x-endstop issue - one more different cause  

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rolf.h2
(@rolf-h2)
New Member

Hello!

After converting my Prusa Mk2S to Mk2.5, I'm also having trouble with reaching the x-endstop switch. If I move the x-carriage to the left, when I hear the endstop switch click, the cables are already hitting the frame. However, in my case the frame is not hit by the cables inside the spiral wrap, but instead by the hotend thermistor and hotend heater cable bundle. Of course these cables flex away - but in my opinion they are not made for bending and would probably soon be damaged.

To show better what is wrong, I took the following picture (lower part of printhead from the rear side, away from frame in order to be able to take the photo). The thermistor wires (dark grey) get in contact with the frame between the zip tie connecting them only to the hotend heater wires (blue wires) and the back part of the printhead:

cables at printhead

In my opinion, the main problem is that the printed piece to which the spiral wrap is fixed is tilted to the left. It is probably tilted by the spiral wrap. Therefore, its underside moves to the right and the cables fixed to the underside of the peace get too far to the right side.

 

Now my question is: What should I do to fix the problem? I haven't been able to stop the printed part from rotation around the bolt so far. I appreciate any tips or suggestions.

Best regards

Rolf

Posted : 15/03/2020 8:09 pm
joan.t
(@joantabb)
Veteran Member Moderator

Hi Rolf, 

If I understand correctly, the bolt on your cable restraint is tight, but the plastic cable restraint is free to rotate around the bolt? 

Can you undo the bolt, and screw another nut onto the threaded part of the bolt like step 57 but two nuts,
then re fix the bolt to the Extruder backplate like step 58, BUT in addition to fastening one nut against the extruder backplate, fasten the other against the end of the printed plastic cable tie part... 

regards Joan

 

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK...
Posted : 15/03/2020 11:08 pm
me-7
 me-7
(@me-7)
New Member

You might consider the cable management that is on the Mk3 and 3s.  It's the same basic design but the piece that everything straps to is bigger and mounts a bit more securely.  

Posted : 16/03/2020 4:36 am
ajisis
(@ajisis)
Eminent Member

I managed to get the hotend cables right up into the rounded slot underneath the carriage.  Put the thinner thermistor cables in first, and then the heater ones.  Also found I could remove that original cable tie nearest the heater block, get all the cables in place, and put a tie around the cables and up over the bolt which holds the main cable attachment in place.  That seems to fix it.  The first thing that hits the frame is then only the outer sheath of the whole bundle, and then it only just touches before the X endstop is hit.

This post was modified 2 weeks ago by ajisis
Posted : 16/03/2020 10:48 pm
rolf.h2
(@rolf-h2)
New Member

Many thanks for your help. I used both the suggestions from Joan and from ajisis (i.e. I added the missing nut and an additional zip tie). Now it works well.

Again many thanks for your help and best regards

Rolf

Posted : 20/03/2020 6:27 pm
topsiopav.el
(@topsiopav-el)
New Member

It is usually associated with improper movement of the X-axis and/or the Y-axis, leading the extruder head to be misaligned mid-printing. To troubleshoot the issue correctly, it is crucial to recognize in which axis did the layers shift. See the 3 photos below demonstrating three different kinds of layer shifts.

Posted : 26/03/2020 7:05 am
ajisis
(@ajisis)
Eminent Member

@topsiopav-el

Sorry, but you are answering a totally different problem.

Posted : 26/03/2020 10:07 pm
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