WIP: Bowden Based Dual Extruder (More Reliable, Too!)

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superhornet59
Posts: 60
Joined: Wed Apr 03, 2013 1:58 am

Re: WIP: Bowden Based Dual Extruder (More Reliable, Too!)

Post by superhornet59 »

WOW Stephen, that looks awesome! Can't wait to see some finished stuff once you get all of the software stuff going.

As for the dual-extrusion system, I can finally say... it's ready. I'm a little bit of a perfectionist, so I had to iron out some kinks before posting everything. All of the STL's and documentation (including bill of materials) are there for download. In addition, I took the liberty of attaching dual-extrusion-enabled firmware for both the Felix 1.5 and 2.0. Note that I don't own a 1.5 so I hope someone will take the leap and test it out.

The KISStruder:
http://www.thingiverse.com/thing:130730

The Felix End
http://www.thingiverse.com/thing:130740

Happy printing!

seaton
Posts: 291
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Location: Bunbury, Western Australia
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Post by seaton »

Thanks for that Matt,

Great work!!!

Now you've posted the rest of the extruder I'll print that up so I can finish testing the laser head, I don't want to be swapping carriages if I need to print :)

Stephen...
Stephen...

Felix 2.0 -> Felix 3.0 dual
Simplify3D Slicer, Kisslicer
Have you added your Felix to the Map? http://goo.gl/maps/HajnZ

http://blog.strobotics.com.au

Bachgassenbande
Posts: 132
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Location: Würzburg

Post by Bachgassenbande »

Would a Nema 23 motor solve the higher demand for the tension?
Felix 2.0
E3D Kraken Hotend
3mm Glas bed
LED light bar upgrade

superhornet59
Posts: 60
Joined: Wed Apr 03, 2013 1:58 am

Post by superhornet59 »

Short answer is: it's overkill. The Felix, unlike some other printers out there, is designed to be directly driven, and therefore it's motors are quite torquey. A gear requires more force to bite into filament than does a hobbed wheel, but in exchange it offers unparalleled grip.

A Nema 23 is a *beast* of a motor, and if you decided you needed more torque for some reason, you should know that Nema 17's come in a variety of styles that offer different specifications, including very high torques. Basically, while Nema 17's have a standard height/width for mounting, there a variety of lengths (or if you prefer, 'depths') of motors out there. Generally the longer the motor, the more torque it offers. Then you have different types of magnets, coils, etc. There's a Nema 17 for everyone out there. :P

seaton
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Post by seaton »

Update: Pinion gear has been ordered but is going to take two weeks sigh!!

....so once I get that I'll be moving across to test this extruder and the laser head.
Stephen...

Felix 2.0 -> Felix 3.0 dual
Simplify3D Slicer, Kisslicer
Have you added your Felix to the Map? http://goo.gl/maps/HajnZ

http://blog.strobotics.com.au

Bachgassenbande
Posts: 132
Joined: Sat Jul 20, 2013 12:50 pm
Location: Würzburg

Post by Bachgassenbande »

just a quick question as I'm new to dual extruders.

What slicer do you use? How does you profile do look like.
How do you calibrate with two hot ends?
If you want to print a part in two colors, how to proceed?
If you want to print a part with one hot end and another part with the other, how to do?

Parts printed already,
Gear recieved
Bearings will come in this week
Nema 17 motors come in this weeks
Felix 2.0
E3D Kraken Hotend
3mm Glas bed
LED light bar upgrade

superhornet59
Posts: 60
Joined: Wed Apr 03, 2013 1:58 am

Post by superhornet59 »

hey Bachgassenbande, I'll just quote what I wrote in another thread which answers most of your questions:
I use Cura for slicing, and while it has support for dual extruders, the G-code it generates doesn't *actually* switch extruders, just does it all on one. Silly glitch that should be fixed soon. I did try on Slic3r though, and I can tell you, leakage is a big problem. So, while you're printing with your primary extruder, the support one 'leaks' filament all over the place, then when it's time for it to start printing support it takes a while for it to start flowing. Meanwhile the primary one is leaking, and you've got the same problem on the part. It sounds like something retraction would fix, but the g-code I've gotten from slic3r has been lousy about it, and the nozzles don't like long-time retraction because the plastic at the end inside the extruder sort of 'bulges' and doesn't extrude right at the beginning of the switch.

Really stupid stuff, but I'm sure there will be a fix. Then there's the problem of adjusting the nozzles. I have mine set up so one is slightly loose and can be screwed in or out. This gives me some nice on-the-fly height adjustment which helps with getting the nozzles in-line, but it's tough because if they are not perfectly aligned, the higher extruder will not get proper bed adhesion, and the lower one will crash into what the other one printed and tear it all apart. This also happens if your first layer is too smushed. Basically, it's really hard to even get a first layer. I know it's not impossible, but damn, if you've ever had problems with single extrusion printing, dual extrusion printing is 10x worse.

As far as I know, only three people on this forum have a dual extruder set-up installed on their printers.. but last I've heard, zero of us actually use it. I for one just single-extrude everything, and like you I try to avoid printing things that require support, so I feel your pain.

I don't mean to sound discouraging to anyone, these problems will be overcome, but it will take time and patience before a reliable solution emerges.
I haven't tried printing multi-colored parts, nor have I tried to simultaneously print multiple parts which each use a different extruder. Cura simply has a button for 'enable dual extrusion' and that's it. I don't know how multi-colored parts are sliced. The problem with the current version of Cura (13.6.4) is that it has a *completely* different slicing algorithm from the previous version.. I love it because not only is it reliable and simple, it's SOOOO fast, but because it's been redone, a lot of features are missing. I'm sure they'll re-appear with the next couple of releases and all will be good.

I actually run a small prototyping business and I use my printer as a part of it, so I rarely have the printer available for testing out dual extrusion. Therefore, I'm really hoping you AWESOME guys (pioneers! visionaries!) who are trying this out will be able to do some rigorous testing and come up with the perfect settings.

On a side note I also have an.......

*******************************************************
UPDATE:

First of all I got pretty fed up with trying to guesstimate the extrusion multiplier, especially because I prefer to print from SD. So, I went ahead and calibrated the extruder. You can adjust the EEPROM settings via repetier host or uploaded the new firmware which I will put on the Thingiverse soon. It's the same firmware I've already uploaded, but with reduced acceleration (better quality) and my calibrated e-steps/mm value set as default. For some reason when I did it via repetier host, it switched the extruder to running backwards lol. Even after upoading the new firmware (with the new setting put as 'default') I had to click 'restore factory settings' then 'reload config' to get the settings to kick in. No idea what that's all about lol, maybe it's just a glitch in my computer. Anyway, if you try to upload the new value to EEPROM via repetier, the e-steps/mm setting is 104.30. You should still do a calibration just in case though, following these guidlines:
http://www.instructables.com/id/How-to- ... 3d-Printer

Next up, I'm going to be releasing some STL files as "V2" files, for both the extruder and the felix end shortly afterwards. All of the parts fit the old ones so you don't have to upgrade everything at once. In order of importance:

*Redid the extruder tensioner arm. The original wasn't very beefy, and it slowly deformed over time. seems like that happens with the factory extruder parts too, so I think PLA might just be susceptible to creep. The new extruder arm is way beefier so it won't deform, it supports the bearing from both ends so there is no net moment acting on the bearing bolt, and it seems like it doesn't really need a nut to work.. the recess for the m4 nut is still there, but so far the plastic seems to grab the tensioner bolt quite nicely.

*Thickened the extruder base. Seems like the motor heats up if you really crank up the extruder potentiometer, and over time that heat deforms this part, which causes problems. So I made it thicker, and made a couple parts of it a little beefier too. Moderating the extruder voltage is probably still a good idea though.

On the Felix end, I chamfered a few corners that were once unchamfered, which will reduce the likelihood of warp during printing, which can happen when printing solid-infill parts. It's too small of a change to bother releasing.. however I really do plan on getting around to a cooling fan setup, and then I will release it all together.

I'm just a little stuck right now because the cooling duct I want to design will be impossible to print without internal support.. so I need to get around that first. When I do, you guys will be the first to know!

That's all for now... Cheers!

Bachgassenbande
Posts: 132
Joined: Sat Jul 20, 2013 12:50 pm
Location: Würzburg

Post by Bachgassenbande »

Thanks for your excelent reply superhornet5.
Also thanks for the link how to calibrate the extruder (was looking for that, especally for the EPROM programming)
Felix 2.0
E3D Kraken Hotend
3mm Glas bed
LED light bar upgrade

seaton
Posts: 291
Joined: Tue May 14, 2013 9:04 am
Location: Bunbury, Western Australia
Contact:

Post by seaton »

Well today I've finally received my Pinion gears so looks like this weekend I'll be converting over and testing :)
Stephen...

Felix 2.0 -> Felix 3.0 dual
Simplify3D Slicer, Kisslicer
Have you added your Felix to the Map? http://goo.gl/maps/HajnZ

http://blog.strobotics.com.au

seaton
Posts: 291
Joined: Tue May 14, 2013 9:04 am
Location: Bunbury, Western Australia
Contact:

Post by seaton »

For those interested I've remixed the carriage for a GT2 Belt. Can be found here http://www.thingiverse.com/thing:150139

Image

Regards,

Stephen...
Stephen...

Felix 2.0 -> Felix 3.0 dual
Simplify3D Slicer, Kisslicer
Have you added your Felix to the Map? http://goo.gl/maps/HajnZ

http://blog.strobotics.com.au

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