Hello philgib,

Welcome to CR4

Looks like a fun project! How about looking at the basic chassis of a gocart? You could adapt the chassis to accomodate the load and bigger wheels to lift you off the ground more. Also change the geometry of the seat position to give you an optimum pedal position! Anyway, lett us know how it goes and good luck!

Welcome to CR4 philgib!

WHo said it had to be tubing?

My recumbent bike e is basically an aluminum extrusion with wheels.

Thats pretty simple design!

You might want to double this up if you are committed to a 4 wheel pedal car.

Could brazing of aluminum work for your application?

milo

Milo,

I wasn't aware that brazing of aluminum was possible. Can you tell me more about that?

I like your bike. Is that your design? Did you build it?

Hi Shadetree,

My best friend got me hooked on recumbents. His has a faring, custom gears and the works. mine just has a cateye onboard computer and rechargeable lights. First time i ever did over 35 mph (down hill of course) was on his fared bike e and I was hooked.

I bought my bike e when I changed jobs in 2002 or 2003. Its a great "old guy bike" for me at 55 years of increasing experience.

Its crazy how you have to pedal up hills in a recumbent, but the not riding on ones prostate makes cycling a joy.

I have attached the brazing aluminum links in my other post to the list.

I'don't do brazing myself (I'm more a machining kind of guy) but have seen this done.

Thanks for the interest.

milo

That is a great looking bike. How much ride time do you get on it?

Hi bob c.

~1000 miles a year (Essentially summer) until I started my MBA.

a set of tires every other year.

Im just a recreational rider.

Now that I'm studying and working full time, its just a couple of mornings a week.

I'm hoping to return to a thousand mile summer next year when I ve graduated. A couple of century rides (100 miles) on the summer holidays should make that easy to achieve.

milo

At 59 I finally have a bicycle that I am enjoying riding again. It is just an average mass marketed "mountain" bike, but it is all mine. I have not ridden a bike since I got a driver's licence 42 years ago. I only get about an hour a week on it. Too many other projects.

philgib,

One thing there is usually plenty of is used bicycle frames. These are also fairly easy to work with since the best way to put them together is by brazing. They are usually made of chromoly steel which gives the best strength/lightness per $. Once you have your design you will know how many frames you have to salvage. If you are interested I will post pics of one I have been building.

Another way to go is to build a fiberglass shell, though you will probably still need to incorporate some metal to attach your suspension to.

Please provide a rough sketch of what you have in mind.

Milo's bike is very impressive and certainly gives me some material to think about for a few nights.

Shadetree, sticking a few second-hand bikes together is actually my original idea. I was thinking of changing 4 bikes into 2 "limo" bikes, than sort of welding them side.by.side, only moving the pedals to the seat level, and joining the front wheels into one single command.

It is a problem though to find 2 identical second-hand bikes, and having to purchase two new bikes made me look at other ways, like building a super-simple chassis from scratch.

Here is quite an akward drawing, to illustrate what I was thinking of.

I understand that weight is an issue, but I want to keep the project practical. It does not matter if the quad only goes to 15mph instead of 20 mph (speed is not an issue in Mexico :-) ). I care more about stability and longest distance possible between two recharging stops. People here are practical, not rich geeks.

What do you think ? You can obviously see that I am not an engineer.

Philippe

But LIMO very pretyy bike may indeed do a nice quad too. Do you know the approximate weight of your bike Limo ?

Weight of bike about 13.2 kg or 29 lbs;

brazing aluminum:

http://www.weldguru.com/braze-aluminum.html

http://www.aluminumrepair.com/

http://www.keep-it-kool.com/braze/braze_1.html

more bike e stuff:

http://www.tachyonlabs.com/mybike.html

http://www.bikee.org/bikes.htm

Electric bike e:

http://www.wisechat.com/carl/bikee.htm

http://www.geocities.com/jason_m_norris/ebikee.html

Keep us posted!

milo (I do think of my bike e as a LIMO)

Thanks Milo,

I do like your limo and I appreciate the links.

Hi philgib,

There are some people that have built some of what you are talking about. You might want to go to their website and see if you can get any ideas that will help with the building of yours:

http://www.champiot.com/arpower.html

http://www.treehugger.com/files/2006/08/humancars_elect.php

http://www.humancar.com/overview.htm

Interesting stuff in this article about electric motors for the type of quad you are talking of:

http://www.teamhybrid.co.uk/quadviper.htm

Good reading, might give you some ideas.

Ken

Oh yes, my idea is certainly not new, just look at the first Ford car... And every single kid has already played with or seen a pedal kart.

My question here is about having the purest yet stiff enough chassis, that is why I am asking engineers here about the best structure.

There are already some progresses thanks to Limo. I went down to the below structure. 3 parallel triangles at the back where most of the drivers weight is. Is it still possible to make even more simple still ? What diameter should be the hardware ?

I was once under a design contract to a manufacturer of open differential gear boxes located in Pennsylvania.

Their single largest market is electric golf carts but they do provide motors and gear boxes to a manufacturer in Mexico who builds small, battery powered delivery carts.

The controller for the 24 volt DC system is quite sophisticated. It uses regenerative braking to convert kinetic energy to feed back into the batteries.

I have a home in Cuautla (Morelos) and will be traveling there this winter. Between now and then, I'll see if I can find out from the gearbox company what the cart manufacturer's name is and where they are located. I've an interest in this too.

L. J.

I would still suggest using aluminum. Your frame could weigh 1/3 that of a steel frame. Welding aluminum can still be simple if you can weld steel with a mig gas fed welder. For a prototype, steel is probably best. But they do sell aluminum wire spools and spool guns. You would need a different gas such as Argon for the process. Good luck.

I worked a few hours last night on Photoshop using Milo's Ebike chassis idea. My chassis would actually be made of 6 large aluminum portions like the main one showing on Milo's bike.

Here is the result. Up to 2 adults and 1 child in the middle could feet.

The extra 2 sides are supposed to act like bumpers. I guess it could be plastic too to save on weight. For sure aluminium for the chassis would be the best solution. I am going to hunt for an alu welder in my city

1- What typical shops sell large/thick alu parts like the main part from Milo's bike?

2- Engineers from this forum, would you please have a look at the below chassis. Does the structure makes sense ? Top is where the 2 solar panels will sit.

Thanks

Philippe

http://www.americanaluminum.com/

http://www.extrusions.com/

http://www.futuraind.com/

Solar panels- stop thinking flat. Sun is low in sky in am and evening, so on sides at an upward facing angle are possible.

No reason they have to be only big flat up facing rectangular panels.

Put on all surfaces of a streamlined cowling.

university of miichigan solar cars maize and bluelook here: http://en.wikipedia.org/wiki/1993_%22Maize_%26_Blue%22_University_of_Michigan_Solar_Car_Team

http://video.google.com/videoplay?docid=143192687118710102

http://www.engin.umich.edu/solarcar/video.html

These are more extreme than what you're trying, but should give some tips. As you can see you need a lot of cells and very low mass!

Enjoy!

milo

Milo,

Thanks for the interesting links.

Do you know what is called the piece of extruded aluminium which is the main piece of the chassis ? Is it a "beam" ? A "rail" ? English not being my native language does not help...

Thanks

Philippe

I have to think that Laughing Jaguar has the correct idea for you. The problem at this point is that you will need to do a lot of changes until you work out some details. How about a used riding lawn mower. It starts with the correct weight. Has a drive system in place already. Has a steering system in place. And is made of steel, which means that you can drill and bolt on parts as needed, or braze, or use any welder you can find. You will have two side "C" channels for frame rails, and some cross members. It don't get any more simple than that. These frames are also strong. Are used riding mowers available where you are?

Once you get a working prototype, then go to the composite. I have herd that resin soaked balsa wood is one of the strongest structures possible. Good luck, and send progress reports.

Well the truth is that a person with ciseaux is much cheaper than purchasing a lawn mower in my aera but this is certainly a great idea and I can always try to find out what a lawn mower chassis looks like. Thx for that !

I have worked with fiberglass when I was young as I was a sailing competitor for my country, and I have to say that it was really a horrible job, scratching for hours, provocating allergies, toxic resines...That was tough ! But that was 20 years ago. I do not know whether this is still the case or not.

So I would rather have to braze everything...

I will attempt to find a good picture of a small riding mower frame to send. Please explain what you mean by " a person with ciseaux"

A gardener cutting the grass with simple mechanical tools.

Good news. System is up and running.

I finally went for the cheapest and easiest :

- 2 cheapest new bikes I could find in a shop to guarantee exact set-up

- 5 steel tubes across the 2 bikes, 5 feet long

- Seats for another 2 adults between the 2 bikes.

System is really fun, and no wonder people used to call it a "sociable" at the beginning of the century. 4 folks on the same line... Hilarious.

Until now it costed me 260 dollars for the 2 new steel bikes, including shock absorbers on each wheel, and another 100 dollars on steel tubes and soldering.

The bikes can be ridden separately or joined together in about 5 minutes.

I promise some pics as soon as the seats in the middle obtain their cushins. Hopefully in 2 days.

I have a problem though. ROTATION. The 2 bikes are so far apart that when turning, the bike front wheels must not be parallel or the trike gets stocked / does not like it.

When there are 2 drivers, it is easy, the driver inside the curb knowing that he has to exaggerate the turn, and then the trike turns in a remarquable short circle, almost on itself.

I mean, the bike inside the curb has to make a circle much smaller than the bike on the outside of the bike. Conclusion : the inside-bike front wheel must be turned as almost twice the angle of the outside-bike front wheel.

Consequently, a simple bar joining the two front wheels does not work efficiently.

Any idea of how I can do it ? Having the inside-curb front wheel to automatically double the angle of the outside-curn angle, and that on both side ? How are cars doing ?

I am going to the beach in 2 weeks and ideally I could finalise the trike asap so that we can have lots of fun there with the 4 members of the family.

Thank you

Philippe

I make a new post specific to akerman steering arms as it seems to be the best solution

This is great news.

CAn't wait to see photos.

A few other things to think about:

Center of mass: HAving it low improves stabilityand closer to the front reduces forces need to keep it stable and to turn.

Speed: at slow speeds you require larger angles to turn than the bike would at faster (normal bike)speeds.

Trail: Modifying the fork angle to improve the trail of the front tires could help with control and steering:

Trail is the distance that te front wheel's ground contact point trails behind the steering axis's ground contact point. The steering axis is the axis about which the entire steering mechanism (fork, handlebars, front wheel, etc.) pivots.

The more trail a bike has, the more stable it feels. Bikes with negative trail (where the contact patch is actually in front of where the steering axis intersects the ground), while still ridable, feel very unstable. The opposite is true too, as bikes with too much trail feel difficult to steer.

Lean: Bicycles typically steer by mving the center of mass by leaning, as well as diverting the front tire's angle from the longitudinal axis ofthe bike.
As a quad, you lose this ability to lean, so you will have to deal with the imbalance of forces on the inner and outer wheels, which will be greater than expected because of loss of lean.

Do send pictures, I noticed that you used the word "trike" and I have envisioned a Quad.

milo