Solar Velo Build

[jlpmedia]

I've been working on a solar powered velomobile for over a year now and after much trial and error have come to a point of near completion.
I had started making a trike from random bicycle parts and scraps of metal lying around the shop. Trips to the local hardware store were quite recurrent to get stainless hardware, tools, and random odds and ends that I didnt feel like fabricating myself.

My whole idea behind this build was for everyday transportation to work which is a 52 mile round trip commute on a main road with traffic speed maxing out at 55mph. The build had to be completely weather proof where I would be dry in the rain, warm in the winter, and cool in the summer. I'm by no means an avid cyclist, I'm just trying to save a few bucks over the long term, not having to pay for gas, insurance, registration, or anything else the state or government can tax me with. The result of this build came out decent so far, I can only say I'll do better next time. I've learned so much in the process of Doing. These next few posts will give you a better understanding of what I'm trying to accomplish.

 

[jlpmedia]

Trike A-Arms

Rear Wheel Mounted

Rolling Chasis

Suspension

Like I said earlier, this whole process has been trial and error. I couldnt figure out the geometry with direct steering so I opted for a steer by wire.(tie-rod shown in the image) But I can honestly say I liked it better because it was lighter and offered a greater range of steer adjustment. When I first tested my steer by wire it was extremely squirrely at speeds above 25mph. This was easily fixed by widening the steering linkage. essentially meaning that i would have to turn the steering handle more to turn the same arc.

I also learned about an efficient chainline, this design is everything but that.

 

[jlpmedia]

Now came time to build the body (Version 1)

Supplies

Cutting out the templates

Assembly

Assembly Continues

Filling in the Ribs

Front View

FIberglassing

I've been doing computer animation for a few years so I was able to design everything in the computer (Lightwave 3d) and make slices of my model to use as templates. I printed it to scale on hundreds of sheets of computer paper, pieced them together using a 1" grid that i had overlayed the actual design as a reference so I knew that the pieces of paper would match up. After I cut the foam out to the shape i pieced it all together and glued it together with Great Stuf expanding foam. they were $3.99 a can and I probably used about 6 cans.

This was my first time fiberglassing so I now realize how horrible of a job I did. I knew that fiberglass resin would eat away at the foam so i put a thin layer of bondo on. Well, little did i know that the bondo would generate enough heat to melt the foam. so i ended up putting a thicker 2nd application. once everything was dry and sanded I used vasoline so the fiberglass wouldnt stick. This actually worked out pretty good and was cheaper than buying paste wax.

 

[jlpmedia]

Okay, so now that I got the learning out of the way the real fun begins. The season had changed as it was winter now. and the kids room was the only room big enough for me to work.

I bought a KMX Venom. no it doesnt have any suspension, but it was the lightest, strongest frame I could find and with it being constructed out of aluminum I didnt have to worry about freakin rust. The design of the frame made it ideal for my idea, where a lot of trikes I saw, the frame hugged the back of the seat before dropping down to the rear wheel.

I also went on ebay and bought a 48v 1000w motor and a 48v 20ah headway battery from BMSbattery.com - of which I despise btw. This provided me with enough fun so i can drift, i mean drive it in the snow. The motor didnt hold up for too long. i think too much moisture got into it, but needless to say the motor works now.
well, this little 48v 1000w motor helped me reach speeds in excess of 30mph. which is awesome...if i was 6. I wanted to go faster. I needed to go faster. I ended up buying a Bafang BPM2 8FUN motor. It was 48v @500w but I have big plans. The new motor was geared which is perfect for me because that meant I could regear the motor to make it spin faster. The BPM2 has a rpm of 328 and a gear reduction ratio of 5:1, so in actuality it has a rpm of 1640 and a top speed of (I'm guessing) 22mph. so to make this motor faster i would have to reduce the gear ratio to 2.5:1. This obviously would decrease the amount of torque but provide me with the higher rpm im looking for. 656 rpm on a 26" wheel(25.25" Diameter) would give me 44mph, so ill round down to 40mph.

When I took the motor apart I first thought that they used aluminum wire. Why on earth would they do that. aluminum has a lower melting point than copper. Well, it turns out it's just tinned copper...or so i now suspect. Either way, the wires definitely needed an upgrade. Another trip to the local hardware store to get some 14g and 10g wire. I stripped the wire of it's insulation and put on some thinner walled heat shrink. I ended up buying 5' of blue, green, yellow for the phase, and red, black, yellow, blue, green for the hall sensor wires. It was enough so if I screwed up, I could redo it. I had to bore out one side of the motor axle by 150 thou so the wires had enough room to feed through it. I took special care to ensure there were no burrs so i wouldnt strip any of the wires when i fed it through causing it to short out.


KMX Venom with pvc frame mockup, battery suspended mid-frame and hub motor installed

Bending the pvc to the shape I need took patience and very little heat.

fiberglassing the turtledeck with solar panel cutouts

Turtledeck mounted but not trimmed- I also repainted the frame, I had the option of getting a free paint upgrade through UtahTrikes.com, but I wanted the trike in a hurry so I could get to building. It was a big mistake as the paint easily flaked off. But I took it to my local paint guy and he sandblasted and powder coated the frame a matte black for $120.

The Haro wheel covers were a bit expensive at $80? for x1 20" BMX wheel. so I only used x1 half on each front wheel. the rear wheel i used corrugated plastic aka coroplast. it was ideal because of it's strength, light weight and weather resistance. you can also get this stuff for free right around election time. most campaign signs are made of this amazing stuff.

Disassembly of the motor with a flywheel puller(a MUST have)

Taking measurements of the hub cover so i can fabricate a wrench

Machined a new lightweight aluminum core to replace the steel gear. I plan on casting the nylon 42T gear out of aluminum to replace the original 21T steel gear. So essentially, ill be swapping the 42T and 21T gear to get my new gear ratio. But I want metal gear turning a plastic gear, turning a metal gear so it will run quiet.

Getting ready to upgrade wires

Vacuum Forming the fiberglass body

 

[jlpmedia]

The motor threw a few obstacles at me, first was taking the thing apart. If you dont have the motor cover wrench ($35-greenbikekit.com) you will need to make one. You can always try the flat head screwdriver and hammer method, but you will bang it up a lot. it unthreads regularly-counterclockwise.

You dont need a gear puller, but it made everything incredible easy. i probably could have forced the clutch off with just my hands, but why risk it when I have this tool readily available to me?

The nylon gears came off by doing the following: removing the C-clip. I used small pliers but they do sell a tool specifically for this purpose. the nylon gears did take a bit of mechanical leverage. I took 2 flat head screw drivers and lightly hammered them on either side of the gear. when i had enough clearance, i used my gear puller to get them off and later used the gear puller to separate the gear from the bearing. I did this because I plan on casting it out of aluminum. This Could be done with a propane torch, scrap metal, and some greensand. but for the propane torch to work effectively, you will need to convect the heat.

My idea is to swap the position of the 42T and the 21T gear to get the gear ratio im looking for. but in order to do this i will have cast a few parts out of plastic and aluminum as well as machine a new clutch, but im thinking that i dont want a clutch so i can get regenerative braking on my ride.

 

[amberwolf]

Looks interesting so far--I've pondered a tilting trike that would be a little like this, but have yet to do any kind of fabrication as the design isn't even sketched out yet.

 

[veloman]

Looks like you made a nice mold for the fairing body. That is the method I will use too.

 

[jlpmedia]

@amberwolf: oh god. there's that dreaded word 'interesting'. which usually means you are unsure about whether or not you like it or agree with what I'm doing.

@ veloman: I got the concept of using foam from Rick Wianecki. his velo build can be found here. http://www.recumbents.com/wisil/wianecki/velomobile/default.htm


after boring out the axle to 19/64 I was able to barely squeeze the thicker wires through. I double checked the wires with each other to make sure they weren't going to short each other out.
I thought I could get away with boring out the hole with a wood drill bit, but I had to get a titanium drill(cobalt was unavailable) to drill through the hardened steel axle

 

[bowlofsalad]

I am not sure why you need the approval of others. If you are posting these this for emotional fulfillment and would collapse under the notion of criticism, you may be doing the wrong thing.

I think it is a mistake using aluminum. I think there might be some things about aluminum you don't understand. Fatigue limit and strength to weight ratio are two important ideas to understand when engineering anything. To give you an example to help understand something, what I guess you are using as a base, an aluminum trike (your posts seems very sporadic, I struggle to follow, maybe you just wanted to post a bunch of history about some things you were doing, like this is a blog) likely wasn't designed with speeds and weights you have in mind. Hitting a hard bump like a pothole or something at 30mph+ with no suspension will cause a large amount of fatigue to the frame. This will only become exasperated with the additional weight you are throwing on top of it. I don't know if you simply scrapped the idea of using the frame you were in the beginning, but I think that was unwise if that was what occurred.

At 55mph, cops might pull you over. Without insurance, registration or anything like that, this could be bad for you. 55mph means you are a motorcycle to the law pretty much anywhere you go on Earth I think, short of unincorporated regions. I'd say you could probably pull off 30mph or so, but 55mph would likely be way too fast for not getting noticed.

 

[xenodius]

Amberwolf, have you seen the Jetrike.com plans for a self-centering leaning delta? OSS, MBB... rear suspension easily integrated into the leaning geometry. I would love to build one with a full fairing carefully covered in small groups of flexible cells, lean-lock, front suspension, serial drivetrain, at least 3kWh of lifepo4 with a meanwell super charger, and a sturdy trunk in the tail. I figure a 200 mile range should be quite achievable.

bowlofsalad, ease up a bit. Rigid velo's go 55mph all the time, when they go down hills. Many cruise at 35mph on the flat. Also frame material is irrelevant, by using appropriate tube diameters and the correct thickness, you can achieve the same load bearing capabilities AND, contrary to popular belief, rigidity. Also, aluminum doesn't rust, I believe that's why he chose it. And that trike is rated for 300lbs on the road... should be plenty... KMX's are super durable. You should probably run balloon tires though.

 

[jlpmedia]

thank you for the psycho analysis. haha

The aluminum Im using is heat treated aircraft grade quality, so im more than confident that it will hold up to any amount of stress. But regardless, I feel like with any motor design you need at least 1 fail safe...1 part that will break so you dont damage a more costly component. or am i wrong?
My trike has the suspension built into the wheel of which I can't disclose to the public at this time...it's been a WIP for ~6 years now. But I can tell you that It is similar in concept to 'loopwheels' but a much more affordable and customizable option. And it has been tested and works great!
I've gone faster than 50mph without the aid of a motor passing law enforcement officers and they have yet to pull me over...so i think once the motor is complete and the velo shell covers everything up, Ill be in the clear. or so i hope. then again, ive been riding my motorcycle since 2003 with no fender and just this year i got pulled over for not having one...10 years later.

but thanks for your input, I greatly appreciate it!

on a less than significant note, why is my post sporadic again? I talked about the frame, to the body, to (a different frame) but still on the topic of a body, to the electric motor...seems to be in order to me...

 

[xenodius]

you're fine. but question, loopwheels dont look like they will hold up to side loading at all! Did you do anything to work it out, or are they rigid enough?

 

[John in CR]

Looking good. How is the solar going to come into play? It will be interesting if you can get a sustained 55mph out of a Bafang. What are your plans to keep it cool?

 

[cal3thousand]

I like this project. We need more velomobiles around here. Good for you for taking on such a big project. And kudos to the wife for being OK with you working in the baby's room

Your writing style seems fine to me and I appreciate the candidness with regard to your learning experiences.



BTW... what are you able to power with those panels? They don't seem very large; maybe I'm not seeing the full picture?

subscribed

 

[xenodius]

My goal for solar power on a velo would be 250w. That's enough to basically ride itself as long as its sunny. my envelope math tells me twice that should be achievable if a fairing was completely covered. I'd want to put some kind of enamel or clear coat on it over the panels though.

 

[cal3thousand]

My goal for solar power on a velo would be 250w. That's enough to basically ride itself as long as its sunny. my envelope math tells me twice that should be achievable if a fairing was completely covered. I'd want to put some kind of enamel or clear coat on it over the panels though.

So, is the idea that you charge at 250W while the thing is parked and also get the same 250W to supplement the battery reservoir?

 

[xenodius]

Yes. Extend range and charge in the boonies.

 

[cal3thousand]

I would love that for commuting; much safer for charging if it is done outside with only 250W.

Problem is using a Velo in Los Angeles

 

[Dauntless]

I'm supposed to be learning to make a body, a buck, etc. the way you did. How did you come by this process? Your vacuum bag has a certain 'If all else fails' feel to it. Why are the wheels in there with it?

 

[lbz5mc12]

Only problem I see with using a Velo in L.A. would be if you left it anywhere for any length of time the taggers would have at it. They'd treat you like a bus or a train car lol.

 

[Jason27]

Yes a 250 watt setup would be perfect for solar. Light commuting to work like within 6 miles would be ideal.

 

[Cowardlyduck]

Love this build.

Mind if I ask for some specifics on the solar panels and charging setup your using with them.

I ultimately plan to do something similar with my Stealth Fighter's side panels.

Cheers