Tall prints & the PTFE tube

[ccompton2003]

Printer Model

2.4

Extruder Type

Clockwork 2

Cooling Type

Stealthburner

So, built a 350mm 2.4 and have been running it for several months with really good success. I did my first really big, tall print a couple days ago. It progressed beuatifully up to the last ~40mm in height. At that point, I believe that the PTFE tube feeding filament flopped under the gantry cable chain and jammed the print head. This caused the belt to skip a tooth or two resulting in a large offset at the top of the print. Dissappointing after working non-stop for a little over 2 days. Has anyone run into this, and what solutions did you come up with to keep the tube out of the way at the end of tall prints?

[edit] Fixed my spelling.

 

[NoGuru]

The PTFE should be just long enough to reach the corners. If its longer trim it. I do not have an exhaust port so mine comes in through there along with my CAN bus connection and I have clips that hold the two together.

 

[Indeed]

What NoGuru said.
In addition I have also mounted a top hat and have the PTFE tube enter through the hat, about 120 mm higher up than otherwise possible. It helps a lot.

A top hat - like the one for Voron0 V0.2 but big enough to fit a v2.4 - is nice to have when the gantry is high up. I no longer have to worry about the PTFE tube and the umbilical cord taking damage because of the small bend radius. I also have a flexible air tube (CPAP) 15 mm in diameter for part cooling. Without a top hat there wouldn't be enough space to mount the CPAP tube to the top of the toolhead.

Edit: If not a top hat, then perhaps something like the "Bowden Tube Guide by Galvanic" might help: https://mods.vorondesign.com/detail/8CxQeqS1lXhlGphwkyqh7g

 

[ccompton2003]

Thanks for the suggestions. The tube is trimmed as short as it can go and still reach the corners. I found this https://www.teamfdm.com/files/file/601-bowden-tube-guide/ that looks like it would at least kick the tube to the other side so it can't get under the cable chain. I think I'm going to try that for a start.

 

[jaskajj]

A top hat - like the one for Voron0 V0.2 but big enough to fit a v2.4 - is nice to have when the gantry is high up. I no longer have to worry about the PTFE tube and the umbilical cord taking damage because of the small bend radius. I also have a flexible air tube (CPAP) 15 mm in diameter for part cooling. Without a top hat there wouldn't be enough space to mount the CPAP tube to the top of the toolhead.

Do you have any pictures how you have implemented and attached your tophat ?

I'm in the process of adding a tophat as well, as I'm missing the few centimeters of print height that the printer is otherwise able to use, but the ptfe-tube doesn't have enough room at the moment (LDO kit).
Therefore I've ordered a new set of aluminium profile kit and I'm going to just shorten the four vertical profiles and add some plexiglass to the sides eventually.

It would still be interesting to find a most practical way to attach the tophat into the v2.4 frame properly.

 

[NoGuru]

Thanks for the suggestions. The tube is trimmed as short as it can go and still reach the corners. I found this https://www.teamfdm.com/files/file/601-bowden-tube-guide/ that looks like it would at least kick the tube to the other side so it can't get under the cable chain. I think I'm going to try that for a start.

I tried that but I could not keep the nut attached to the bolt. its so close to the top that you are very limited using that method.

 

[Indeed]

About my tophat:
I cut some pieces of leftover extrusions I had. Unfortunately not black, but I used what I had.
Mounted together same as the voron frame, with "Blind Joints". See Voron 2.4 Assembly Manual page 10.
It's mounted to the 2.4 frame with ordinary corner connectors, like this one: https://www.motedis.com/en/Bracket-20x20-B-type-slot-6

I also made a "bottom hat" with a sliding electronics drawer.

Pictures you say... Not really, but here's a pic anyway.
Right now the printer is very much in pieces becuase I'm tinkering with it. As usual.
Tophat side panels are not attached. The lid is not properly mounted and so on.
I guess you just have to imagine what it's going to look like when finished.
I'm just about to replace the afterburner+tap (yes, it's possible if you drill a couple of holes in the right places) toolhead for a home made contraption with orbiter, metal reinforced tap, and external part cooling fan.

Ok, here goes. Please don't laugh...

 

[NoGuru]

@Indeed I have some many questions now

1. Is your CPAP fan in the tophat?
2. I still see a part cooling fan on your afterburner, is that just disconnected?

The slide out E try is super cool. I too have used a small PC like the one you have connected to convert a RepRap x400 ($15,000 printer) to using Klipper in the same fashion.

 

[Indeed]

@NoGuru -
1. Yes, the CPAP fan is strung up between springs inside the metal box seen to the left of the tophat. The box has a filter on the suction side and silencers on both inlet and outlet. It's very quiet. At least at speeds suitable for PLA printing. At full speed it sounds like a quite noisy vacuum cleaner but without motor sound, only lots of air hissing. I'd say my CPAP fan is way too overpowered and more than overkill, but it's what I have so I'm going to use it. It's a 24V fan, but even at 12V it moves more than enough air for PLA at less than 20% PWM setting. Maybe I'll have to restrict the air flow to be able to use it at all with ABS, we'll see.

2. The afterburner is currently not connected to the CPAP, it uses the stock fan. Though some trials were done with the CPAP hose attached to the afterburner fan inlet using lots of duct tape. But the Orbiter+Tap contraption - part of it can be seen at the left of the build plate - will be permanently connected to the still uncut CPAP tube that's connected to the fan box outlet.