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

Much Progress!

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last post here.

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

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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.

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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.

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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.

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

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Spun great!

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Yay!

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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.

endcap

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

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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!

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And, assembled! It is a very beautiful assembly.

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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.

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I also milled the encoder mounting feature.

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

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

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

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What a good object!

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

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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.

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

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

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

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

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

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

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

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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!

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