For what could almost be an impulse junkyard pickup, 200kw seems like insanity.
From the gen3 video, it looked super stable at 18C, though he never tips past 50A or so.
Based off that, I suspect you could get a pretty good short kick if you have the cells and cooling to back it up…
What are your thoughts on a new motor build? Easiest route seems like it would be siamese-ing two stators together (assuming they’re laminations) so you don’t have to get 100 steel plates cut out to stack your own. Magnets looked like they could be thickened from one of the teardown videos, but I have no idea how efficiency calculations would play out.
I thought it was interesting that he required very little power to maintain a cruising speed. This gives me hope for the Laser having really low usage stats. I aim to maximise ‘fuel’ economy on the Laser to get the most range from what will be a small traction pack. This will include things bigger/smaller wheels and having different ‘gears’ to select different power. Imagine a 4 speed shifter (which the Laser has) where gear 1 is using MG1, gear 2 used MG2, gear 3 uses MG1+MG2 and gear 4 uses MG1+MG2 but overamped (would determine what is the safe amp value for say 5 min continuous operation, I can’t think of a situation where I’d be pulling max power for 5 mins straight).
So I was thinking of simply taking a couple of the Gen2 MG2 stators and rotors and making significantly smaller housings that don’t include any sort of transmission. Then siamese a couple for some crazy torque at what should be fairly low weight. As far as I can tell the stator is simply bolted into the housig, but I’m not sure because the magnetic power holding that shit together is beyond my physical limits.
The motors shown here are pretty good, if the specs are legit. Over 1000nm on a ~200kg motor is insanity. Might have to contact this seller and see what a APEV80-12 (23B) goes for. I wanna do a Ford Falcon 500 drag car and this would be perfect. Those motor RPMs will also eliminate the need for a transmission which lowers weight. Au Arduino, which will be used elsewhere in this vehicle for control, can monitor the gear selector position and then push the required user profile to the inverter.
The relatively low cruising consumption makes sense to me. “Object in motion…” and all, that and the E39 is a pretty slippery car (drag coef of .27 apparently).
The Prius’s econo tires seem like a pretty good place to start if that’s the route you want to go (assuming they make them in the laser’s size…). Might have to lose the rear louvers, since I suspect they aren’t helping the drag.
I don’t know how much you’ll gain in terms of economy with the different MG1/2 combinations since it’s still (power out)=(power in - losses). This is where I think the original transmission might be nice to try staying in the motor’s ideal RPM/current draw, but testing the different motor combinations doesn’t seem like it’d be an excessive amount of extra design work, so I’m happy to have my gut reaction be proven wrong.
A quarter mile pull shouldn’t take more than 15 seconds even with some of the pokiest of cars, so 5 minutes is more than enough to get you into trouble
The siamesed stators seem like the economical route again, especially if that $800-$5000 range is accurate for the APEV80-12.
But… if you’re going for an all out drag car (a 500 would be absolutely sick), something meant to move a bus is a good place to start. And still cheaper than a model S drive unit.
http://store.evtv.me/proddetail.php?prod=1PV5135
So for comparison, this is an AC induction motor from Siemens that was used in the Ford eTransit van project. They do 47kw continuous and can peak far higher. Up to 297 Newton Meters at 300v and 400 amps. They retail for $2695usd before shipping. A Prius gen2 transaxle can do ~85kw and 500+nm in EV mode. Two MG2s siamesed (or paralleled… ) would be 100kw and 800nm, crazy power for what could be a 120kg motor depending on how they’re packaged, and costing under $500 for two prius gen2 transaxles. We are living in a great time to be building electric vehicles
I have definitely considered an MG2 per wheel. As you stated, packaging would be a big problem. Have a gear reduction could work, and I have seen gear reduction per wheel on a production vehicle before (can’t remember which) so I know it works. Controllers would simply be 2 Gen3 inverters
Very cool feature, would be great for doing a quick Uturn. Handling is more dynamic with torque vectoring so its a great addition to vehicles. I think Rivian’s styling is atrocious. Would love to implement some sort of torque vectoring here but I think that would be better saved for a larger vehicle (Landcruiser 80series conversion…)
So I found this table, exactly describing the specs of the transaxle that I am using in my conversion, where was this the last few months. With a final drive ratio of ~4(trying to confirm this) and with a max RPM of 10k, with the wheel diameter of the laser of 572mm we get a final theoretical maximum speed of 269km/hr…
With such a difference between these numbers, I would be worried about how much efficiency you are going to be loosing vs the prius drivetrain. Will be interesting to see.
Have you seen the yumcha in wheel electric motor conversions… #Aliexpress AU $845.75 | QS Motor E-car 273 6000W 45H V3 Electric car single shaft hub motor
Since you seem to be having trouble finding a way to ship batteries from the US to Aus any reason why you haven’t reached out to this AUS based buy who builds large packs? I wish he was in Canada as he appears to make great packs.
I haven’t seen anyone use them but have been aware of the option. 6KW*4 would make for a pretty slow car but it is an easy way of saving space of course. Torque vectoring would also be possible here
From what I can tell dude uses LiPos exclusively, and his orders are often for customer provided cells. While I love the look of the packs, for something like this project I value my safety and reliability far higher than having more amps. Just checked and the cost of a 48S1P pack of the LiPos he uses is $750 just in cells, which really isn’t very cheap at all. I’ve been looking at used cells currently for testing but in the future I would place a very large battery order once I’ve got the money. I can go out and buy a Nissan Leaf battery right now if I wanted to as there’s someone fairly local with some, simply don’t have a spare $6k for it
So the prius transmission contains both the electric motors as well as the gear reductions to get the whole thing running. Only other thing that I will need to mount in the engine bay is the controller/inverter, which unfortunately I don’t think will fit into the dashboard space. I also need to keep any extra dashboard space for installing a PTC heater and possibly even air conditioning. I’ve been meaning to get into the Laser’s dash to figure out how much space I’m working with. Maybe I’ll do that today
Hey, saw your posts in other threads and thought I’d drop in again to see if I can help.
Any chance you can measure the motor’s resistance and inductance with an RCL meter? That might be one reason why some ESCs have trouble spinning it up, etc.
I am looking for a 15kw hub motor for my E motorbike project next year. They do exist but they are expensive and inefficient. In wheel is a cool concept but I don’t see them producing tons of torque.
) would be 100kw and 800nm, crazy power for what could be a 120kg motor depending on how they’re packaged, and costing under $500 for two prius gen2 transaxles. We are living in a great time to be building electric vehicles
