Wondering about potential of plywood velomobile

[anotherkiwi]

You could just buy plans...

https://www.velomobilforum.de/forum/index.php?attachments/new-look-jpg.265867/

This is my Agilo, #1 on the road and now there are 3-4 of us.

https://www.sitko-velo.de/log-in/

I am still refining things but have peaked at 72.7 km/h downhill and it drives 30-35 km/h on the flat with a 66 year old motor. It also has European street legal electrical assistance up to 25 km/h thanks to a 44v Bafang BBS01B, 36v is not fast enough for my 90 RPM pedal cadence. With an unrestricted motor testing has yet to be done but I would estimate no problems with such a weak motor reaching between 45 and 60 km/h on flat roads thanks to the aerodynamics.

Mine is much too heavy because I made a couple of mistakes and used gaboon ply instead of poplar. But it is very strong which is a good thing for a daily driver.

 

[ThLynn]

The composite would make the sacraficial ply on the outside. If you put it on the inside for structural support you need a balanced ply on the outside. The stronger it is the more self destructive an unbalanced ply can be. The inside is still surface.

More important is the strategic placement of the stiffening. When they do aftermarket stiffening of a street car some use cable. Not even stiff, probably not near as strong as the frame, but working in exact the direction they want the stiffening. What people think is the driveshaft space inside the car is called the chassis tunnel, no driveshaft inside but greatly strengthening the chassis lengthwise. Put a roll like that in a sheet of paper and look how it doesn't flex when you lift the end. Even with tissue paper, I sat here and tested that before i posted it. longer floppy. Adding weight with a laminate doesn't have that effect, they make leaf springs from composite and they flex.

Okay so let me prefis this by saying I have no spelling skills due to dyslexia so play nice. Anyway I admit I am a complete newbe at all of this trike building but after searching high and low for information on it, and coming up short to say the least I finally decided to follow the bamboo build I saw on you tube. Sort of, As I dont have bamboo or balsa at an affordable price I thought I would try multipal Iner locked layers of PVC pipes and old Bike parts to fabricate a recumbent tadpole design I think they call it but the main trouble I have found is the fact that I need it to be a hand rowing model. ( Not hand Pedaling Hand Rowing please don't ask ) So my Grandson and I have been buying and cutting up Bikes for the past week or so, and after designing and re designing I think We are going to go with a old pedal car bent axle, design I found on Pintrest. We can use the pedal stems as our rotory input points and then by bringing the armatures forward to the bent axle we can transition to our linnier motion from our land ores as it were. this will all be housed under and behind the drivers seat. We re used the back half of a mountain bike for the drive hub as well as the wheel mound and frame, with 2 frunt bike forks at the frunt mounted under the body fenders / frame to provide a steerable front end, via a set of foot pedals that run from the axle bolts through the fender so we can push one or the other to steer in that given direction the oposit side is tide to it via tie rods. It is our hope that the several layers of PVC will give us strength while also allowing for some give in the ride to smooth things out a bit. A feature that I designed into our build when we get to the body build up is a set of head lights that will be housed in cases mounted on the tops of each of the afore mentioned frunt forks so that as the wheels turn these lights will follow the motion and direction of the wheels much like the I beleave it was the Tucker that came out ( well tried to ) with this set up on their car a design before its time but not to be thanks to the then Big 3 American auto makers. We are using these build methods and materials as we don't have or know how to weld. and as for our body panels we are going to up cycle old grocery bags into light weight strong material that I do know and have worked well with. Nice thing about it is all it takes is bags, a cloths iron, and some parchment paper. no glue or resigns needed. and yes before someone asks yes we will spray6 paint to treat it for UV degredasion. Okay enough of my ramblings any help and or ideas to help us out will be welcomed thanx see you in the funny papers

 

[amberwolf]

If you have not already checked it out, you might peruse eRowbike & eSkyBike Documentation and rowbiker 's posts.

 

[classicalgas]

If you have not already checked it out, you might peruse eRowbike & eSkyBike Documentation and rowbiker 's posts.

I'm doing scale models of a tadpole trike based plywood body velomobile Some experiments with 3mm plywood from a builder's store seems to be following my model fairly well.

I started with corroplast, but the amount of "forever"plastic waste, resistance to smooth curves, and general floppiness convinced me to try plywood. Single layers where I have edge control and gentle curves, reinforced with a second layer on edges where I need some strength (cockpit and seat edges ) two layers ( formed over bike rims and laminated) where I need tighter curves that will hold their shape. Nose will swing up and foreward for entry (on a pivot system sold for trike fairings) rear hatch will lift up for cargo on the rack inside. Powered with a TZ mid drive run off pair of "56v" EGO tool packs under the seat. Full belly pan is one layer of 3mm ply with edge reinforcement. Overall style is 1920's retro with WWI fighter plane influences.

 

[Logic11]

I'm doing scale models of a tadpole trike based plywood body velomobile Some experiments with 3mm plywood from a builder's store seems to be following my model fairly well.

I started with corroplast, but the amount of "forever"plastic waste, resistance to smooth curves, and general floppiness convinced me to try plywood. Single layers where I have edge control and gentle curves, reinforced with a second layer on edges where I need some strength (cockpit and seat edges ) two layers ( formed over bike rims and laminated) where I need tighter curves that will hold their shape. Nose will swing up and foreward for entry (on a pivot system sold for trike fairings) rear hatch will lift up for cargo on the rack inside. Powered with a TZ mid drive run off pair of "56v" EGO tool packs under the seat. Full belly pan is one layer of 3mm ply with edge reinforcement. Overall style is 1920's retro with WWI fighter plane influences.

That model looks very close to this:

Along with the rounded nose I'd add, but I'd round it more than in that model
(Half an ellipse with a 3 to 1 ratio has best aero)

A 'Make it with a Jig-Saw' wood 'velomobile'. Cheap and cheerful

FROM WATCHING THE series I NB that he started with a thick heavy T shaped wooden frame, but as the plywood skin went on; so the need for its diminished and it's changed into a hollow box to hold up the seat and somewhere to mount the cranks.
ie: the strength/rigidity now comes from the skin.

Also NB the double ply (with a large gap) sides around the occupant.
That might be filled with honeycomb that comes in everything from cardboard to fiber, to aluminum if you want serious crash protection.

If you want to save on weight; a lot of the less structural plywood body might be removed, leaving 'frames' (triangular) and covered with this stuff.

 

[classicalgas]

That model looks very close to this:

...Except longer, more rounded nose ( half circle and angled back) tail stays less than 12 deg. departure angle ( to keep airflow attached) less frontal area, no flat facets, smaller cockpit opening, fairing behind drivers head, and lower, with a flat belly pan back to the rear axle.

Also lighter...two and a half 4'x8' sheets of 3mm plywood and two alloy bike rims for the entire body ( 15 lbs ) Frame and running gear is a trike that weighed 45 lbs before I added 25 lbs of battery and motor. Add a rear rack to support the cargo box and rear fairing, and the pivot mechanism for the "hood" to that. It should be easy to keep the finished velomobile well under a hundred pounds. Under ninety, if I'm lucky.

What did the final jigsaw/plywood car weigh?

 

[classicalgas]

...Except longer, more rounded nose ( half circle and angled back) tail stays less than 12 deg. departure angle ( to keep airflow attached) less frontal area, no flat facets, smaller cockpit opening, fairing behind drivers head, and lower, with a flat belly pan back to the rear axle.

Also lighter...two and a half 4'x8' sheets of 3mm plywood and two alloy bike rims for the entire body ( 15 lbs ) Frame and running gear is a trike that weighed 45 lbs before I added 25 lbs of battery and motor. Add a rear rack to support the cargo box and rear fairing, and the pivot mechanism for the "hood" to that. It should be easy to keep the finished velomobile well under a hundred pounds. Under ninety, if I'm lucky.

What did the final jigsaw/plywood car weigh?

Found it...the Mott weighed in on the recyc station scale at 70kg/ 154 lbs..less than I expected. That's up in the range of some of the two seat and cargo velomobiles on the market, but not the heaviest of those.

 

[Logic11]

...Except longer, more rounded nose ( half circle and angled back) tail stays less than 12 deg. departure angle ( to keep airflow attached) less frontal area, no flat facets, smaller cockpit opening, fairing behind drivers head, and lower, with a flat belly pan back to the rear axle.

Also lighter...two and a half 4'x8' sheets of 3mm plywood and two alloy bike rims for the entire body ( 15 lbs ) Frame and running gear is a trike that weighed 45 lbs before I added 25 lbs of battery and motor. Add a rear rack to support the cargo box and rear fairing, and the pivot mechanism for the "hood" to that. It should be easy to keep the finished velomobile well under a hundred pounds. Under ninety, if I'm lucky.

What did the final jigsaw/plywood car weigh?

Ye, I said: "Along with the rounded nose I'd add.."
Ideally a half ellipse with a 3 to 1 ratio if we're being technical.
No front facing surface would be anything but that on 'my velo'.
I'm think hot wire cut, replaceable styrofoam is light, cheap and may even help in a head on collision.
Speaking of head on collisions a telescopic steering shaft is an omitted must have in my linked pedal-car!

And yes; with a hub motor you can do reverse and eliminate the need for a hole for Flintstone reverse.
A flat underside makes a huge difference for aero and you stay dry...er.

I see you found the weight. Quite impressive for a plywood velo-Noddy-car.

 

[classicalgas]

Ye, I said: "Along with the rounded nose I'd add.."
Ideally a half ellipse with a 3 to 1 ratio if we're being technical.
No front facing surface would be anything but that on 'my velo'.
I'm think hot wire cut, replaceable styrofoam is light, cheap and may even help in a head on collision.
Speaking of head on collisions a telescopic steering shaft is an omitted must have in my linked pedal-car!

And yes; with a hub motor you can do reverse and eliminate the need for a hole for Flintstone reverse.
A flat underside makes a huge difference for aero and you stay dry...er.

I see you found the weight. Quite impressive for a plywood velo-Noddy-car.

Most people aren't set up for, or good at wire cut foam, sanding it is messy, and toxic, and vinyl doesn't stick to it without a lot of post shaping prep.

Tadpoles reverse easily if you can reach your front tire with your hand, but I've driven full size cars with no reverse gear (and those you can't pick up the back end with one hand)

I've got no use for DD hub motors, I may add a small geared rear hub to the mid drive.

Steering shafts are a very bad idea. Tank steering is much safer and entry/exit friendly.

So far I'm using a box knife, straightedge and a sanding block to shape the 3mm ply I'm using. Cordless sander to smooth the varnish layers. I did have the box store precut the ply to manageable pieces.