Slow progress but progress (DIY two seater tadpole trike, 9hp Honda diesel)
 

http://ecomodder.com/forum/attachmen...p;d=1372194027

Here are some photos of my ongoing project two seater tadpole trike, considered a motorcycle in Virginia. The engine is a 9 HP Honda Diesel 432 CC single cylinder rated for 3000 RPM sustained. The tranny is a Harley 5 speed with the rest of the (rear) drive wheel components using harley parts. The harley starter will start the otherwise manual start diesel engine.
The front end is a 1971 VW beam axle.

As you can see the shape is exactly according to the ideal aero shape posted many times on this forum.

regards
Mech

I'm going to use a small alternator as the primary chain tensioner. The drive will be a Harley belt design used from 1999 on. This particular one was a 2001 Dyna Softail that the owner upgraded to a high performace engine and primary belt drive, so I got all of the parts he removed from his bike from the transmission to the rear wheel, including clutch, brake components, drive belt and sprockets, rear wheel, trailing arm and the twin pull shock-springs used on the softail design. He even rebuilt the transmission for me.

regards
Mech

It looks great! :)

This looks promising.

I'd love to see the details of steering and turning the wheels when it comes time to reveal.

Are those old style VW Beetle torsion bars up front?

This is going to be awesome. How much cabin enclosure are you planning for?

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This looks real good!
 

Keep it going. Subscribed.

2 or 1 seater? looking forward to how everything in the drive components and suspension come together. have any target cargo weight and speed or just slap it together and find its limits? Sub'd

Very interesting. :)

Side by side two seater, seats close together. No center console or transmission tunnel, cabin width less than 60 inches. Thats the center to center track width of the front tires. Basically length a little over 12 feet, width about 66 inches.

71 VW beam front axle with drum brakes. Probably the only vehicle on the planet with drum fronts and disc rear, at least for now, might put discs on the front later.
Tires are the same Bridgestones that are factory on a Smart Car.

I'm thinking roll cage with gullwing doors and a wide angle mirror above the drivers line of sight that covers the rear view completely.

Front wheels will be skirted once we get the suspension range and turning dimensions loaded and unloaded. Skirts removeable for tire repair.

Windshield and side windows will be lexan. I might try to get the front glass shaped with compound curves (bubble canopy), but for right now it will be curved to the shape of the front end, which is basically round but without a front to rear curve (if that makes any sense).

The rear drive will be configured so it could easily accomodate a different engine, or batteries and electric drive, but the long term objective is to build my patented drive for the single rear drive wheel. The Honda (single cylinder shown in picture) engine, almost .5 liter was basically a trade with my oldest brother. He got it new in the box as a donation and it has probably less than 5 hours running time.

regards
Mech

As far as weight I just have a rough estimate of around 1200 pounds. I am hoping the CD is low enough to see it hit 60 MPH. It won't be much on hills, but around here they are not that bad. If the lower aero drag allows it to go faster then that would be fantastic. Overall final drive ratio can be changed by increasing the primary ratio between the engine and transmission.

If I see battery tech get realistic then I might just go with an on-off switched electric driven hydraulic pump to charge the accumulator and my drive in the rear to recpature braking forces hydraulically. No controller would be necessary.

So it could be diesel or battery electric or any other configuration or combination of primary propulsion. For now the diesel was cheap.

I think at WOT (sustained power not short term) the engine burns a half a gallon an hour, so we will see how fast that will take it.

regards
Mech

That's so cool! Looks like a VW IRS trailing arm for the rear. As light as that's going to end up I don't think discs up front will be much of an improvement. My sand rail would lock the front wheels up regularly with stock VW drums up front. It was 1000 Lbs. soaking wet (most of it over the back wheels). I could pick the front end up enough to scoot it around if I needed to with the stock steel wheels and plywood floor.

That's what I want to see...:thumbup:

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Interesting build OM. What is the estimated weight distribution?

COOL x 100

I can't wait to see the finished project and will be following this closely.

I don't know if it is feasible but there are 6 speed trans kits for Harleys giving you a 6th gear overdrive. .087 or something like that.

S&S Transmissions/Baker Drivetrain/JIMS Machine are three of the manufacturers IIRC.

I have not really tried to calculate the weight distribution, or even the overall weight. I can pick up the engine, frame, and front axle myself (individually), maybe 500 pounds total for all 3 or a little more. I think I might go lightweight on the upper structure other than the roll cage. It will have a roll bar behind the seats and another that will serve as the windshield frame. The parallel frame rails will have sheet metal between them, which will add some weight.
As far as distribution front to rear, it will probably be close to 50-50, of course depending on the number of people on board since the would be about 30% of the total weight, assuming two people at 400 pounds.

As far as overall drive ratio, that can be adjusted with the primary sprockets.
In the next few days I will get the transmission and the rest of the powertrain components, basically everything you would need except the Harley motor. Hopefully in a few weeks it will be a roller, maybe even a driver, but I have found predictions that rely on other peoples work tend to be optimistic.

regards
Mech

Another good engine choice is a diesel motor out of a Themo King refrigeration unit. They are little 4 cyl motors made by Isuzu very economical and reliable. I've seen them put in Bobcats before. I want to say somewhere around 30hp so it wouldn't be very fast.

Given a single rear wheel, there is essentially no roll stability at the rear. Since it isn't a 'tilter', the front axle (w/two wheels) provides the only roll stability for the entire vehicle. Also, the 3-wheeled configuration gets complex when suspension is involved because the suspended front axle will allow a given amount of roll, exacerbating the tendency to lean in corners. Just a suggestion, but I would strongly encourage a minimum weight distribution of 65% front/35% rear, and a stiff anti-sway bar on the front. Yes, agreed, keep the mass as low as possible... especially on the rear half of the chassis.

At 500 lbs total, you can probably get away with using bathroom scales under each wheel. This will easily ballpark your weight distribution (given approx. 33% under each wheel). If only one scale is available, just make sure the vehicle is level by using blocks or spacers under the other two wheels when weighing.

-kenny-

Tadpole trike project pictures
 

It's a roller.

We think it still is under 1000 pounds. I can lift one side off the ground including one of the front wheels.

Now I need to find a 17 inch narrow passenger car tire for the rear Harley wheel. With 400 pounds of payload the suspension compresses about an inch front and rear.

regards
Mech

Very cool project!

OM,

Nice work so far I am curious as to the gear ratios and final drive ratio you are planning to use?

Also its a bit tough to see in the pics but how is the rear suspension set up?

GH :)

The rear suspension is a Harley softtail, as well as the transmission with the Harley belt drive. The primary will be chain drive from the engine to the transmission. Planning on using an alternator as the primary chain rensioner.

regards
Mech

By using a Harley softail powertrain and retaining the dimensions of the original bike's powertrain components, I have only to connect the diesel motor to the transmission input with a chain (primary). The donor bike was "upgraded to a stronger engine, transmission and final drive as well as a 4 inch belt primary (engine to transmission). The seller also rebuilt the transmission for me. He works with another Harley tech and they do engines and transmissions for local shops who prefer to farm the work out. They used to build drag race bikes until their sponsor lost interest.

I am hoping that between the rear tire, probably a 195/65/17 Bridgestone Ecopia (28.5 inch diameter) and the primary engine sprocket which will be the largest I can find, within reason, I am hoping the trike will get close to 60 MPH top speed. It will be interesting to see if it can get there, if not maybe a small turbo to get a little more power.

This allows the use of the Harley starter, which I got for $20. It mounts to the transmission and works through the transmission primary chain drive to the engine, which gives me electric start. A small single wire GM type alternator on an adjustable bracket that acts as a primary chain tensioner as well as providing a charging system.

I think the gas tank that came with the engine is 2 gallons capacity. No AC but for heat I am thinking a heat exchanger like the old VWs with an added exhaust system.

I plan on all lights being LED, with the possible exception of the headlight. Seating will be side by side with significant side crash protection. The sides of the frame will be covered in sheet steel, at least where a side impact could cause an injury.

regards
Mech

That's a nice project. So, are you considering to upgrade its drive layout to that hydraulic system you developed?

I keep forgetting my camera, might have to ride up there this week and take some pictures. The rear upper structure framework is fabbed in aluminum. Working on the front now, might see if I can form a lexan canopy with compound curves. Lowes has 3X6 sheets of .092 inch thickness for under $100 a sheet.

I weighed it using my bathroom scale, which maxes out at 270 pounds. It was 265 for each front wheel and 330 for the rear wheel, which is beyond the scales designed capacity but seemed fairly close. That's 860 pounds right now, so it should be around 1000 or so finished as long as we focus on minimal weight from here on.

Cripple Rooster, I plan on eventually using my design, either driving the rear wheel or in the wheel itself. I figured it's like "Which came first the chicken or the egg? A drive without a vehicle is less useful than a vehicle without a drive. When I put the patented drive in this vehicle, I might put the diesel-harley setup in a bike, but will probably use the same diesel engine. Who knows, if things go well I might just make it electric with a battery and low pressure switch, where the electric motor recharges the accumulator.

regards
Mech

The overall final drive (3.15) works out to the theoretical top speed of 83 MPH. Peak torque at 2500 RPM will be 55-60 MPH in 5th gear. First gear at max (3600) RPM works out to right at 22-24 MPH, according to my calculations.

At max power the fuel consumption is .5 GPH (180 grams per shaft HP per hour=about 33-34% efficiency). At peak torque it's probably 60% of that amount, so if I can get peak torque to sustain 55 MPH the mileage should be pushing 200MPG if it will maintain 55 MPH at 60% of peak consumption.

Double that if electric, and no need for a speed controller, with the hydraulic setup.

regards
Mech

edit:

canopy
 

You may have already blown plastic before,but if not, we used to have a local skylight manufacturing plant in Denton with a clever (simple) process.
The plastic was clamped atop an airtight frame which defined the base perimeter.
After reaching 'sag' in an electric pizza oven it was sealed to the table top by quick-clamping air clamps.
A light source/photo-cell was set at the desired height of the bubble which would open-circuit the air tables supply valve.
As the bubble rose,when it reached the set elevation,the photo-cell cut the air.If the bubble 'sank',pressure was restored,and this process repeated until the plastic cooled enough to set.Really elegant engineering.:)

Pictures.

regards
Mech

More pictures. You can get a perspective comparing it to the Fiesta. Frontal area should be about 60% of the Fiesta. I'm hoping the CD will be around .15.

regards
Mech

pictures
 

Saliva's dripping all over the keyboard!
What a great project! Thanks!!!!!!!!!!!!!!!!!!!!:D

I have not blown any plastic, and the gent who is building the bike has plans for the windshield, but I think it will not be a compound curve. The upper structure will be aluminum sheet welded to the framework in the photos. He is a real artist and has followed my basic configuration. The vehicle is within a foot of the same length as the Fiesta. I told him Lowes has 3X6 sheets of .092 for just under $100 and he told me he can do much better than that through his race car connections and the lexan needs to be thicker than .092.

Thanks everyone for the positive support. Every time I think about it I get a little concerned about the money spent, then I go look at it and get charged up all over again.

regards
Mech

Wow, what an awesome project! Thanks for sharing your progress with us! Looking forward to seeing it on the road.

It's been a while since i last popped in for any updates, looks beast! lovin the fiesta comparison too! wish I had the hatchback :(, great tanks on it as well:thumbup:...

Will look fantastic when its on the road!
Anxious to see how the seating/peddle/steering layout will be. Guessing that you have left the nose as a crumple zone?
I'm gonna guess your integrate lights as best you can?
Maybe a bit overkill, but are you gonna add a cross sectional tube to the frame behind the seats? A side collision(hopefully never) doesn't look like there is much of "margin" compliance if hit at a higher speed..


If not, What kind of thickness tubing are you using for the frame? as a basis for my own project (eventually)...
Also have you looked into Formed Plastic if your budget allows for body work (here and there)?

staying tuned! (better this time)

The core of the whole structure will be the passenger-driver area. This was built from the outside in, basically the aero template drawn on a large steel plate on his floor. From that he bent the sides to match the profile perfectly. Connect the two halves, two more connected halves 18 inches above the first two running parallel, then fill in the rest with his freehand design and knowledge of building NASCAR type racing chassis'.

The tubing is 1/8th wall, 1.5 inches diameter. The sides will have sheet steel welded in the occupant area from the lower to upper paralled tubes. There will be cross bracing behind the seating area and where you would normally see a dashboard (good observation). Both front and rear ends are designed to progressively collapse in a front or rear impact, intentionally weak areas to avoid the situation where there would be no structural deforming and impact would be transferred to the occupants directly. Crush zones, in other words.
The top line front to rear matches one half of the parallel bottom bars, also the template published on this forum. It was designed that way from day one.
Controls are not absolutely configured at this point. It's a tight fit inside, by design, very snug if I have to wear a helmet. I dont' think my butt will be more than 10-12 inches from the ground.

regards
Mech

you are currently living my dream!

If you don't mind me asking, how much do you have into the build?

Do you or will you have build diagrams? I might like to copy the chassis design someday..

I can totally get behind this one; there are no grandiose plans to market to rich people, no baseless performance claims, no reliance on unicorn technology, no huge naive assumptions about building it, no begging for money before any progress takes place, no press releases, photo-ops, or endless self-promotion. It is simply on it's way to happening. :thumbup:

The closest parallel to this vehicle that I can think of is the original VW L1 prototype - it had an 8.5HP single cylinder diesel and a teardrop shape. It was built using virtually every bit of unobtainium, though and it was *not* very quick; in fact I'm sure that it was quite slow.

I think that gearing is going to be your challenge, and weight. Your aero looks damn good, and it seems to be very robust, and carefully constructed.

Hydro Jim, to put it bluntly, it ain't cheap. I will have more in this vehicle than I paid for my Fiesta ($10K), but a significant portion of that cost was profit from other investments, or it would never have happened.

Christ, the machine shop owners dad commented on how it was the only thing they had ever built that really had no detailed plans other than the external shape which was drawn on the steel plate by me with a magic marker! You are more than welcome to copy anything that you wish as far as the vehicle, I have no intentions to patent that and now that it is in the public domain, it couldn't be patented anyway.

Frank, to hear that from you means a lot to me. I tried to find funding through universities as well as the govt, without success. While outside funding would be great, with that same funding comes expectations, deadlines and other pressures that seem to make an already grueling process exponentially more difficult. This way I don't have to meet with people whose money I have spent and live up to their demands, which would transform this to a political process, something I abhorr.

This began a decade ago. I was raised a Presbyterian, a religion that believes in predestination although I am not very religious at all, but I do think there is a power greater than myself involved in this process. I guess I am a combination of bull headed, dogged determination, that some greater power chose for this process because of those character "flaws" if you want to call them that.

This vehicle should be just about as close to a perfect platform for my ideas as I will ever see. In the decade I have spent following my dream, I have always looked for the "game changer" that would make my design obsolete. I haven't seen anything close to that "game changer" but the most impressive of the developments was the VW 1liter in it's original configuration and this follows that design closely with the exception of the materials VW used.

Again thanks everyone. It is greatly appreciated.

regards
Mech