The drive pulleys for the X and Y motors arrived the other day, so I was able to finish installing the belts and install the heated bed. The current Prusa model that this is based on uses "mesh bed leveling" instead of having adjustment knobs at the corners for bed leveling (i.e. tramming the bed to the print head), which is done using an inductive probe to determine the bed height at 9 locations prior to each print. It's much easier than manual adjustments and it means that instead of adjustment screws, the bed is held to the Y carriage by regular screws with aluminum spacers in between.
I had one of the places I ordered parts from go incommunicado after the automated "thanks for ordering" email went out. Not sure if they are a zombie site or what; I posed the question on the Discord for the Bear mod, and the designer claims to be in contact with the owner and offered to help, but by then I had already turned it over to my credit card company and reordered most of the stuff from another vendor. Except for the stupid spacer kit, which that vendor didn't carry. I ended up making them myself on the lathe.
There are a plethora of alternative screen and controller setups but I stuck with the same electronics that the stock Prusa uses mostly for simplicity's sake. The LCD screen/interface board was made by LDO motors which also makes the steppers for Prusa and probably the LCD unit as well. I printed up a "smooth" version of the housing without the Prusa logo. There's several printable housings to choose from since the Bear re-uses the Prusa part with its own printed mounts to the front frame extrusion.
The mechanical aspects being finished, I am wading into the wiring and electronics. I have the controller board mounted on the left and the steppers (except for the extruder stepper) plugged in. I need to hit the hardware store for 4mm screws to mount the power supply unit on the other side. I would have preferred to use the standard Delta power supply that Prusa uses, but they don't seem to be available anywhere right now, including from Prusa. They are still shipping printers, so I assume they are only able to get enough to use with new printers.
I bought a Meanwell LRS-350-24 which is arguably a better power supply in some ways (higher wattage rating) but it does mean that I had to seek out and print a dedicated lower case and set of mounts to use it with the Bear, since the official mod only has mount options for stock Prusa PSUs. I am still waiting for the switch and plug (which has support for the "power panic" feature that is supposed to let you resume a print after a power failure), and I will need to get some silicon wire and make up my own wiring to the controller board due to the non standard installation.
One thing I really like is the printed parts for the Bear mod include these awesome cable clips that twist into the extrusions. Prusa didn't include anything like that, although I did find some that will fit the 3030 extrusions, so after this printer is up and running, I will go back and clean up the wiring for the first printer a little.
The other thing I am waiting on is some 3mm nylon line which is used as a support for the extruder wiring bundle between the extruder X carriage and the wiring pass through at the controller box. I found limited choices for this... I could buy the replacement part for the Prusa which is cut to the exact length needed in the stock printer, and which therefore is probably too short due to my 100mm extended Z height. I could buy a whole roll of 3mm nylon printer filament and cut off what I need, and then have an entire roll of filament I have no use for since pretty much all printers use 1.75mm filament these days. I eventually found some 3mm string trimmer line on Amazon which I am now waiting on, and which was cheaper. No dice finding it locally at Los Depot.
Anyway, it's progress and I am slowly getting closer to the point where I have to figure out how to set up the firmware for this beast.
