My mods and upgrades

Actually I plan on running 110VAC so only 3A to get 330W. The connectors I plan to use will handle well into the 60A range.

Right now nothing special, just a 10x15x3/16 plate with magnets glued to it. I put the stock holders and rods together on a table, put wax paper over that, put the HomeDepot magnets over the bottom ones, applied Gorilla glue, put glass on top of magnets, stacked 10kg of weigh on it, and hen wait 24 hours.

 

Yes. Planning to use an XT60 for the main power and a JST for the thermistor since that's what I have handy. Depending on the wire gauge I may go XT30 instead, either is overkill for 3 amps.

 

Posted my custom spacer and screw holder to thingiverse in case anyone needs them for their XXL case. Later on I'll have a RPi 3 mount and a SainSmart 2 relay board mount you can doubled sided tape to the inside Robo base.

I have a UPS hat for the RPi 3 to avoid any nasty file system corruption issues. I swapped out the stock Mega with a replacement so that I could keep the USB cable inside the base. Turns out that a right angle USB fits great in the place they used the adapter in.

 

After being completely disappointed with the bed holders I received from 3DHubs and then trying some from thingiverse on my own that didn't fit, I'm designing my own in OpenSCAD. This has slowed progress a bit but it gives me something to do while I wait for the new bed heater from China. I just hope PLA works long enough for me to finish more heat resistant ones in Talman BluPrint.

I'm also ditching the glass plate for some 1/4in aluminum tooling plate.

I have so voided my 6 month warranty at this point.

 

Not sure what will happen here. Aluminium is a much better heat conductor than glass and my heater will go all the way to within 10mm of the PLA bed holder. If all else fails I may have to see if someone here can print my design in PETG or BluPrint and work a deal.

 

Thanks. I'm still working out the design and will print some in PLA while I wait for the other parts. If when I get it all together it melts down I'll take you up on that offer. Right now I'm hoping to do the bootstrap method. Print the PLA ones on my unseated bed, use them to build fancy new heated bed, print BluPrint ones and have fancy heat resistant new bed. Use heat resistant fancy new bed to print special extended bed holders to get Y to 330mm or more using 495mm smooth rods and some new bearing holders I have yet to layout.

Before anyone asks, no I'm not planning to include a magnetic attachment at this time and yes I do make things more complicated than need be.

 

Worse, I started as an Electrical Engineer and the switched to Computer Science.

My work history is as colored as my educational past.

 

Got the new bed heater from China. Was trying to design/print some new bed holders but finally gave in and just decided to reuse the stock ones. Had to Dremel out a slot for my heater/thermister wire because it was perfectly aligned with the middle bump that isn't used for anything. Need to locate the green connector again for DC/AC SSR to the heater MOSFET connection and do some fiddling at the AC inputs to splice in the heater power and it should be ready to test the new improved heater on the replacement glass bed.

 

What a trip this has been. Got it mostly going but still need to some work on the software side to integrate the GPIO calls for the relay board into OctoPrint. Still don't have Raspicam working due to needing to design a mount for the flat cable to HDMI cable converter on the Pi side and a camera mount for the bed. Put some LED strip lights in the cover that can be turned on/of via OctoPrint once I setup the menus.

The really fun part was figuring out how to not have the Raspberry keep the Arduino powered when I switch the printer off due to supplying 5V via USB. Turns out for the USB interface to be recognized you must leave the 5V line in place so to not have the Arduino/LCD running all the time (like the server) I had to remove the P-FET that controls the switching between USB and the power input.

 

Well the relay board worked great for an entire two days and then died this afternoon. Not like it was expensive but that is disappointing. Now I have to troubleshoot if it was the board itself or if I blew the GPIO pins on thr RPi. I suspect the cheap relay board.