16 May 2013

Todays result: 72 playing tiles

I printed a set of game tiles for a friend. They are in a gift box waiting to be discovered.

They took about three weeks of evenings to print which included a lot of failures. This print taught me the importance of correct extruder settings. I probably lost a half a spool of plastic to failed or poor prints. I noticed by chance that Cura was setting its own extruder steeps and overriding the correct value in firmware. Prints would use too much plastic and cause infill to bulge up. The bulges would catch the end of the nozzle and either cause the X/Y motors to miss steps and misalign the extruder or just knock the tile free of the bed.

I used green for the base and grey for the top. I stole the idea from images of other people’s prints. The tiles came as separated models for the base and tops. My printer has a single extruder. To achieve two colours I printed the green base for a plate first, changed the filament, reset the z value back to zero, and then printed the grey tops. The base and top where sliced independently with different settings and printed as separate jobs on top of each other.

The tiles where arranged in plates of 9. Often some of the tiles where ok while other printed poorly. To replace failed tiles I ended up cutting up the plates then reforming my own arrangements.

The grey top didn't always span the same horizontal area as the green base. This would lead to misalignment as Cura would centre each job. When I figured out what was going on I started using cooling cones at each corned to force the equal horizontal areas and ensure alignment. The cooling cones also produced better prints of towers and cloisters.

Some of the pieces had tab/sockets that where too small and needed to be made larger. Other model changes included adding a shield to the four way city, trim the corner walls to match the other wall heights, add corner wall to cities, elevate city shields, and add a termination to the T intersection. Use rounded corner roads.

Changes to slicing settings for the base
  • Leave the heater and bed on at the end of the print, remove M104 S0 and M140 S0
  • Leave the Z height at the level it finishes printing, remove G1 Z+0.5 or similar

Changes to slicer settings for the top
  • Set Z to 0, G92 Z0
  • Turn off skirt
  • Do not home Z, remove Z0 from the G28 line, but leave G28 X0 Y0

The model is available here

All 72 tiles

Close up of connected tiles