Had some time this weekend to try out the anchor nuts and pins idea.
I created a 6 x 6 tile pattern on an offcut of 6mm MDF, then printed out a series of tiles to mix up both the M3 nut anchor tiles and regular tiles. This gives a useful test of real world tolerances.
The slightly lighter colour tiles at the back are printed with a 0.3mm nozzle, to see whether the increased detail is worth it over 0.4mm. To me at least it doesn’t seem worth the extra print time.
The anchor nut tiles (with M3 Nylok nuts in them) should work well, and I can use some longer threaded rod to create some fairly tall structures. Happy with that.
The tolerances on the pins measured approx. -0.4 to +0.4 across various ranges, I guess that’s in line with what I was expecting. The hole pitch is 42mm, on the 50mm tiles.
I printed out some test pieces with 1mm pins spaced at 42mm, 92mm and 142mm, left the pins protruding out 3mm.
I just cut them from piano wire, and the first thing to note is they’ll easily rip your skin if you’re not careful!. I ground them a bit smoother, but maybe there’s a commercially available dowel pin that might be better. Needs to be about 10mm.
The short version - it works really well! The sweet spot seems to be a 1.3mm hole in each corner of the tile. The pins will bend ever so slightly in the hole to accommodate. All 3 test pieces fit anywhere on the board I tried, no play.
Next step is to modify the tile STLs I have to put pin holes in, and some anchor nuts with suitable detail to add camouflage.
And I’m putting off setting up the drill press to counter bore the magnets for the main board sections. I know that’s going to be a job I don’t want to screw up
