Has anyone figured out how to keep the Nextruder cables (and filament tubes) from falling forward?
 
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Has anyone figured out how to keep the Nextruder cables (and filament tubes) from falling forward?  

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Steve
(@steve-4)
Estimable Member
Has anyone figured out how to keep the Nextruder cables (and filament tubes) from falling forward?

Has anybody figured out how to get the Nextruder cables and filament tubes to lean back (like they are supposed to)? Mine fall forward enough to cause a Nextruder (when moved to the right side of the bed) to snag on the cables of the parked Nextruder. It is causing prints to fail.

I tried using a spring to pull back the cables, but I couldn't find one weak enough.

Senior Life member of IEEE.

Posted : 13/01/2025 12:58 am
Brian
(@brian-12)
Honorable Member
RE: Has anyone figured out how to keep the Nextruder cables (and filament tubes) from falling forward?

Can you upload some pictures?

Posted : 13/01/2025 1:04 am
Steve
(@steve-4)
Estimable Member
Topic starter answered:
RE: Has anyone figured out how to keep the Nextruder cables (and filament tubes) from falling forward?

Here's a picture.

Senior Life member of IEEE.

Posted : 13/01/2025 1:30 am
Brian
(@brian-12)
Honorable Member
RE: Has anyone figured out how to keep the Nextruder cables (and filament tubes) from falling forward?

It's hard to tell from that angle, but it looks like some of your clips are not in the right spot, and it's possible that where the lengths of cable are at is not ideal.  

Maybe show a front picture as well. 

Here's a picture of mine.  They are not sagging at all and I've had my machine for a year. 

Posted : 13/01/2025 2:11 am
FoxRun3D
(@foxrun3d)
Famed Member
RE: Has anyone figured out how to keep the Nextruder cables (and filament tubes) from falling forward?

Hard to tell from the photo what's going on. But the flex plates that guide the cable bundle look way too loose from this angle. Are they properly installed (per https://help.prusa3d.com/guide/3-printer-set-up_498606#498932) ?

Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...

Posted : 13/01/2025 9:12 pm
pcgeekesq
(@pcgeekesq)
Eminent Member
RE: Has anyone figured out how to keep the Nextruder cables (and filament tubes) from falling forward?

 

Posted by: @steve-4

Here's a picture.

The bowden tube not being plugged into the parked nextruder is not helping.  And as another poster intimated, sliding the tubes and cables in the clips may help reshape them.

I have some snagging of adjacent tubing when operating an nextruder near the other side of the build plate from the nextruder's dock.
It hasn't caused a print failure (or even a layer shift) yet.
Even so, if I know I'll be printing with, for example, tools 4 and 5, I'll position the print as far to that side as possible.

Posted : 15/01/2025 11:07 pm
beegmouse
(@beegmouse)
Eminent Member
RE: Has anyone figured out how to keep the Nextruder cables (and filament tubes) from falling forward?

Half your ptfe tubes aren't plugged in, missing or not clipped in.

Those are what bring the stiffness in the Y axis to the loops.

Posted : 20/01/2025 9:50 am
Steve
(@steve-4)
Estimable Member
Topic starter answered:
RE: Has anyone figured out how to keep the Nextruder cables (and filament tubes) from falling forward?

First, I gotta say that the entire design of the 5 supports and the filament feed is a really bad design.  They used the E3D toolchanger design, and tried to scale it up.  The problems I now now have working with this are the result of this.

It may well be so that the PTFE tubes contribute to the stiffness of the supports, but they really shouldn't.  The main secret to keeping them more upright is to manipulate the braid-covered wires though the clips until the support and feeds are nearly upright.  Unfortunately, the clips allow the braid to slip through them, so this soluation is only temporary until I can figure out some way to prevent this.  The 5 toolheads should have been fed from the top (instead of the rear), and the filament should have been fed from the rear (instead of the side with the side sensors).  What also I have found is that some slip-streaming by Prusa.  The rear PETG supports on my machine are leaning back, as well as an early drawing showing the supports lean back (the new ones are straight up and down), and when I chatted with support and they sent me 5 new straps, these straps are MUCH stiffer than the ones on my XL.

I am still waiting for a new firmware that doesn't bring the nozzle temperature to 175, then back to 70, then up to 175 (for PETG).  Seems like a waste, and too much thermal cycling for the hotend.  I have been waiting for a decent firmware for over a year.  Software isn't Prusa's forte.

I still can't get Prusa's belt tuner to work on my phone (a Samsung Galaxy S24).  Their older program worked just fine on a Samsung S9, which is how I tuned the belts on my MK4.  Support has given me the run-around on this.  To tune belts (based on a recommendation in a forum post), I am using a guitar tuner app, and it works pretty well.

 

I will work with the cables and supports to get them straight.  I might have to re-enginner the clips to give them a rough gripping surface on the inside of the big opening to really grip the braid.  The ulitmate solution of course, is to redesign the entire mess.  Prusa should have done this before releasing the machine.  I am not impressed by Prusa's software skills, and now I am doubting their hardware design.  Bedslinger printers are easy, CoreXY machines are a bit more difficult, and toolchangers are really difficult.  When they work, they can work great.  If you are lucky, they will work great for you.  If you aren't,......

Senior Life member of IEEE.

Posted : 20/01/2025 8:17 pm
pcgeekesq
(@pcgeekesq)
Eminent Member
RE: Has anyone figured out how to keep the Nextruder cables (and filament tubes) from falling forward?

From what I've seen, every tool changer out there is using an umbilical system similar to the Original Prusa XL. I do remember one video, which I couldn't find today to link to unfortunately, of someone who tried something different in their home-brew tool-changer printer (specifically, they tried feeding the filament from the front with the electrical umbilical still running to where the tools docked in the back) and it failed because of intrinsic properties of that topology.

So, as long as PTFE tubes need to be part of the umbilicals -- and it appears that they do --  and need to be stiff -- which it appears that they do -- why not rely on them to stiffen the umbilicals?  What's the down side? And what's the alternative, and who if anyone has put it into production?

It makes me wonder why you removed or unplugged the PTFE tubing in the first place -- and what other clever tweaks you've done.
The rest of us 5T XL users, who in the main assume that Prusa generally knows better than we do how to build FDM printers* and therefore left our PTFE tubes in the umbilicals and plugged in, don't seem to be having the problems you are.

*the biggest IMHO exception being the XL's side filament sensors, where the magnet-based mods on Printables are way better than the originals.  With the mods, I can feed even 95A TPU from my drybox all the way to the Nextruder with zero issues.

Posted by: @steve-4

First, I gotta say that the entire design of the 5 supports and the filament feed is a really bad design.  They used the E3D toolchanger design, and tried to scale it up.  The problems I now now have working with this are the result of this.

It may well be so that the PTFE tubes contribute to the stiffness of the supports, but they really shouldn't. 

 

Posted : 20/01/2025 8:52 pm
Brian
(@brian-12)
Honorable Member
RE:

 

Posted by: @steve-4

First, I gotta say that the entire design of the 5 supports and the filament feed is a really bad design.  They used the E3D toolchanger design, and tried to scale it up.  The problems I now now have working with this are the result of this.

It may well be so that the PTFE tubes contribute to the stiffness of the supports, but they really shouldn't.  The main secret to keeping them more upright is to manipulate the braid-covered wires though the clips until the support and feeds are nearly upright.  Unfortunately, the clips allow the braid to slip through them, so this soluation is only temporary until I can figure out some way to prevent this.  The 5 toolheads should have been fed from the top (instead of the rear), and the filament should have been fed from the rear (instead of the side with the side sensors).  What also I have found is that some slip-streaming by Prusa.  The rear PETG supports on my machine are leaning back, as well as an early drawing showing the supports lean back (the new ones are straight up and down), and when I chatted with support and they sent me 5 new straps, these straps are MUCH stiffer than the ones on my XL.

I am still waiting for a new firmware that doesn't bring the nozzle temperature to 175, then back to 70, then up to 175 (for PETG).  Seems like a waste, and too much thermal cycling for the hotend.  I have been waiting for a decent firmware for over a year.  Software isn't Prusa's forte.

I still can't get Prusa's belt tuner to work on my phone (a Samsung Galaxy S24).  Their older program worked just fine on a Samsung S9, which is how I tuned the belts on my MK4.  Support has given me the run-around on this.  To tune belts (based on a recommendation in a forum post), I am using a guitar tuner app, and it works pretty well.

 

I will work with the cables and supports to get them straight.  I might have to re-enginner the clips to give them a rough gripping surface on the inside of the big opening to really grip the braid.  The ulitmate solution of course, is to redesign the entire mess.  Prusa should have done this before releasing the machine.  I am not impressed by Prusa's software skills, and now I am doubting their hardware design.  Bedslinger printers are easy, CoreXY machines are a bit more difficult, and toolchangers are really difficult.  When they work, they can work great.  If you are lucky, they will work great for you.  If you aren't,......

You looked at my photos right?  There's nothing wrong with mine.  1 year old, over 1600 hours of print time in an enclosure. 

So Im not sure where your coming from. Your perceived big problems seem minor since they have caused no issues in my case.

 

Posted : 20/01/2025 10:36 pm
pcgeekesq liked
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