my first build, now with a shady m1 pack

gestalt

10 kW
Joined
Oct 19, 2009
Messages
750
Location
Austin, TX
As many of you also must have I saw a youtube video with a 48v electric flat tracker built from a beach cruiser frame. From that moment I became obsessed and just had to build one of my own, but better. So when I got my tax refund check I bought two things, a tablet pc for ease of designing and a stretch cruiser bicycle. So far I've been able to transform the bike from this,
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to this.
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The only parts I kept on there from the original bike is the frame, stem, bars and chain. I swapped out the rear wheel for a surly large marge rim and sturmy archer hub. As for the front, I have a disk hub but I think I'm going to be replacing that with a dual disk hub to be mounted on a custom springer fork I'm building based on John Brains design.
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I have all the steel and hardware together finally and found a place here in boston that I can do my welding work free of charge. Also I have a 48v-5000w brushless motor from golden motors.
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But being a young proletariat I have run into the ol finacial wall, but it was a rather well timed one as I still have to weld in the motor mount and build the fork before I get going on the battery and controller. Which is why I'm here, I still have many questions on what direction to go. It was suggested on another forum that I run this thing at 24 volts but it seems like I would be wasting that powerful motors potential. A123 systems headquarters is right down the street from me and I've been trying to get friendly with those guys as I think they are one of the few battery technologies that could supply the juice I need to power this thing at 48v.

So as it stands right now my next purchase will be an alltrax controller so I can do motor and drive train testing with an alternate power supply before I make that significant battery purchase, but would like some advice from all you ev wizards out there. I've been lurking in here for a while and it's time to step out of the shadows. Any advice would be much appreciated.
 
Nice cruiser i like the lines.

I have built a Springer fork using John Brains plans, they are nice fork and work very well
for on road use, well..they work 'well' as far as a Springer goes they aren't exactly 'cutting edge fork design'.
I can give you some advice on improving the Springer from the plans, instead of the bolts on the rockers
where the fork tube and Springer tube connect pick up some rose joint ends, bolting
like John suggests in the plans will wear as the rocker pivots over time and making
the fork very sloppy in the process. I have only used the rose joint ends on the Springer tube
but plan to change out the pivot on the rocker also...heres a pic of my cruiser (still constructing)
with the Springer fork on it.

Best of luck...

KiM
 
That is a rockin chopper man, I saw your trike on YouTube a while back. Are you going to electrify that one? And if so, what kind of setup are you going to throw in it?
 
Sounds like a good plan, especially the free welding.

IIRC, Alltrax is a brushed controller, you might consider a Kelly or Sevcon.
 
Sounds like a good plan, especially the free welding.

IIRC, Alltrax is a brushed controller, you might consider a Kelly or Sevcon.

wow, don't I feel like a dumbass. I looked up sevcon and it seems they make only ac controllers, and I'm not sure which model of the kelly controllers will work for 48v and have regen as their site is not the most informative when it comes down to the specific models. any ideas?

-be seeing you
 
gestalt said:
That is a rockin chopper man, I saw your trike on YouTube a while back. Are you going to electrify that one? And if so, what kind of setup are you going to throw in it?

Yup i have a 6500watt RC Brushless outrunner (initially 2nd to be added in future) for it be running 44v 20ah of Lithium polymer batteries
full worklog from start is viewable here on ES check link in my sig :)

For your controller checkout Methods Crystalite 100amp 72v fully programmable regen units.

KiM
 
gestalt said:
I'm not sure which model of the kelly controllers will work for 48v and have regen as their site is not the most informative when it comes down to the specific models. any ideas?

Well... it sorta depends on how much current you want to put through it. They have a 4KW and a 6KW.
 
I started contstruction on the housing for the controller. Following aussiejesters lead I believe I'm going to go with a fiberglass case to look somewhat like a gas tank with air scoops.
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this is just kind of a rush mock up job to see what shape works for me and I plan on shaping the final product out of a solid block of styrofoam instead of gluing together three sheets.
 
Hey man, nice shot ! (yea i know, ive had it on repeat for a 12mi rain ride).

Seriously nice ride, hey um... since someone will do it (should) and since you say that's a rough up in 3 piece styrofoam - want to send it flying my way when you do v2.0 mach up?

Can't blame a guy for asking and if your not going to use it for a positive mold then the foam will survive your testing right?

One other question - more generic to composite construction? I've seen many positive mold fiberglass pieces made in the forums but I've not seen anyone using kerosene or acetone to disolve the foam when done... it seems everyone is hacking it out, I've only made one part from composite in my life and I did the hack it out way but then stumbled on using a solvent in some composite forum - I can't remember.

So the question - why don't more people use a solvent to dissolve the foam core? Is there a reason for EV use that we shouldn't?

Thanks,
Mike
 
mwkeefer said:
So the question - why don't more people use a solvent to dissolve the foam core? Is there a reason for EV use that we shouldn't?

Thanks,
Mike

Not that I am aware of, in fact in my research into diy carbon fiber frames I noticed that that is exactly what many builders do so I really cant see a reason why not.

And as far as the mock-1 you are more than welcome to it after I use it for reference while I make the next one. I'm sure that it wont be damaged and probably wouldn't cost much to ship as it weighs almost nothing. Do you have a cruiser or some other bike in mind for it? If you were to fiberglass it there would be plenty of room inside for a controller and all the wires and such.
 
If that is your 'normal' run of the mill polystyrene it will melt the second the resin touches it in case your not aware...You will definitely
need to coat it with bondo, up side when you want to get rid of the polystyrene simply bore a couple of holes in the enclosure and pour petrol in to dissolve the foam :)

Best of luck shall watch with interest :)

KiM

p.s HEAPS of rubber gloves acetone or methylated spirirts rags and newspaper required when fiberglassing its freakin messy stick horrible stuff.

EDIT: mwkeefer...not all foam dissolves with kero and acetone...the eco-foam i used is resistant to chemicals hence it had to be dug out..
 
Rocking!

I am planning a chopper build and figuring that your rough up would make a good starting point - add a bit of bondo and smooth/shape it (auto body repair and finishing I do know) it would be a very nice positive mold.. I would hate to destroy it and given the size I may actually throw my hand at negative casting using your positive as a starting block.

It seems to me, the best method for fiberglass or carbon fiber is to use the re-usable negative mold and vaccume forming for better strength, lower weight, higher temp tolerance once bake is completed.

If the offer stands when your done with the mold... PM me, I will gladly pay to have it shipped here... your right that could be the lightest gas tank I've ever had shipped.

One suggestion... I would route an opening at the bottom and mount the controller inside the bottom upside down - it could be recessed but should allow the controller sink fins to protrude for cooling (this is the design I will end up with) - Actually now that I mentally picture it, I think a compartmentalized or baffled "tank" will be the best option with a removable bottom panel and recess for the controller mounting - so I don't have to remove packs in case of controller failure, access will be provided from below tank via 4-8 screws along inset seam.

Im craptastic about explaining things but once I can see them in my minds eye, my relative lack of knowledge doesn't hold me back - i just learn what I need, as I need it...

It just dawned on me, when I did car stereo... I worked with alot of fiberglass and we used plain ol gasoline to melt the positives away... Then there was somethign we primed the final fiberglass mold with so it could be used as a vaccum negative - I was more into MDF and wave guides and digital delays for proper time alignment of all channels to construct a proper sound stage - but Ive sent an email to my old partner who was the fiberglass guy. I can't rememebr what the prime to use the initial fiberglass as a negative mold.

-Mike
 
Thanks for the heads up Kim, I had figured as much but wasn't sure what to use to coat the foam with. I think I found a place to order the block from so payday I'll probably send away for it. I'm really stuck in the "do what you can afford" mode right now so this is a great piece to work on. '

In other news I'm going to start volunteering for the MIT electric vehicle team, going to my first meeting on monday. Can't wait to see what is going on behind the scenes there, their electric cars have some serious range, they did some 100 mile ride a few weeks back around my area. Who knows, prehpps I'll try to go back to school at some point but for now doing intern-like service in one of the most technologicly advanced schools in the world will be great learning value for my wallet.
 
I like the way this one turned out, though not the color really. Made some more room on the inside and larger air scoops.

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Next up is to coat and sand some bondo onto it and get it ready for fiberglass. though I am thinking carbon fiber. Anyone know the cost differences between the two
 
gestalt said:
I am thinking carbon fiber. Anyone know the cost differences between the two

A HELL of alot of money... my fibver glass was under 10 dollars a meter, carbon fiber is over 80 ...

KiM
 
I was really stressed out because when I first attempted to disassemble my motor I got a few bolt into it before I noticed that the axle was not spinning anymore. And furthermore after getting the rest of the bolts out I couldn't seem to get the rear housing off. But with a little help from David at MIT and a large press we got that puppy naked no problem.

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it looks like those first bolts I took of act as spacers for the stator so when I took them out the whole thing shifted and wouldn't spin anymore. It's still going to take quite a bit of adjusting to get it back on track, but at least there is now a light at the end of the "did I just throw away almost $500 to satisfy my curiosity?" tunnel.

And I know you guys love your cnc and controller pron, but how about this battery pron?

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and yup, they're all full of nanophosphate deliciousness. How did I overcome the urge to slip one of those boxes into my messenger bag you might ask, sheer frickin will man, sheer will. And on top of the table those cases are sitting under they have a setup with a single a123 cell being fast charged in four minutes then discharged in four minutes back to back and it has been going for weeks.
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It's a test to see how fast charging affects the life span of the cell. So far the cell is fine and they'll keep it going until it reaches 1000 cycles. It's a pretty cool setup that has web monitoring and will even send a text message to one of the crew if something should go wrong.
 
I did a little more fine sanding and rigged up a hot wire to slice the mold in two. used a couple bamboo skewers to keep the two halves together on the bike.

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cant say I'm thrilled to have the pink back on the bike but tis only temporary.
 
I'm liking the shape of the tank the scoops look scwheeet tooo...

My mate was looking at my battery enclosure over the weekend, he said, "you know what you could do."
as he lifted the top off it and turned it side on to the frames top tube, "use the top as plug to make a mould for a tank
too fit more Lipos in!
" It actually looked pretty good as is, with a lil fiddling it would suit the
lines of the bike, and extra 8 packs could be shoe horned into it bring totally capacity to
a possible 44v 60ah haha..serious range... :p

Look forward to seeing the outcome of this glass job, have you picked up the resin and fiberglass yet?


KiM
 
No, I have to wait till payday to spend any more money that I shouldn't be spending on this project. what kind of bondo should I be getting for this? There are some rather large nicks and pock marks that need to be filled in.

Oh, I did manage to pick up the second to last 100a controller from methods. I suppose that's worth mentioning. No turning back now, that will be the controller to go into the and I feel great about it. Though I do wish I got in on it back when they were just $300. Whatever, what's a hundred bucks.
 
gestalt said:
what kind of bondo should I be getting for this?

Cheapest you can find, we call it 'Bog' down in Australia. Whatever you get GET IT SOON im hanging to see this finished hahaha...

KiM
 
Ok, so methy's controller should be hitting my doorstep this week. Also I was looking at my tax Info and with about $1000 comming back my way in about three months I will be shopping around for battery tech. Now I know 1k really isn't all that much to throw around but it is what it is. I really want to try putting an a123 pack together especially since I have access to a great tab welder. Should I hold out for prismatic cells with those tabs that would make such simple pack and bms design? Or let's throw caution to the wind and go lipo I don't know. Looking for at least twenty and hopefully thirty miles range, of course that wold be taking it easy on the throttle. But one thing is for certain and that's that I want to use the controller to i'ts full potential.
 
gestalt said:
I really want to try putting an a123 pack together especially since I have access to a great tab welder. Should I hold out for prismatic cells with those tabs that would make such simple pack and bms design? Or let's throw caution to the wind and go lipo I don't know.

ES member cell_man has the prismatic cells you seek theres a thread here on them...

http://endless-sphere.com/forums/viewtopic.php?f=9&t=14832

Very impressive cells too

KiM
 
Thanks bro, those are definitely the cells I am going to go with. Not only are the discharge capabilities able to keep up with my motor and controller having less cells will make for a much simpler bms system. The MIT guys also think these cells will handle fast charge just fine.

On another note I think I will definitely be going with a disk on the rear, though I still have no clue on how to make a caliper mount that will work with the horizontal drop outs. I'm a bit torn though on whether to use a dual disk front hub and attatch the belt cog to one of the disk mounts, or use a single speed disk hub and have the belt cog thread onto the freewheel mount. The former would make for much easier fabrication of the cog but I really like the idea of a cog that just screws right on in one move and might be sturdier.

Also, does anyone here have a source for 12 or 13 gauge spokes in odd lenghts?
 
gestalt said:
Also, does anyone here have a source for 12 or 13 gauge spokes in odd lenghts?

There's these guys on eBay:

http://cgi.ebay.com.au/CUSTOM-LENGTH-WHEELSMITH-STAINLESS-BLACK-14g-SPOKES-32_W0QQitemZ370159420812QQcmdZViewItemQQptZCycling_Parts_Accessories?hash=item562f38858c#ht_3527wt_941

eBay has others also. I haven't compared prices.

Cheers, Ben.
 
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