Next challenge was making the controller lid. I wasn't sure if I wanted to resin print it, resin cast it or pay to have it CNC'd out of polycarbonate. Since the former is easiest and the latter the hardest and more expensive I decided to give it a shot. My curing station looks like I'm up to some evil shenanigans so enjoy a picture of that.
I won't bore you with the early prototypes and failures with me snapping one in half because I overcooked it with the print settings. Instead here's pretty happy final versions
Bottom one is the new one. Seems counter intuitive at first but printing with all the nasty support on the flat nice side allows you to easily sand down the surface and get a suuuuuper smooth finish. 1000 grit final and a light buff with some clear coat made it pop.
I still need to work on the gaskets and I had a dilema. Do the stock black one that's kinda boring and keep it vanilla ooooor use a much more thematically coloured TFL gasket. I put a poll out on Insta and the results spoke for themselves.
So guess I'll be making go faster blue gaskets when I get the material and dye.
Meanwhile a little care package came in the post. Thanks to the legend himself Radim Klaska for sending me a GT controller, BMS and a pint controller for some future devious plans. Using them side by side with the GTXS you can kinda see how similar I managed to get them.
I'll be pulling it apart to reverse engineer a custom controller and get a schematic out of it for some experiments I have planned. However here it serves well to demonstrate scale 😊
Back to the main goal again. The board won't do much if I don't get a charger made for it so with callipers at the ready I managed to replicate a brick and cram some magic smoke inside. I'm using a USB PD module to take in power and request 20v. Then a CC-CV boost converter to take the 20v and send a set current into the board until it gets near 29.4v where it'll hold that voltage to top off the cells. Basically how any normal lithium charger works that's not complete trash.
For the charge port itself I'm using some magnetic pogo pin connectors. They work really well and despite being 6mm in diameter this one can do 2amps. Added bonus is they're super satisfying to snap in. It's like magsafe for Onewheels (for ants)
Will come back to this when I resin print the final parts for the plug and charge brick. In the meantime I needed to figure out the harness. I wanted it to be orange like the GTS but finding multicore cable with 2x14awg + 3x24awg wire inside less than 8mm in diameter was a bit of a stretch so I came up with a solution.
Use a mould to encase the wires taught and in position then pour a flexible silicone over. Once cured demould and use heat shrink to get a uniformly round and flexible cable. Heat shrink alone will be weird and kinky. as it conforms to the wires inside and be less durable. I did a test piece first with some offcuts and despite being very messy it worked!
You can also see I made my own glands. The existing ones on the market just didn't scale right and the fitment was poor so a bit of CAD resulted in some functional yet scale looking glands.
In an older prototype the cable fits nice and snug. Minor kinks where some silicone hadn't set right or the wiring wasn't taught but overall looks great!
With that being a success it was time to crack on with the final one. I did have to crimp some insanely small connectors for the headlight and battery harness wires. Did these with some tweezers. They are tiny! Here's one under the scope.
I changed the mould a little this time and taught the cables before putting in which helped a lot although made slotting them in a faff. But it all went in well and cast really nicely.
I ran out of time last night to put the headers and connectors on controller side but I'll hopefully do that tonight and share the results of the board running off it's own power 🥰
Until then enjoy this render and little pic I took for my application to this years OpenSauce.
