Stepper Gear Wearing

Support for UP BOX and UP BOX+. To report a bug, post with a title [BUG REPORT]. To request a feature, post with a title [FEATURE REQUEST]
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Re: Stepper Gear Wearing

Post by DrewPetitclerc » Tue Oct 10, 2017 6:14 pm

OwenSparks wrote:
brunningm wrote:
OwenSparks wrote:There's 2 things going on with this mod. The gripper, and the additional cooling. I't be nice to know if one or other has the most impact. If it's cooling then we could handle that with some printed parts...
Owen S.
The cooling part of the design was to battle the problem of PLA and the high temps of the extruder motor passing this heat to the feeder gear and pre-softening the plastic allowing it to expand and stick to the all metal barrels, causing excess back pressure up to the gear and "chew-outs", ABS generally does not need this as it does not "soak up" the heat and retain it longer in a softened state like PLA does.

All my part designs are fully available to mod for your application and can be machined or cast then machined and there are services online to make them for you at reasonable prices.
Drew Petitclerc
Petitclerc Designs
Owner/Senior Principal Designer, prototype, tooling and test equipment design and 3D printing

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Re: Stepper Gear Wearing

Post by carbokart » Wed Oct 11, 2017 2:18 am

brunningm wrote:
OwenSparks wrote:
brunningm wrote: Currently eSun PLA+, which runs a bit hotter. Between 205 and 225. I'm running it at 220. I've printed in ABS before at 270 without too much issue, so Im not sure this is an issue.

This is the second motor, and I've got four nozzles I clean pretty regularly.

It could just be a bad roll. Happened before.
eSun filament doesn't seem to have any specification in term of diameter tolerance.
I've been using almost exclusively HatchBox and AMZ3D because those are diameter tolerance of 0.05mm and even 0.03mm for AMZ3D material. I rarely get a jam, not to say never. Cleaning nozzle is about the only thing I have to do to maintain good print quality. With a 0.4mm nozzle, when the output filament size is less than 0.45mm, it usually need cleaning (soaking in acetone), to clean to conic shape inside also.

Lately I tried to spend some left over I had from other filament brands I had, and got jammed in the middle of the first overnight print. So I say it's either the diameter tolerance, the material quality (consistency and purity) or both. Nothing to do with the printer itself. In my opinion, mods are just a workaround to make it print bad material.

I had an UP-Mini for a few years, and I tried mods of the roller/spring type among other mods and never made safe overnight prints. I've bought my UpBox+ to solve the problem, it was better but it didn't really solve the problem until I bought material which has a diameter tolerance specified.

I just wanted to share my experience in case it could help someone. So I hope this can help.

Owen Sparks aka Marksman
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Re: Stepper Gear Wearing

Post by Owen Sparks aka Marksman » Wed Oct 11, 2017 7:10 am

DrewPetitclerc wrote: Chewing the filament from both sides before pushing it down the tube has a few problems, one is the gap between the gears and the tube opening is a relief valve for the plastic to "elbow" out and cause a jam, look at the trouble "rubber" filaments have with this design of "pusher" extruder.
Next would be the pulsations in the the outflow caused by the gaps made by the teeth in the filament, these lead to trapped air and pulse or pops in outflow from the nozzle, in observing the first lay down of the plastic if you look closely you will see this as a pulse in the width of the line being laid down some of it can be due to stepping but I have observed odd pulses and pops, even the smoothest looking print these pulses can be seen if you look closely.
Great insight DrewPetitclerc thank you for posting.

Owen S.

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