Beginner configuration of Chinese red board TB6560 3 axis breakout

Hi everyone,

First time LinuxCNC user here, and I am running into some silly issues that I hope can be resolved easily. A GRBL board on a machine of mine died, and so I decided to make the switch to LinuxCNC with a chinese TB6560 board with integrated 3 amp drivers, however, I didn't know that it had a bit of a bad reputation before I picked it up. 

I have LinucCNC installed on an old Core2Duo motherboard with integrated parallel port, configured the pinout for the parallel port and all that appears to be running. However, whenever I try and test the axis the motors just shake, hum, and don''t move smoothly. I've run across this problem many times before on homemade 3d printers, but it has always come down to a stupid wiring mistake. However, no amount of messing with currents, timings, or wiring is seeming to resolve the issue.

Does anybody have any example configurations or general advise? Should I return the board to amazon in favor of a simple breakout board and individual drivers?

Here is the board I purchased: 

And Here is a PDF manual I found about this board:

I also noticed that during my configuration, my latency was incredibly bad, hitting 200,000 ns (200 microseconds) when jumping through youtube very quickly. It has a GTX 760 I believe, as the core 2 duo does not have integrated graphics. Is this the main reason for my issues? If so, does this mean that I should pick up a new motherboard for the project? I'm not married to this setup, and I have a 4670s cpu on my desk as a backup in case this older setup isn't cutting it. 

Thanks everyone!

Hey Andy, thank you for the fast reply.

Yes, the amplifier enable pin is working correctly. When logic is flipped on that pin nothing at all happens with any of the drivers.

I have tried step lengths from 5000 to 20,000, with no real apparent difference besides speed (pitch) of the motor buzzing.

To add more context, the motor sometimes rotates a revolution or so then stops, but 95% of the times it just bounces back and fourth a step (or, maybe a few). I had it move an axis of my machine a few inches, but it was incredibly rough and bouncy. But, it shows that things are indeed happening.

I just tested things when flipping axis step and direction pins in the step configurator, and nothing improves. Do you have any other recommendations on things I should try?

I have verified the wiring on the 6-wire motors using a meter, and have verified that they are wired correctly on the board as far as the manual states. On Monday I am going to check the input signal to the board and the output coils using my oscilloscope to see what that tells me.

Any recommendations on other boards or configurations for a low-cost, but also low-demand setup? For my lathe (the next retrofit) I want to go all-in, but I want to make sure linuxcnc works for me on this machine before I invest a lot into several retrofits.

So I tried this and came up with some interesting results. This worked, but not on the stepper motors I intended to use.

The steppers I got working have a 50 ohm winding, 6 wire, and I am leaving the center taps of the windings open. They are pinned out differently, where pins 1 and 3 are one winding, and 4 and 6 is the second winding.

The steppers I initially tried are also 6 wire, but only about 4-5 ohms. Much higher current draw, and are the generic 3d printer nema 17 that I have been using for a year or so. They are more powerful and smoother, but would not run. These also have the center taps of the windings left disconnected, and have coil pairs at pin 1 and 4, and 3 and 6.

Both are nema 17's, and when testing I am indeed flipping the two center wires when switching test motors.

At this point I am successfully moving the machine, but only with the spare older motors.

I'm pretty confused now. Is it still a timing issue? Are the steppers pulling too much current from the drivers? I am feeding the board 12.5 volts at a max of 3.5 amps on my power supply, but it's not taking that much current. Not even close.

I just wrote a long paragraph describing the motor differences and right before I posted I got the meter out and double checked and..... yup, I was wrong. 

I've had this machine for a year, but never messed with the wiring, I just assumed (there's the key word right there) that they were the same steppers as the steppers I bought for my CoreXY printer, as I had no reason to believe they were different, and I /thought/ they were wired the same based on wire arrangements of the original setup. 

Turns out that the old motors and the machine motors are the same pinout-wise, but I just hooked up the original ones with the center wired flipped (which WOULD be correct with the most recent motors I bought...)

Anyways, all seems to be working okay now. I'm still getting errors due to latency when starting linuxcnc, but it seems to be working fine right now. I'm now testing timings and getting everything sorted. Thank you all for your help! I very much appreciate it!