Extruder harness knocked tall parts off the bed - General discussion, announcements and releases

RE: Extruder harness knocked tall parts off the bed

Jimbo70 — Tue, 18 Oct 2022 13:25:03 +0000

I agree, my Z axis top bearing is flush with the top of the plastic.

RE: Extruder harness knocked tall parts off the bed

Netpackrat — Tue, 18 Oct 2022 00:50:40 +0000

Posted by: @drb1515
Really? How do you know?

Gaping hole in your X-end where the Z rod goes through it vertically. There should be two linear bearings in that hole and they should pretty much take up all the space there. Looks like you are either short a bearing, or maybe somebody substituted a single one of the longer version of the 8mm linear bearings, which are not as long as the 2 bearings end to end (the 2 bearings is the standard setup).

RE: Extruder harness knocked tall parts off the bed

drb1515 — Mon, 17 Oct 2022 23:21:57 +0000

Really? How do you know?

RE: Extruder harness knocked tall parts off the bed

Netpackrat — Mon, 17 Oct 2022 23:07:31 +0000

You appear to be missing a linear bearing on the Z axis.

RE: Extruder harness knocked tall parts off the bed

Thejiral — Mon, 17 Oct 2022 10:35:26 +0000

I have the Mk3s now in an enclosure for more than 2 years and not seen any such drooping. What I have seen was the extruder cable drooping as the screw fixing the cable outrigger at the back of the extruder having come loose. Have you checked if that outrigger is sill firmly attached to the extruder?

What are your enclosure temperatures?

RE: Extruder harness knocked tall parts off the bed

drb1515 — Sun, 16 Oct 2022 22:52:51 +0000

Nah, looked there first more likely my enclosure caused it to droop because of gravity and heat.

Diem — Sun, 16 Oct 2022 22:26:52 +0000

It looks like your Nylon Guide Filament has come loose, probably at the electronics box end.

See step 60 on:

https://help.prusa3d.com/guide/5-e-axis-assembly_169235

And steps 30, 32 on:

https://help.prusa3d.com/guide/8-electronics-assembly_174100

Cheerio,

RE: Extruder harness knocked tall parts off the bed

Jimbo70 — Sun, 16 Oct 2022 21:42:18 +0000

Nice fix! I live your idea.

Extruder harness knocked tall parts off the bed

drb1515 — Sun, 16 Oct 2022 12:25:43 +0000

So I have two MK3S for over a year and never encountered this before. I print rocket models non stop. I recently made a Falcon Heavy model and that had the build plate quite full. The first print came out ok but had some unexplained layer shift about ¾ the way up on one part only. The next print was complete failure and had parts fall of the bed. The third print I happened to be right next to the printer when I heard the print start to get seperated from the bed. I noticed that the extruder cable droops below the parts in that corner and made contact with my model. This only happens when the parts are quite tall, the bad thing is that's 24 hours print time wasted. I took some pics of my "mod" and I hope this helps someone else in the future.

The eye hook is simply superglued into one of the factory holes in the gantry, and I used two tie wraps to keep the harness more vertical.