change these to negative to get it to work

So -2291.831 in unit values makes it so the bit rises less than a half inch when I ask it to go up 2".

I messed with the unit values and made z -21,000 to get it to be close to going up 2" when I asked it to go up 2".

That seems way too high, and makes a funny noise, which tells me I must have another setting wrong.

Is there a setting other than unit values that I missed? I have a ball screw z axis.

Tom Hartnett has been helping me a lot with this. He says that Frank will be back on Wednesday, and can help with it then. I just figured I would throw it out there in case this sounds familiar to someone.

Thanks again
Jim