The PukE Project !

Alright now...

Last year, i picked up a Pukka Mini-Electric bike !

Had a tonne of fun on this little hunk of metal..

Drove the crap out of it.. held up like a champ.. pulled a 250 lb friend around my block as the acid test ( poor thing had a hard time but got it done ! ) !!!... quite impressive !

My original pukka was sold to a friend who drove it to the ground.. his kid and friends litterally tore it apart after ALOT of hard miles.... I do not know it's current situation..

BUT !.... 8)

He came to me a few months back. And had a request... We have an indoor Cart Track in town, and on some weeknights they have pocket bike races.... he wants to compete with the pocket racers on a pukka !

I contacted Tim Chapin ( tchapin " at " bf.umich.edu ) - whom i had purchased my original pukka, great guy, and he hooked me up with a used pukka he had left over missing a motor and batteries.. Perfect !

The motor is already sorted out.. I picked up a few Kollmorgen motors from Bob McRee a while back, the Kol's with reversed controllers... I plan to remove the stock 24v controller and retrofit a 48v 40 amp Crystalyte unit .

Batteries.. now this one is still up for debate.. either nicads.. or SLA's.. not sure yet.. Lipo's would rock.. maybe Thunder Power Lipo's .... I need to call the track info line and find out lenght of each heat... probably will need multiple packs.

Rear shock will be replaced with a gas charged chock.

Front forks replaced with disk brake unit..

Anyone up for a 30 mph PUkka !..

I've decided to call this the Puke.. ( if you don't barf after a 5 minute run on this thing.. you never reached full speed ! )

Great stuff! I'll be watching this with interest. My pocketbike conversion stalled after I did a quick and dirty job with the gearmotor, plenty of torque, but sooooooo slow. I wonder if the Kollmorgan will have enough mumbo to compete with the ICE bikes though. The ebikes I've seen spanking the ICE ones were etek powered!

I recently started playing again, I've got a series wound (can you say torque ) motor with a planetary gearbox on the end (more torque!) It's 12V but I'm stoking it with 36V which should bring the rpm up, so provided it doesn't throw a winding it should be a good thing.

I tried it last night with a 24V 30A controller, wouldn't move. Attempt #2 36V 40A controller, just barely crawled forwards. Hmmm, series wound motors need a lotta amps to generate a magnetic field. Lets try my 36/48V 100A/150A peak controller @ 36V. Now we're cooking! Blew the 40A fuse inside my ebike battery pack (that I was using for testing purposes) in about 1.5 seconds. I think we have a winner :lol:

Unfortunately where I live there are no pocketbike races, but it's my dream to travel to one one day and spank the ICE bikes. Hope it's a short race though, I've only got bronze bushes in my motor instead of real bearings

Anyway, enough of the hijack, looking forward to hearing more about your Puke/Pukka! When I progress further (in a fortnight or so) I'll start my own thread.

It looks like you might be able to fit a BMC motor on that. If you can find a burnt one for cheap, you can rewire it for external control. PowerPack motors has them already wired. The motor can take more than 60 amps.

I think you'd have a hard time keeping the front wheel down. I think it would compete with an Etek powered pocket bike too, since they would have the same problem.

This BMC motor you speak of.. 60 amps at what voltage ? I know of Eteks.. Perm motors.. ( an 080 would be cool to have handy !..) but wich BMC ?

The Koll motor ( see picture ) run at 48v 40 amp on a 10 inch wheel should scoot right along. And i have 2 of them.. ( Dual motor maybe ? )

Probably going to run 48v 20 ah nimh or nicad.. I'd like lithium but the idea of this gonig sidways into a wall of tires might be an issue..

I am tearing it apart completely and cleaning/lube/checking every nut and bolt... Need a wash badly

One of these:
You could go up to 72v with a Crystallyte controller.

I forgot to mention, the BMC motor mounting holes have the same spacing as a Kollmorgen. The shaft is thicker, so you would need to get a new sprocket, but they are readily available.

I don't think the BMC could take 60 amps for more than a few minutes without getting really hot, but with forced air cooling, it does pretty good.
Of course, at 60 amps, you would have a really hard time staying on that thing

What kind of controller do you have?

The controller will be a Clyte.. i have 36 / 48/ and 72v on hand.

I am leaning towards a 48v setup, simply for battery reasons.. 20 ah should do nicely.

How big of a performance difference between the BMC and the Kol ? They seem similar in size and weight.. both brushless.

48v x 40 amps + = 1900w peak on something that was originally 400w... . I'm going to try this combination for now and upgrade later if required !hehe..

The windings in the BMC are about twice as heavy. It will take a lot more amps to melt them. The rotor is a bit longer also. It will make my Vego SX-600 do a wheelie, so I can't imagine not having enough power on a Pukka. My Vego is geared for about 28mph @ 48v. I'm going to try 60v sometime when it quits raining.

If you don't want to modify an internally controlled motor, you can buy one already setup for external control from PowerPack Motors.

Another Pic

Wow.. that little pocket bike looks cool !.. still got it ?

I am working on the pukka little by little.. i have it all torn apart and cleaned up.. she was dirtay..

The rear shock was shot.. no oil left and all seized up.. i unfroze it.. had to get the BIGGER hammer out to get the pin out of the shock tower..

I'm having the mounts beefed up.. Taking the rear shock from my Norco and installing it on the pukka... and my norco gets an upgrade with a gas charged shock with external reservoire !!! 8)

joystix2, can you post details of motor RPM and your gearing please? 30mph is my target top speed (maybe a bit more).

Thanks Ric! I've got a JX MY1020 or 1050 or whatever they call it. 2400rpm @ 36V and I'm trying to figure out if I should persevere with trying to use my pocketbike stock gearing (17/54T) which uses funny chain, and I have to adapt the sprocket to the motor, or if I should try and use the sprocket that it came with (11T) and a rear sprocket and chain to suit (62T seems to be the smallest I can find). I don't think the 11/62 will give me enough speed in a 8" wheel (10 rolling diameter) at 2400rpm. I calculate a pathetic 12mph top speed with that gearing.

Yeah, I'm not really expecting much from the JX motor although I was impressed because the commutator end bell is slotted to adjust timing and the brushes can be replaced without dismantling the motor. Wish it had neodymium magnets.

I threw a motorcycle starter motor (series wound) on my pocketbike just to see how it would perform. Overvolted from 12 to 36V with a 100A controller the acceleration was good but top speed way too low. Then the wires melted anyway :wink:

Yo.. Ypedal.... What is happening with the PukE and Chopper projects??

Oh they are happening.. just not at the top of the priority list at the moment ! :lol:

I"m running out of nails to chew waiting for my parts from crystalyte.. still in beijing ....

My norco is almost done and ready.. will have pictures of that shortly ( by the weekend.. i promise !! ) I'm rebuilding the batter packs into nicer metal boxes with vented fans and all that fancy stuff.. will look pretty snazy... !!

After the Norco.. is the 2 Honda scooters i have partially done as they need to be sold.. this will fund both the PukkE and the Chopper !

It never ends... never... :wink:

looking forward to seing the norco mate
i have to mount my lipo's too so i'm going to work on that some on sunday, i hope you manage to get some shots up of the battery boxes again, as i said in another thread i think a lot of potential users are put off by the cumbersome batts available off the shelf - i'll have to mount as well as i can with mine but really im loving yours and maytags battery setup and i think thats the way to go for my next bike (already talking about the next one, is that the bug?)lol
get her done!!



D

yo Y!!!!!

where the hell is our update man????
bug,bug,bug lol
we want to see norco fury!!

Cheers

D