Tonight, I worked on a few projects for this printer.
- Checked the standoff mounting holes that I put loctite into last night. Two of the holes seemed to work well, one less well, so I just did the same thing one more time on the third hole and will check again tomorrow.
- Scribed lines on the bottom of the bed to center the heater.
The heater is a 500W 120V 200mm x 200mm heater on a 224x275mm bed; I have a theory that this is OK because aluminum conducts heat well. (I have a 300x300 mm heater on my 330x330mm bed on the corexy and heat doesn’t drop of precipitously in the outside 15mm.) 500W is a lot for that size, but it was what I got cheap. - Polished and cleaned the underside of the bed.
- Mounted the heater on the bed
- Put a 192⁰C TCO on one of the heater wires to the bed.
I used crimp connections; soldering a TCO seems like a bad idea for multiple reasons. Labeled the bed 192⁰ so I remember later which TCO I used. - Scribed lines for the locations for my kinematic mount feature blocks.
-
Experiment I used RTV silicone as an adhesive to hold the kinematic mount feature blocks to the bed.
I discovered that the scribed positioning lines were useless when the RTV squished out and covered them, so I had to use calipers to position the blocks correctly. If I messed up, I’ll end up with a crooked bed.
Each block has a 15mm x 10mm contact area touching the bed. I left them clamped to the bed overnight to set. (If this doesn’t work, I can re-do it with JB Weld but that’s rather more permanent, so if I end up needing to recreate the feature blocks it would be inconvenient.) - Ran a bead of RTV silicone around the edge of the bed heater, as recommended by Keenovo
- Put a huge bolus of RTV over the TCO, then used duck tape to hold it down to set.
- Sprayed water mist on all the RTV to ensure it sets.
Then I moved to working on the electronics case.
- The longest pan head hex socket M3 screws I have were only barely long enough to attach the display. Holding the M3 nuts in place at the inside of the assembly took some creativity.
- With the display in place, the reset button works perfectly, it couldn’t be better!
- All the other screws fit fine. I used pan head hex socket M3 screws of various lengths everywhere, and it looks beautiful to me.
- The USB ports, microsd, and sd slots all are accessible and function well.
I didn’t do any wiring. I’m hoping I don’t have to remove the display to attach the wiring to it, because holding those nuts in place was tricky.
Here’s the reference kinematic feature block:
Not much extra room on that screw (sorry, bad picture):
Looking better in real life than in this picture, again without great color balance:
The slots are too long and bend easily. They are probably going to break some day. I should probably have done what I’ve done with some designs in OpenSCAD where I’ve patterned hexagons; those can print vertically and look really nice without support, and can be very strong. But it’s not important enough right now to print another 1/3kg or so to change.