VRdublove
100 W
Also do you have a CA hooked up? What amperage are you seeing and is Richard's board turned the whole way up or what?
Project #3. Two motors, Three wheels, Six grand!
- Thread starter recumpence
- Start date
recumpence
1 GW
No CA and no current limiting yet (remember, I do not have a 300 amp version yet :wink: ).
The motors run warm to the touch (not hot, but very warm) and the controllers are barely over ambient temperature.
This thing is really strange in that it runs plenty smooth and docile at partial throttle, but when the throttle is moved, it just assigns a new RPM to the motors and they instantly adopt the new RPM wether the tire can handle it or not. And it is not like the road is wet or anything like that. When the tire spins, it still is pulling really hard.
Oh, also, I did alot of drifting with it today. I am enjoying the left side 2/3 length twist grip. It feels great the way it is setup.
So, here is how I ride (drive?) it; I get on the throttle and wheelspin to the first corner, at that point, I nail the brakes, turn in hard, and get back on the throttle just past the apex. This gives me wheelspin and a good drift as I exit the corner. Then I modulate the throttle to keep the rear end in line and continue the wheelspin to the next corner where the process repeats.
All this wheelspin would normally be disconcerting. However, as it is, the accelleration is plenty strong and I am glad to know the drive line will not break. But, I still will do some traction experimentation. I doubt I can improve the handling, though. It corners so well, I do not want to ruin it. The torque is crazy and I am not even overtaxing the drive. I can tell because of the lack of heat buildup.
Anyway, I will try to get a vid up sometime soon.
Matt
The motors run warm to the touch (not hot, but very warm) and the controllers are barely over ambient temperature.
This thing is really strange in that it runs plenty smooth and docile at partial throttle, but when the throttle is moved, it just assigns a new RPM to the motors and they instantly adopt the new RPM wether the tire can handle it or not. And it is not like the road is wet or anything like that. When the tire spins, it still is pulling really hard.
Oh, also, I did alot of drifting with it today. I am enjoying the left side 2/3 length twist grip. It feels great the way it is setup.
So, here is how I ride (drive?) it; I get on the throttle and wheelspin to the first corner, at that point, I nail the brakes, turn in hard, and get back on the throttle just past the apex. This gives me wheelspin and a good drift as I exit the corner. Then I modulate the throttle to keep the rear end in line and continue the wheelspin to the next corner where the process repeats.
All this wheelspin would normally be disconcerting. However, as it is, the accelleration is plenty strong and I am glad to know the drive line will not break. But, I still will do some traction experimentation. I doubt I can improve the handling, though. It corners so well, I do not want to ruin it. The torque is crazy and I am not even overtaxing the drive. I can tell because of the lack of heat buildup.
Anyway, I will try to get a vid up sometime soon.
Matt
TPA
10 kW
Well....
Unless you improve traction, you have hit your useful power limit.
Unless you improve traction, you have hit your useful power limit.
recumpence
1 GW
Yup, agreed.
It pulls WAAAAYYYYY harder than I ever imagined, though. So, I do not feel I need more. Of course, I only need 5% of this power to get me around town. :wink:
Anyway, I will experiment with traction improvement. But, again, the wheelspin is not from a lack of traction, per-se. It is from an over abundance of power.
It accellerates like a Vette! (up to about 40mph or so).
Matt
It pulls WAAAAYYYYY harder than I ever imagined, though. So, I do not feel I need more. Of course, I only need 5% of this power to get me around town. :wink:
Anyway, I will experiment with traction improvement. But, again, the wheelspin is not from a lack of traction, per-se. It is from an over abundance of power.
It accellerates like a Vette! (up to about 40mph or so).
Matt
grindz145
1 MW
I love that! As much as I tend to build something which is more efficient, and less powerful, something like this really captures the imagination of the general public and that's good for EVs in general, torque is a very good thing:-D. look forward to seeing some data (numbers) on how this bad boy performs:-D
Cheers
Cheers
12p3phPMDC
1 kW
- Joined
- Mar 16, 2009
- Messages
- 462
OMG dude,
8)
that sounds fr%@#^)#@kn awesome....!!!
What do you think your power to weight ratio is?
Ahhh....looking forward to the new tire setup...!
8)
that sounds fr%@#^)#@kn awesome....!!!
What do you think your power to weight ratio is?
Ahhh....looking forward to the new tire setup...!
VRdublove
100 W
Matt:
I seem to have found the perfect tire for high stakes, gut wrenching and torque ridden rides such as yours:
Treadlife is apparently infinite
I seem to have found the perfect tire for high stakes, gut wrenching and torque ridden rides such as yours:
Treadlife is apparently infinite
paultrafalgar
10 kW
Matt, all you need is a full fairing and a production line and you will be a millionaire before 2011!
recumpence
1 GW
VR,
I love the kitty patern. That tire is just screaming to be shredded down the pavement. :wink:
The power is at least 18hp. I figure, very conservatively, about 12,500 watts. The trike weighs 90 pounds and I weigh 190 pounds. When I went on-line, it looks like my power to weight ratio with me on-board is roughly that of an Eclipse (I think turbo version). But, the HP is not really well represented in the crazy torque I have. We all know this to be true. EVs have stupidly high torque compared to an equal HP per pound gas engined vehicle. So, though my HP per pound is roughly that of a relatively mild sports-car, the torque is more like a Vette or maybe a Mustang GT.
At least, that is how it feels to ride. It is hard to quantify feeling while riding, though. It is a strange thing to explain.
My personal impression may be a bit off, though. It may be that a drag race with a car may reveal that it is not accellerating as hard as I think. That is possible. But, again, it accellerates like I never thought possible with bicycle components.
I actually have a G-force sensor that can be used on an Eagle Tree data-logger. So, I can (eventually) get you G-force accelleration data.
Matt
I love the kitty patern. That tire is just screaming to be shredded down the pavement. :wink:
The power is at least 18hp. I figure, very conservatively, about 12,500 watts. The trike weighs 90 pounds and I weigh 190 pounds. When I went on-line, it looks like my power to weight ratio with me on-board is roughly that of an Eclipse (I think turbo version). But, the HP is not really well represented in the crazy torque I have. We all know this to be true. EVs have stupidly high torque compared to an equal HP per pound gas engined vehicle. So, though my HP per pound is roughly that of a relatively mild sports-car, the torque is more like a Vette or maybe a Mustang GT.
At least, that is how it feels to ride. It is hard to quantify feeling while riding, though. It is a strange thing to explain.
My personal impression may be a bit off, though. It may be that a drag race with a car may reveal that it is not accellerating as hard as I think. That is possible. But, again, it accellerates like I never thought possible with bicycle components.
I actually have a G-force sensor that can be used on an Eagle Tree data-logger. So, I can (eventually) get you G-force accelleration data.
Matt
liveforphysics
100 TW
Sounds thrilling! Great job!
With your short gearing and loads of torque, acceleration could definately be at or above typical sports car levels for the 0-40mph.
The key to getting traction with any RWD is to make weight shift to the drive wheels (or wheel in your case). You only need enough weight shift to start the process of shifting, and the increase in acceleration does the rest, right up to the point the front wheels start to lift, which means you have finally reached peak traction.
Since the weight of the rider is such a big part of our bike-ish contraptions, something as simple as raising the seat 2-3 inches could be all the COG position increase you need to make it stick rather than spin. Of course it has the trade-off of hurting cornering limits. Something to keep in mind if you are going to try for some acceleration tests though. Even just sitting on a couple pillows could make a huge boost in dynamic traction through the improvment in weight shift ability.
Awesome project! Excited for the vids!
-Luke
With your short gearing and loads of torque, acceleration could definately be at or above typical sports car levels for the 0-40mph.
The key to getting traction with any RWD is to make weight shift to the drive wheels (or wheel in your case). You only need enough weight shift to start the process of shifting, and the increase in acceleration does the rest, right up to the point the front wheels start to lift, which means you have finally reached peak traction.
Since the weight of the rider is such a big part of our bike-ish contraptions, something as simple as raising the seat 2-3 inches could be all the COG position increase you need to make it stick rather than spin. Of course it has the trade-off of hurting cornering limits. Something to keep in mind if you are going to try for some acceleration tests though. Even just sitting on a couple pillows could make a huge boost in dynamic traction through the improvment in weight shift ability.
Awesome project! Excited for the vids!
-Luke
recumpence
1 GW
Even the temp and overall weather affects the accelleration.
Also, yes, seat position makes a big difference. I had already begun researching that. :wink:
There is a happy medium between cornering and accelleration. I am fine tuning to find the perfect point.
Matt
Also, yes, seat position makes a big difference. I had already begun researching that. :wink:
There is a happy medium between cornering and accelleration. I am fine tuning to find the perfect point.
Matt
TPA
10 kW
All your torque is going to a single wheel.
I guess you need to start powering the other two!
I guess you need to start powering the other two!
liveforphysics
100 TW
TPA said:All your torque is going to a single wheel.
I guess you need to start powering the other two!
That's a common misperception for cars on solid surfaces like pavement. For maximum acceleration, powering the front wheels makes things only slower to accelerate due to additional mass and/or drivetrain complexity.
Its all about weight shift. Once you get the weight to transfer correctly, the front wheels should have zero weight on them during accel, so they offer zero additional help, powered or not.
This is why once AWD cars get to be very fast, they always convert to RWD. The lack of additional drivetrain weight up front improves the ability of the car to rapidly transfer weight to the rear wheels, so they become able to launch harder and accelerate faster.
GGoodrum
1 MW
I too have a hard time imagining how much power/torque two 3220s can have. I rode my single 3220-equipped 20" folding bike full blast through all three gears in the short block (three condo buildings long...) in front of our place here, and hit over 30 mph at the end of the block. Scary, seriously. 
I have some video in my iPhone, which I strapped to the front basket, and as soon as I figure out how to get it into YouTube, I'll post it in my thread.
Anyway, I seriously can't see a real practical use for dual 3220s on anything with two wheels, unless it is for Luke.
I have some video in my iPhone, which I strapped to the front basket, and as soon as I figure out how to get it into YouTube, I'll post it in my thread.Anyway, I seriously can't see a real practical use for dual 3220s on anything with two wheels, unless it is for Luke.
Incredible Matt!
I read through the thread, and great job with the entire build!!!
The first and only thing that cought me off guard is the wire lengths and AWG like boostjuice pointed out. I resoldered my entire system in 8 AWG wire and the wires still warmed up pulling an average of "only" 60amps with 90-100amp bursts. I will be going to at least 4 AWG next. I read you were going to look at changing the wiring, do you have updated pics? Have you felt the wires for any warmth yet? A wires' ampacity limit is very important to considder with these high current setups.
I've got my kleenex ready for the vids!!
Later,
Jay
I read through the thread, and great job with the entire build!!!
The first and only thing that cought me off guard is the wire lengths and AWG like boostjuice pointed out. I resoldered my entire system in 8 AWG wire and the wires still warmed up pulling an average of "only" 60amps with 90-100amp bursts. I will be going to at least 4 AWG next. I read you were going to look at changing the wiring, do you have updated pics? Have you felt the wires for any warmth yet? A wires' ampacity limit is very important to considder with these high current setups.
I've got my kleenex ready for the vids!!
Later,
Jay
recumpence
1 GW
I haven't relocated my controllers for the shorter wire runs yet. I was so close as it was that I just wired it and ran it. I could not stand waiting!
The wires do warm up a bit. But, not too bad, maybe 10 degrees over ambeint temp if I had to guess. However, I do know I am losing voltage through them.
I am definately relocating the controllers. But, for now, I wanted to varify everything would work together first, before I go too crazy on the wiring. You would think I would have automatically defaulted to my car audio background and went with big wire and huge buss bars. But, that will come. Oh, yes, that will come!
Gary,
I totally agree. It is stupid quick and powerful. There is absolutely no reason for this much power.
That just makes me want it even more. :wink:
Anyway, I am totally thrilled with it. Remember, the whole point of this build was to kick off my KMX E-trike build business.
No-one "Needs" a 625hp Vette. But, it generates sales for GM.
Anyway, I am very impressed by the simplicity of your folding bike with single stage. That thing, running through a geared hub, has got to be freakish to ride.
Matt
The wires do warm up a bit. But, not too bad, maybe 10 degrees over ambeint temp if I had to guess. However, I do know I am losing voltage through them.
I am definately relocating the controllers. But, for now, I wanted to varify everything would work together first, before I go too crazy on the wiring. You would think I would have automatically defaulted to my car audio background and went with big wire and huge buss bars. But, that will come. Oh, yes, that will come!
Gary,
I totally agree. It is stupid quick and powerful. There is absolutely no reason for this much power.
That just makes me want it even more. :wink:
Anyway, I am totally thrilled with it. Remember, the whole point of this build was to kick off my KMX E-trike build business.
No-one "Needs" a 625hp Vette. But, it generates sales for GM.
Anyway, I am very impressed by the simplicity of your folding bike with single stage. That thing, running through a geared hub, has got to be freakish to ride.
Matt
recumpence
1 GW
Well, I have a few more miles on the trike.
I leaned the seat back one notch farther. I had to move some wiring to do it. But, the accelleration is even harder now!
Also, I took the pack up to 64% charge (up from 50% charge). I am using my tiny little 100 watt Hyperion charger from my recumbent. So, it takes a friggin eternity to charge up the big 1.4kwh trike pack (I am getting a better charger). But, for now, I am dealing with the slow charging. Anyway, at 64% charge, my speed is up to 43mph now. Add to that the greater weight on the rear wheel from leaning my seat back and it is actually starting to scare me. The trike isn't scaring me as much as how rapidly it accellerates in my small neighborhood/town streets. There are no streets suitable for this thing near me.
It is hooking far better now, but still roasting the tire. After a tire burning accelleration session (maybe 2 seconds of wheelspin bringing me up to 25mph or so), I let off and am immediately showered by a bunch of small gravel and other assorted crap that the, now sticky, rear tire picks up and spits on top of my head. Looks like it is fender time!
Anyway, this thing is a beast. If I set my throttle limitter (end point limitter) for 50%, it is docile to ride, but these two motors and controllers run like a big block with a high lift cam. They kind of run a touch irratic. Nothing bad, but not buttery smooth. So, even with low throttle settings, the insane power lets itself be known.
This trike (if it doesn't sell) will probably be treated by me like a blown streetrod. It will be a weekend warrior. It is just to freakin wild and insane to ride on the street daily.
I LOVE IT!!!!!
Matt
I leaned the seat back one notch farther. I had to move some wiring to do it. But, the accelleration is even harder now!
Also, I took the pack up to 64% charge (up from 50% charge). I am using my tiny little 100 watt Hyperion charger from my recumbent. So, it takes a friggin eternity to charge up the big 1.4kwh trike pack (I am getting a better charger). But, for now, I am dealing with the slow charging. Anyway, at 64% charge, my speed is up to 43mph now. Add to that the greater weight on the rear wheel from leaning my seat back and it is actually starting to scare me. The trike isn't scaring me as much as how rapidly it accellerates in my small neighborhood/town streets. There are no streets suitable for this thing near me.
It is hooking far better now, but still roasting the tire. After a tire burning accelleration session (maybe 2 seconds of wheelspin bringing me up to 25mph or so), I let off and am immediately showered by a bunch of small gravel and other assorted crap that the, now sticky, rear tire picks up and spits on top of my head. Looks like it is fender time!
Anyway, this thing is a beast. If I set my throttle limitter (end point limitter) for 50%, it is docile to ride, but these two motors and controllers run like a big block with a high lift cam. They kind of run a touch irratic. Nothing bad, but not buttery smooth. So, even with low throttle settings, the insane power lets itself be known.
This trike (if it doesn't sell) will probably be treated by me like a blown streetrod. It will be a weekend warrior. It is just to freakin wild and insane to ride on the street daily.
I LOVE IT!!!!!
Matt
recumpence
1 GW
Wow, I am noticing quite a difference in accelleration (traction) with temperature.
The other day, it was close to 90 degrees outside. The tire was really grabbing. I mean, it was spinning and smoking, but still accellerating really hard. Today it was in the mid 70s and it was nothing but wheelspin most of the time. It still hooked OK. But, not nearly as well as it did when the weather was hot.
I think I need a wider tire and lower pressure..........
Matt
The other day, it was close to 90 degrees outside. The tire was really grabbing. I mean, it was spinning and smoking, but still accellerating really hard. Today it was in the mid 70s and it was nothing but wheelspin most of the time. It still hooked OK. But, not nearly as well as it did when the weather was hot.
I think I need a wider tire and lower pressure..........
Matt
JEB
100 W
Hi Matt;
I know you think some of my ideas are from "left field"- but what I am running on one of my trikes is a 16" with 3/16" tread depth hiway trailer tire that has 3 1/2 inches of tread width on pavement, It's the only tire that holds up well so far with the Perm 132 motor that I am using, with a solid steel rim no spoke problems, Northern Tool .com has larger sizes.
Jim
I know you think some of my ideas are from "left field"- but what I am running on one of my trikes is a 16" with 3/16" tread depth hiway trailer tire that has 3 1/2 inches of tread width on pavement, It's the only tire that holds up well so far with the Perm 132 motor that I am using, with a solid steel rim no spoke problems, Northern Tool .com has larger sizes.
Jim
JEB
100 W
I built the tadpole type trike from scratch, no handling problems with the exception of sitting too high on a office chair, (the cg is too high), I have tipped it over making a tight u turn. It also has electrical brakeing dumping energy into resistors, can suck up over one horsepower going 20mph down a slight hill.
recumpence
1 GW
Storm said:
It is VERY controllable in a slide. It drifts fantastic! The secret is a good rear tire.
I did some serious drifting for a friend this afternoon. It was funny, even the front tires are heating up! Also, I got the front rotors to blue from the hard riding.
This thing is a blast! I am finally getting used to the explosive torque. Now I can take it out without feeling so intimidated.
I love it!
Matt
glv
10 W
recumpence said:
You need to get a video camera in that friend's hand. We need to see some tire smoke!
recumpence
1 GW
We need higher temps for good traction and tire smoke. Right now, the tire will spin (a bit too much) and it will heat up, but it hooks and smokes much better when the pavement is hot. :wink:
Matt
Matt
