My first PB+ Dual Extrusion print!

[Tdeagan]

Woohoo, the planets aligned and I got a successful dual extrusion print from my hybrid Pinrtrbot Plus V1 printer!

Ramps 1.4 electronics with SmartLCD

Extruder 1 = Stock Wade's extruder mounted on X carriage driving directly into 3mm Ubis hotend, Black ABS
Extruder 2 = Printed Wade's extruder mounted on top of Z shaft driving through Bowden tube into 1.75mm Ubis hotend, Green ABS

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Full documentation to come.

[drawcut]

Very cool. Glad you go it working.

[REPRAP SQUAD]

Good work sir. Im still waiting for my RAMPS replacement but in the meantime I got a Simple and a new printrboard. I also got a 1.75mm ubis hotend so it looks like I will be doing a dual bowden Printrbot plus soon. Too many projects and too little time. Hopefully you can point me in the right direction when I set up my Printrbot plus RAMPS 1.4. I more then likely will order ACME rods and I already replaced all my motors with kysans.

[Tdeagan]

Thanks! I've still got a long way to go. I've trashed another dozen prints after that one as I work through the requisite tuning. So far:
- Getting the two hotends dead level. Absolutely critical and very frustrating.
- Getting the correct offset between the two hotends correct. Harder than it seems.
- I bailed on the different nozzle sizes (started with .35 & .5, now using .5 on both.) adds a lot of complication.
- Correct current levels on stepper drivers. lots of missed steps along the way
- Bowden ooze is vicious! trying to get it to not ooze while the other print head is working is a mess
- Off-tool waiting is a pisser. The number of times the off-tool extruder declines to print when it's their turn is painful

The LCD is nice. I like seeing the temps and being able to preheat without starting up Pronterface.

Also, as best I can tell, Kisslicer is declining dual extrusion capabilities at this time (at least with the AMF-like capabilities of Slic3r.) Despite forays into Kisslicer and ReplicatorG, I'm back with Pronterface and Slic3r. It's kinda nice!

[Tdeagan]

Getting there!

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[Tdeagan]

First reaction to dual extrusion printing. Take every frustration you've ever had with slicing, filament feeding, and general printing grief and square it.

[Mochaboy]

dude

respect...

You're paving the way for the rest of the team

[Tdeagan]

Thanks! Chasing this stuff down has forced me out into a lot of other 3D printing forums. It's really brought home how much I like the Printrbottalk community. This forum has a confidence inspiring vibe that is not as tangible in a lot of other forums. I hope I can return enough in useful documentation to pay back the good stuff I've gotten from here.

I should have Part 2 of my Dual Extruder oddessy (Ramps1.4,) done in a couple days and the final Part 3 (Dual Extruder Printing) not far behind.

[mattjoyce]

I have been following this project with interest, and I really appreciate your detailed knowledge sharing.

Interesting to see you kept the original extruder riding the x-carriage, and added the 2nd Ubis in front.
Does the extra mass make any difference?

I'm considering using dual Bowden extruders, mounted either on the Z smooth rods, or on a crossbar.
That would enable me to have the hot ends side by side, as close as possible, and provide room to good fan positioning (and less overall weight on the x-carriage).

With regards to you PTFE tube, in part 1 you mentioned yours is OD6mm ID4mm, do you think 4mm is the smallest that can be used with 3mm filament?
I've seen some 3.1mm, and I wondered is the tighter fit, would reduce slack, and therefore ooze.

Anyway, bravo for all your efforts.

Matt

[Tdeagan]

Thanks!

I found that the additional mass of the Bowden setup (hot end, adapter, extended carriage) really made no difference to the effective inertial mass (it's more, but not enough more to make a difference.)

Dual bowdens is definitely the lightest/fastest approach. My concern, and it's turning out to be valid, is that most of the time I'm not printing dual extruder prints. I want it when it need it, but for a lot of what I print I want to get the best cleanest single material print possible. For those, I want the stock wade's, not a Bowden print. The tuning to get the Bowden quality on par with the stock extruder is murder.

I haven't tried a tube smaller than 4mm for 3mm filament. I do run a 2mm tube for my 1.75mm filament. I'm a believer that the excess tube diameter is the major contributor to ooze, but even PTFE isn't friction free and when the carriage is at the position where the tube is at max bend, too tight a tube is going to max bind at that point and I don't know when that's too much.

[REPRAP SQUAD]

Cross bar mounting of the bowden extruder works the best. I did quite a bit of testing when setting mine up and its definitely the best location. That way the tube doesn't bend in weird positions. Here's how I mounted mine.

[mattjoyce]

Dual bowdens is definitely the lightest/fastest approach. My concern, and it's turning out to be valid, is that most of the time I'm not printing dual extruder prints. I want it when it need it, but for a lot of what I print I want to get the best cleanest single material print possible. For those, I want the stock wade's, not a Bowden print. The tuning to get the Bowden quality on par with the stock extruder is murder.

Ah, great point. Sage advice indeed.