Lowracer BMX Conversion

[Anonymous]

It now has a front brake! Got the posts welded on this morning, and scored a cable and housing on my way home this afternoon. I just pieced it all together tonight and i'm ready to start doing some effective stopping, hehe!

I put an SLA pack in there for now, a set of three 12-12's that i'm going to hook up to a solar array. Right now my issue is that i need to charge in parallel and discharge in series, so i need to do some sort of trickery with wires, switches, and a charge controller somewhere on the birdnest of wiring. Eventually though, maybe this week i'm going to start ordering some 18650s and part together a tab welder so i can build a pair of 10s5p packs. The plan is to have a pack discharging and one charging from a 'house' bank of 12v SLA's on the solar controller and use some sort of balance charger for the drive packs. Right now i've got a B6 i use but i'd either need two of them or i'd need to buy/build a 10s charger.

Next up is going to be to mount some sort of sunshade until i can get the real shell built proper and set up with a cooling system. I'll probably do something like a loop of PVC with awning canvas stretched to cover the cockpit and aligned with the airflow as not to be too draggy.

For the shell i'm thinking of building a plywood form of the rough shape, covering with 1" foam panels and carving/sanding the outer contours, curves, naca vents and such as well as support hardpoints, skinning with s-glass and dissolving the foam with acetone. Basically a lost foam mold over a box.

 

[amberwolf]

My sunshade is an old aluminum folding cot frame (half of one, really), with the center "leg" used to brace the end (rear) leg against the rest o the frame so it will stay at right angles to it, and then clamped to the trike frame behind my seat. It has no front support and works fine that way (I did have a front support when on teh bike, but not practical on the trike in any quick/easy way so i didn't make one).

The covering is a "big dog" brand (cuz it has st bernards on it) snuggy, (cuz I had it already), ziptied to the frame over some bagged insulation. There's a few posts in my trike thread that show good views of it, from the last few months, and in the bike thread from last summer.

with the insulation under the snuggy it keeps the sun heat off my mostly-bare head top very very well, even though it's only an inch or so above my head at most, IIRC.


I found some of my vinyl "seatcover" snap-on stuff that I used for my first seat of the bike, and it is exactly the right size to fit over the frame, so it's going to replace the snuggy at some point since it's actually waterproof (though even riding in rain none has gotten thru the canopy yet).

 

[Anonymous]

So i did a PVC "rollcage" that i'm going to cover with fabric as a sunshade, and also got a solar panel and charge controller on it to charge my bank of three 12-12 sla batteries that i have for now.

My issue though is that i need to set up the wiring so that i can switch between charging in parallel from my solar charge controller to discharging in series to the motor. What's the 'right' way to do this? Is there some kind of series-parallel selector on the market? I know i can do it with a couple of DPDT switches, but is there a more elegant solution?

 

[Anonymous]

Check it out, got the ball link steering, front V brake, "rollcage" frame for sunshade, and charging off solar. It charges slow with just the single panel, but i'll soon have a trailer with more panels as soon as i can score another 20" rim. Ordered a 4 pole double throw 3 position industrial grade switch rated for 15a at 360v, it has a center off position so hopefully that will provide sufficient isolation during actuation.

I also ordered one of those fancy LED digital readout multi voltage twist throttles on ebay for $14 or so since i broke mine last night dismounting, kicked it as i was stepping off and now it's ziptied together, it works, barely. Once i get the series/parallel switch working i'm going to wire it up where i can reach it in the cockpit. I'll probably also build a battery shelf/box somewhere low and discrete, like behind the seat and inside the axle frame. I'm thinking of hanging a panel off the rear aft of the basket on a bracket that future me will make somehow, and maybe doing two more panels up front on either side of the headset and one on the "rollcage", that'll give me about 60w of charging, but once i get this thing further along i'll buy some serious panels in the 100-360w range. Between the bike and trailer i'd like to get as close to a 1kw array as i can, mppt controller, charging a 12v SLA that cascade charges the LiPo drive packs through a battery selector.

I think it might need some fuzzy dice hanging from the rollcage and purple shag carpeted seat soon, hehe!

 

[amberwolf]

Side view kinda reminds me of a sandrail.

If you were ever passing thru Phoenix you could pickup a handful of twist throttles from me; I've got a small box full I got to experiment with using hte analog halls for analog ebrakes and other sensors once I get a controller built that will use them.