Making printrbot jr from parts assembling now.Going to add 1.75 extruder direct drive

Making printrbot jr from parts assembling now.Going to add 1.75 extruder direct drive without gearbox

I wouldn’t recommend acrylic for the printrbot at all. It’s not optimized for the forces that are put on the nut traps, and it tends to fracture pretty easily. Sounds like a perfect design to fail over time. There are some things you can do to mitigate these effects, but acrylic = bad idea.

Working fine so far. Other option was mdf.

As I said. Perfect design to fail over time. You can modify the design to fight the forces that will cause it to crack, by taking every 90 degree inner corner, and adding a 3/4 circular pocket to the corner.

Also, not to rain on your parade, unless you used a direct-drive extruder before and have good experience with it I wouldn’t recommend it either… It’s hard to set it up so that the stepper doesn’t skip. If you can get a stepper with a 5:1 planetary gearbox I would strongly recommend it. Although they usually have 8mm shafts you can get the Mk7 drive gear from here:

i have used wade. makergear and metal gearbox microextruder before i think i can handle it.

@Karan_Chaphekar , I didn’t mean that you couldn’t handle it :slight_smile: I was just giving you a heads up regarding direct-drive extruders. I too was looking forward to using it for its simplicity but even a 70 stepper didn’t have enough torque to work reliably.
However, I’m now realising you will not be using bowden feed which should work better (I did use bowden with my Rostock Delta printer).
Anyway, good luck!

Hey I will know when I try it. I have full proof method in jhead plus geared motor. Just searching for cheaper option. I should also consider qu-bd extruder with modification.

I agree with @ThantiK acrylic is ok but when tighting the nut bolts i cant tight it enough. also acrylic is expensive. i am finding birch plywood locally but chances are slim. can you suggest any other wood material (i can do mdf but its not good for tabs and all.) or any other material suitable for printrbot jr. ?