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Direct Extrusion

Posted by Kafledelius 
Direct Extrusion
April 16, 2016 05:20PM
Hey Reprappers!

I'm running a wooden Smartrapcore - and i am getting really bad Zits and blobs.
There fore, i am really wanting to try a direct extruder (non-bowden).
I am using the E3D V6 Hotend.

Does anyone have some STL's for this? smiling smiley
Re: Direct Extrusion
April 17, 2016 03:58PM
You might be able to use the one from the 300xl but I can't find any stl's yet I do not think Smartfriendz have uploaded them anywhere so far.

Any nema 17 motor will add quite a bit of mass to the print head, so fast, accurate printing might be less achievable - have you considered the flex3drive from Mutley3D.
[mutley3d.com]

I am using one its 85g, direct (since the motor is stationary and connected via a flexible driveshaft) and the print quality is stunning.


Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions
Re: Direct Extrusion
April 18, 2016 06:01AM
Yea i looked at that.

Its a Bit too expensive for me at the moment confused smiley So was hoping for a regular extruder smiling smiley

Edited 1 time(s). Last edit at 04/18/2016 06:18AM by Kafledelius.
Re: Direct Extrusion
April 18, 2016 08:17AM
I am using one but would like to see if there is a way to suspend an extruder on elastic above the printer so I have only a short bowden cable like the delta flying extruder mod.


Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions
Re: Direct Extrusion
April 19, 2016 02:15PM
DjDemonD - Would you mind sharing your carraige design for the Flex3Drive? - Best guess is im gonna end up buying one after all tongue sticking out smiley
Re: Direct Extrusion
April 19, 2016 03:51PM
[www.thingiverse.com]

If you're any good at cad feel free to improve on it and share it's a nasty mash up but it works.

Once its working you won't be disappointed it's very good. If using 1.75mm filament tighten the idler really tight.

Edited 1 time(s). Last edit at 04/19/2016 03:55PM by DjDemonD.


Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions
Re: Direct Extrusion
April 20, 2016 01:30AM
Thanks man! I'm not that good at cad yet :/ unfortunatly.
Re: Direct Extrusion
May 06, 2016 03:23PM
Guys i'm wondering, would a direct extruder add too much mass to the x carriage ? I'm fine with less speed than the bowden, but i want to print flexible filaments and other strange filaments and with direct it might be more easy ... What about a titan e3d with a little nema 17 like in this video ?
Re: Direct Extrusion
May 06, 2016 03:38PM
That's what I'd like to try, I've got a titan but installed it on my delta instead. It does work with the 20mm motor with 1.75mm filament. Let me know if you try it on the smartrapcore, I'm sure it will work - it's just how fast you'll be able to go before losing the quality. I've still not really tried to get mine up to ludicrous speed, it's goes fast enough. So I haven't got a baseline.

Edited 1 time(s). Last edit at 05/06/2016 03:57PM by DjDemonD.


Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions
Re: Direct Extrusion
May 06, 2016 04:21PM
Well, my problem isn't speed, i want to print with all the filaments i want, and an e3d v6 plus titan seems to be my best bet, and having it as a direct drive extruder seems even better ...
The fact is, that's going to be around 140€, which is around the price of the flex3drive, shit.
So, i think i'm gonna first evaluate all my problems, then i'm thinking of a way to solve them.

Worst case scenario i'm reusing the parts of the smartrapcore to build an indie 2, (which is a bukito clone) but with direct extruder. I always loved this design

My main doubt though is the weight, wouldn't the rods flex ? I read a discussion somewhere here about rods flexing

Edited 1 time(s). Last edit at 05/06/2016 04:25PM by Gibbon91.
Re: Direct Extrusion
May 09, 2016 08:54AM
The files for the direct extruder of the XL are available on Onshape.

[cad.onshape.com]

And it does it's job and I haven't noticed any flexing of the rods so far.

What's the normal speed you'd get with the bowden setup?
Re: Direct Extrusion
May 12, 2016 02:41AM
I found a simpler solution, get rid of the pressfit connector on the top of your extruder (cold end) body and use a 4mm nut on the ptfe tube. Example of this would be the airtripper. The pressfits wear out, and have too much slop/movement in them. Anchoring the ptfe tube is the key to consistent extrusion and therefore reduing blobs and zits. Ive noticed my retraction amount is smaller and print quality has increased dramatically since ive down it.
Re: Direct Extrusion
May 12, 2016 05:11AM
Quote
ixlix
I found a simpler solution, get rid of the pressfit connector on the top of your extruder (cold end) body and use a 4mm nut on the ptfe tube. Example of this would be the airtripper. The pressfits wear out, and have too much slop/movement in them. Anchoring the ptfe tube is the key to consistent extrusion and therefore reduing blobs and zits. Ive noticed my retraction amount is smaller and print quality has increased dramatically since ive down it.

That's a good idea and I am sure that one of the problems Bowden setups encounter is movement in the couplers, but solve this problem and you still have the elasticity of the filament, the friction of the bowden tube, and the poor fit between the bowden tube and most filaments which allows the filament to squirm in the tube.

I am still waiting for someone to demonstrate a bowden setup which actually has precise filament control and can compete with a direct setup. I've made a choice that I'd rather have a flex3drive or a super lightweight direct extruder over a bowden, the quality difference is noticeable.


Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions
Re: Direct Extrusion
May 12, 2016 07:44AM
Yeah the flex3drive looks nice but its expensive.
Re: Direct Extrusion
May 12, 2016 08:35AM
Relative to a printed extruder yes, but you could make one its a worm gear, a drive gear and a flex shaft such as those on a dremel drill. I thought about it and decided that it was less costly of my time to buy one.


Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions
Re: Direct Extrusion
May 12, 2016 08:58AM
ixlix - Do you have a picture of that solution?
It sounds worth trying smiling smiley

I also ended up ordering a Flex3Drive - Awaiting it in the mail any day now smiling smiley
Re: Direct Extrusion
May 12, 2016 10:39PM
im currently usin this one, but i find the tension bolt nuts hard to keep in place when i need to loosen it to change filaments.

airtripper

But have also printed this one as it uses 2 m4 nuts either side which should help even more, and the nut is more captive.

scholtz

thingiverse page
Re: Direct Extrusion
May 13, 2016 03:48AM
I've used the Scholtz one for a while and was very pleased with it, only recently been superceded by e3d titan, which so far works flawlessly and using only a 20mm nema 17 motor.


Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions
Re: Direct Extrusion
May 13, 2016 07:15AM
DjdemonD - are you using the G2 Desing of the Flex3drive?
Re: Direct Extrusion
May 13, 2016 09:56AM
If that's the smaller one yes I've a photo of it on my thingiverse I made an adaptor for the scalu. [www.thingiverse.com]


Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions
Re: Direct Extrusion
May 13, 2016 10:01AM
So far it's been extremely good, retraction is a bit slower than a "direct" drive bowden type extruder but perfectly usable. I'm hoping to speed it up with a bit of tuning mutley3d who makes them is very helpful. If using 1.75mm you need to put a filament guide tube from the extruder to hot end and tuck it in quite close to the drive gear but that's easy enough.

Tempted to try the Titan on the scalu but flex3drive is lighter, I have one already, its installed and working and i don't need it for anything else. If I take it off the printer for some other reason I'll try a titan in its place.


Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions
Re: Direct Extrusion
May 15, 2016 04:39PM
DjDemonD - I gotta agree with you! Flex3Drive is amazing!! Its a breeze to use and Jason from Mutley3D is giving the best support i've ever experienced.
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