Electrified Bombardier Recreational Products!
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Cobra R Member
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Electrified Bombardier Recreational Products!
So I thought I'd start a little thread just to show off the fun things me and a couple friends do at school. We're a team of about 10 students now, a bunch of engineering undergrads at McGill University and one Masters student who got it all started a couple years ago. Basically, we put together electric and hybrid electric vehicles as student design projects, most often for the sake of various SAE collegiate design competitions.
We just got back from the SAE Clean Snowmobile Challenge a couple weeks ago. That competition's been around for about 5 or 6 years, and has mainly involved teams that take stock snowmobiles and improve them in terms of efficiency, noise, and emissions. A couple years ago, that McGill Masters student showed up with something completely different: an electric snowmobile. In its first year, it wasn't even running, and it was sorta a joke to the whole competition. Two years ago, they had something running on an old Ski-Doo Summit platform, and it worked! Not very fast, couldn't go very far, and it definitely could not really compete in any of the events.
Last year though, we showed up with a brand new chasis, a 2006 Tundra that was an early prototype that we somehow got our hands on. We somehow got ourselves enough cash to invest in an incredible battery pack from Lithium Technology Corporation. It weighed about 80 pounds, was about 10"x10"x20", and we were able to go about 10 miles on a charge. Now that definitely doesn't sound very impressive, i know... The CSC at this point had actually recognized electric snowmobiles as something interesting and gave us our own category with our own events to compete in, and there actually was a second team with an electric (a third team just never made it). These electric snowmobiles weren't to be geared towards typical riders, but more as Utility sleds for ski hills and stuff like that.
More significantly, the National Science Foundation was very interested. They have a research station up in Greenland where they take very sensitive measurements of pollution up in the arctic. Now they don't wanna pollute their own samples, so they have a No-Vehicle Zone set up a good deals away from their base with all its generators and stuff. That meant though that they needed to get there on skis. So obviously, an electric snowmobile that could get them there and back pretty quick and tow a bunch of equipment is very attractive to them.
Last year, in the end we didn't do all that well. We had a great sled, it was the lightest at the CSC, at 521 pounds, even lighter than all the gas powered sleds (i think a stock Tundra weighs about 400 pounds though, so we were starting from a good spot). The only other electric snowmobile was more what you expect from EVs, since it was running on Lead acid batteries... It weighed over 1000 pounds. Nevertheless, our brushless AC motor was a piece of junk, overly complicated, and the company wouldn't give us a hand at all in figuring out why it broke down. We ended up reverse engineering the circuit board on the back till we found a burnt fuse a few days later. By then it was too late though, the comp was pretty much over.
This year, we worked on two things. First of all, taking last years electric sled and making it reliable, easier to use with a nice user interface, and redistributing the weight for amazing handling. Secondly, we wanted to work on an all new snowmobile, a series hybrid build off the Ski Doo MXZ.
The electric is probably the most impressive of the two at this point. It works really well, handles INCREDIBLY. We disassembled the Lithium battery pack from last year, and build our own casing for the 20 cells, CNC machined out of delron, into just the right shape to fit into the space available in the engine compartment. We also ditched that crappy motor for a really compact permanent magnet DC motor, its about 9 inch diameter and about 5 inches long, can put out a peak of about 12kW and weighs only about 30 pounds. So in the end, we reduced the weight of the sled to 499lbs, still the lightest at the Comp. The next lightest was a 2-stroke MXZ at 570lbs. But the key is that we took all the weight of the batteries off the back end and shoved it up front and down low, giving it a really low center of gravity. Whereas the other electric sleds typically have a HUGE battery pack under the seat, giving it a really tippy ride, I couldn't even roll this electric if I tried.
Here's a shot of how it looked last year, followed by its current form. Last year, the batteries were just sitting out in the back, and all the electronics were actually under the seat where the gas tank usually goes. Now the updated version has nothing outside of the engine compartment. Tons of empty space in the gas tank and out back. You can really toss this thing around and get the tail to kick out, its really fun:
We just got back from the SAE Clean Snowmobile Challenge a couple weeks ago. That competition's been around for about 5 or 6 years, and has mainly involved teams that take stock snowmobiles and improve them in terms of efficiency, noise, and emissions. A couple years ago, that McGill Masters student showed up with something completely different: an electric snowmobile. In its first year, it wasn't even running, and it was sorta a joke to the whole competition. Two years ago, they had something running on an old Ski-Doo Summit platform, and it worked! Not very fast, couldn't go very far, and it definitely could not really compete in any of the events.
Last year though, we showed up with a brand new chasis, a 2006 Tundra that was an early prototype that we somehow got our hands on. We somehow got ourselves enough cash to invest in an incredible battery pack from Lithium Technology Corporation. It weighed about 80 pounds, was about 10"x10"x20", and we were able to go about 10 miles on a charge. Now that definitely doesn't sound very impressive, i know... The CSC at this point had actually recognized electric snowmobiles as something interesting and gave us our own category with our own events to compete in, and there actually was a second team with an electric (a third team just never made it). These electric snowmobiles weren't to be geared towards typical riders, but more as Utility sleds for ski hills and stuff like that.
More significantly, the National Science Foundation was very interested. They have a research station up in Greenland where they take very sensitive measurements of pollution up in the arctic. Now they don't wanna pollute their own samples, so they have a No-Vehicle Zone set up a good deals away from their base with all its generators and stuff. That meant though that they needed to get there on skis. So obviously, an electric snowmobile that could get them there and back pretty quick and tow a bunch of equipment is very attractive to them.
Last year, in the end we didn't do all that well. We had a great sled, it was the lightest at the CSC, at 521 pounds, even lighter than all the gas powered sleds (i think a stock Tundra weighs about 400 pounds though, so we were starting from a good spot). The only other electric snowmobile was more what you expect from EVs, since it was running on Lead acid batteries... It weighed over 1000 pounds. Nevertheless, our brushless AC motor was a piece of junk, overly complicated, and the company wouldn't give us a hand at all in figuring out why it broke down. We ended up reverse engineering the circuit board on the back till we found a burnt fuse a few days later. By then it was too late though, the comp was pretty much over.
This year, we worked on two things. First of all, taking last years electric sled and making it reliable, easier to use with a nice user interface, and redistributing the weight for amazing handling. Secondly, we wanted to work on an all new snowmobile, a series hybrid build off the Ski Doo MXZ.
The electric is probably the most impressive of the two at this point. It works really well, handles INCREDIBLY. We disassembled the Lithium battery pack from last year, and build our own casing for the 20 cells, CNC machined out of delron, into just the right shape to fit into the space available in the engine compartment. We also ditched that crappy motor for a really compact permanent magnet DC motor, its about 9 inch diameter and about 5 inches long, can put out a peak of about 12kW and weighs only about 30 pounds. So in the end, we reduced the weight of the sled to 499lbs, still the lightest at the Comp. The next lightest was a 2-stroke MXZ at 570lbs. But the key is that we took all the weight of the batteries off the back end and shoved it up front and down low, giving it a really low center of gravity. Whereas the other electric sleds typically have a HUGE battery pack under the seat, giving it a really tippy ride, I couldn't even roll this electric if I tried.
Here's a shot of how it looked last year, followed by its current form. Last year, the batteries were just sitting out in the back, and all the electronics were actually under the seat where the gas tank usually goes. Now the updated version has nothing outside of the engine compartment. Tons of empty space in the gas tank and out back. You can really toss this thing around and get the tail to kick out, its really fun:
Thread Starter
Cobra R Member
Joined: March 18, 2004
Posts: 1,502
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Vital stats for the Electric... now don't get your hopes up, its still an EV, and one that's not really geared at all towards. We've got a pretty small market base for a vehicle like this, but nevertheless, there has still been a good deal of interest from people who really value a zero-emissions vehicle.
Top Speed: about 35 miles an hour
Max Towing: total towing force of 430lbs, meaning it could pull a 430lb weight straight up if it was dangling off a cliff. As to how heavy a trailer it could actually tow, that depends on how well it slides on the snow. This things got some nice torque at low speeds, my guess is over 1000lbs.
Max Range: about 12 miles at 20 miles an hour, farther if you go slower, not as far if you go faster... kinda like in a car eh?
Handling: on a scale of zero to awesome, it is awesome.
Animal resemblance: kinda looks like a buldog
Weight: 499lbs
Batteries: 20 Li-ion cells, each at 3.6 Volts for a total of 72 Volts. Weighs 80lbs. Custom made Packs.
Motor: PMG 132, rated at 110amps, 7.2kW, but you can squeeze a bit more out for short periods.
And now on to my baby... the Hybrid!
Top Speed: about 35 miles an hour
Max Towing: total towing force of 430lbs, meaning it could pull a 430lb weight straight up if it was dangling off a cliff. As to how heavy a trailer it could actually tow, that depends on how well it slides on the snow. This things got some nice torque at low speeds, my guess is over 1000lbs.
Max Range: about 12 miles at 20 miles an hour, farther if you go slower, not as far if you go faster... kinda like in a car eh?
Handling: on a scale of zero to awesome, it is awesome.
Animal resemblance: kinda looks like a buldog
Weight: 499lbs
Batteries: 20 Li-ion cells, each at 3.6 Volts for a total of 72 Volts. Weighs 80lbs. Custom made Packs.
Motor: PMG 132, rated at 110amps, 7.2kW, but you can squeeze a bit more out for short periods.
And now on to my baby... the Hybrid!
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Cobra R Member
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The Hybrid is based on an MXZ Renegade, a real beast of a snowmobile. So we took out that 140 horse, 800HO Rotax engine and gave it a 7hp single cylinder subaru!
My Lord! What have we done? So true, but that little engine, 211cc four-stroke, is just our "range extender" as they like to call it.
Here's how our hybrid works. Take our electric. Replace that 80 lbs Li-ion pack, with three 80lbs Li-ion packs. A total of 60 Cells, connected in parallels of three, so we're still running 72V and still able to use just one LTC provided battery management system. Replace that little 7kW motor with a 100lb monster of a DC motor, can put out up to like 35kW or something, I can never remember. And now, add on a 72V, gas powered generator.
That generator is what I spent a lot of time with. You can't really find too many 72V DC generators lying around, so we basically built our own that fit our needs.... kinda well. Its a 211cc Subaru EX-21 engine coupled directly to the same kind of motor that powers our electric sled, only here it acts as a generator. The Engine turns the shaft of the motor, which spits out 72V when the engine is running at its optimum rpm. We bought the engine based on something that would be running at its peak efficiency at 72V. The generated current is then either sent to the batteries to top them up, or is sent directly to the drive motor, depending on whether the driver wants to move or not. Once the driver asks to go faster than the little generator can go, the batteries start kicking in, and this thing can really move.
What's really cool is that this thing doesn't require any fancy electronic controls at all. The electrical system balances itself out, thanks to the shear bulk of that battery pack and the little mechanical governor on the engine. The engine will automatically slow down to match the charge of the battery pack, and we don't have to worry about it overcharging the batteries at all.
The only problem is that there's no way we could fit all that into the engine compartment. The generator and main drive motor are all under the hood, but that huge battery pack got shoved out behind the seat again. So that's 240lbs of battery way up high in the back, where the stance is narrow and it'll be happy to tip over... Kinda like all the other electric sleds at the competition this year, those who aren't fortunate enough like us to have the huge list of sponsors to help invest in compact lithium batteries.
So all this gives us a snowmobile that can go 30 miles in all electric mode. If you've got that generator running, it can get you as far as 100 miles depending on how fast you're going. Unfortunately, that engine isn't quite powerful enough though. If you're cruising at an average of 40 miles an hour, that battery will discharge a hell of a lot quicker than your generator is charging, so soon your batteries will be empty and you'll have to have a lunch break while you wait for it to recharge again. But if you've got enough stopping and going, that'll give this thing a chance to keep up. Nevertheless, that's pretty lame. Ideally, we'd have an engine in there that could spit out about the same power we need to cruise at a decent clip, such that the batteries wouldn't gradually drain, and you would only be limited by your gas tank. Nevertheless, that engine would be much smaller than a typical snowmobile engine. This little engine would provide the cruising power, while the beast of an electric motor would be there for when you really wanna move, taking care of those peak demands without running a huge engine for no reason. So we're working on that one already for next year.
Vital Stats for the hybrid:
Chassis: Ski-Doo MXZ
Weight: about 850lbs
Range: electric - 30 miles
gas - up to 100 miles if you take your time
Top Speed: not too sure yet, probably about 50mph
Batteries: 60 3.6V Li-ion cells. Three packs of 20 in parallel for a total of 72V.
Motor: Advance DC, 8inch, 100lbs, rated at 15kW, lots of TORQUE!
Generator: Subaru EX-21 - 7hp, 4-stroke
coupled to a PMG 132 electric motor
Center of gravity: see picture
My Lord! What have we done? So true, but that little engine, 211cc four-stroke, is just our "range extender" as they like to call it.
Here's how our hybrid works. Take our electric. Replace that 80 lbs Li-ion pack, with three 80lbs Li-ion packs. A total of 60 Cells, connected in parallels of three, so we're still running 72V and still able to use just one LTC provided battery management system. Replace that little 7kW motor with a 100lb monster of a DC motor, can put out up to like 35kW or something, I can never remember. And now, add on a 72V, gas powered generator.
That generator is what I spent a lot of time with. You can't really find too many 72V DC generators lying around, so we basically built our own that fit our needs.... kinda well. Its a 211cc Subaru EX-21 engine coupled directly to the same kind of motor that powers our electric sled, only here it acts as a generator. The Engine turns the shaft of the motor, which spits out 72V when the engine is running at its optimum rpm. We bought the engine based on something that would be running at its peak efficiency at 72V. The generated current is then either sent to the batteries to top them up, or is sent directly to the drive motor, depending on whether the driver wants to move or not. Once the driver asks to go faster than the little generator can go, the batteries start kicking in, and this thing can really move.
What's really cool is that this thing doesn't require any fancy electronic controls at all. The electrical system balances itself out, thanks to the shear bulk of that battery pack and the little mechanical governor on the engine. The engine will automatically slow down to match the charge of the battery pack, and we don't have to worry about it overcharging the batteries at all.
The only problem is that there's no way we could fit all that into the engine compartment. The generator and main drive motor are all under the hood, but that huge battery pack got shoved out behind the seat again. So that's 240lbs of battery way up high in the back, where the stance is narrow and it'll be happy to tip over... Kinda like all the other electric sleds at the competition this year, those who aren't fortunate enough like us to have the huge list of sponsors to help invest in compact lithium batteries.
So all this gives us a snowmobile that can go 30 miles in all electric mode. If you've got that generator running, it can get you as far as 100 miles depending on how fast you're going. Unfortunately, that engine isn't quite powerful enough though. If you're cruising at an average of 40 miles an hour, that battery will discharge a hell of a lot quicker than your generator is charging, so soon your batteries will be empty and you'll have to have a lunch break while you wait for it to recharge again. But if you've got enough stopping and going, that'll give this thing a chance to keep up. Nevertheless, that's pretty lame. Ideally, we'd have an engine in there that could spit out about the same power we need to cruise at a decent clip, such that the batteries wouldn't gradually drain, and you would only be limited by your gas tank. Nevertheless, that engine would be much smaller than a typical snowmobile engine. This little engine would provide the cruising power, while the beast of an electric motor would be there for when you really wanna move, taking care of those peak demands without running a huge engine for no reason. So we're working on that one already for next year.
Vital Stats for the hybrid:
Chassis: Ski-Doo MXZ
Weight: about 850lbs
Range: electric - 30 miles
gas - up to 100 miles if you take your time
Top Speed: not too sure yet, probably about 50mph
Batteries: 60 3.6V Li-ion cells. Three packs of 20 in parallel for a total of 72V.
Motor: Advance DC, 8inch, 100lbs, rated at 15kW, lots of TORQUE!
Generator: Subaru EX-21 - 7hp, 4-stroke
coupled to a PMG 132 electric motor
Center of gravity: see picture
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Cobra R Member
Joined: March 18, 2004
Posts: 1,502
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So that's pretty much what I do at school, its really fun and I don't really wanna graduate quite yet. Right now we're working on taking that hybrid drive train and installing it into an old Formula SAE car to go to the Formula Hybrid competition at Dartmouth. It should be fun.
Hope somebody actually found this interesting. If you want I'll borrow somebody's camera to snap some photos of the insides.
Hope somebody actually found this interesting. If you want I'll borrow somebody's camera to snap some photos of the insides.
Thread Starter
Cobra R Member
Joined: March 18, 2004
Posts: 1,502
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http://youtube.com/watch?v=BSbfczLmkF0
not to keep spamming about my stuff, but there's a video if you're interested, or if you just happen to like the Beastie Boys.
The video is us tooling around with our temporary lead acid pack sitting out on the tail. The weight of the batteries and the rough landings we took gave us some nice sag on the back of the tunnel.
Fortunately now we have a pack that weighs about half as much, fits into the front of the snowmobile, and lets us go about 3 times as far.
not to keep spamming about my stuff, but there's a video if you're interested, or if you just happen to like the Beastie Boys.
The video is us tooling around with our temporary lead acid pack sitting out on the tail. The weight of the batteries and the rough landings we took gave us some nice sag on the back of the tunnel.
Fortunately now we have a pack that weighs about half as much, fits into the front of the snowmobile, and lets us go about 3 times as far.
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