D&M 5 Spindle Help

[Richieboy]

Hello everyone, I recently bought an old D&M 5 lathe and am having some trouble getting the spindle to run.

The machine was upgraded by its previous owner to run on Mach3.

When I first power on the machine and click the spindle button in Mach the spindle will turn very slowly and make a loud "thunking" sound as it spins. After a couple seconds of this, the spindle stops and will not restart unless I turn the machine off and on again. Everything in the headstock feels tight, and to me it seems like the power to the spindle motor is alternating between forward and reverse which is tweaking the motor or belt system and making the thunking sound. It does not always spin, and sometimes will just sit there and hum like the motor is bound up, but everything spins freely by hand.

This is my first CNC machine and I have no idea how to test or fix this problem. Any help or ideas would be greatly appreciated.

According to the previous owner, this is how the machine is configured:

"I bypassed the stock controller and installed a C11 control board from CNC4PC, while I was at it, I installed an encoder to use as an MPG. The lathe uses the stock drivers, they work fine so I didn’t up-grade them. The spindle is controlled via the 0 to 10volt analog board (CCW only), and runs about 2600rpm. The Lathe has a digital RPM readout located on the head stock. The Lathe has a homing/over travel switch on the -Z axis"

Thanks,
Rich

[ibuildstuff4u]

There could be a few things that is causing this problem. First of all the motor could have a bad winding or a short in it, did this problem just start?

The other problem could be your motor controller. The first thing that I would do is unwire the breakout board from the motor controller and try to use the board with a manual pot switch. You can buy a 5K pot switch from Radio Shack for around $3.00 and easily wire it in. If you tell me what motor control you have or post a picture of it I can tell you where to wire in the pot switch.

If you still are having problems with the manual control then you know it's your motor controller or motor that is causing this problem. Replacement motor controllers can be found on E-bay for reasonable prices.

Several people have had problems with the CNC4PC board frying their motor controller so I wouldn't be surprised if that is what happened to you. I bought a few of their breakout boards and had nothing be issues my self. In the end if you do find that your motor board is shot I would NOT hook it back up to the CNC4PC breakout board and just use the manual pot switch to control the speed.

If you need more info feel free to E-mail me at dpynenberg@new.rr.com

Send me a few pictures of the wiring and I can help you sort the problem out.

Good luck!

Dale P.