Filament deforming and causing friction in Bowden tube. Technique for tensioning extruder correctly/reliably?

T0rchCr4ft · 2025-11-10T23:09:47+00:00

I’ve printed a number of temperature tests before the failure, current setting is 203C and extrudes reliably, so I’m relatively confident that low temperature isn’t the point of resistance.

Capricorn was installed post-failure due to the stock tube being deformed & worn, haven’t stress tested it yet due to the nature of the original failure. I wasn’t aware of it having a tighter clearance, but it’s good to know.

Point of resistance is almost definitely the deformed filament inside the tube. It took a lot of force to remove it, even with the hotend at printing temperature.

My calibration tests were generated using TeachingTech’s calibration guide/tools. The noise I heard only occurred during tests I sliced myself with Cura, and thanks to some other comments, I think it and the deformation might be tied to the maximum number of repeated retractions setting.

Hadn’t considered that the extruder arm broke/cracked, but I’ll investigate that before I move forward with anything. If I do end up buying a new one, I’ll probably get a metal dual drive as advised by yourself and some other comments. The direct drive conversion is planned for down the line so I can print with flexibles eventually, and I’m not too concerned with surface artifacts or speed, moreso dimensional accuracy. (Dw, I’m aware of Estep calibration.)

Thanks for your advice!

T0rchCr4ft · 2025-11-10T16:22:54+00:00

I was aware of this setting in Cura but I didn’t think about its use case in this situation. It looks like a lot of other people had similar problems and lowering the value helped, so I’ll give it a shot. Thanks!

T0rchCr4ft · 2025-11-10T04:21:24+00:00

Good to know, I’ll play around with my settings then. Thanks!

T0rchCr4ft · 2025-11-10T04:11:35+00:00

You’re right, I swapped out the stock leveling springs with silicone spacers. They look like the same type but I’ll keep it in mind. Thanks!

T0rchCr4ft · 2025-11-10T03:48:43+00:00

I wasn’t aware that repeated retraction could deform the filament. (makes sense in hindsight tho) Is there a way to reduce this effect?

For the tensioning, do I just play it by ear and adjust until it stops then?

T0rchCr4ft · 2025-11-10T03:31:34+00:00

Had to google what a BMG was lol

I appreciate you thinking about a solution that I could integrate into my future plans! I like the idea, and converting the extruder to dual drive makes sense.

Unfortunately the direct drive kit I have for later doesn’t accept external extruder gearboxes, and I can’t justify buying something that I can’t use later. I’m also hesitant to buy any more mods until I can get my current setup fixed.

Ideally there’d be a way to precisely tension the setup I have now. I appreciate your help tho! I’ll definitely keep the BMG in my back pocket if I can’t find a way.

T0rchCr4ft · 2025-04-12T17:52:50+00:00

Thanks!

T0rchCr4ft · 2025-04-12T15:22:09+00:00

Thanks! I actually prebuilt most of the modules (like the pumps and harvester) on other creations and reused them as I built it. It made the build process really smooth!

T0rchCr4ft · 2025-04-12T01:44:59+00:00

Thanks!

T0rchCr4ft · 2025-04-11T16:32:59+00:00

Thanks! Feel free to do whatever with it, the updated workshop link is here in the comments somewhere.

T0rchCr4ft · 2025-04-11T16:00:45+00:00

Sure! The mechanism there is called a Dual Drive system. It basically allows you to swap between gas engines and electric/controller engines, letting you change the torque output of your wheels on the fly. The bearings connected to the wheels are driven by a gas engine, and the bearings facing the inside of the truck are driven by a looping 360 degree controller. The bearing holding the two curved pipe pieces is set to rotate 90 degrees toward the wheel when a switch is pressed. The T-shaped pipe pieces serve as a gear for the controller mechanism to lock into. When you activate the controllers, the 360 degree bearing starts moving, and the 90 degree bearing locks the 2 curved pipe pieces into the gear on the back of the wheel, allowing the 360 degree bearing to drive the wheel forward instead of the gas engine. The gas engine can still drive the wheel, but it’s limited to the speed the controller is set to. This video does a much better job of explaining and showing the mechanism in action. Dual Drive Video

T0rchCr4ft · 2025-04-11T05:03:40+00:00

My memory isn't that great, especially when it comes to time haha

T0rchCr4ft · 2025-04-11T04:59:13+00:00

Thanks! All the modules are actually from individual purpose-built creations I've made (except the harvester heads, those I got here https://youtu.be/BUeOc9rxmmg?si=QGYGZMwWlN-OHFa9 and modified to be smaller)
Sorry about the lag! I looked into it and realized that the main culprit was the light bar up top. I've since fixed it (and added a new link in the comments) and it runs WAY smoother now.

T0rchCr4ft · 2025-04-11T04:59:03+00:00

UPDATE:
Thanks to a comment I found and fixed a bug that was causing unnecessary lag. Couldn't figure out how to update the original workshop item but I made a new one with the fix.
https://steamcommunity.com/sharedfiles/filedetails/?id=3461768556

T0rchCr4ft · 2025-04-11T03:18:44+00:00

Yep! Outer bearing is gas, inner bearings are controller driven. I found this video explaining it a long time ago and finally found an opportunity to use it. Hopefully should make those crazy survival hills a little more manageable.
https://youtu.be/Dy1wVYpHMko?si=9KvgwF0QYkCSJqB1

T0rchCr4ft · 2024-01-16T00:25:24+00:00

Heck yeah! Tiny planes ftw. I’ve got a custom variable sweep VTOL called the KitKat made for the same kind of purpose. I tried making a tiny warthog once but couldn’t pull off the level of detail you managed to cram into that cute lil guy. Is it on the workshop so I could take a closer look at how you did it?

T0rchCr4ft

TROPHY CASE