Winching...

[Timoj]

Lots of ways.

There's the simple mechanical ones, such as bending or wearing the drive shaft in the motor from uneven loading. Then there's complex ones like wearing out the encoder or uneven demagnetization or heat damage to controller coils or capacitors.

I'm not saying I think it's likely, though, just that it's plausible.

-Crissa

I guess it’s good to play devils advocate on these things but I’m pretty sure a competent engineer can solve for failure modes of intermittent use.

 

[ajdelange]

How would you damage the traction motor?

It wasn't damage I had in mind. The traction motors and gearing are designed to transmit power to the wheels of the vehicle and to do so at the maximum possible efficiency and that efficiency is chased to a fraction of a percent. To split the power mechanically would require extra gears, clutches, shafts, bearings etc and even while in the "disconnected" mode those components would introduce losses. That's not acceptable here where every watt counts. In addition you can't put a PTO shaft just anywhere. But you can run wire just anywhere.

Think a bit about the heat pump compressor. Why do you think it is driven by a separate electric motor as opposed to using mechanical takeoff from the traction motor as is done in ICE vehicles?

 

[ldjessee]

Having seen a wide variety of electric motors burn out, from aircraft tugs to forklifts to 3/4" drive hammer drills... electric motors can be burnt out. And, I have seen people offroading burn up or otherwise damage gas and diesel engines as well...

Things fail, got abused, or something weird happens and before you know it... blam.

 

[Timoj]

It wasn't damage I had in mind. The traction motors and gearing are designed to transmit power to the wheels of the vehicle and to do so at the maximum possible efficiency and that efficiency is chased to a fraction of a percent. To split the power mechanically would require extra gears, clutches, shafts, bearings etc and even while in the "disconnected" mode those components would introduce losses. That's not acceptable here where every watt counts. In addition you can't put a PTO shaft just anywhere. But you can run wire just anywhere.

Think a bit about the heat pump compressor. Why do you think it is driven by a separate electric motor as opposed to using mechanical takeoff from the traction motor as is done in ICE vehicles?

I hear you. But a heat pump is used every time the vehicle moves. Generally in an ICE vehicle the engine is running the whole time and it’s just advantageous to use an easily controlled electric motor. I believe the Bollinger B1&B2 are going to include a hydraulic winch because they’re using hydro-pneumatic suspension.

A winch “should” realistically only be used a few times a year. Which is why the suboptimal 12v electric motor is used, cheap simple to install aftermarket. The duty cycle and power of a small motor is only just functional for those rare use cases.

The efficiency price is definitely an engineering challenge but considering the use cases a PTO still has merit.

All that said I think Tesla will just provide 110v/240v and control wires to the front/rear and provide user customisable software to control what ever is plugged in to it.
I wonder which aftermarket manufacturers will be the first to build the appropriate winch to utilise it.....!?