openinverter forum

So finally back at the model 3 board. Design has evolved a little from the initial concept. Decided on a board stack system that will allow interchange and upgrade of the main logic pcb with no soldering. The IC replacement board will now just carry two 70 way Molex 52991-0708 board to board connectors. The main logic pcb can then be larger and or double sided smd if required and simply clip into the adapter board. In other news it seems the Musk has kinda stolen Johannes's idea and implemented a software resolver interface:)

Thats are very neat idea.
Yes I'm sure Elon has stolen from me So thats a +1 for interfacing.

Adapter boards ordered. Now onto laying out the actual logic board. This will be an intermediate design for development. Hence me learning a new trick (vhdl)

One thing I miss out on by not having a drive unit is the ability to run the motor from an external inverter just to prove it will turn under Hubner control.

Jack Bauer wrote: ↑Thu Apr 04, 2019 3:47 pm One thing I miss out on by not having a drive unit is the ability to run the motor from an external inverter just to prove it will turn under Hubner control.

We might be able to help you there. Have a drive unit and v3 Hübner controller just need an inverter to play with.

A Prius inverter would probably do the job. I'll ship one over. Thanks:)

Who said I'd lost my Mojo:)
All the M3 stuff is giving me the final push to start doing some Verilog. Should have some nice knock on for further developments on other inverter boards.

Interesting read

STMicroelectronics SiC Module - Tesla Model 3 Inverter - Power Semiconductor report by Elena Barbarin

I'll have a M3 drive unit soon, and on our dedicated motor Dyno, will probably use the VESC to control it since they have good IPM code going.

Just this morning I woke to a quite lengthy email from a gentleman proporting to have "cracked" the Tesla Model 3 rear drive unit. I am being offered access to this solution so that I , and a very exclusive group of individuals, may sell this to others wishing to run the M3 drive unit in conversions. There are extensive terms and conditions to which I would have to adhere and of course no access to the source material. All for a very hefty "license fee".

I declined with thanks pointing to my opensource philosophy. An email came right back. I would really be wasting my time due to the complexity involved. That's ok I replied, I've been using a soldering iron for years and only burnt myself twice.

Hilarious

With recent developments on the BluePill board using the 48 pin STM32F103C8T6 mcu it looks like I'll be able to squeeze everything onto a single sided smt 4 layer board with castelated edges which will replace the TMS C2000.

What we know : Ground, power (3v3 and 1v2), JTAG, Reset, analog refs, can.
the analog pins run at 3v3 and the digital at 1v2.

What we don't know : what analog pins do what and what digital pins do what.

Plan for the development board is to route the unknown pins to pads which can be hardwired to the STM32 using wire wrap wire once functions are determined. The its a simple mater of routing the pcb for the finished design once we get moving.

Not sure we've captured this information anywhere... Model 3 battery module information from EVTV (here);

"The two 23 cell modules are at each edge of the pack and 67 1/2 inches long, 11 1/2 inches wide and 3 1/2 inches thick and weigh 191 lbs.

The two 25 cell modules are located in the middle of the pack and 73 inches long, 11 1/2 inches wide and 3 1/2 inches thick and weigh 207 lbs."

Note: the CAD models seem accurate (here).

Time for a little update. I was in the car 5 hours today and my thoughts drifted to Model 3 DU hacking. My previous plan revolved around removing the TI micro and replacing it with a daughter board carrying a mini Johannes brain. Turns out there's no need to do that.

Jack Bauer wrote: ↑Fri Feb 14, 2020 5:04 pm Turns out there's no need to do that.

Jack Bauer wrote: ↑Fri Feb 14, 2020 5:04 pm Turns out there's no need to do that.

Are you saying you have a plan that does not involve jumping through many hoops and having the patience of a monk?

Sir, you had my curiosity now you have my attention.

It appears being still in a car makes your mind run.

Maybe you should travel more often

Yeah my brain is weird at the best of times:)

Regarding model 3 drive unit hardware side, are the drive shaft splines same in model 3 and model S on the drive unit CV joint part?

Main consern:
Can a Model S driveshaft be used with model 3 drive unit for DIY EV?

JaniK wrote: ↑Fri Apr 17, 2020 9:36 pm Regarding model 3 drive unit hardware side, are the drive shaft splines same in model 3 and model S on the drive unit CV joint part?

The splines are the same but iirc the oil seals are different.

Sorry I was in wrong thread, thanks for moving.

I asked because the model S driveshaft is half price and for conversions it will be modified anyways.

Do you think they could be used, or would you pay 200€ more to get the model 3 shafts?

I think later in the game the model 3 parts will be cheaper than model S because of the volume of production. But for today its still the opposite.

JaniK wrote: ↑Sat Apr 18, 2020 8:04 am Do you think they could be used, or would you pay 200€ more to get the model 3 shafts?

I'll try and find the reference to the seal difference. I understand you can fit new seals but don't know the financial implications of that.

Edit: watch from 1:18;

Kevin Sharpe wrote: ↑Sat Apr 18, 2020 8:32 am

JaniK wrote: ↑Sat Apr 18, 2020 8:04 am Do you think they could be used, or would you pay 200€ more to get the model 3 shafts?

I'll try and find the reference to the seal difference. I understand you can fit new seals but don't know the financial implications of that.

Edit: watch from 1:18;

WoW that was quick turnaround:
S dimension 44mm and 3 is 40mm.

Conclusion:

Seals from S
Or
Machine shop and a just milling of 44mm->40mm

Thanks alot Kevin!

Allright then. It appears a BMW seal is available with identical outer and inner dimensions. Thickness for Tesla seal is still mystery..

Testing needed, Model3 DU and Model S shafts with this BMW differential seal:
https://m.autodoc.co.uk/elring/207708

Can you check seal thickness if The BMW seals work? They would then work for model S too?

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