Progress of my smaller Eustathios.

D Rob Thanks for the video, now I know there are some room for adjustment even when drilling not accurate. There are combination drill/tap/deburr bit that make tapping easy.

Mike Thornbury, I heard different 2020 suppliers have different end hole size. I could imagine with the correct hole size, self tapping screw will give more strength. Does your method require accurate drilling? Could the screw slide before tightening?

@Eclsnowman Thanks, I’m sure I’ll forget some nuts, and I don’t like to have extra nuts in the slot that give strange noise when the frame vibrate. I’ll depend on the insertable T-nuts to save the day.

I’m surprised the tapping method is stronger than the bracket. Need to adjust the design accordingly.

@Mike_Miller Thanks, I checked the spacing is OK. The frame is bigger than necessary. I was tempted to shrink the frame further, but one thing I learn from my makibox experience is the more optimized in space, the more difficult for future mod.

I covered up my Prusa i3 in a big box with no problem, so I assume the stepper will be fine with 20 degree more ambient temp, but I may be wrong. Don’t like the long GT2 belt when putting motor at bottom. Also, use of cheaper GT2 pulley block one belt path, so the motor move above the gantry. Need more consideration here.

I always drill the end. It doesn’t need ‘precision’ - the drill bit seems to automatically follow the path of least resistance. Always lubricate! I use TF2 (I have it in my toolbox for RC) or silicone spray. I have my cordless drill set on ‘driver’ speed, rather than drill speed and back it out a lot to remove the swarf. It sounds complicated, but when you have all your extrusion clamped together and with the ends facing you, it’s really quick and easy and intuitive. I use a lot of 60 and 80 profile, where you will have 3 or 4 holes to drill every end. If it wasn’t for self-tapping bolts I would have gone crazy.

If you are committed to tapping, for whatever reason (need low-profile heads to fit a particular installation, for example), you can get a drill-driver tapping bit, but not here in the third world.