oatnet
1 MW
Nice workshop - I envy the space!
-JD
-JD
Motorcycle class Hub Motor
- Thread starter markcycle
- Start date
johnhead@frontiernet.net
100 mW
- Joined
- Feb 1, 2009
- Messages
- 41
Mark, Will you be offering the caliper and rotor in the future as a complete "Braking" package "option"?
I won't need it as I did get in new rotors for my two motors. I may be doing a slight redesign on the anchoring of my two however. Innovation can be fun and hopefully rewarding?
Regards
John
I won't need it as I did get in new rotors for my two motors. I may be doing a slight redesign on the anchoring of my two however. Innovation can be fun and hopefully rewarding?
Regards
John
markcycle
10 kW
johnhead@frontiernet.net said:
Yes
I needed to make it easy for drum brake bikes to be converted. Keeping the braking system self contained to the wheel does that.
Mark
markcycle
10 kW
tritonwow said:
Doing two Swingarm conversions at once and yes it is yours with a exact duplicate (as far as the brake is concerned) being someones else's
Mark
Wow, that's awsome !!! great pictures indeed ! you've come a long way ! Keep up the great work mark ! 8)
markcycle
10 kW
TomA said:
About 50 pounds
Mark
paultrafalgar
10 kW
todayican2 said:
I got 404 file not found on that link. Is this the one?
http://www.treehugger.com/files/2009/10/three-wheelers-approved-funding-doe.php
todayican2
100 W
- Joined
- Apr 22, 2009
- Messages
- 139
Yes. That is the article I was referring to, but...
The scuttlebut seems to be that this funding bill is a bit of an "end run" to let aptera in on some funding and any other trike company that wants to do the whole crash testing thing (ridiculusly expensive)
The scuttlebut seems to be that this funding bill is a bit of an "end run" to let aptera in on some funding and any other trike company that wants to do the whole crash testing thing (ridiculusly expensive)
markcycle
10 kW
I think this configuration is right on for the relatively rare Urba Electric plans-built car fro RQ Riley.
The design called for a snowmobile-style CVT between a Baldor 8hp motor and the driveshafts, but it became unavailable, and the cars, which were to be built with Honda 600 or early Civic drive axles and suspensions, wound up with a poorly designed substitute two-motor chain drive arrangement- one to each drive shaft- if any ever really got that working. Its a design that needs revision, even according to R.Q. Riley, who never throws anything away. This twin hub motor set up would solve about all of those problems, and could put one of these Urba cars back on the road. I saw one on ebay over the summer- no motors but otherwise all there and pretty nicely finished. Its a design that's been waiting around for 35 years for LiFePO4 and twin motors, Mark. Yours, in this arrangement, lightened up by switching lead for lithium power, seems to me to be exactly the right thing for the Urba, and man, how cool would it be to wake up a super-classic EV like this now?
If we can find the right car, I will buy it and take it on. I'm in White Plains so I could bring it to you for study and development.
OK, so where is there an Urba Electric?
TomA
The design called for a snowmobile-style CVT between a Baldor 8hp motor and the driveshafts, but it became unavailable, and the cars, which were to be built with Honda 600 or early Civic drive axles and suspensions, wound up with a poorly designed substitute two-motor chain drive arrangement- one to each drive shaft- if any ever really got that working. Its a design that needs revision, even according to R.Q. Riley, who never throws anything away. This twin hub motor set up would solve about all of those problems, and could put one of these Urba cars back on the road. I saw one on ebay over the summer- no motors but otherwise all there and pretty nicely finished. Its a design that's been waiting around for 35 years for LiFePO4 and twin motors, Mark. Yours, in this arrangement, lightened up by switching lead for lithium power, seems to me to be exactly the right thing for the Urba, and man, how cool would it be to wake up a super-classic EV like this now?
If we can find the right car, I will buy it and take it on. I'm in White Plains so I could bring it to you for study and development.
OK, so where is there an Urba Electric?
TomA
OK, I found it!
The transmission is known as a DAF Variomatic, and it saw light vehicle production in the 1950s through the early 1970s. It used snowmobile-style CVT pulleys to drive the wheels independently. DAF was sold to Volvo, but the Variomatic has bounced around even until 1993, when Williams built an F1 car around it. Its complex, but interesting, and fairly light when you eliminate the differential case, which twin electric motors wouldn't need. There are several working references of the setup that you can see on YouTube, its a pretty neat system. Seach "DAF Variomatic" and see what you find. I also found a cool illustration of it on Page 101 of Walter Korff's fantastic 1980 book: "Designing Tomorrow's Cars."
This is almost certainly the original drive system from the Urba Electric, but I also thought it might be a useful reference for your twin motor small car powerplant project. This thing might be usable as is, substituting the twin hub motors for the diff and using the dual CVTs, but the really neat thing to me is that small reduction gear at the end of each tailshaft. That might allow you to bolt the motors directly to the axle assemblies. DAF made about 1/2 million of these transmissions, so while they may not be common here, they can't ultimately be that hard to find, especially if you don't need the CVT parts and can bolt your motors onto the axles.
Just a thought...
TomA
The transmission is known as a DAF Variomatic, and it saw light vehicle production in the 1950s through the early 1970s. It used snowmobile-style CVT pulleys to drive the wheels independently. DAF was sold to Volvo, but the Variomatic has bounced around even until 1993, when Williams built an F1 car around it. Its complex, but interesting, and fairly light when you eliminate the differential case, which twin electric motors wouldn't need. There are several working references of the setup that you can see on YouTube, its a pretty neat system. Seach "DAF Variomatic" and see what you find. I also found a cool illustration of it on Page 101 of Walter Korff's fantastic 1980 book: "Designing Tomorrow's Cars."
This is almost certainly the original drive system from the Urba Electric, but I also thought it might be a useful reference for your twin motor small car powerplant project. This thing might be usable as is, substituting the twin hub motors for the diff and using the dual CVTs, but the really neat thing to me is that small reduction gear at the end of each tailshaft. That might allow you to bolt the motors directly to the axle assemblies. DAF made about 1/2 million of these transmissions, so while they may not be common here, they can't ultimately be that hard to find, especially if you don't need the CVT parts and can bolt your motors onto the axles.
Just a thought...
TomA
thomas
10 W
They still make this kind of cvt
http://en.wikipedia.org/wiki/Variomatic
I think Bosh owns the company making them.
http://en.wikipedia.org/wiki/Variomatic
I think Bosh owns the company making them.
Well, yes and no...
The Variomatic CVT is the two-pulley gearing setup, not the whole split/dual rear axle drive system from the DAF. The CVT design itself is indeed common, from snowmobiles to the Subaru Justy, etc. That split/dual rear axle final drive setup is unique to the DAF, though, and while it uses two of the CVTs, that isn't what would make it most interesting to Mark. He might be able to ditch the whole secondary drive gear system, CVTs and all, and simply bolt one of his motors to each axle stub where one of the CVT pulleys is now. Clean and simple.
Transplanting it into a non-DAF glider probaby isn't simpler than picking up the half-shafts of a FWD car with a custom adapter on each hub motor, but it would be a simple drop-in rear drive set for something small, and the reason I brought it up was that it might be a straight bolt-on solution for the Urba Electric kit car, which uses this very rear axle and actually needs a two-motor electric drive solution. I'll drop the subject now, its far enough off-topic already...
The Variomatic CVT is the two-pulley gearing setup, not the whole split/dual rear axle drive system from the DAF. The CVT design itself is indeed common, from snowmobiles to the Subaru Justy, etc. That split/dual rear axle final drive setup is unique to the DAF, though, and while it uses two of the CVTs, that isn't what would make it most interesting to Mark. He might be able to ditch the whole secondary drive gear system, CVTs and all, and simply bolt one of his motors to each axle stub where one of the CVT pulleys is now. Clean and simple.
Transplanting it into a non-DAF glider probaby isn't simpler than picking up the half-shafts of a FWD car with a custom adapter on each hub motor, but it would be a simple drop-in rear drive set for something small, and the reason I brought it up was that it might be a straight bolt-on solution for the Urba Electric kit car, which uses this very rear axle and actually needs a two-motor electric drive solution. I'll drop the subject now, its far enough off-topic already...
maydaverave
10 kW
- Joined
- Jan 13, 2009
- Messages
- 542
How many bikes have this hub motor now and can we see some pics?
I spent all morning reading this entire post and it has really spiked my interest for converting my Ninja 250. I have considered converting my bike in the past but this hub motor would make everything much easier to do. A little background about myself. I am an electrical engineer that builds high power (240kW to 10MW) power supplies for use in high energy physics labs. I am also an avid model car racer where I race brushless powered offroad and onroad cars. This is where my interest in this thread really stems from since almost all of this technology is paralleled in the RC industry. Hub motors are almost the same thing as spinning can motors that the model plane guys use. The batteries are also similar since A123 and Lipo batteries are very popular with all of the RC market. Out of curiosity I decided to calculate the price of a motorcycle battery built of of model car Lipo packs. I chose to use 4s, 5000mAh packs as my basis since they are popular with the cars I race. The nearest multiple to 34 Thundersky batteries would be 8 packs of 4S (14.8v) in series and 8 in parallel ( to get 40Ah). There is a source for these out of China that makes these packs relatively cheap compared to the US market. The numbers look like this.
34 Thundersky 40 Ah batteries
-$2,720
-51kg
-85.33 Wh/kg
-1.6 Wh/$ (from electric motorsport)
64 Zippy Flightmax 4S 5000mAh packs
-32.19kg
-$4,096
-147.13 Wh/kg
-1.16 Wh/$ (from hobby city)
If one wanted to they could redo this to get closer in voltage. I find it intesting that the pricing is actually similar although Lipo doesn't have the same level of safety as LiFePO4. If one was really trying to build a race bike, the little batteries from models might be the best answer.
Anyway, I look forward to future advances in Markcycle's hub motor and as time and money will allow I will most likely convert my little ninja. Good job on the motor!
34 Thundersky 40 Ah batteries
-$2,720
-51kg
-85.33 Wh/kg
-1.6 Wh/$ (from electric motorsport)
64 Zippy Flightmax 4S 5000mAh packs
-32.19kg
-$4,096
-147.13 Wh/kg
-1.16 Wh/$ (from hobby city)
If one wanted to they could redo this to get closer in voltage. I find it intesting that the pricing is actually similar although Lipo doesn't have the same level of safety as LiFePO4. If one was really trying to build a race bike, the little batteries from models might be the best answer.
Anyway, I look forward to future advances in Markcycle's hub motor and as time and money will allow I will most likely convert my little ninja. Good job on the motor!
Malcolm
10 kW
Interesting comparison. The energy density makes a convincing argument for Lipo, but one thing that caught me eye was your price for Thundersky cells – you can get the 60Ah cells for 2.72 Wh/$ at evcomponents. Edit: to be fair, the Thundersky cells don't really compare on performance either as they're only good for about 5C max. A better comparison might be with the new Headway cells that evcomponents say they'll be offering soon.
Malcolm said:
Ya I forgot to add that number. The cheapest Lipo packs that did the pricing with are rated at 20C continuous and 30C max. I would only run them at 10C to be safe so 10C * 5A-h * 8 in parallel would be 400A. If you used them at full rating (probably not a good idea) you could theoretically get 30C * 5A-h*8 = 1200A for a short duration. There are better RC packs, but they are a lot more money. I have seen 5A-h cells rated at 40C continuous and 60C peak. Those cells would easily double the price of the total pack
If someone had way too much money on their hands and wanted the ultimate commuter bike, they could be used, lol! Or if someone is really interested in racing, the energy density of Lipo cells would be very hard to beat. Space was always my main concern until I found this forum. The hub motor really opens up possibilities for larger more powerful batteries (high J/kg but lower J/Liter).
oatnet
1 MW
Running at 10c continious, even to 100% dod, would give you a 6 minute run time. Would your build be for exhibition or commuting?
-JD
-JD
oatnet said:
The price included having 8 batteries in parallel so 40Ah total. It would be a 32s 8p battery pack. I was actually looking for a good way to get to work with this project. I agree, trying to keep track of this many cells would require one heck of a battery monitor.
markcycle
10 kW
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