axis shift without skipping - when travelling

HI,
I have an anet that works reasonably good with the stock board.
if I use octoprint the print ramdomly goes haywire (most recently, moving z axis instead of x axis causing hot end to punch through print).

so I decided to change the board to mks gen 1.4 with tmc2100 steppers.
no changes to motors, geometry, head etc were made. just the board and the drivers.

main issue:
everything moves properly but when the head "travels" the printer seems to lose position. it shifts left and away (negative on x and positive on y)

I can print a cube - first layer is fine but second layer x and/or y shifted between 1 and 5 mm (x appears mostly ok with increased voltage on driver).
(hot end travels at layer change)

If I print an irregular shape where travel is used, it will be out of alignment. The more travel, the more shifted.
each travel, it shifts again.

I have tried :

1) increasing or lowering stepper voltage - increase on x axis seems to have mostly worked but not y axis.
4.5mv and ,9mv

2) swapping stepper drivers between axes.

3) compiling firmware from vanilla.

4) removed jumpers on board for y axis


The issue does not seem like it is skipping.

attached is an example of the output.

Any assistance would be most welcome.

Sounds like possible interference on the endstop wires from the motor wires.
Make sure wires frome each endstop are twisted, and also each motor wires are twisted.
Try to route enstop wires away from motor wires.
In firmware, there will likely be an option to 'only check endstops when homing', this will elliminate any crosstalk.

Have you checked for loose drive pulleys? Loose belts ? Binding of the mechanism in whichever axis is shifting?

What are the acceleration and jerk settings? How fast are you trying to print? What's the travel speed?

I can't think of any reason for the endstops to have any influence on this behavior.

---

Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Quote
the_digital_dentist
Have you checked for loose drive pulleys? Loose belts ? Binding of the mechanism in whichever axis is shifting?

What are the acceleration and jerk settings? How fast are you trying to print? What's the travel speed?

I can't think of any reason for the endstops to have any influence on this behavior.

yes I have checked physical again. it was working good before change of board.

does changing the drivers change acceleration and jerk?
default settings are lower than the original firmware.

to start with I amended existing firmware for new board , axis inversion etc. so it was minimal changes.

thanks for posting

Quote
obewan
Sounds like possible interference on the endstop wires from the motor wires.
Make sure wires frome each endstop are twisted, and also each motor wires are twisted.
Try to route enstop wires away from motor wires.
In firmware, there will likely be an option to 'only check endstops when homing', this will elliminate any crosstalk.

I will check this out. the only check when homing is possibly on.
I did not twist wires for endstops or steppers bit will give it a go. I was printing with SD card as I suspected RF through Pi connection.

it is strange because it was straight board replacement, so i has be a bit confused.


thanks for the advice

Did you modify your TMC2100 drivers in any way? AFAIK, they are in silent mode from the start and require to be modified to run in stealth-chop mode to be useful for 3D-printers.
There is a longer thread about TMC2100 mods in the general section.

Quote
o_lampe
Did you modify your TMC2100 drivers in any way? AFAIK, they are in silent mode from the start and require to be modified to run in stealth-chop mode to be useful for 3D-printers.
There is a longer thread about TMC2100 mods in the general section.

no mods as yet.
methinks they are in silent mode but people say they should just slot straight in - being a noob at this, I thought I would stick with stock as supplied with board.

I will have a look at the mods to put them into stealth chop mode.

Today I tried re-wiring with twisting etc to reduce RF. no change.
put a fan on drivers and ran them to 1v, the motors get hotter but results vary.
in separate tests, I reduced print speed to 10ms and acceleration to 500. with various voltages too.


the issue is doesnt seem to be jerk or acceleration. it also isnt slipping. it is losing steps somehow on travel.

if no travel, I can print complex movements without issue. first sign of travel and axial positioning is lost.

I am tempted to cannibilise my a4988 drivers from delta printer to see whether it is just tmc settings or it is something in board or marlin.

anyhow, thanks for comments.

How fast are you trying to make it travel? Maybe the motor is running out of torque at that speed.

---

Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Quote
the_digital_dentist
How fast are you trying to make it travel? Maybe the motor is running out of torque at that speed.

slower than before.

I have tested from 10mm/s to 80mm/s = speed is not a factor nor is acceleration (that I can see)

I can print at 80mm/s so long as no travel. sharp corners, round corners are no problem.

further testing.

1) jumper from cg1 to ground installed for spread cycle.
note: remove all 3 jumpers from board when doing this else it wont work and could kill usb somehow (I got warning from usb on over drawn current).
set voltages from .5v to .9v still get shifting on travel.

Still getting shift on travel.

2) set max x/y speed to 500mm/min to slow everything down.
Still getting shift on travel.

3) swapped out tmc2100 drivers for a4988
note: replace board jumpers as motors dont work if you dont.

Reversed travel (drivers work in opposite directions apparently).
Decent first print on calibration cube.

more testing required.

The cg1 jumper thing only works with the original Watterot pcb. The newer white pcb requires soldering on the back of the pcb too.

further testing.
removed 5 pins (cg1,2 etc) and attempted print.
Removed 3 jumpers from main board.

got thermal runaway probably on the driver.

put 3 jumpers back, no run away.

still got same issue.
to get close, I have to up the voltage to 1a which makes motors hot and stepper drivers need cooling.

I am getting to the point of ditching the tmc drivers as a costly learning experience and getting a set of drivers for this printer.

it will be noiser but at least it prints and the doco is a lot easier to find.

thanks

The only thing common in all these tests is the motor cables. I'd inspect them carefully, connectors and wires. An intermittent motor cable could cause this type of problem.

---

Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

an update for anyone watching this.

apparently the tmc2100 drivers have pads underneath that need to be bridged in certain conditions.

so, here is where I am at.
removed unneeded pins.
bridged pad to enable bridging wire from cfg1 to gnd.
after doing this, motor whines.

attempted to bridge cfg4 and cfg5 to remove squeal..
Could not get solder to stick to pads. even with scraping and using needle soldering iron or solder covered wire.
pads lifted.

put a4988 driver in for x and y axes - very noisy but not issues with printing.
waiting for full set of drivers to arrive before attempting to bridge cfg4 to vio.