How to extrapolate the curve that connects airfoil coordinates for aerodynamic shape carved into foam by hand without CAD?

[wizzardworks]

MotoFarang, First guess at the rounded nose. Is this what you were thinking or do you want a bigger or smaller radius. This bit
would need one inch thick foam slices. This is the elliptical cross section continued. I am thinking you will be poking out just
around template 6. Let me know the distance from 6 and the top of your helmut above the top of 6. If you need to resize the
template holes we can print a filler piece that will press into whichever template line you are using with a smaller inside shape.
The canopy needs to be flat wrap in the area of the glass but the rest of the shape can be convex. Just try not to have abrupt
shape changes where it meets the upper fairing shell.

 

[wizzardworks]

MotoFarang, New nose and 24" front wheel, guessing actual diameter

 

[MotoFairing]

It will be short wheel base.

Approximately
Wheelbase: 115-120cm.
Rear axle to bottom bracket: 115cm

 

[wizzardworks]

MotoFarang, Looks like the printer E-Mail address is no good. error "550 no such user here" Do you have any E-Mail we can use?
Send it to my [email protected]

 

[MotoFairing]

Yes I sent you an email.
I did some measurements, I will need to update red parts.

I had the 16" wheel for long wheel base but I decided against it. I will use the 16" wheel front and rear for this frame iteration because they are on hand.

As for the nose, it would follow the airfoil used. Deviation interferes with the pressure.

Widths are
Pedal box: 41.5cm
Shoulder: 43cm

 

[nickec]

The Recumbent Bicycle and Human Powered Vehicle Information Center

Recumbent and Human Powered Vehicle Information Center

www.wisil.recumbents.com

 

[nickec]

It was earlier posted that a body of revolution could be spliced to wedge.

I am uncertain the actual steps were discussed.

A makeshift hotwire lathe produces the the BOR which is cut in half. The edges serve as a template to cut the foam wedge.

To quicken construction an option is to only make 1/4th of the BOR. Less foam, less sanding.

Joggles are formed on the partial BOR - one overlay, one underlay.

This allows making 4 copies and the rest is obvious.

It is the mechanical that thwarts many would-be high speed bike building teams. Steering, brakes, transmission.

You might consider compromising on the shell and placing emphasis on the mechanical aspects.

It is alluring to perfect the shell. IMHO the first forays into HPVs can be daunting.

Very rewarding nevertheless.

P.S.: It is no coincidence that the image strongly resembles very high performance sailplanes. There are subtle differences. Still this simple method can bring you a long way toward your speed goals.

 

[wizzardworks]

MotoFarang, I sent the template files, including a 90% of scale outline inside the full scale outline. Well I backed up to last
weeks model and superimposed the dimensions you sent me. There is one in red I need a number for. The model matches
the full scale templates I sent you. Ignore the round nose it is borrowed off another model just as a place holder. The wheel
fariings are off a later version of this model you hadn't seen, so the ground clearance shown is not set to your dimensions yet.
If you are satisfied with the wheel fairings I can match them up to your 11Cm ground clearance and make them airfoil shaped, as
shown they are just extruded surfaces . I have a BB, pedals, and sprocket model for this sketch but pulled it off so you could
make out where the BB is sitting.

 

[wizzardworks]

MotoFarang, Just thought it needed to be bigger to read the text

 

[wizzardworks]

MotoFarang, Need a little help here. I tried the little man in the model and he fits, however using him to get a guess on knee position
I noticed that the BB is near the tire diameter which makes for a lot of overlap between the chainring and tire. Actually interference and no ability to steer if the front wheel is the steering tire. The 58.99Cm measurement is to the BB not the pedal, 45Cm to the pedal axel.

 

[MotoFairing]

I have done some more measurements.

I have not done any limb measurements.

Yes large wheels have crank overlap and chainring overlap if the chainring is large which is why I have the 16" wheel.

 

[wizzardworks]

Motofarang, I was looking at canopy shapes with 3 options. First is do the mould and blow form PET-G into it for a 1 piece canopy
and paint the inside where you don't want glass. Second do a glass layup in the mould cut out a flat wrap windshield and glue it on
flush with isocyanurate. Option 3, mount the same windshield from option two set back into the fiberglass shell canopy leaving an
annular air intake. At these piper cub type speeds it should gather considerable ventilation flow, be less suseptible to condensation
fogging, and the fiberglass section leading edge (radiused a little) could possibly reestablish laminar flow going aft. The thought
about laminar flow might be similar to the early MIG fighters which had an open nose air intake for the jet engine with a center cone
set inside the opening. Any thinkers out there with an opinion? Keep in mind the speed range is under 90 MPH.

 

[wizzardworks]

MotoFarang, I did a couple wheel farings to see what the steering angles would be with 16 inch and 26 inch wheels.
All these add on pieces need to be sliced for 1" styrofoam, probably the main fairing top could be faired easier with 1" foam as well

 

[wizzardworks]

MotoFarang, I did a little sketch of a way to do the landing gear.