Newb question: I would like to try a bowden tube extruder setup for 3mm filament (I have a Printrbot LC+ v1 & v2). I’m having trouble determining exactly which parts to get (e.g. specs for teflon tubing, push fit connectors). Anybody got specific info for help? USA source links appreciated, thx.
I was told by a 3D printer vet that even with a gear head motor, you would have a hard time tuning retraction due to the slack induced by an ID 4mm tube. I havent tried yet, but i’d like to. My delta is still in its design phase (trying to use leadscrews instead of belts).
Try to find ptfe tubing 3.18mmx6. The pushfit conector for 6mm tubing. You can find it in http://reprapworld.com at lest the tubing and the push fit connectors. Try to use less than 60cm of tubing. And just as an advice for 3mm bowden i will use nema23 and drv8825 driver (just for direct drive extrusion)
@Alvaro_Rey_Rodriguez Thanks. I plan to use my Wade’s geared pusher with current NEMA 17. Plenty of other people have done so successfully. How about some US sources and specific links to the push fit connectors? That is what I have been having difficulty with.
3mm ID tubing is too tight, and 4mm ID is too loose. This is one situation where imperial units, with their screwy fractions, come in handy. 1/8" is 3.175mm, which is just about the ideal tolerance for 3mm filament. http://www.mcmaster.com/#5033k31/=vzxrbm
I find that 1.75mm filament in a 2mm ID tube works better in my experience, though bowden extruders were in their infancy last time I tried a 3mm one.
@Whosa_whatsis Excellent! Any hints/links for the fittings for each end? EDIT: I’ve looked at McMaster and it seems they only have Y shaped ones for 1/4" OD.
Does this look right?
That should work, though I prefer the ones that E3D sells. Some of those fittings have the metal teeth to grip the tube on a separate piece from the plastic release, but I find that those teeth tend to be more fragile. E3D’s have metal teeth molded into the plastic, so the metal that grips the tube doesn’t have to be thin enough to flex for release.
@Whosa_whatsis you can also easily acetone weld, or thermal bond them into properly sized holes in printed parts. The ones e3d selected to use are the best I have found and also very compact.
I’ve also press-fit them into holes in nylon parts. Works great.
Done. I ordered enough for dual extruder/2 single extruders.
Note to self (or anyone else looking for the same thing):
Source: McMaster.com
Part#: 5033K31
Description: Extreme-Temperature Tubing Made with Teflon® PTFE, 1/8" ID, 1/4" OD, 1/16" Wall, Semi-Clear White, 2 ft. Length.
Price each: $7.46 each
Qty: 2
Total: $14.92
Link: McMaster-Carr
Part #: 7880T145
Description: Push-to-Connect Tube Fitting for Air & Water, Adapter with Hex Socket, 1/4" Tube OD x 1/8 NPT Male.
Price each: $3.17
Qty: 4
Total: $12.68
Link: McMaster-Carr
Total order (before UPS ground shipping): $27.60
I’m not sure if acetone would mess with the fitting’s plastic or not, so I will probably just do thermal bonding (i.e. heat it up with a soldering iron and push it in).
Brass ring insert is what gets pressed or acetone welded in. Once cured the plastic fitting gets installed.
Parts received. They were very well packed. And they damn well better have been. The shipping cost was $10.36–on a $27.60 order! So, yay, the parts are good, but I really wish they had pre-order shipment cost estimation. I might even be inclined to order more at once to make the order more cost effective. I mean, these were not heavy parts–the box probably weighs more!
To be clear, I’m not complaining (ok, whining) about the shipping cost (with such great packaging) as much as the lack of setting customer expectations by disclosing the expected shipping costs prior to placing the order.
mini-rant over.
Yeah, McMaster really works better if you can find a local warehouse to pick it up.
I didn’t even know that was an option–I’ll need to look into it and see if they have anything near Bellevue (it’s near Seattle, WA).