M2 nightmare with soft filiment

Ask the MakerGear community for assistance...
airscapes
Posts: 132
Joined: Wed Jan 31, 2018 11:36 pm

Re: M2 nightmare with soft filiment

Post by airscapes » Mon Jul 02, 2018 3:41 pm

I have given up on the grooved sleeve. I guess the printed version was not consistent enough as the groves in the filament from the drive were not consistent and I assume this was due the sleeve being plastic and not perfectly round? I was also testing with PETG and PLA not soft filament.
I know I can print with soft if I get the tension correct and print very slow as has been said by others. So I switched gears and created a Dial indicator so I can adjust the tension for a new filament, write the number on the roll and next time I use that roll there is no guessing or testing time wasted.
viewtopic.php?f=10&t=6748

Gwhite
Posts: 172
Joined: Tue Jul 11, 2017 3:38 pm

Re: M2 nightmare with soft filiment

Post by Gwhite » Tue Jul 17, 2018 12:26 am

I machined an aluminum grooved sleeve using the drawing I posted earlier.
Sleeved Bearing in Drive.jpg
It pressed onto the bearing very nicely, but when I installed it in my worn out factory housing, it wouldn't turn. I recently converted the factory SLT into a Fusion 360 solid model, and when I checked it, I discovered a gotcha. The clearance around the bearing in MOST places is 18 mm in diameter, but at the bottom of the cutout on the "inboard" side, it is down to just under 17 mm, which is the diameter of my sleeve.
Sleeved Bearing Fit in Factory Drive.jpg
Sleeved Bearing Contact Location 2.jpg
You need a little extra clearance to allow the bearing to squeeze the filament, so I don't think you can use this approach with the factory drive housing. You would have to reduce the OD of the sleeve, which would probably reduce the depth of the groove too much.

You might be able to get into the appropriate spot with a needle file to clear out the interference, but it's in a very awkward location. It's probably easier just to print a drive with proper clearance. I have been planning on using sthone's hinged design anyway, so modifying the clearance there (if it needs it) will be fairly straightforward.

jferguson
Posts: 123
Joined: Mon Mar 30, 2015 7:26 pm

Re: M2 nightmare with soft filiment

Post by jferguson » Tue Jul 17, 2018 1:01 am

Gwhite,
That is really slick. How well does it work?

Gwhite
Posts: 172
Joined: Tue Jul 11, 2017 3:38 pm

Re: M2 nightmare with soft filiment

Post by Gwhite » Tue Jul 17, 2018 1:55 am

It doesn't (yet...). I will need to print a new filament drive housing with appropriate clearance so the sleeve/bearing can rotate freely. I plan on using black ePC, but I want to finish at least a few sides of my enclosure to help maintain the high temperatures required.

No one has responded to my query about black ePC printer settings, so I expect a period of experimentation until I get that process dialed in. It's very humid here this time of year, and although I have a dehumidifier that keeps my shop at around 40% RH, I don't want to open up the sealed ePC package until everything is ready to go.

I've already modified the factory drive design to fix the clearance issue.

airscapes
Posts: 132
Joined: Wed Jan 31, 2018 11:36 pm

Re: M2 nightmare with soft filiment

Post by airscapes » Tue Jul 17, 2018 4:11 am

When experimenting with my PETG printed sleeve I used a dremil with a tiny round bit and needle file to adjust the oem drive housing.. Hopefully metal will work better that a plastic sleeve.
Good luck and keep us posted

Post Reply