Tapped all the extrusions, really like how just a mild amount of pull snugs the extrusions up against the new lower corners. Took 3 days of learning about ABS and 2 different filament brands, but getting ‘good enough’ prints to at least get the other printer back up and running.
Atomic ABS, really like it any imperfections are the cantilevered failing bearings and pulleys on my clone i3. Micro Swiss and Atomic ABS are a great functioning combo. No supports needed unless its a reversed overhang that needs a starting point.
Hand tapping aluminum extrusion ends. Use a M3 taper tap. Gradually cuts threads using a taper as the name implies. Bottoming tap has full width threads at start and is harder to tap with but allows screws to be inserted deeper. Use a taper tap, there is risk enough of breaking a tap especially learning how. Maybe even drill out some 2.5mm holes in scrap and practice a few times. I did my first time around and it helped. If you have really long screws and need the extra thread space use a bottoming tap after a taper tap so it has established threads to work with.
To tap, start with a drop of oil into the hole in the extrusion, always make sure to use oil each time you insert the tap to cut. The first cut go about 8mm, retract and clean, 5mm, retract and clean, and the last few mm to bottom a taper tap and chase the threads, and clean.
If you don’t retract and clean you can break the tap in the threads, you REALLY don’t want to do that so be patient and use more not less time. I am not sure extraction would be possible, and you would lose the ability to ever use the extrusion center hole for anything.
Again use a drop of oil or thread cutting fluid every time the tap goes in. It helps it cut smoothly and avoids heating and swelling of the tap binding it.
Clean running hot water through and over them, dry with a shop vac and towel. Job done :o)
Still assembling, should be up and running again tomorrow (I hope but do not expect, ain’t going to rush it).
