Help! Switched to MKS Gen 1.4 (from ramps 1.4), now all my prints suck!

I really can't figure this out. I switched from Ramps 1.4 to MKS 1.4, because i needed the extra fan port (dual extrusion), and also it seemed like a better overall board. I've already melted the power wires off my ramps, resoldered that and then blown the heatbed fuse. So at this point, my ramps is a ghetto zombie board (but at least it actually worked)

Well, i guess i was wrong.

I've done so many tweaks, and test prints and nothing works.

The pic should be .2 layer height, but it ends up looking like what i showed in the pics. But, dimensionally it's not far off.

-Esteps are all calibrated
-extruder motor is calibrated (measured 50mm extruded, and it was dead on)
-Mechanically, NOTHING has changed on my printer and yet you can see the before / after is massively different
-I tried the SAME firmware from my ramps 1.4 board, and even tried making a new firmware from scratch, same problems.

My printer is a Prusa i3 (mostly a custom build)
I've really run out of ideas... could the MKS board have some defect?
The only other thing i can think of.... The MKS board only has ONE Z output while the ramps has TWO, so i made a splitter. I read online this was fine, but maybe it's causing an issue?

Current crappy prints




What it used to print like...

Have you set the stepper motor currents on the MKS board the same as you had on your RAMPS?

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Yes, exactly the same. I even tried taking out the steppers from the ramps and putting them into the MKS. Same result. (they are all A4988 )

Edited 1 time(s). Last edit at 10/06/2016 11:30AM by iCrap.

bump.... anyone got any ideas what could be causing this?

The severe Z banding suggests to me that you may have large fluctuations in the extrusion or heated bed temperature while printing. Try monitoring them during a print.

You probably had the Z driver set to a higher current than X and Y on the RAMPS because the two Z motor outputs are connected in parallel. Assuming that your splitter also connects them in parallel, have you done the same on the new board?

Edited 2 time(s). Last edit at 10/09/2016 03:27AM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Quote
dc42
The severe Z banding suggests to me that you may have large fluctuations in the extrusion or heated bed temperature while printing. Try monitoring them during a print.

You probably had the Z driver set to a higher current than X and Y on the RAMPS because the two Z motor outputs are connected in parallel. Assuming that your splitter also connects them in parallel, have you done the same on the new board?

I monitored the heatbed / extruder temps. They both stayed at 65c / 205c very consistently.
For the Z, i made a Y type splitter and plugged that into the output... so i THINK it should be the same thing. I was also reading online that some people say connecting them in serial is better... but i don't know if that will even help my situation?
When i manually move the axis in repeteir, its very smooth... no binding or anything. And like i said (and you can see the other pic) it used to print totally fine before swapping the boards.

Edited 1 time(s). Last edit at 10/11/2016 05:35PM by iCrap.