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Time to get serious. Let’s try something that looks like a tire. 20% infill. Basically a spur gear with a shallow chamfer and large bore. If this works well I’ll design some treads.
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I think the inner v-groove in first tire was too aggressive. This one has a flat inside profile, but I suspect if I want a gentle concavity to fit a barrel-shaped hub, it'll work fine. The stringing was caused by the v notch. And I don't think supports are a good idea with TPU
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I honestly didn't think I'd be able to get this right... I ordered several sets of toy wheels, expecting I'd have to buy rather than build, but my rover is going to have made-from-scratch wheels
Success Kid Is Successful! GIF
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Yesterday’s success with TPU inspired me to try PETG again. Tried TPU settings (slower movement, overextension) but that didn’t extrude stop all! Realized overextrusion is for soft filaments and PETG is stiffer than PLA. So dialed that back and just used lower speed. Worked ok.
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Comparing failed hotter print (220 instead of 215 or 210… sloppy records), I think I’ve confirmed hypothesis that hotter = more stringing. So@e sort of impurity has snuck into failed print. Either the filament burned or sine foreign stuff. Rafts look similar.
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Ok, slower print failed faster. Maybe I’m going too slow? Again detachment from raft… but happens without raft too 🤔😢
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Microscope on impurity and close up of successful vs hot print. I’m thinking my one successful print was just luck.
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Good thing to try... will try this tomorrow
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Replying to @makeshiftsavant and @vgr
I was able to fix all of my issues with bed adhesion by lowering the first layer so more first layer material gets pressed into the bed and makes a cohesive first layer, but with PETG that might be trickier. Good luck.
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Need to set bed temperature higher, lower the fan speed or turn it off, and maybe mess with first layer settings. Most people have over-strong adhesion problems, not weak adhesion. This needs a spreadsheet.
Replying to
I don’t print PETG but requiring a raft means you have practically no first layer bed adhesion. The first prints I ever did were 3D Benchys that would fail super late into the print simply because they don’t stick. This part, however is super thin so the raft does make sense…
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