Formlabs Form 2 Heater/Tray Detect Cable Installation Tool

thingiverse

This is a tool to assist with replacing a broken heater/tray cable for the Formlabs Form 2 3d printer.The Form 2 printer has a fatigue failure issue with the cable that connects the base to the tray. The tray moves back and forth and after many many prints, the cable will likely fail. In my case this initially manifested itself as a sporadic missing tray detected, and later on by a complete failure of the heater function. There have also been reports that the heater itself has possibly melted insulation on some of the wires (this did not happen in my case).The issue is that the alignment of the moving tray holder to the body is optically critical, and Form has said in the past that the entire optical assembly needs to be removed in order to replace the cable. This tool (which I printed on an FDM printer) assists in replacing the cable without disturbing the optical assembly.I was able to remove the cable connection from under the tray carefully using a long thin metal object such as a flathead screwdriver (and it may be accessible by fingers from the inside.The schematic for the heater cable harness is in the files section. Parts are available from Digikey and/or Amazon. I used a PA-09 crimper from Amazon, and some care to crimp the insulation (without pinching through it) and the conductor separately and carefully (https://www.amazon.com/gp/product/B002AVVO7K)Note that the Pin#1 markings use the connector manufacturer convention (and are well marked in the photos).I chose to use silicone insulated wire (multi-color packs available from amazon) for the replacement, and made the heater wires (red and black) 24 ga (and the rest 26 ga).Even though the bundle of silicone wires is a bit thicker, it still seems to work ok, and it is much more flexible than the original.I reused the plastic clamps from the original as well as the ring terminal (soldered it onto the outside of the used crimp terminal).I recommend a small zip tie as strain relief for the crimp connector ends (and maybe some to hold the bundle together in its twisted state, though I found just the manual twist during installation was sufficient for that.This tool can be used to assist in re-inserting the new cable end without disassembling the tray holder or optical assembly. It's a tight fit, but it helped align the connector end, though I had to get it in initially at about a 45 degree angle, then was able to use the tool to get it lined up vertically, then was able to push up slightly and then push under the tool with a thin screwdriver to get the connector inserted, and then remove the tool.Be careful not to scratch the optical window with anything, and clean the optical window (pec pads / optical cleaner / 99.9% isopropyl alcohol / follow Form's procedure).I was shocked at how poorly designed this harness was for the application. I think the right way to have designed it would have been to make a custom flex cable optimized for carrying the heater current and signal lines, with a large bend radius that withstands the large number of flex cycles the cable is expected to perform.Form has now dropped support for the Form 2 printer unfortunately (I really don't like that they did this given how useful this printer is, and it certainly makes me wonder about how soon they will drop support for future printers). /soapboxFormlabs thread is at:https://forum.formlabs.com/t/form-2-heater-cable-repair/29198