I need some help… watch the video. I am dealing with an issue on my new machine where when I connect a db25 serial cable to my breakout board and power it on all the axis’ either have a jittery drift or just sit and jitter. I disconnect the serial cable and power it on and the machine sits nicely, no drift or jitter and the motors lock. I have replaced the serial cable and tried 2 different computers, the one in the video ran my old cnc router no problem. I have triple checked the wiring, microstepping, and voltages. So I am a little stumped.
If the problem is not your board, it the cable running along something and picking up signal from other things? Just a guess.
I’m will to entertain guesses at this point @NathanielStenzel … lol. I’m so frustrated and I have never seen this before. I’m borrowing my buddy’s spare breakout to rule that out tonight.
Post wiring diagram to include model number of components being utilized.
Also, have you tried a different parallel cable? or ohm it out?
After looking at the video again, there seems to be a chance of one of your many wires or ribbon cables in your controller box coming near a high power one and that the interference is inside your controller box. It could still be outside it, butnI would now consider inside to be something to suspect as well.
Breakout, Drivers: http://www.probotix.com/wiki/index.php/Unity_Controller
X, Y motors (wired bi-polar serial): http://www.automationtechnologiesinc.com/products-page/nema-23/kl23h2100-50-8b
Z motor (wired bi-polar parallel): http://www.automationtechnologiesinc.com/products-page/nema-23/nema-23-bipolar-stepper-motor-quarter-inch-dual-shaft-with-flat-282-oz-in
I have the drivers for the x and y motors set to 4.2A and the z motor set to 2.84A with 16 microsteps
@Matt_Wils so the parallel port controlled CNC machines have to have the cable at a certain resistance? I never dealt with this fancy of a setup myself, but I would like to know for future reference.
The control box is a purchased product @NathanielStenzel from Probotix. Its their unity controller. Probotix is only a 20 minute drive from my house which is really convenient.
DB25 serial cable ? Theres your problem most likely. It’s a parallel interface; a db25 serial cable won’t work.
I can’t tell from your video but do you have the control software open ie. mach3 Linuxcnc, etc? I have seen strange behavior on my small machine during computer boot up due to the computer putting the parallel port into a default state that pulled some of the pins high and floated others. Once I opened my control software the parallel port returned to the expected state.
@Joshua_MalaMaker_Mal it is nice when you have cool places to pick up cool toys within a convenient distance.
@Beau_H I am running LinuxCNC. I had a chance to run to my buddies house and bench test the controller with a spare stepper motor from our local MakerSpace. It appears to be the breakout board. It did the same jittery movement with the spare motor hooked directly to the stepper driver with a 3rd db25 cable. Even with this problem, if you ever are looking for great controllers, the probotix unity controller is awesome and probotix has great support / documentation. I have had their breakouts and drivers for 3 years now, their stuff is always top notch. This controller saved me the hassle of figuring out how to mount the stuff in an enclosure for a fraction more than the cost of the equipment.
You could check if the rate of drift match the power frequency. Take into account if you microstep.
Figured it out for sure!!! My buddy sent a video to the owner of Probotix and he responded last night. The USB power is very critical! If you do not supply enough amperage to the USB you get power bleed and it causes the jittery drift. So since the USB on a computer only supplies so much power to on board USB ports, the USB keyboard and mouse were hogging enough amperage to cause the bleed. I never had this on my old router and equipment because it was always hooked through a powered hub so the hub was supplying enough power for everything. I tested this setup this morning with the hub and things work beautifully. Thanks to all for you suggestions and tips. This fix is one to remember, there is not much out there to point to this solution in terms of the failure mode. This is why I buy Probotix… their owner is dedicated and into the industry!
Indeed interesting, thanks for sharing.