Direct Drive Extruders anyone

Is anyone using a direct drive extruder on their printer?

If so, what recommendations might you have for someone considering it?

I am thinking I want to ditch the bowden and do direct. I was eyeing Walter’s flying extruder and also thinking about just putting it on the carraige directly.

Thanks in advance

Dennis

Walter said he had ringing with it directly on the carriage (though his prints were so impeccable his standards might be higher than mine). I Know some people used this design I made for direct drive:

Other than for flexibles, i have never had much issues using bowden. But I agree, direct drive extruders sure make calibration easier and more consistent across print speeds and materials.

I was looking at what Walter had published-
http://thrinter.com/cartesian-flying-extruder/

BTW: Anyone heard from Walter at all?

I am not sure why he used a jointed arm- I would think that it could add more complexity in the system. Though he does mention a bit of camber in the system to unload the carriage. I think that the height this way would remain constant with the 2 arms.

I can see the shock cord snubber that he used. It looks like he has used a piece of extrusion as a mast to counter balance the whole thing in the back.

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Hey Dennis,

I loved all of Walters designs and was afraid something happened to him. After some creepy googling it looks like he found a job in a large firm, I think consulting for 3d printer manufactures. He even write a scientific paper work a few others about 3d printer. My guess is he is either really busy or is in the 3d business industry and is no longer using sites like thingiverse.

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I’m using Eric’s Titan DD carriage from time to time to print PLA.
There’s certain PLA (ColorFabb black and red) that I can’t get to reliably print on the bowden setup as it keeps underextruding and then overextruding on the nozzle (not an extruder issue but filament must be getting jammed in the tube).
It works well, though I de reduce speed a little compared to the lighter bowden carriage.

I have been working on remixing Eric’s BMG carriage a bit-

I stretched in the X & Y directions to make room for LM8UU bearings to clear each other vertically. After getting some crappy bearings. I took a gamble on the EASE ones from Triangle Lab. Honestly, I am really impressed by the quality. They appear to be fully ground for squareness and length on their ends, the cylinder also look like they are This is the 4th iteration of the carriage. I am literally going to print my first prints with it this weekend.

I had some layer registration issues with the last versions that I hope will be cured with the better bearings.

I ended up opening the bearing housings because no matter what, I could NOT get them to size just right for slip fits without increasing the preloads on the bearings. I also relieved the tops of the bores so that any sag that might occur if you print without supports would not interfere with the bearings.

There is a touch of misalignement on one pair of bearings on my last print- I chased the bores with a 15mm drill bit, but did not get too agressive with it. I really want a 15mm chucking reamer for Christmas (a full set really, but I’d settle for a 15 & a 16mm). The bearings on that axis bid ever so slightly- I think that with time the PETG will relax enough that it might settle in on its own. You can feel the rod slide nicely with one or the other bearing, but with both, you can just feel a tough of binding. Half-a-blonde one as some might say.

I also modified the V6 part coller to be 8.5mm lower than the original in order to use a Volcano hot end. I also built in support blocks 0.2mm seperated from the part faces. I got some sag in the original prints.

I also modded in a 3rd screw to support the fan. The combined weight and moment arm would tweak the fan a bit on the rear screws and sag.


So far, my only dislike is that the cartridge heater wires are too stiff to route nicely.

I am hoping for the best - I will post up proof prints when I can.

Dennis

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Looking great as always Dennis.