How do I make a trike electric?
 

Just a thought, even though my wife is doing well on her trike, we were dealt another health issue for her.

http://i581.photobucket.com/albums/s...keride0005.jpg

She has had issues with her right hip for years, but it has been getting a lot worse lately. Doctors aren't sure if she has a fracture in the socket, or a tumor. So she is on crutches for 4 weeks and will have new xrays and a MRI to see... Fun huh? So went digging in the medical supply store (my basement) for crutches.

So, how hard would an electric setup be to add to a trike? What do I need, what can I fab? I would like to see if I can setup something with a chain and sprocket to drive the axle, but not be a hindrance when pedaling. When we got the trike and I put it together, we added the optional 3 speed hub and coaster brake. I can get another adapter to use a single speed freewheel on the shaft (since I didn't use the included freewheel), so that leaves mating a motor and power controller. Ideas, thoughts, opinions?

(Yes, we ride with helmets, I had her turn around and come back to the truck for the pics...)

I will add, that until her strength and endurance get better, we ride on a flat stretch of road where lots of cyclists go and very limited vehicular traffic. She has done well (since she almost died of double pneumonia in April), keeps a good pace and speed, and has added distance weekly... We have been pleasantly surprised by the encouragement of most riders with very very few snobs (roadies, you know who you are!).

what is your budget? what kind of speed?

Front hub motor FTW. If that's not cost effective (~$300 for a kit on eBay), then a freewheeling motor in line w/ the axle chain and a couple batteries in the basket on the back. Don't forget you need at least 45* tooth engagement for a good bite on the chain.

500w or so DC motor attached to rear axle with a simple PWM controller using a relay to switch to regen mode. Normally, the positive side of the motor would connect to the positive supply and the negative side to the PWM, but engage regen and the positive side reconnects to the PWM and the negative side to ground. http://techno-fandom.org/~hobbit/cars/boost-hack/

A high side MOSFET can provide for synchronous rectification and regen without a relay, but there isn't much to gain from synchronous rectification and a regen relay would likely be simpler and cheaper.

I'm thinking I can add a second sprocket to the rear axle, which would be a freewheel. So I don't think there would be much regenerative charging.

Budget, less than $100. Batteries aren't a real issue, I might be able to get some freebie recycle turn-ins.

Speed, 10 MPH or less. Would like a range of 15 miles, but less isn't bad. I just want the thing to get up hills around town here, and with it freewheeling when pedaling, be almost transparent (minus the battery weight...).

I'll get and post a pic or two of the rear axle and drive stuff later.

The Easy Way
 

[QUOTE=Christ;127324]Front hub motor

I second that suggestion.

Use a 500w or so motor geared for high torque, so it tops out at 15MPH or so. You'll get plenty of regen going down the hills, especially with the motor geared for torque. Like you said, it should neither accelerate nor regen by default, but just freewheel. That's easy since all it needs to do is leave the PWM off. You'll have a potentiometer to adjust PWM power (amount of acceleration or regen) and a switch to select between acceleration and regen. (As unusual as that sounds, someone on a hybrid bike site actually uses that "sign magnitude" setup daily. A more usual center position for freewheel is actually more complex to design for a brush type motor, but merely a software setting for brushless DC.)

Just my opinion- those old design diamond frame trikes are unsafe disasters at all speeds. I had an old Huffy in the mid 1970s and at 2 mph it threw me off hitting a driveway and I fell a long way then rolled into a busy street.

Undaunted; the next day it wouldn't stay on the ground around a corner- tipped, went over- bloodied up badly. That was at 5 mph. Granted- about 10 to 20 pounds of battery would have helped, it would not help my grip or balance problem. Bye bye diamond frame trike.

My solution was to be low, but that is not for everybody. I have a hub motorised trike and an EV microcar 3-wheeler- both are a little bit faster than 10 mph (legally in CA.: 20/50 mph) I would never EVER try that on a diamond frame trike!

Converting it to a recumbent should greatly improve stability.

In all honesty, should she be riding a bicycle? With that health rep sheet I would be afraid to get out of the house.

Adding rake to the front forks helps with stability on delta trikes. If you check out the street legal "Tri-Sport" trikes, they have a decent rake and a low stance. I've never seen one 2-wheel before, unless forced to do so. Under "normal" driving conditions, they're fairly stable.

Try telling her that!! I'll stand back for the blood bath. Seriously, the last thing she wants is to give up, or slow down anymore than she already has.

If she's determined to keep going, let her keep going, I say... there is a limit, though, where she's not going to do any good for herself... you, as her mate, have to watch for that.

I am well over the trikes weight limit, it flexes a lot more than I would like it to when I sit on it. My son and daughter (21 and 19) enjoy riding it, though my son prefers to ride it with the non-driven wheel in the air (I'll see if I can a pic when he is home this weekend). The upside to the two wheel antics showed my wife that the trike isn't as stable as she expected.

She has ridden a recumbent trike, but that aggravated her hip.

Please understand that I'm just looking for ways to keep her active despite her ailments and frailties. We're only 4 days into using crutches and I think she is ready to wrap one around my neck... Mainly because I refuse to pull her wheelchair back out (she needed that two years ago...).

To that end, here is the rear drive on the trike, I have room to add another "hub" on the axle for a regular freewheel...
http://i581.photobucket.com/albums/s...e/100_4213.jpg

Oh yeah, I'm watching. Been looking after her for 26 years, but the medical issues have been with us for about 15... Now I have to be careful that I don't sacrifice my own issues. I just had a second gel injection (of three) in my left knee. I'm a candidate for replacement. Yippee, huh? Falling apart too young I tell ya...

The design looks almost perfect for a HSD retrofit (replace transmission with PSD/MG1 and add MG2) but it won't offer much in your application considering it will run in EV mode most of the time.

An IMA setup, however, is very easy. Add another gear on the drive shaft and mount the motor to the frame. Use sheet metal to make a bracket for the motor.

zjrog, how much do you way? If you are exceeding the weight limit of the bike you a probably a rather large man. I would try to lose weight, that will help tons of health factors.

I can sure understand that! Being stubborn helped me!

That trike is probably independent (one wheel) rear drive. Some had differentials, but not many. If a motor powers one wheel that would probably be an uneven motion under acceleration.

Front wheel drive would be safer I think- hub drive or scrub drive (on the tire) if they still sell that option! Best of luck!

I just assumed it was a live axle.

Madison, yes, I am a large guy. But the trike isn't for me, its limit is 250#. And I am losing a bit (why I'm on my own bike). My knee issues are divided between bad genetics, and not being so good to myself in my younger years. Downside to being a bigger guy, people expect me to help them move heavy stuff (or break loose big tight fittings...). Also, being larger, means not fitting in some cars. For instance, I can only fit in a Toyota MR2 with the door open and the roof off.

Rear axle has a standard three pin drive hub on the right side, the left side is just riding on bearings.

Mike, man... I'm not understanding your acronyms. But I won't have any issue fabricating stuff... I'm a Jeep guy!!!

I don't get candidacy for knee replacement until I'm 40. I'm 24, and have no bursa behind my knee caps. :) I feel your pain. Literally. Both knees.

Yeah. I'm only 46. I got less than 1mm of cartilage left in the joint. I've had issues for years, but, you know, I'm a guy, don't need no stinkin' doctors. But this past year has just been too much. And then I see how bad it is... Ugh... When one of the best sports orthopedics in the state says thats ugly, well... We tried all non-narcotic solutions, cortisone only lasts a shrot while, trying the gel now.

IMA = Integrated Motor Assist, which means the addition of a motor driving the wheels. Just like its implementation in an Insight.
HSD = Hybrid Synergy Drive. Look it up to understand how it works, but it basically integrates an eCVT into the hybrid system, just like in the Prius. MG1/2 are the motor/generators in HSD and PSD is the Power Split Device.

Id go for a front hub motor.
Basic bolt on kits aren't too expensive, and come with everything, from the wheel to the battery pack, charger, throttle..