Here is the build log for Friday night. I decided to mount the extruder directly on the bracket, without additional plates, brackets etc. The majority of the mass is the stepper motor, so I need to make sure I constrain it to the bracket properly, otherwise during high accelerations it’ll live its own life and will wobble around.
So I did the unthinkable. Those Chinese designers who put the casting marks inside the bracket will curse my name. I removed the non-drive end bracket from the stepper and recreated it in 3D. Later I tried to find a place for two M4 holes that will not intrude into the mounting holes, and the screws will still have 3-4 threads engaged. Since the M4 pitch is 0.8 this meant 2.4-3.2 mm wall thickness. It was tough but I managed to design it properly. The holes are 9.4 mm from the edge. Here is a drawing.
And here is a view of the holes on the bracket. I drilled and tapped the holes, and I’m using two 8 mm long M4 screws. 3.2 mm of that is the hadron bracket thickness, the rest goes inside the motor bracket. I made sure the screws will not touch the insulator or field coils inside the motor.
I also added a hole to the filament block. This way I’m going to have three bolts mounting the extruder, and a three legged table will never wobble, right? I have to file off the corner of the filament block, this was necessary because the bracket has a larger bend radius than the 3D model. I believe they had issues with the thicker aluminum plate when they bent it.
Finally here is how the extruder looks on the bracket. Notice my fortune cookie message for today: Learn Chinese: Electricity, Dian...
Chelsea. No problem. I like challenges, and I overcame all of them as you can see. I drilled out the holes tonight for the heater element and it slid in without any issues. I appreciate your offer, but I'm going to kindly decline it.