Must-have promega idler/gearbox mods!

bass4aj
Posts: 6
Joined: Thu Oct 04, 2018 11:07 pm

Must-have promega idler/gearbox mods!

Post by bass4aj » Thu Oct 04, 2018 11:10 pm

For those of you potentially interested in Alden Nayel's idler mod (with aluminum bracket) or my gear system (still in testing), I have a local robotics team that is interested in making and selling the parts (to order) for fundraising. If you are interested or want to see more about the mods, please fill out your information on this form. The prices on here are estimates and subject to minor changes. https://goo.gl/forms/nadFT8JN7laQflzE2

What do the mods do?

The idler mod replaces the idlers on the linear rails on either side of the print head. It uses bigger bearings to eliminate the banding that can be seen in prints, due to the teeth on the belts. This mod was designed by @Alden Nayel and he has shown some truly beautiful prints after doing this mod.

The gearbox mod is still in development and being tested, but it would gear the current promega extruders 3:1 while only costing a little build space in the Y axis. This would effectively eliminate any print issues related to speed, underextrusion, and PLA on both ktana and compound. Testing by @talryyn(John) shows that gearing up the motors fixes these issues, while also keeping the motors cool. This mod will perform the gearing in an extremely small, efficient space.
Attachments
idler mod 1.jpg
idler mod 1.jpg (11.15 KiB) Viewed 3065 times
idler mod 1.jpg
idler mod 1.jpg (11.15 KiB) Viewed 3065 times
idler mod 1.jpg
idler mod 1.jpg (11.15 KiB) Viewed 3065 times
idler mod 1.jpg
idler mod 1.jpg (11.15 KiB) Viewed 3065 times
idler mod 2.jpg
idler mod 2.jpg (9.96 KiB) Viewed 3065 times
idler mod 2.jpg
idler mod 2.jpg (9.96 KiB) Viewed 3065 times
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20181003_222547.jpg
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bass4aj
Posts: 6
Joined: Thu Oct 04, 2018 11:07 pm

Re: Must-have promega idler/gearbox mods!

Post by bass4aj » Sun Oct 07, 2018 10:05 pm

Here are some progress photos of first prototypes. Idler bracket is milled. Bearings in the photo are not actual orientation, just put on for show. Gearbox is being ran for many hours to break in the gears before adding force. Running at 350mA
idler mod.jpg
idler bracket.jpg
gearbox break in testing.jpg
20181007_220119.jpg

jwmueller
Posts: 10
Joined: Tue Sep 11, 2018 4:30 pm

Re: Must-have promega idler/gearbox mods!

Post by jwmueller » Mon Oct 08, 2018 12:44 pm

Here is some early testing for what has become the basis of the gearbox mod.



(don't try this one at home, the HT nozzle does get more heat creep that in most cases causes it to not like PLA. I was using a high temp version of PLA in this video. The print finished fine, but low temp PLA trials were not good) Worked fine for PETG. The standard K'tana nozzle with the PTFE liner worked fine on this gearbox setup.

jwmueller
Posts: 10
Joined: Tue Sep 11, 2018 4:30 pm

Re: Must-have promega idler/gearbox mods!

Post by jwmueller » Mon Oct 08, 2018 6:33 pm

Test site for now - http://bit.ly/PromegaMods

bass4aj
Posts: 6
Joined: Thu Oct 04, 2018 11:07 pm

Re: Must-have promega idler/gearbox mods!

Post by bass4aj » Thu Oct 11, 2018 10:19 am

Gearbox mod is coming along well. here are some images of the new all-metal body and how it fits together.
Attachments
20181009_223406.jpg
20181009_223117.jpg
20181009_223006.jpg
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20181009_222146.jpg

bass4aj
Posts: 6
Joined: Thu Oct 04, 2018 11:07 pm

Re: Must-have promega idler/gearbox mods!

Post by bass4aj » Thu Oct 11, 2018 10:21 am

Mod Updates!
Attachments
20181010_144216.jpg
These are laser cut acetal spacers for the idler mod. I was unable to find the perfect spacers online, so I thought maybe we could laser cut them to the right size! I think they came out great!
20181010_151907.jpg
This is the inside of the new gearbox with the acrylic ring gears. The colors will not apply to the production versions.

bass4aj
Posts: 6
Joined: Thu Oct 04, 2018 11:07 pm

Re: Must-have promega idler/gearbox mods!

Post by bass4aj » Fri Oct 12, 2018 9:07 am

First extrusion test passed with flying colors!!!!

link to extrusion test video https://photos.app.goo.gl/xFKxhFvGvFerhmjg6

ktapper
Posts: 10
Joined: Sun Oct 07, 2018 7:47 pm

Re: Must-have promega idler/gearbox mods!

Post by ktapper » Sun Oct 14, 2018 10:51 am

Ok at this point I am buying both....

jwmueller
Posts: 10
Joined: Tue Sep 11, 2018 4:30 pm

Re: Must-have promega idler/gearbox mods!

Post by jwmueller » Tue Oct 30, 2018 4:24 pm

Hopefully by next week! More soon... (how is my marketing talk?)

TheBum
Posts: 44
Joined: Tue Sep 11, 2018 4:41 pm

Re: Must-have promega idler/gearbox mods!

Post by TheBum » Wed Feb 13, 2019 12:36 pm

I got my Promega back up and running after the gearbox and idler mods and my first print came out quite well. This is before I've done any tweaking in the slicer (Simplify3D). Before the mods, I couldn't run more than about 10mm/sec, and even then I got motor skipping and artifacts as a result. I ran my first post-mod print at 40mm/sec. I was getting some clicking noises on abrupt changes of direction of the print head, but nothing I could attribute to the extruder.

I do need to recheck my Z axis setup though because I didn't get the three bottom skin layers, even though the print head was going through the motions. I had a bed crash just before I printed (accidentally left my Z probe attached) and my Z axis height may have gotten messed up. I did re-mesh the bed and skipped it level again, but the nozzle seemed awfully low. I even baby-stepped the nozzle up 150 microns.

The rest of the layers were clean except for some mild globbing in curves. I will probably use the printed objects (Z sliders with heat inserts) despite the bad first layers; I ran 50% infill, so they're plenty strong.

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