Term 2 Holidays, transmission repaint, designing, coupling, electric motor CNC

Its been quite an eventful holidays with this project as I tried to hit out as much of it in the first week or so as there is still heaps of work to go!


I finished stripping out all the unnecessary stuff like the radiator, condenser, coolant pipes and tubes, AC compressor and fuel lines.
It is surprisingly spacious with plenty of room for my electric car design.

I also got to cleaning and repainting my transmission which is looking so much better now.

I also got to designing an adapting plate for the electric motor to bolt onto the transmission securely, I would ideally like to cut it out of a thick aluminium plate professionally, although there are other methods of doing this too without an adapting plate, when I get to this part in the build I will go more indepth into it.

I then removed the clutch and flywheel assembly from the old motor (now a parts motor), and then removed the crankshaft which I plan to use its flywheel coupling on the SmartDrive shaft. This involved a bit of brute force to get the thing out!

I had tried cutting down the flywheel coupling piece and lathing it down at school to fit the SmartDrive shaft in. I then plan to put an M6 bolt through the shaft. Although this is quite a small equivalent key of maybe a 40mm squared, which could be 4mm wide and 10mm long. This is plenty to handle the torque loads of my motor in combination with a tight, almost interference fit.

One of the main things I began doing in the holidays was setting up and beginning to CNC my steel rotor housing (magnet rotor). I first planed off the CNC board a couple weeks before, to which I screwed a piece of pine over the top (to reduce swelling if oil/lubricant for cutting spills). 

I layed a plastic sheet underneath all of these to seal off the oil soaking into the wood as much as possible. I managed to get a tolerance of about 0.1mm difference from one end of my 3mm steel stock to the other which I am fairly happy with.

Anyway I began cutting it out on Tuesday in the second week of the holiday, going for a solid 2 or 3 hours cutting out about half of the magnet tracks. I found the first 6mm flat endmill I tried was not designed for steel cutting as it went blunt in the first couple passes (probably about 1000 passes in total so no where near). Luckily, I found a carbide 6mm flat endmill which I chucked in and it cut out so much better at 15% speed. I dabbed a bit of lubricant every so often but it was doing very well without any supervision, which meant I could go on to working on the coupling stuff above.

By the end of the holidays, I managed to get all the magnet tracks rebate cut in, which I aimed to do before the wood began to swell a little and throw off my leveling.

By Monday, Week 1 of Term 3, I got to cutting out the rotor housing and am about halfway through.

It was good that I managed to cut the magnet tracks earlier as now the tolerance was about 0.3 or 0.4mm just from the swelling. The cut out file doesnt matter too much as the depths are not affected therefore it will cut out the same.