WIP: Dual extruder

This is the place to show off your felix printer hacks and improvements.
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Kjetilei
Posts: 334
Joined: Fri Mar 16, 2012 8:26 pm
Location: Stavanger, Norway

Re: WIP: Dual extruder

Post by Kjetilei »

I haven't been able to test more dual extrusions lately due to lack of time and upgrading to Felix 1.5.

But switching to Felix 1.5 parts meant that I had to update the extruder base.

I used a photo of Guillaume's updated single extruder base as the starting point (to get the nice tensioning solution etc.) and ended up with a part that works great. I had a software crash that meant that I lost some minor updates/modifications to the design, but not a big deal...

The part was printed without a cooling fan on the PLA, so the quality is not great, but good enough.
dual_extr_hiwin.JPG
I have been able to test one test print with the upgraded 1.5 parts and the improvements where big! Even with some binding on the belts for both axes and other imperfections that will be fixed/adjusted/fine tuned.

I printed the planetary gear set using the high quality profile. It turned out nice even without the cooling fan (I can not understand how that was possible without the fan). But due to the missing fan and some lack of bonding to the bed, some of the printed screws loosened from the hot bed mid-print and did some damage to other parts as well due to melting...

But I no longer have the dreaded problems with backlash! Joy!
gears.jpg
The remaining work on the dual extruder design as I currently see it is some minor tweaks to the filament path to let the insert piece get some better grip on the filament and design an air duct to cool the printed parts. I have also thought about better/"invisible" guiding of the wires and will see if I have the time to do a redesign to implement it.

dognotdog
Posts: 181
Joined: Tue Sep 04, 2012 9:22 pm

Post by dognotdog »

Have you done the slicing via sfact/skeinforge or slic3r? I finally got my dual extruders setup, but I can't get slic3r to work with it :(

Kjetilei
Posts: 334
Joined: Fri Mar 16, 2012 8:26 pm
Location: Stavanger, Norway

Post by Kjetilei »

I use Cura for dual extrusion and import into Repetier Host.

stratogavster
Posts: 120
Joined: Tue Jul 17, 2012 9:04 pm
Location: United Kingdom

Post by stratogavster »

Hello All,

Wondered if there has been any progress with the dual-extrusion?....any examples to show us all?

Kjetilei
Posts: 334
Joined: Fri Mar 16, 2012 8:26 pm
Location: Stavanger, Norway

Post by Kjetilei »

Although I haven't printed with dual extrusions lately (been occupied with the LCD/SD setup) I use my dual extruder for all prints. I need to print the slightly updated tensioning arms and tighten one of the extruders before I can commence with the dual extrusion. And I need to redesign the airduct/airduct mounts to be able to use the whole width of the hotbed.

stratogavster
Posts: 120
Joined: Tue Jul 17, 2012 9:04 pm
Location: United Kingdom

Post by stratogavster »

Great, well keep up the good work!....only have read a few articles about dual extrusion.....any tips on how to confiture firmware/software etc?

Kjetilei
Posts: 334
Joined: Fri Mar 16, 2012 8:26 pm
Location: Stavanger, Norway

Post by Kjetilei »

Things I experienced/learnt:

General
- Dual extrusion is not easy ;)
- You need to set aside a lot of time to figure out things and learn the DOs and DON'Ts
- Don't expect perfect results - oozing and stringing can easily create colour contamination in the print
- The satisfaction of (somewhat) mastering it can feel really good :)

Hardware
- Look up the wiki/schematics/drawings for RAMPS 1.4 at reprap.org
-You need to replace the wires for the fan in D9 with the wires to the heater cartridge of the second extruder. Redirect the fan wires to 5v or 12v output from the PSU
-You might find it easier to flip the plug for the 4 stepper wires 180-degrees instead of adjusting the firmware if the stepper retract when it should extrude
- You have to be really careful with the z-alignment of the hotends and the aligning of the hotbed. It needs to be pretty close to perfect to avoid one extruder hitting into printed areas or the hotbed

Firmware
- You need to take the time to understand the code or use a predefined setup (I plan to send my setup to Guillaume very soon and hopefully he'll publish it in the thread with the firmwares)
- Changes are needed (if I remember correctly) in configuration.h and configuration_adv.h (I have made changes in pins.h as well but think that was only for LCD/SD stuff)

Software
- Dual extrusion is not extremely well supported yet
- Use Cura for creating dual extrusion gcode (Slic3r was not quite ready for the big game when I tried it last)
- Hotend offsets differ for all implementations and you need to take the time needed to get it right
- If you use Repetier Host (you should ;)) you have to remember to heat up and turn off both extruders (if you have not added this in your gcode). Switch between extruders with T0 and T1 (case sensitive) commands in the G-Code field under the Print Panel Tab

I could write a lot more but this should give you some input.

stratogavster
Posts: 120
Joined: Tue Jul 17, 2012 9:04 pm
Location: United Kingdom

Post by stratogavster »

thanks for the insight!! sounds like scary stuff and not for the faint hearted!! :)

Kjetilei
Posts: 334
Joined: Fri Mar 16, 2012 8:26 pm
Location: Stavanger, Norway

Post by Kjetilei »

Not scary, but time consuming and sometimes frustrating. But fun and fascinating :)

With the new rubber/flexible filament types, wood filament (and hopefully sooner than later support material) the usage for multi extrusion is increasing (although I don't know yet if the different filaments would bond satisfactory to each other).

WayneMc
Posts: 4
Joined: Tue Apr 23, 2013 8:29 am

Post by WayneMc »

Hi guys. Yes I am a complete newby. I don't even know how to use a forum so am not sure who this is going out to. I got my felix 2 about three weeks ago and love it. Printed a lot of stuff for some rubber prototypes I am making currently. Have been using the new flexible material from Guillaume and overcoming the challenges.
One of those was my need of dual extrusion for support. Got busy last weekend and created a duel extruder. Big thanks to Guillaume for the stl files of the original parts and advice as well. This version is a shameless cut and paste of his design as I am new to modelling and it seemed easier to modify the original.
Features are:
1. All adjustments are from the front.
2. Extruders pull out individually for cleaning. These are on jacking screws so they screw tight and jack themselves out as well without disturbing anything else. Simple washer in front of and behind the socket head embeded in the part.
3. One fan to cool both top ends with good air flow. Have yet verify it this is enough cooling. Only printed a couple of things with this.
4. Wire harness now under belt and doesn't foul my top mount filament roller.
5. Dual fans for cooling. Hope this is enough.Have some mods in mind already for this to channel flow directions. Still fan seems to be only running at part speed so could juice it up with firmware if I can work out how.
6. Smoother air flow from airduct design. No internals cross members, elliptical shape and larger inlet diameter. Mainly did this because I could not work out how to print the original. Only found out that it prints on 45degrees after finishing this one. Derrr

Have only run the test print with this duel design so far but printed perfectly so the extra mass does not seem to have detrimental effect at 40mm/s. Will have a go as some others tonight to see how 80mm/s infil goes. The extra mass will like effect the max speed this can go. I think this can be managed by reducing the max acceleration in the jerk profile. Will try that once my prototype deadline is passed and I have more time to play.

Have started on the firmware even though I know nothing about it. Only just got onto this forum and found you guys have been real busy with this all along. Love your work. Will try your firmware so my motors go the right way. Thanks. Just one question. I have the ATmega 2560 board. What are you using?

Have a fine adjust on the nozzle. Not needed at this point as they came out perfectly aligned first time.

My main reason for bothering you is that I have no idea how to get a slice into the Repetier host to make a two material head work at all. Have tried Slice3r and end up with a two material slice side by side. Combined the files in slic3r first then sliced. Haven't tried to print it yet but doesn't look good.

Any advice on getting a model in would be welcome.
Attachments
dualOpen.jpg
dualClosed.jpg

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