Prius A/C IPM Part 2: JaredTroller Assembly and Housing Machining

Much Progress!


last post here.

The JaredTroller boards arrived. The text got a bit messed up but other than that they looked great.


The footprint I made fit the brick perfectly. It fit very snugly. The capacitors did not fit very well though, as they were wider than expected.


Some slight belt sanding was necessary to make the capacitors fit. I also made a derp heatskink from a CPU cooler. Unfortunately it ate a drill bit as it is copper.

Time for some soldering. I attached the STM32F303 and it programmed! For the first time I even used a real programming connector as well, in this case a 2.0mm JST header. The regulator I used was a bit messed up as first because I layed out the board for a 1117 regulator, and all I had was a 7805, which has its pins one step counter-clockwise.


The rest of the components arrived and I soldered them on. Included was the proper 1117 regulator, so I fixed that. I set up the timers such that the PWM worked correctly with the shunts.


Time for a test run. I hooked it up the the Motor Science Rig.


Spun great!




Finally, I did a bit of testing of the transforms to ensure everything looked correct. I generated fake adc current readings and a fake encoder reading and ran the commutation. Everything looked as expected.

7 all good

Next up: Mechanical!

Here is the final CAD model, a nice housing.

stator n rotor 2

I modified the model slightly to fit a MITERS bearing in the front and the original compressor bearing in the back. I added some fillets to be milled with a ball mill.


I milled both endcaps on the MITERS CNC out of 1″ stock. Both came out beautifully.


I turned the tube on Pat’s lathe, as it was a bit big for the Hardinge and the Clausing has a broken belt. I also turned a little ring to hold the stator in place.

All the parts!


And, assembled! It is a very beautiful assembly.


Next up was rotor insertion. I faced off the stock on the front endcap so that the shaft could stick out, and installed the front bearing.


I also milled the encoder mounting feature.


Bearings installed, rotor cleansed of all its MITERS magnetic grit…..


With some precision finagling, the endcaps snapped on! Rotor fit and spun beautifully.


The tube had no holes so it was secured from falling apart with clamps. Bayley was impressed.


What a good object!



Time to actually bolt the housing together. Drilling and tapping the main tube:


Back end plate attached. The back holes are M4 tapped, so I drilled them with a 3.3mm drill. On one hole however I drilled 1mm down with a 4mm bit, so that hole could be used as a locating feature with the back end of the drill bit.


I drilled the holes for the front endplate in a similar fashion.

Next up was tube broaching to fit the keyway in the stator:


I made a key out of aluminum and sanded it til it fit just right.


Bridgeported off the leftover stock on the back endcap and then polished it on the lathe. The Hardinge really is a wonderful lathe.


I dremeled off the magnet wire insulation and soldered on some Hobbyking wire. Time for final assembly!!!!


And time for controller mating. I soldered on the encoder wires and soldered bullets onto the controller.


and she spun just great. I got field weakening working as well, meaning that the motor spins quite fast even at only 30v.


Ah, what a good feeling! I’ve done a lot of work, but much more still needs to be done. Next up: generating the lookup tables and testing on the Emcore!