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  1. JBee

    610 miles of range for Cybertruck - is it for real?

    I'm a bit confused why a PM motor needs a carbon wrap to hold the coils on the rotor together at high rpm centrifugal forces. Why have we got coils on a PM rotor?
  2. JBee

    610 miles of range for Cybertruck - is it for real?

    @ Hauling Current regen rate and profile doesn't reflect system capability, rather what is acceptable for the customer in terms of driveability. In that high declaration low rpm braking can cause uncomfortable cogging and an abrupt stop. @Adjelange Motor rpm is controlled by phase switching...
  3. JBee

    610 miles of range for Cybertruck - is it for real?

    Ok those numbers sound better, as well as the units ;-) So we need 871kW to do 1g braking on a MX. But current battery tech (18650?) in MX only allows for 80kW regen. How fast can your MX charge at a supercharger? M3 is 250kW but with a 75kWh battery using 2170s? So if a TM has a 200kWh pack...
  4. JBee

    610 miles of range for Cybertruck - is it for real?

    Adjelange I think either your units or numbers are out. Should be around 1kWh. Remember the battery isn't big enough (878kWh) to accelerate to 80mph otherwise! :) Also the eddy currents in the discs slow the induction retarder down, so not really a dump load or a geny. Would be nice to make it...
  5. JBee

    610 miles of range for Cybertruck - is it for real?

    I will repeat this statement for the third time: The plaid already accelerates faster with electric motors than it can decelerate with it's "sporty" friction brakes. This means that all components in the drivetrain, except the charging C rate of the battery used (as discussed separately), but...
  6. JBee

    610 miles of range for Cybertruck - is it for real?

    Still, as above, just add an induction retarder to the motor setup. Actually works better at higher rpm too. But you will need quad motors (1 per wheel) to make ABS etc work. Another thing I'm interested in is the Roadster SpaceX package for braking. Why be limited to tyre adhesion. :unsure:
  7. JBee

    610 miles of range for Cybertruck - is it for real?

    Yes it is fun! Well technically the current EV friction brakes also converts the momentum into heat :p At least with a load dump you could make it useful to heat up the pack so you can regen more next time? And nobody should be fully charging their battery if they're worried about cycle life...
  8. JBee

    Will the truck come with a full size spare?

    I agree that you can't have enough storage on a truck. I went back to my CAD drawing and really the best solution would be to have a rear draw behind the bumper. I saw an option on the first page of this thread, where if the motor assembly/casting would be low enough you could have a full bed...
  9. JBee

    610 miles of range for Cybertruck - is it for real?

    Its a fun exercise to explore the possibility though :-) You do have a point with the TM only having one front motor, that likely won't absorb full adhesion regen, but it wouldn't be possible to have a single motor front braking anyway, you need a motor per front wheel to modulate ABS otherwise...
  10. JBee

    Will the truck come with a full size spare?

    I tried putting the spare in the frunk of the CAD model before. It does work if you have some sort of draw that slides it halfway under the dash. But its not a good spot for absorbing crash energy. Plus I'd rather have a large frunk for tools and luggage. They just need to jiggle the...
  11. JBee

    610 miles of range for Cybertruck - is it for real?

    So with the Plaid they are already reaching the adhesion limits with acceleration and they are accelerating faster (avg 1.14g) with the motors than the friction brakes can deccelerate (1.11g) according to the Motortrend test...
  12. JBee

    610 miles of range for Cybertruck - is it for real?

    You might get the electronics and software to a insignificant lag time, but brake pressure modulation is a bit harder. Hopefully they can make it much better. Best part is no part, so I'm wondering at what point we might actually see the brakes being removed instead :) The Plaid can already...
  13. JBee

    610 miles of range for Cybertruck - is it for real?

    Ideally we'd have 2 independant motors up the front as well for off-road torque distribution! :-D I can agree that in many situations traction control on the front will suffice on a TM. But on a dual motor you'd be back down to a 2x4 with two diffs. With a diff and having to brake costs a...
  14. JBee

    Will the truck come with a full size spare?

    BTW just to clarify when I say CT tyre I mean a custom tyre that Tesla is likely to have made, because I doubt they will find an off the shelf product that has the onroad performance to make the advertised range viable, let alone have some off-road cred. They already had some custom sidewalls...
  15. JBee

    Will the truck come with a full size spare?

    Tyre availability won't be trivial especially in remote places where EV and CTs are less common. A bit like EV chargers, in that nobody wants to put up a charger if there's no EVs to charge and no-one wants a EV if there's no chargers nearby. It's just that 4x4 tyres are at least one if not...
  16. JBee

    610 miles of range for Cybertruck - is it for real?

    I'm pretty sure that Tesla will use identical rear drive motors on the Plaid drivetrain and because of that can neglect having a rear differential. There is a cost/packing/weight/manufacturing advantage plus it improves vehicle performance as this also helps to use torque vector control for...
  17. JBee

    610 miles of range for Cybertruck - is it for real?

    Sorry I should use stricter terminology. Tractive force would be better...depending on which version you use. ;) However, technically traction is not normally linear through velocity (tyre deformation vs centripetal force etc) and the coeffcient or friction can change by temperature too - hence...
  18. JBee

    Will the truck come with a full size spare?

    If they want a spare that rear under bed storage has to go as well. Even then its really close to fit the wheel behind the rear wheel centers (driveshafts) and inside the rear the bumper (as per picture above). I'm hoping they do, and at a minimum offer the space for a spare and make the wheel...
  19. JBee

    610 miles of range for Cybertruck - is it for real?

    @ajdelange Having enough torque is one thing but having enough traction is another. A typical launch control method is to reduce torque to the wheels on launch and add torque/power with speed. Given that they also have a gear ratio to give it more motor rpm, and aren't direct drive, the IM's...
  20. JBee

    610 miles of range for Cybertruck - is it for real?

    I expect the IMs to stay because of cost/resource use, price/performance and torque profile. The PMs are there to extend range and provide front axle drive, the IMs are for peak output and rear axle drive. Each serves a purpose to cover the full dynamic range of driving. A hybrid motor...


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