Bowden vs direct setup

Well, the subject is much discussed. I did my research and read a lot about it which got me even more confused than I used to be in the first place.
I assembled the machine in my signature about 6 months ago and have managed to tune it up in such a way that it makes pretty decent prints (when printing with my "A-game settings", otherwise I still experiment a lot).

I have a genuine E3d v6 hotend with greg wade's extruder. Bowden setup in order to reduce weight on the X-axis. However, the bowden tends to get jammed from time to time and the E-steps per mm vary every couple of prints (doesn't seem to be a bolt tension issue).
So I thought I'd ask you: Do you prefer direct setup vs bowden? Extra weight vs all sorts of other trouble? I am thinking of checking it out.

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Self-sourced Mendelmax 2.0-based Reprap Machine -- Ramps 1.4 & Mega 2560 -- DRV8825 (Z@1A, [email protected], [email protected], E@1A) -- genuine E3D v6 direct setup -- 350W custom silicone heated bed -- ABS 1,75mm -- Marlin 1.1.0-RC7 -- Cura 15.04.6

I'm not the source of info here, but my experiences fall inline with what you were describing.

MANY iterations of extruder combos on my i3, both bowden and direct feed. I do prefer direct feed myself, due the oozing of the nozzle (I'm currently on a dual-extrusion build on the thing) - but there in lies the rub, where the weight of the direct feed dual-extruder makes me print quite a bit slower.

I may explore converting it to a bowden again in the future.

Regardless of any of this - I feel your pain in the jams. After my 3rd or 4th J-Head from Ebay, I gave in and decided no more "half-measures". I ended up grabbing this:

[printrbot.com]

For each of the extruders on my i3. It made THAT much of a difference (never once had a single jam since) - I ended up grabbing that assembly for my 2 other printers as well. One of which, is a kossel mini kit with an e3d v6. It's never jammed using that setup.

The "gear-head" extruder, mixed with the e3d v6, it's pretty close to the cost of the whole kits from Ebay, so the cost is definately not anything to take lightly. That being said, all 3 of my printers haven't jammed since using it. - Just my 2 cents.

Hello,

Did you really have a J-Head from e-bay? Most of these are either knock-offs of the real thing or e3d knock-offs where they steal the name..

Brian

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usslindstrom
I'm not the source of info here, but my experiences fall inline with what you were describing.

MANY iterations of extruder combos on my i3, both bowden and direct feed. I do prefer direct feed myself, due the oozing of the nozzle (I'm currently on a dual-extrusion build on the thing) - but there in lies the rub, where the weight of the direct feed dual-extruder makes me print quite a bit slower.

I may explore converting it to a bowden again in the future.

Regardless of any of this - I feel your pain in the jams. After my 3rd or 4th J-Head from Ebay, I gave in and decided no more "half-measures". I ended up grabbing this:

[printrbot.com]

For each of the extruders on my i3. It made THAT much of a difference (never once had a single jam since) - I ended up grabbing that assembly for my 2 other printers as well. One of which, is a kossel mini kit with an e3d v6. It's never jammed using that setup.

The "gear-head" extruder, mixed with the e3d v6, it's pretty close to the cost of the whole kits from Ebay, so the cost is definately not anything to take lightly. That being said, all 3 of my printers haven't jammed since using it. - Just my 2 cents.

Edited 1 time(s). Last edit at 02/23/2016 09:57PM by reifsnyderb.

Well, my e3d v6 is genuine. Bought from an authorized reseller and not off ebay.

Back to the subject, my hot end and consequently the extruder do get jammed from time to time. The hot end is properly cooled. Do you think that switching to direct setup would improve this?

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Self-sourced Mendelmax 2.0-based Reprap Machine -- Ramps 1.4 & Mega 2560 -- DRV8825 (Z@1A, [email protected], [email protected], E@1A) -- genuine E3D v6 direct setup -- 350W custom silicone heated bed -- ABS 1,75mm -- Marlin 1.1.0-RC7 -- Cura 15.04.6

A genuine J-Head would have not caused you problems.

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icefire
Well, my e3d v6 is genuine. Bought from an authorized reseller and not off ebay.

Back to the subject, my hot end and consequently the extruder do get jammed from time to time. The hot end is properly cooled. Do you think that switching to direct setup would improve this?

Quote
icefire
Well, my e3d v6 is genuine. Bought from an authorized reseller and not off ebay.

Back to the subject, my hot end and consequently the extruder do get jammed from time to time. The hot end is properly cooled. Do you think that switching to direct setup would improve this?

I have a genuine E3Dv6 and a Bowden tube more then 600mm long. I was getting the occasional hot end jam, caused by the filament forming a bulb at the end of the Bowden tube. Here's how to avoid it:

1. Taper the end of the Bowden tube using a pencil sharpener before inserting it into the E3D. Apparently the bottom of the Bowden tube inlet on the E3D has a taper too, and if the Bowden tube is cut off square then this leaves a space that semi-molten filament can expand into. Thanks to Tim at Filastruder for this tip.

2. Don't retract filament too far too fast. When unloading filament, retract the first 20mm very slowly. If you have a retraction command in your end gcode to avoid the filament oozing while the hot end cools down, make it a very slow retraction.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Just got finished swapping my delta to a direct setup, couldn't be happier and won't consider Bowden again.

I agree... On my statements above, had I gone with genuine, I may not have had the same issues I described.

Even though the Ebay stuff is quite literally a fraction of the cost, it definitely shows in the quality of build. The genuine e3d v6 has definitely shed light to this concept as well. (Just as I'm sure a genuine j-head would as well).

That being said, you mentioned the delta is on the direct setup now. I was always afraid to do this, since the weight of the motor would cause some hate and discontent with the motors. You seeing any negative outcomes with it? i.e. having to ramp up the voltage to your motors?

Just curious.

My printer build is not typical. I have zero concerns hanging one direct drive unit on it and very few concerns about going to dual extrusion soon too. No change was made to motor drive voltage. Everyone's mileage will vary depending on their setup.

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dc42

I have a genuine E3Dv6 and a Bowden tube more then 600mm long. I was getting the occasional hot end jam, caused by the filament forming a bulb at the end of the Bowden tube. Here's how to avoid it:

2. Don't retract filament too far too fast. When unloading filament, retract the first 20mm very slowly. If you have a retraction command in your end gcode to avoid the filament oozing while the hot end cools down, make it a very slow retraction.

what is a good retraction speed? I have tried with 40 and 60, but I guess you mean something like 20mm/min or so...

What about the distance? I retract 4mm, because e3d state on their website that more than 5mm is dangerous. Less than 4mm results in infinite ooze.

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Self-sourced Mendelmax 2.0-based Reprap Machine -- Ramps 1.4 & Mega 2560 -- DRV8825 (Z@1A, [email protected], [email protected], E@1A) -- genuine E3D v6 direct setup -- 350W custom silicone heated bed -- ABS 1,75mm -- Marlin 1.1.0-RC7 -- Cura 15.04.6

Just changed it to direct setup. It is much better because the extrusion is much more precise and the oozing is gone. Haven't noticed more visible backlash in X. So I would recommend direct setup over bowden, at least for a cartesian printer.

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Self-sourced Mendelmax 2.0-based Reprap Machine -- Ramps 1.4 & Mega 2560 -- DRV8825 (Z@1A, [email protected], [email protected], E@1A) -- genuine E3D v6 direct setup -- 350W custom silicone heated bed -- ABS 1,75mm -- Marlin 1.1.0-RC7 -- Cura 15.04.6

My first 3d printer experience was with an i3 with a wades geared extruder which seemed to control the filament very precisely. Then I got a kossel mini with an immense bowden tube 80cm or so. The filament control was all over the place, but it took me a while to work this out as I was struggling with calibration and just plain figuring out how deltas work. I then switched to a flying extruder cutting down the bowden tube to 10cm, the difference was stunning (see the thread on flying extruder for a stunning before and after Marvin model). So there is no doubt that bowden makes filament control problematic. Some claim they've tuned them and achieved reasonable precision, but its a bit like trying to wiggle a cable down a tube - until someone invents a material with almost zero friction, so that the tube can be very tightly fitting around the filament, which then has to be extremely rigid and precisely the diameter it is meant to be, then they are never going to be as good as direct, they are a compromise which we put up with because we don't want a big heavy motor on our print head/effector.

My latest machine is a smartrapcore alu with a 50cm bowden, which given I've more experience with them, I've tuned fairly well, its still not perfect. I have a flex3drive kit which I am going to fit - in theory the best of both worlds, lightweight print head (80g) and direct drive.

I agree with DJDemonD:

Bowden is great to lower your effector mass, but keep that tube short.

Here's the before and after shot that DJDemonD was talking about:



This is with a bowden tube of about 10cm, vs the left image with a bowden tube of 5 times that. I was having all manner of crosstalk issues with the long bowden tube, but now I'm really happy with my prints (they've improved since that shot was taken as well).