Heat Bed Wire Mount by chuteroo

Last crawled date: 3 years ago

The Thing:
A heat bed wiring fastener that helps provide mechanical support to preserve the integrity of the solder joints.
To Print:
1x Heatbed Clip
2x Heatbed Clip Bar
Vitamins:
Small bolts and nuts to secure the parts together. I used Nylon Lock Nuts Screw Fastener Zinc Plated Black Hex Insert Female M3x0.5mm and M3x14mm Screw Cap Point Hex Socket Screws Bolts.
Epoxy
How to Use:
1). Thread wires through gap in "Heatbed Clip"
2). Position "Heatbed Clip" such that it gently presses the wires against the edge of the heat bed and temporarily clamp it in place
3). Solder wires to the appropriate terminals on the heat bed
4). Screw "Heatbed Clip Bar" onto wires against "Heatbed Clip" using the holes closer to the heat bed. Tighten until the wires cannot move easily. Repeat with distal holes.
5). If satisfied with solder joints and positioning of all parts, epoxy the "Heatbed Clip" to the bottom of the heat bed. Clamp in place until dry.
6). Happy printing!
The Story:
After burning out the original heat bed wiring I tried replacing it with 10 gauge threaded wire, which admittedly was a bit excessive but satisfying. Unfortunately, such thick wire was somewhat stiff and after around twenty hours printing snapped the heatbed terminals despite my attempt to offset the mechanical stress using zipties and looping the wires around the existing heatbed connector. As such, I had to resolder the leads directly to the heatbed, but that left me with no mechanical support whatsoever. To address this issue, I CADed and printed this assembly (on a different printer). After 30 hours it has suffered no apparent strain.
Potential Improvements:
I'm most worried about the epoxy eventually failing due to thermal stresses. A good improvement would be providing a structural means to secure the assembly to the heatbed without infringing upon the heatbed surface while remaining thin underneath to avoid collisions with y-axis motor. My original prototype attempted to fasten itself to the screws connecting the heat bed to the T-bar but proved unstable with a tendency to sag and jam on the y-axis motor. As such I removed it and settled for epoxy, but would be happy to see someone succeed in fastening the assembly with a structural rather than adhesive means.