RE: Tension pulley broken
good to hear!
Since I have these 7 new nozzles I was going to print the XL and core one nozzle replacement tools in that YXPOLYER filament. I tried the print twice on the XL. Both times the filament snapped in the bowden tube one hour or so into the print! Super brittle. It's a shame, the quality was actually looking on par with the prusa printed parts too. I put it in the filament dryer again over night. I might try a test print again over the weekend. I ended up throwing some galaxy black prusament petg in the core one and printing the parts overnight. It's a bit of a pain currently to roll the printers over and hook up to outside ventilation so I don't often print with things like abs or now this pc-cf.
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I settled on an EM of .90 for that IEMAI PCCF.
Printing the Original Prusa pulley the square nut fits in nice and snug at .90, just like the Prusa supplied one in the kit.
At .85 the square nut slipped in and out a bit too easily. I think any greater than .90 and I'm risking breaking the part or injuring myself to get the square nut in.
I now have more Pulley tensioners than I know what to do with 😂
When I get the chance I'll try that EM calibration print you used, but I think .90 can't be too far off.
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I've printed a few parts with 0.90 too - they come out fine without looking like they're over-extruding. They have a nice finish too. I'm a little more hesitant to recommend this filament now though - I printed a part in this and ABS, and the IEMAI part wasn't as strong - I was just about able to break the part with my bare hands and it broke along the layer lines, whereas the ABS part is too strong to break by hand. It was an unfair test, as the part in question would never experience that kind of force, but nevertheless it does call into question how much benefit the CF is bringing in this filament - it's not as strong as ABS, and it's not as rigid as Prusament PC-CF. I haven't tried anything bigger than about 6cm yet, so I'm planning to print a larger, mostly flat part that I'm quite familiar with in ABS and ASA.
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I've printed a few parts with 0.90 too - they come out fine without looking like they're over-extruding. They have a nice finish too. I'm a little more hesitant to recommend this filament now though - I printed a part in this and ABS, and the IEMAI part wasn't as strong - I was just about able to break the part with my bare hands and it broke along the layer lines, whereas the ABS part is too strong to break by hand. It was an unfair test, as the part in question would never experience that kind of force, but nevertheless it does call into question how much benefit the CF is bringing in this filament - it's not as strong as ABS, and it's not as rigid as Prusament PC-CF. I haven't tried anything bigger than about 6cm yet, so I'm planning to print a larger, mostly flat part that I'm quite familiar with in ABS and ASA.
Am I right in thinking all filled filaments would be weaker than their non filled counterparts along layer lines? I swear I read that somewhere.
i don’t have any experience with PC so Ive nothing to compare it to. For my application I just need something that can withstand chamber temperatures, I don’t need any real impact resistance or load bearing qualities.
RE: Tension pulley broken
Am I right in thinking all filled filaments would be weaker than their non filled counterparts along layer lines? I swear I read that somewhere.
i don’t have any experience with PC so Ive nothing to compare it to. For my application I just need something that can withstand chamber temperatures, I don’t need any real impact resistance or load bearing qualities.
I think you're probably right - that's a good point.
RE: Tension pulley broken
A podcast I am following by people way more experienced than me keep saying CF additions don’t add strength, the fibers are to short for that, but that fibers being there can mess with layer adhesion making the part weaker. I see other claims that CF addition reduces warping and adds stiffness but I don’t have much to compare to.
/Anders
RE: Tension pulley broken
Yeah I think primarily it aims to reduce with warping, and increased stiffness and dimensional accuracy.
RE: Tension pulley broken
Was reviewing assembly instructions for other reasons and am pretty sure this is new...
RE: Tension pulley broken
It certainly wasn't in the MK4->C1 conversion kit instructions I followed 'bout a month ago.....
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It's 100% new. They've obviously been sending loads out due to the galling effect.
RE: Tension pulley broken
Does anyone know if its possible to buy a threaded version anywhere? I havent yet fixed mine (its been like this ever since my last comment, about 2 months or so) but this time i want to do it right but i dont have a thred injector at my disposal nor i can print 'smelly filaments' at home ;(
RE: Tension pulley broken
Does anyone know if it’s possible to buy a threaded version anywhere? I havent yet fixed mine (its been like this ever since my last comment, about 2 months or so) but this time i want to do it right but i dont have a thred injector at my disposal nor i can print 'smelly filaments' at home ;(
Somebody on here nay be able to oblige. Where are you based?
RE: Tension pulley broken
I had the exact same tension pulley failure where the nut chews through the printed element when the screw seizes up. After trying various approaches, I found the only reliable long-term fix is to reprint the part in PCXT with 100% infill.
The original infill density just isn't sufficient for the mechanical stresses - when the screw locks (dirt, overtightening, whatever), the nut cuts right through the plastic making tensioning impossible. With 100% infill, the nut simply can't eat through the material anymore.
Fair warning though - getting the nut inserted into a 100% infill part is significantly harder, but it's worth the extra effort for a permanent solution. This basically trades easy assembly for long-term reliability, which seems like the right call given how difficult these are to remove once they fail.
As others mentioned, if you're trying to remove a pulley with a seized screw, be very careful not to tilt too hard against the belt tensioner or you'll crack it. Much better to prevent the issue entirely with the beefed-up part.
This seems like a design weakness that could probably be addressed in future revisions, but for now the 100% infill reprint works perfectly.
RE: Tension pulley broken
I'm from Poland 😉
RE: Tension pulley broken
yeah, I'm hoping someone more geographically close to you is willing. The shipping alone from where I am, Colorado, would be prohibitive.