at a cross roads lately where i dont really want to devote 100% of my time to robots or 100% of my time to minibikes.

so what better way to alleviate a problem like this then to construct some horrific engineering mistake and right the wrongs of the last version i tried to make. So heres an off topic build report.

putting this brushless etek



into this $70 chinese "CNC" chassis. (is cnc chinese for slaves with hand files? im pretty sure thats how this one was made) should prove sufficient.




id prefer to not die so this one will be considerably better then my last effort. although considering my best efforts are pretty woeful id still call it epic under-engineered

i cant weld aluminium yet so its all going to have to bolt together. so some panels will have to be remade in order to fit some items - namely the 10kg etek. thus the tedious task of properly cadding every single piece begins.

this is after 2 days... anyone got a digitizer but on the plus side i did get the full version of Vray. i think it looks pretty decent! some of the cadded parts for comparison..




so yeah thats the basis for now. ill throw up pictures and the like as i go. hoping to have raced it by the last race of the year which is late november i think!

general specifications

- Mars brushless motor
- sevcon millipak controller
- oatley throttle
- 100 A123 cells, 36v at 22Ah
- gearing is a 26 tooth sprocket on the front and a 40 tooth on the back. so top speed should be about 90kmh with about the same torque as a gsxr1000. fun!

will have to do a lot of work to get the weight out of it. most of the normal gas bikes are about 20kg and the heaviest is 25kg so if i can make the entire thing weigh in at 35kg complete ill be happy.

main jobs for now are to cad up a new side panel that integrates the etek motor mount into it and get that made and get the rear drive sprocket and modified to attach to the rear wheel.

also need to look at a way of bypassing the large + heavy safety solenoid on the sevcon.

till next time
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http://www.youtube.com/user/HyzerGlen - Videoooozzz

Last edited by Glen on Sun Jul 26, 2009 12:23 am; edited 1 time in total

LMAO

Rip glen...

Glen was a poor man a happy man a very insane man speeding across the planes in a etek powered monkey driven lmao.......

And it gose on like that.
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Tim Team Reaper.

LMFAO

in impotence and in potence....

and another for yah


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http://www.youtube.com/user/HyzerGlen - Videoooozzz

Interesting build!

From the photos and the CAD, it looks like you are going to replace the central ladder frame part that most of the other frame parts hang off. Fitting the motor looks like an epic challenge as its so much wider than the original frame - getting the sprocket on the motor to line up with the rear wheel sprocket is going to be nigh impossible.

How about an intermediate shaft to help adapt the motor shaft to the wheel? have a shorter chain from the motor to a shaft somewhere near to where the original ICE motor out put shaft was, it could run outside the bike's frame so yoy can get the motor's weight down the centre of the frame.

ill snap a pic of the motor jigged up inside but it does cradle inside the ladder frame *JUST* and if i sit the sprocket where it is in the render it lines up with the back wheel. the motors not that wide once you take off the fan and fan cover and use the unkeyed part of the shaft (clamp style sprocket)

only part ill need to have remade is the center park with the 3 pockets cut in it on either side. itll be the exact same part but itll extend out further to bolt to the motor on either side to support it.

but a jackshaft could work good for keeping the motor a little more centralised. ill see how it pans out when i get it 100% cadded. trying to balance 40 parts upright in real life is none too easy
_________________
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http://www.youtube.com/user/HyzerGlen - Videoooozzz

frame is done with a few bolts.


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www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz

That's really impressive reverse engineering! Looking at that render, it doesn't seem there is any rear suspension; is that right or am I missing something?

none in the conventional form. the tracks are really smooth and its only a 20kg bike so you dont really need it.

when your turning the swingarm and the central chassis has a fair bit of engineered flex to it to act like suspension. which is surprisingly effective. thats what the pockets in the side plates are

seems the frame as it stands in the render weighs about 4.5kg. and id estimate the wheels and front forks to be about another 10 or so max. so thats pretty well on track.

doesnt look like ill be able to get rid of the solenoid either its a "safety" solenoid according to sevcon and the controller actually checks that it opens and closes + cuts off power to the controller somehow.. i tried to bypass it using a few methods and it wouldnt work. so ill either have to make up a massive 800 amp fet bank or just find a lighter solenoid

but on the real world side of things i did get the motor sprocket complete. its a split sprocket now with a pair of M6 bolts clamping it onto the shaft. its a press fit as it stands and a pair of grub screws will make that a pretty bullet proof piece.

bonus is i can cut off the extra shaft and save nearly half a kilo mounting the sprocket the way i have. after i check you can get spare shafts of course
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http://www.youtube.com/user/HyzerGlen - Videoooozzz

I was just thinking about your 100x A123 powah.
Thats ~36Kw worth of power there, thats in the ballpark of a fairly decent road bike.

You might need to bump up your chain sizes to cope, snapping a chain off the line would suck ;->
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Mechanical engineers build weapons, civil engineers build targets

one of the things that always put me off using large numbers of small cells in an EV is the charging & balancing. The balance connector for a 100 cell apck would be just a bit large

Are you going to use one large HV charger and no balancing, or multiple smaller packs and a bank of smaller R/C chargers?

well its using #40 1/2" pitch chain which is getting pretty close to motorbike size. if not the same.

charging is an unknown quantity at this stage. probably will use banks of 10 cell packs in parrallel and charge them all at once at the track and balance them all individually once i get home.

22ah worth of a123 will probably only need to get charged once in the day - probably about 40 minutes run time total - so im sure i could get away with one charge without a balancer in between balanced charges.

guess thats another thing to look into for next week im sure theres some kind of battery management system for this kind of thing.
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http://www.youtube.com/user/HyzerGlen - Videoooozzz

Build them in parallel as bricks. John Reid has done this with BETA.

Only need 1 balance wire for each cell in series, instead of a balance wire for each cell.
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https://www.halfdonethings.com/

Would this sort of pack work for you? http://cgi.ebay.com.au/LiFePO4-36v-20Ah-BATTERY-FOR-ELECTRIC-SCOTTER-E-BIKE_W0QQitemZ370226848337QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item56333d6251&_trksid=p3911.c0.m14&_trkparms=65%3A1%7C66%3A2%7C39%3A1%7C293%3A1%7C294%3A50
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So even the rain that falls isn't actually going to fill our dams and our river systems

the parrallel pack idea looks good . that big brick pack is only rated for 50 amps discharge or so, and who knows what quality it is so ill probably go with new a123 cells.

did a fairly comprehensive weight spreadsheet. looks like it is exactly 30kg not including a few things like the chain, rear sprocket, brake disks and plastic fairings + the mounts for everything.

oddly enough the solenoid is actually really light. probably less then 200 grams so ill just retain that unmodified.

can knock 1kg even off by changing the forks and handle bars to aluminium. so a 35kg total is looking pretty realistic. with much more $$$ i could knock it back to 30kg im sure with things like CNC wheels, aluminium sprockets cutting the etek shafts down etc etc but to just have it all work perfect for now will be a challenge enough

should have the whole cad finished by monday tuesday then i can work on getting the mounts for the electronics and motor sorted.

tempted to see if i can maybe trade the sevcon for a kelly controller because there a bit smaller and will fit better in the frame + no need for the safety solenoid.

heres a bit more work on the cad. front end mostly done.


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http://www.youtube.com/user/HyzerGlen - Videoooozzz

good things come to those who wait.

instead of trying to do the next to impossible - aka cram motor into diminutive frame. ill just put it into something of a much more realistic size.

taddaaaa



this one weighs about 60kg and its about half the size of a real bike. so it doesnt cripple you trying to ride it and its got a 50cc version of the CT110 motor

best of all there is plenty of room for meaty SLAs, and its already setup for a big #40 chain and has some serious engine mounts (6mm steel) so it should be a quick conversion.

or if someone buys the etek ill be putting an RM250cc motor into it either way. fun it will be
_________________
www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz