CoPrint Chromahead mount for Tronxy XY-100 (Also known as iMakr STARTT)

As part of our plan to upgrade our TronXY XY-100 (also sold as iMakr STARTT) printer with a CoPrint system it was necessary to mount the ChromaHead to the printer, and while I was redesigning the head mounting plate I took the opportunity to add proper belt tensioning which the original printer lacked.

This plate should be printed in a strong, rigid, heat-tolerant material as it's going to see high temperatures and sustained forces for long periods. I used eSun's red ABS-GF which seems to be working OK so far. I've printed this on a 0.6mm nozzle which seems to work well, although you might get better engagement with the belt grips if printed on a 0.4mm nozzle. I used 4 perimeters and 35% infill as strength and good anchoring of the heat-set inserts is vital.

I'd strongly recommend the installation of locking screws into the x-axis idler bracket. Because this design includes measures to properly tighten the belt it can exert far more force on the x-axis brackets than the original does. Without some method to retain the axis rods securely in the idler bracket it's likely that the Z-axis rods and lead screws will be pulled inwards enough to cause printing problems

Once it's printed, it should be fitted like this

1. Install Heat set inserts as shown in the photos, if you've printed this right then the heat-sets will raise a burr/bulge as they're fitted so you'll need to sand that down flat afterwards. It is important that the front surface of the plate be flat or the Chromahead might rock
2. Install the X-axis endstop as shown, be sure the screws do not protrude though the front of the plate
3. Install one end of the belt into the belt retainer on the back of the plate
4. At this point you will probably want to install heat-set inserts and locking screws into the x-axis idler (see note above)
5. Screw the adapter plate onto the x-axis bearings (I found I had to use an M4 tap to open out the threads a little to get the screws to go all the way in)
6. Route the belt as shown
7. Install the other end of the belt into the tensioner and add the retaining cap
8. Using a long M3 cap-head bolt, install the tensioner block into the adapter plate as shown and apply some tension to the belt. Do not tension the belt too tightly as the tension will increase a little when the chromahead is fitted!
9. Install the chromahead, doing so will clamp the tensioner block into place and slightly increase the belt tension
10. Check belt tension and free movement of the X and Z axis.

Hope this all works well for you, check out this collection for other items from our upgrade project on this printer.