Bowden or direct feed?

Hey, I am currently using a bowden reprap, I was thinking of changing it to a direct feed where the extruder sits on the carriage, i understand bowden is lighter in weight, but i think my printer will work better with nylon and softer filaments.


What do you guys prefer ? Am i thinking correctly about this?

I dont think the extra weight in my cause should matter to much with the speeds i use, I notice the ultimate maker using bowden and mostly PLA, I found pla works well, so does abs really.

I have the same thing.. Also i think some quality issues might be caused by the bowden. I think the best case is to have both. I mean, just have quick-fit or some with really short tube underneath, and you can switch out the short tube for a long one.

Getting the tubes on like that is really easy, btw M4 nuts fit right on those 2mm-4mm inner-outer PFTE tubes basically you slide it in some slot and there is a smaller slot for the tube, and a hole down in the bottom for the filament. Once the filament is through it cant slide out. (the PFTE tube can be compressed a bit to hold it with friction too.

jh_pusher.scad contains an example here. (I have been meaning to 'release' that..) Imo with that approach i dont really see the point of pneufits or those things with 'tongues'?

Anyway afaik a design that does that doesnt quite exist yet? And i think there needs to be some discussion if we can make something like quick-fit that works in the different sorts of carriages out there. I'd expect the quick-fit not to be very suitable for delta printers for instance??(or the sort of mini-quickfit i have)

And such a system would be useful for tool-head switching in general.(pen plotting, paste extruders, pippettes etcetera)

But i am talking more long term, you just want to do stuff now. Maybe you got too much friction in the bowden tube this youtube movie shows a solution that worked for him, just lubricating, of course. However unclear how well that works.

Also i got some weed whacker, dont think that'd have a problem other that the radius being awfully close to the inner radius of the bowden tube

Edited 1 time(s). Last edit at 11/01/2013 12:39PM by Jasper1984.

Hey, I don't think friction is the big player there, i think when i use trimmer line, or soft moisture bound Nylon, It will squish up, also retraction seems to be less effective with bowden, still works, but looks like it would be hard to fine tune, not so bad with PLA but nylon i do have issues.


Like it all works, i just feel i might have better results, I also have a bowden tube thats is extremely no stickily, its slippery in my hands, my stock bowden tube the printer came with is no where near as slippery.
I have tried oils and other lubricants, I don't really need them cause it does not get to bad, i also can get hi feed rates with PLA and ABS, nylon is much slower tho


MY ID of the bowden tube is about 1 or 2 mm larger than the filament, hmm I'm sure i read some standard sizes around here,

Get direct. I have nothing but trouble with mine. Although I saw on my towns maker faire bowden extruders with double the length of mine and they worked perfect, retracting with almost direct extruder setting. I haven´t resolved these issues in my bowden.

Its has its advantages but its all a bit more experimental.

go direct. get the printer working first, then try the cable. bowden systems are quite more complex.

True, i still get some effect due to the bowden. Speed changes seem to cause a bit of overextrusion sometimes. Lowering speed or increasing acceleration decreases speed changes. I think that is probably what makes the bowden on the ultimaker work well.(it has a rigid frame to deal with the accelleration.)

What i said about friction and bowden was about the video, where flexible(apparently a bit rubbery, higher friction) PLA was used, friction isnt typically an issue.