Hello Steve, hello together,
What do you think about PETG for the gears?
I built a few clocks SP4 and SP5 that way and to me that feels very good, less friction.
A clear disadvantage is the tendency of PETG to produce more stringing.
So you have to inspect the results carefully.
What do you think?
Cheers, Frank
My initial experiments with PETG show no improvement compared to PLA. I even tried silk vs non-silk PLA and found slightly better results with silk PLA. This is an extremely small sample size, so I am not going to draw any conclusion from it.
My PETG experiment only replaced gear 4 to the pallet.
Here is what I have learned:
1) PLA, silk PLA, and PETG are all acceptable for the gears. I do almost all of my prototyping using silk PLA. There does not appear to be a significant enough performance difference in the other materials to exclude them.
2) PETG is a tiny bit "squishier" than PLA. There might be some additional deformation near the winding drum. This part is designed with thick features and should be OK with PETG, but I have not actually tested it yet.
3) Silk PLA often prints with fewer surface defects compared to non-silk PLA. Maybe the surface tension that pulls silk PLA into itself helps reduce random blobs.
4) The PTFE infused PETG should be a huge improvement. It is too bad it is so expensive. I design assuming hundreds of makers will be printing them, so it is hard to recommend it as a requirement.
Hi Frank and Steve,
I was having stopping issues with SP8, and I tried re-printing with a few filaments, but when I ordered this PTFE-filled PETG, I saw big improvements. I used for the deadbeat pallet, escapement gear, and gear 2.
I saw big improvements ( by eye) in the pendulum swing angle. I would guess about a 50% improvement.
No stopping since I made the change around the first of the year.
Best, Dave
https://www.robotshop.com/products/3d-printing-canada-usa-spectrum-iron-grey-petg-ptfe-175mm-filament-1-kg
I have no data to say if it will work or not. On one hand they are just gears, but on the other hand they can be very finicky.
I am in the middle of an experiment to see if non-silk PLA performs better than silk PLA. My next experiment will be a test with PETG to see how it compares. I should have the results in less than a week. Feel free to try it yourself.
My latest SP4 prototype was stopping at the same spot with silk PLA. There was a tiny defect on gear 2 where a tooth lifted on the first layer. The defect was barely noticeable, but it was enough to stall the escapement. 32 day mode does not have a lot of tolerance for stringing or defects near the escapement.