Starter motor E-Bike

[MetroMPG]

You'll always go further by "driving without brakes" in an EV/hybrid than you will by using regen! The Autospeed guy used a permanent magnet motor, which is why getting regen was pretty straightforward.

The aircraft starter motor/generators used in EV conversions have proper bearings in them, FYI.

[WannabeEVer]

Well the starter motor i got was free so I might as well give it a try. And yeah, in the Autospeed article there's two separate switches, they're just in the same box. This is just a school project I'm working on and if it works out well I might, in the future, try tinkering with an EV. I'm going to be working on it again tomorrow so I'll try to get some pictures up. So far its just the lever to move the motor on and off the wheel that I'm working on.

[WannabeEVer]

Alright, i've finally got pictures to put up of my bike and the lever to lift the motor. It's not anything special and i've got to cut some pieces but it works. I'm hoping to get the batteries and control swtiches over the christmas break and hopefully get it running soon after. Sorry the close up one is a little blurry.

[MetroMPG]

Cool! When you get it going, you've got to post up a YouTube vid too.

[Christ]

Since the starter motor will overheat quickly, P&G will be mandatory in this case.

A pulse at full potential (what the starter motor was designed to do) will accelerate very quickly - and take much less than 10 seconds to reach it's maximum speed.

Assuming a 10 speed bike, you could "pulse" in high gear, reaching a very high speed quite quickly, then "bleed off" slowly, using your own light pedaling in whatever gear will help you maintain the speed for the longest time before pulsing again.

I'm afraid that using a normal car's starter will require something like this, as they heat up VERY quickly, and the resin that holds the coils together will melt, not to mention the magnets on the armature will crack - quickly.

My Uncle Jimmy used to rebuild starters and alternators, of all shapes and sizes, and I used to help him on weekends.

[bennelson]

The motor could also have a large heat-sink, blower, or both to help cool it.

I would suggest just experimenting with the motor to see how much of an issue heating actually is, then you can decide what the best way to deal with it is.

Nice simple design though, should be fun to play with!!

[WannabeEVer]

Well if i would be riding it today it would have no problem cooling itself. It's been around -30 C for the past few days. Frickin cold! But yeah, P & G would be what i'd be doing, there wouldn't be much of a point going continuously. Now its time to go battery shopping, anyone know where to find cheap atv or motorcycle batteries?

[Christ]

Country areas around you? Do you mind reviving dead batteries?

Salvage batteries can normally be had from any tractor supply company (farm equipment), since they usually pay people up to $3 each for scrap batteries (undrained).

Let them know what you're doing, and they may be willing to help out.

Junkyards are typically a good place to get halfway decent batteries as well, and if nothing else, you could even start off with a small battery from a power-wheels toy or something, whatever you can make provide 12V.

You might find some rechargeable 6V flash light dry-cells relatively cheap too. The lantern batteries, I mean. (You can actually start a car on two new ones, wired in series.)

[bennelson]

Look to see if you have a computer recycler in your area. They gets tons of great small batteries from power backups. Small batteries can go in series for high voltage speed, or in parallel for more range capacity.

[order99]

Most of the Computer Recyclers end up dealing with the NiMH or Lithiums, don't they? I'd normally consider this a bonus...but can a cheap standard charger work with non-Lead chemistry? Or is that only when you're trying to balance a pack?

When I have time to start my own project, i'll probably go with dual 12V, 20 Ahr Wheelchair Batteries-I have a standard 12V charger and can just charge one at a time(at least Balancing won't be a problem!).

I was toying with another option briefly-my Dad picked up a half-dozen old NiMH packs-and Chargers- for his Cordless tools for peanuts at a yard sale and is testing them out(if even one of them works he's got his money's worth!). It got me thinking... 12V NiMH packs for tools only hold about 4Ahrs apiece, but four strings of doubled packs=24V and 16Ahrs, bulky but light. Hold on, let me try some ASCII :

--p---p---p---p-
--b---b---b---b-

Ok. The roughly L-shaped packs are jammed into the box (which uses
contact-springs just like the Cordless packs for instant Swapping) and fits below the Center support. Behind the seat are 8 individual chargers(assuming that, like my Dad, you found the chargers with the packs!) hooked up to a Powerstrip and secured by a similar box. I'm told NiMHs can discharge more deeply than LA, so...let's assume about 12-14 miles per charge(i'm lowballing). If you start out with a full charge you have roughly 12-14 miles range, are a two-minute switchout away from another 12-14 mile charge-the fresh ones in the Charger Array-and then you can hook the Array up for roughly 45 minutes and have another 12-14 miles...in other words, you could take a long lunch(90 minutes) and have roughly 60 miles of travel under your belt. Then it's time for a long dinner and another 28 miles or so...if you're in an Urban environment and nobody begrudges you a Plug-in, you could run out of juice before the bike does! And this is assuming minimal pedaling...

This naturally assumes that I have my Dad's incredible Scrounging abilities though. Otherwise, it's LA for now.

Oh, WannabeEVer-glad to see you've got your project started! I just put new paint on my Donor (and the solid tubes-wish i'd had these as a kid). I've still got the Network test to go before i'm employable-did I mention I got my A+ cert(YAHOO!!!) so it looks like I get to learn from your setbacks...speaking of setbacks, Dad found out I had 'his' old VW generator and politely requested it back. And the transformer.

Not to worry though-when I mentioned the uses I had planned to put the parts to, he fished out a broken Craftsman 18V, 450W Hammerdrill, a handful of low-voltage Contactors, various Fuses and a few 12V Non-rechargeable Dry Cells to test everything with...

Dad also casually mentioned that the VW Generator( 1.8+HP at 24V) would have probably turned my light Touring frame into a screaming 30MPH+ Motorbike-not what I want with one back-wheel brake! With this Drill motor though, I might be able to go for a 1/3 gear ratio and have a nice, high-torque hill-climber at 15-18MPH. Yep, Dad's joined my design team-I might actually have a chance to pull this off now!

Ok, breaktime's over-got to hit the books one more time before bed. One more Test and it's Interview time...