i3v Dual Extruders/All Metal Extruder?

[MiniMadRyan]

Hey everyone,

After building my i3v (with the help of this forum and its awesome members), I've had pretty good results with the smaller items I've printed. Like some, I've had my doubts about the printed extruder and its longevity and accuracy. Looking at my Printrbot, I'm wondering if the all metal extruder would be a good upgrade for our i3v's.

http://printrbot.com/shop/printrbot-alu-extruder/

The extruder is considerably smaller and lighter than the current set up, and up to this point has been very reliable and consistent in the prints its produces, not to mention easier to load filament. From it's appearances, it seems it should mount up fine with the Hexagon hot end, and should mount to the x-carriage with only a few holes to be drilled.

More importantly, with some quick measurements, it would appear that one could fit two extruders back to back, and with the stock carriage, create a dual extruder set-up. Has anyone thought about this route, or have any experience with direct drive/metal extruders or dual extruder set ups?


Ryan

[DjWang]

Hello Ryan,

Something to think about, not sure if it is a real world issue: Will having a aluminum extruder mounted to a hot stepper motor and above a hot end absorb a lot of that heat and possibly melt or deform the filament passing through it?

[MiniMadRyan]

Hello Ryan,

Something to think about, not sure if it is a real world issue: Will having a aluminum extruder mounted to a hot stepper motor and above a hot end absorb a lot of that heat and possibly melt or deform the filament passing through it?

That's a good point. I've run the all metal extruder on my printrbot for the last 6 months, and with a properly tuned stepper, the heat hasn't been much of an issue on longer prints (6 hours or so) I would probably run some of the cork insulators between the extruder and the stepper, and if need be, switch out the MakerFarm stepper with a printrbot stepper (as they seem to run a bit cooler) As it is, my current stepper on my MakerFarm hasn't gotten too warm, certainly within acceptable limits (after tweaking the stepper pot of course)

[DjWang]

You could print out the plastic version someone made on Thingiverse first, see if it fits then get the aluminum one if everything looks good.
http://www.thingiverse.com/thing:281015

[printbus]

So that direct drive seems to do OK on the printrbot? I've always wondered whether the lack of gearing on the motor leads to too much "steppiness" in the extrusion or inadequate extrusion torque from the motor. Especially with the large diameter drive gear that it uses.

[MiniMadRyan]

I completely forgot about the 3d printable version. I think I'd have to try mastering printing ABS before I print one of those, but a PLA model would be good for mock-up. Regarding the metal extruder, I haven't had any issues with it thus far. I had to re-calculate my extruder steps in the firmware, but haven't had any issues since then. I haven't experienced any ill-effects, and the prints I've generated on it have been comparable to that of my Prusa too. I've heard of a lot of people having temp issues with the stepper motor running too hot, and heating up the entire block, but in most cases, a lot of those complaints were corrected by tuning the stepper motor pots down some. For me personally, it's been a very good upgrade.....much better than the aluminum print bed was!