4 hour part ruined 5 times!


#1

[size=150]K8200 loses the x or y axis 1.5 hours into a 4 hour job.[/size]

We’ve had this printer a year now and have been successful with a number of jobs. At first we had trouble with the stepper driver voltages but once we got them all to 0.425V everything was fine.

However just recently, it loses sense of the x or y axis during the job. The first part was ok , if a little rough. then the next two failed at about 1.5 hours. The following day it completed another similar part okay and then failed the next 3 times at the same sort of point.

Just before the last attempt I checked the stepper voltages again and they had indeed changed slightly. So, having found something wrong, off we went again only to experience the same problem.

Does anyone have a suggestion?

I’m feeling very frustrated because I can normally work it out :frowning:


#2

0.55 is the sweet spot for the drivers.
You should start there.
You should make sure they are not over heating as well.


#3

Thank you for the advice wrong way.

I’ve just started one of the jobs that failed and the working temperature of the driver chips is about 40 degrees Celsius. So we will see if it maintains the datum with the X & Y ???

It does seem much better now that I’ve turned up the driver voltages to 0.55v as you suggested. The movement seems much smoother and stronger as well.

I’ve also re-adjusted the Z homing screw and checked the bed levelling too.

Bob :slight_smile:


#4

I adjusted them to 0,6V and put a 12V fan at it for cooling.


#5

Careful
0.6 is the limit.
Anything higher will make them over heat and do crazy things.


#6

I’ve read lots of things (good and bad) about the K8200.

My personal experience, follow the build instructions carefully, complete the calibration, and understand the slic3r settings. All that’s needed to get great quality prints. It really is a fantastic machine.

Skipping will be caused by:

  1. wrong motor voltages (should be 0.55v)
  2. incorrect tension on the x,y belts (either too loose and skipping teeth or too tight not allowing the x,y carriage to move smoothly)
  3. incorrect slic3r settings (telling the printer to do something odd (less likely)

If the machine is doing odd things, go back to calibration and make sure 1 & 2 aren’t a problem. If so, try print a simple test circle to see how the machine operates. Alternatively, use a different program (such as MatterControl (free download)) to see if there’s some odd setting in RepetierHost which is causing the problem.

Good Luck! :- )


#7

In addition to belt tension, it is also important to check the alignment of the belt brackets on the frame. If the belts do not run straight, the teeth of the belt will rub against the washers on the bracket making a rubbing/sawing noise during fast axis movement. This causes a lot of drag and friction, especially near the limits of motion (ie: on larger prints.)


#8

I think the shifting problem is related to the phenomenon as described below.

viewtopic.php?f=53&t=16375


#9

@Bubbason

Thanks for pointing out MatterControl. I have some problems with my printer as well, this tool looks a bit more ‘complete’ to me than the old and out dated Repetier version that Velleman is offering.
Especially the Slic3r version, it sometimes doesn’t complete it’s g-code generation(It just hangs) with larger/more complex objects.