And if you do want to eliminate the bowden..... look at this....
https://ultimaker.com/en/community/35608-zero-gravity-direct-drive-extruder
And if you do want to eliminate the bowden..... look at this....
https://ultimaker.com/en/community/35608-zero-gravity-direct-drive-extruder
Thanks for the reply @ultiarjan.
In fact, i use one of your feeder designs. Only flaw in it was, after many hundred meters of filament, that the feeder wore out at the bottom, where the filament goes in. I've printed a lot more with a small piece of metal filling the gap. No problems there. I saw you improved that in your latest design.
The Bond-tech thing does not solve the real problem, it only reduces the effects. It addresses the problem at the wrong place.
The Zero-gravity design is a bit like what i had in mind: a direct feed, but without the weight on the extruder. Nice and also possible without the Bond-tech feeder.
Edited by GuestCorrection: i use an iRobert feeder: https://www.youmagine.com/designs/alternative-um2-feeder-version-two. Just fixed the flaw by putting in 2 cm of the bowden tube at the bottom. The hole was large enough by now to squeeze it in.
The extruder-top-feeder is in my opinion also makeable with the standard UM2 feeder wheel and stepper motor.
I think the wheel can be mounted directly to the end of the long square pin in a printable feeder construction.
On the rear corner of the UM2 case the stepper motor has a bevel gear driving a similar bevel gear where the square pin slides through.
So the sliding is done at the back end (not on top of the extruder), leaving an even lighter part on top of the extruder. The only haulage is the bevel gear. And no need for adjustments in Cura.
I'll ask some mechanical engineering students here at Stenden to work in this.
Edited by GuestI don't think there is a fundamental problem with Bowden, only a little drawback. Two of the very commercially successful printers Ultimaker and BCN Sigma both use Bowden drive.
The problem with drive gear directly attached to stepper motor, like the one you are using, is that the motor heats up and soften the filament making it likely to grind.
Also, if the spring compression is not strong enough, it's more likely for the filament to slip and grind.
Geared feeder with decent ratio could eliminate the heat transfer as well as increase the drive force of stepper motor. A Bowden feeder with direct gear is too old fashioned.
Dual drive gears increases grip to filament and reduce the chance of grinding, like Bondtech UltiArjan mentioned.
You could also check out the one I recently made with dual drive gears and 3:1 ratio:
http://www.thingiverse.com/thing:2289203
https://www.youmagine.com/designs/b2d-extruder-strong-and-silent-bowden-extruder
Edited by Guest
Recommended Posts
ultiarjan 1,223
Are you still using the old Ultimaker2 feeder? the black one?
In that case I would definitely upgrade.
You could get the UM2+ upgrade, but rather expensive as you already have upgraded to the Olson block (removable nozzles) if I understand you correctly, so ytou don't need most parts.
I guess the most logical upgrade in this case is a bondtech.
http://shop.bondtech.se/ec/extruders/bondtech-qr-30-universal.html
You could also get a Ultimaker2+ feeder, as an alternative, but Ultimaker has been making it overly complicated to buy these, though some re-sellers have them.
There's not much you can do with the bowden length, you need to cover the whole printarea, but I did mount my bondtech a bit higher than the original feeder location, but I mainly did that to improve the entrance angle of the filament.
Link to post
Share on other sites