Head spinning...could use some guidance.

[Red_Liner740]

Okay, first of all, i wanna thank all of you who have contributed to this community. I have been taking in so much data in the last week or so that i feel like my heads gonna explode.

I need guidance from people who have done or know about the project i intend to do.

Basically, i use my car 90% of the time to commute to work and back. I just recently bought a house thats closer to work and the commute is in a rural area mostly. no highways, 60km/h speed limits, very little traffic. So the plan was to park the car, remove the insurance for the warm summer months and use a home built e-trike to commute. The commute is 23km long but is unfortunately in a hilly area...think rolling hills with 100ft elevation changes. the actual elevation from start to finish doesnt change much but there are some pretty decent hills.

The powertrain is giving me fits. Choosing the right powertrain actually is whats causing a dilemma.

so to summarize: Homebuilt recumbent tadpole trike ala Atomic Zombie Warrior. Me, 215lbs, range, 30ish km (18.6 miles) in hilly terrain with cruising speed of 50km/h+ and not too much slowdown up the hills.

I basically have three options.

1. RC motor powered, using HobbyKings Turnigy 80-100-A 180Kv Brushless Outrunner. I work in a shop with access to aluminum plate, hardware, mill and lathe (we're not really supposed to touch the last two...stupid health and safety). So creating a custom step down transmission is not a very big concern. The concern here is the controller. i have no clue which controller to run, or any advanced electricals associated with the RC setup. Electronics are not really my forte, probably why i didnt go for Avionics but chose Aircraft Maintenance. Something tells me this would be the most "performance" path but also the one that would be the hardest to fine tune and keep running.

2. Scooter motor. http://tncscooters.com/product.php?sku=106165 36V 1000w, i'm pretty sure this will have no issues propelling me. since its being installed on a trike weight and size of motor and components isnt that critical. If i understand correctly, controllers for these motors arent as expensive or complicated as for the RC setup?

3. Plain jane hub motor driving the rear 26" wheel. But with so many options in price/voltage/design/amperage its very hard to know what the actual needs are. I really dont want to spend 500+ on a 5303 Crystalite but at the same time, how bad of a Russian roulette am i playing with those sub $300 ebay kits. And will these hub motors be able to keep up on the hilly terrain? with the RC and scooter motors i would run them through the rear cassette offering me different gearing.

anywho, the battery pack is still undecided between 36v or a 48v,i'm shooting for 20ah, and it will either be cobbled together from old laptop batteries or Ping or HobbyKing battery packs.

i appreciate all your input and before someone yells out the "search button is in the top right corner!" The database is HUGE with a lot of information that is dated and the links/pictures are dead. Its a LOT of wading through tons of posts...and i've been doing it for the last week...

 

[Andje]

well, welcome

1. the controllers are the easiest part of rc, the hard part is the step down transmission. You would need an expensive controller (300~ i think) and one of matt schumaker's throttle kits for a plug and play solution with an rc motor if you built yourself the tranny. Matt could sell you both of these, as well as the transmission if you wanted. With the purchase you'd get unparalleled customer service as well. Such a motor and controller would certainly get you to 50-60 on 36 or 48 v probably.

2. Don't. You could. But don't unless you have no money; you will merely find yourself burning these motors and replacing if you really want 50+ for 18 miles up hills and such.

3. Lots of options, for 50+ and that range with good hill climbing in a rear wheel trike, you could go with Crystalyte 5300 or HS35 series. Nine Continent 2700 series, and there is a new i think BMC geared hub on sale now in the for sale section that might be good if you wanted the freewheel. But basically, that speed is doable by a number of hubs, they vary in price and design. Crystalyte is heavier but more powerful and rugged. Nine continent hubs are much lighter but close in power and also quite rugged; they are so much cheaper you can get two maybe three for the same price as a crystalyte. The geared hubs are notoriously under designed; as you overvolt them or even just demand a lot of torque off the line they tend to eat their own internal gears. Still, they have a freewheel so you experience no drag when pedaling without the motor, so that is pretty awesome. I would never consider pedaling my 9c or HS for any conceivable distance.
Don't get confused with all the voltage/amperages. All the hub motors can be powered by any voltage/amperage you want to put to them, that part all depends on the controller and the batteries. Since you can get hub motors separately from controllers (and you should to get the best ones) you choice is unlimited; for 50-60 km/h you will need to be looking at putting 2-3000 watts into your motor when you are going up hill (At least). So whatever voltage you end up running, divide 3k by that and you will see how many amps you would need, then look for a controller that will do that voltage/amperage. Lyen has excellent controllers, other vendors have stock things with waranties, but for that speed with those motors you'd be looking around 100-200 for a controller that will be rock solid. there are simulators that are much more accurate of course to model this, this is just an example.

Battery wise, laptop batts can't put out the amperage you will require. You should commit now to lipo, get a proper charging solution so that it is not dangerous and work all that into your budget up front. Hobbyking lipo is the standard for us all at this point. Lipofe4 i think is still in the hands of A123.

 

[amberwolf]

The single thing I would suggest is that you use a solution that will let you run the motor thru the gear system to the rear wheel, because being able to shift to low gears on the uphills will lessen the current load on the controller and motor and battery. Either that or a two-speed gearbox system just for the motor like the one Thud has made.

A hubmotor could be used this way (like the STokeMonkey does, among others), as can teh RC motor or scooter motor. I don't like the scooter motors like the one you linked to, as they don't have great reputations (and I didn't much like the one I tried, though it was very early in my ebike quest).

RC motors can be great, as they are small and so are their controllers...but they can be very noisy depending on how the reduction and whatnot is setup, and under some kinds of loads at startup the cheap controllers can be damaged easily. Better controllers handle that a lot better, but may still require modifications (like adding capacitors), depending on the setup. Matt's stuff (Recumpence here on ES) would be the best way to do this, I think; he has some good experience at high-powered RC stuff with that "killer trike" of his. :lol:

Other types of motors can also be used, if you are trying to save money or DIY things. Powerchair motors work pretty well; if I had not had frame-twist problems causing derailing, I'd still be using mine on CrazyBike2. They often have right-angle reduction gearboxes on them already, making setting them up to fit in bicycle-sized spaces fairly easy, and are also often made to clamp right onto tubing (though fairly small diameter, this can be fixed with a bit of grinding).

For the kind of speeds you want up the hills, you'd probably need an active cooling solution for a powerchair motor, ducting air thru it with a good squirrel-cage type fan or something, since they're usually brushed motors and typically meant to directly drive a 10"-15" wheel at 4-8MPH (but to do that all day every day without complaint or warming up much).

There's other motor solutions around, too, but that's enough to ponder for now.

 

[Andje]

i am the last person to hate on power through the gears, but if you just run the hub motors at 66-88v in the first place, you can laugh at hills all day and still stay at a low amperage. Mine will accelerate up a steep grade to 75 km/h+ with only about 3000w.

 

[dogman dan]

If you do go hub, the plain jane 9 continent kit would do the trick. 2807 motor, sometimes called 9x7. Run the kit on 48v. At 48v with the stock controllers 7% hills will be no problem, and 10% hills go no problem with some pedaling.

One of the big reasons for the 9c recomendation is that the more recent rear hub motors avaliable fit rear wheels a lot better. Disk ready, and no more dang radical wheel dish. Look for the flat style covers. The Ebay stuff, who knows what it will take to make it all work.

Ebikes-ca or Ebikekit are the north american suppliers.

The larger gearmotors would be good too, such as BMC , Mac ,and Puma. Cellman has a good deal on the Mac.

 

[Red_Liner740]

Thanks for the suggestions guys! appreciate it.

looks like i'm leaning towards 9 continents hub motors.

 

[Andje]

you won't regret it; they work reliably up to about 5kw if you drill cooling holes, maxing out around 85-90 km/h.. many overvolters have used them for years, basically the civic of hubs.

 

[dogman dan]

Well sorta reliably. I've melted down two of em now, but I was playing with 4kw. A lot depends on how long you are at 4kw continuously.

I will say though, they can take a lot more than the rated 800 watts. 72v 20 amps gives you about 1300 watts measured in the real world, and it takes that no problem for quite a while. Same thing would apply to more than 20 amps of 48v.

 

[Red_Liner740]

well its been settled. As much as i drool over the RC setups and the higher apparent efficency of chain driven systems, truth is, all of them are loud...much louder than the hub kit, and i kinda wanna have a small profile. i'll be living in a small town and passing by the cop station on my commute so i'd rather no whizz by with a whine. Bored cops = curious cops.

regarding the laptop battery derived packs, i understand they only have a 1C reliable, continuous discharge capacity and therefore you are limited on the amperage you can use, BUT if they can be built for cheaper, having a higher voltage with huge A/h rating would be feasible. Anyone drooling of 48V 40ah pack? cuz i am! calculating number of cells needed using 3.7V 2.2a/h cells = approximately 236 give or take. say average of 4 cells per laptop battery are still good = 58 laptop batteries. i'm a 1/3 there and it cost me $30. Just gotta source out more batteries.

 

[Andje]

hah. you say that. but you haven't wired them together yet. Beyond anything else, batteries and the charging/discharging of them is the hardest nut to crack in this hobby. most people are now endorsing hobbyking lipo for a reason; it is as cheap as it gets while still being reasonable quality. How are you going to monitor your 200+ cells? will you run a balancer somehow, because just bulk charging such a thing the cells will go out of balance and you will soon be discharging/charging them past extremes and damaging them.
even wiring hobbyking batts in series and paralel is difficult the first time, especially if you have to build your balancing wires.

 

[Red_Liner740]

^^ I hear what you're saying, and i fully understand, and there has always been a trade off between difficulty and cost.

You could pack all your stuff and rent your own truck and move yourself and save money OOOR you could just plop down the cash and have someone else do it all for u as u just point fingers to things u want packed. I was never the one to take that easy route...

anyways, i just scored a MAJOR prize i'm still giggling about it.

*drumroll...

100 laptop batteries for......0.75 cents a pound. 100 bats ended up costing me 55.84 with tax. And i have the option of getting more! I called up a local recycling depot and gave them a semi truthful story about a university project thats trying to come up with new tech for reviving dead or dying cells...

i hear you about the balancing, and i guess thats a hurdle i will have to cross....as of now i'm thinking of having it separated into sections, with individual 48v 2.2a/h (or whatever most of the cells a/h rating is) packs...so there would be 20 of those packs. so once a month or so, maybe even longer, the whole pack would get broken down and maintenance would be run on them, each individual pack would be balanced and charged, while during regular riding days it would just be topped off without balancing....

 

[neptronix]

you won't regret it; they work reliably up to about 5kw if you drill cooling holes, maxing out around 85-90 km/h.. many overvolters have used them for years, basically the civic of hubs.

And Crystalyte 5 series would then be the Acura Integra, huh?