Elegoo Centauri Carbon printhead bumper bar

With all the great light weight printhead covers available, there is a temptation to operate the printer without the rear cover. Doing this risks the capacitor and heatsink on the PCB banging into one or other of the stepper motors at the rear of the printer. In an argument between a component on the PCB and a solid lump of metal, there is no doubt who the winner will be. You will then be up for a replacement board or at least some new parts and some delicate repairs.

Thanks to @RobertSamples_345778 and members of the OpenCentauri forum on Discord, for pointing out this problem to me.

This little bumper will protect the parts.

I printed this in Elegoo TPU95 on a Bambu Lab A1. First time I've tried TPU in the A1, so its not tuned very well and rough.

Layer height 0.2mm. Five walls of 0.42mm width. Five top layers for a thickness of 1mm. Ten bottom layers with a thickness of 2mm. 15% cubic infill.

Uses 5.5 grams of filament and takes around 30 minutes to print if you go carefully.

Important: Classic wall generator, inner/outer wall order. Using outer/inner or inner/outer/inner may lead to unsupported lines on the lower bevel.

The idea of all this is to have a hard shell, especially on the bottom, which becomes the back when the bumper is fitted, and a softer core.

Other parts needed: One M3 x 10 mm bolt, countersunk head type.

Installation:

1. Power off and pull the power cable out. If you try and do this powered on, you risk shorting something on the PCB.

2. Bolt the bumper to the back of the toolhead. Use the existing central threaded insert.

3. Test by moving the printhead manually, you should be able to move it over the poop chute and wiping brush.

4. If it all looks good, power on, and use the controls to nudge the printhead around.

5. Try a test print, unloading and loading filament.

6. It's not hard. 

Replaced the rear cover of the printhead with a small, light bumper bar