The Hell Ya Beller Fun with hot, pointy, sharp, and caustic stuff.

7May/114

Mendel Heated Bed

I've been struggling for months to get my "Sells" Mendel working reliably.  The mechanicals have been solid for a long time, but I've had flaky problems with the electronics and extruder all along.

I finally broke down and replaced the Gen3 electronics with a RAMPS board and after working through some issues, it finally seems to be working.

I usually print in ABS so I also invested in a Prusa PCB heat bed from Ultimachine.  There isn't much information out there on mounting the thing and most of the pictures I saw had people mounting them on a piece of plywood.  This is probably perfectly safe but there's something that bothers me about mounting something designed to get hot on top of something flammable.

I had a piece of 12" smooth Hardiboard.  This is siding material made from cement infused fiber.  It's very flat, very hard and heat resistant.   As a test, I held the torch on a scrap for a while to see what the result would be.  It scorched the topside but barely penetrated at all.

It's a little heavier than I'd like, but the combination of the hardiboard and PCB is actually lighter than the old acrylic and removable MDF that I was using before.

The downside is this stuff is damn hard to cut and throws off a lot of dust.  I milled a couple pockets for the thermistor and the wires so the bed would lay flat.   I also cut a few notches to remove material and lighten it further.  It seems to be working well.