Cable bend causes fan to cut off when z=66, x < 100
On my factory built MK2 I started to notice that the fan on the cold end started to cut off on a large model I was printing when z = 100, x < 100.
I played with the harness coming out of the rambo box and got the fan to come back on. To keep the fan on to complete the print, I added zip ties.
I was printing this model: http://www.thingiverse.com/thing:22656
Any else notice this? What is the point of stress / failure? The print was running for 20hrs. Do the wires in the harness get hot which may be a parameter causing stress on the harness?
Re: Cable bend causes fan to cut off when z=66, x > 100
More photos of my temp solution
Re: Cable bend causes fan to cut off when z=66, x > 100
If you want to see if this is an issue on your MK2, I guess you could do the following.
- Heat to PLA temps.
- Move to x = 50
- Raise the Z up and down to see if the fan cuts off
I would like get data points from others.
Re: Cable bend causes fan to cut off when z=66, x < 100
In investigating more, I'm not sure if the fault is at the rambo board or where the harness meets the print head. Which is more likely?
Re: Cable bend causes fan to cut off when z=66, x < 100
I now see that that the fan cutting off is not related to the x,y,z position.
The fan cuts off when I wiggle the harness going to the print head.
Re: Cable bend causes fan to cut off when z=66, x < 100
Problem identified.
Fix implemented: http://shop.prusa3d.com/forum/prusa-i3-kit-building-calibrating-first-print-main-f6/problem-solved-after-45-days-of-continous-printing-t3107.html#p23955
Re: Cable bend causes fan to cut off when z=66, x < 100
Usually the cables break where they are bent 90deg at the back of the extruder, where the cable keeps bending again and again with each X-axis move.
I installed a nail to stffen up that area, so far so good, time will tell if cables break somewhere else next, or if they stay intact.
Re: Cable bend causes fan to cut off when z=66, x < 100
I like your solution.
Based on this I will do the same, but I have thick copper wire that is used to run AC lines in the house which I will replace the nail.