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  1. M

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

    Road use, something cool and exciting to ride. Front wheel drive can be a hassle but everything is a compromise, no constant velocity joint in the drive train With head out design the seat inclination is set that the eye line is just above the knee top so you can see the road. Head bubbles have...
  2. M

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

    Stacked foam is logical choice as I have a hot wire cutting table. I will have to test clearances and decide on fairing then I will go ahead with the foam. Yes I'll have a wing to mount front and rear lights for visability. I have no plans for camera operation, I'll need to make a windscreen...
  3. M

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

    That's a lot of airfoils. For the fairing I am leaning towards an established design because I'm not skilled enough to improve upon it. Here is the top and side view, I would omit the two wheel fairings from the plug giving me the option to raise the fairing or make it a trike...
  4. M

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

    Busy day today, I showed the pictures to a local foam manufacturer. He said with his 2D machine he can cut the top and side view into a block of "m" grade polystyrene. "M" grade is used for surf boards is a bit smaller and better for sanding he says. He needs: 1) DXF file with both profiles...
  5. M

    Foam core composite motorcycle top box surface finishing advice please

    Update: This box has increased my fuel economy from 50.9km per litre to 55.9km per litre and has been very handy.
  6. M

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

    If I have the width and the height, I need to connect those two points with a curve. I have a hot wire cutter, random orbital sander, angle grinder, saws, sand paper, soft sanding blocks from the surf board shop, a sharpie and a rule. I don't have great sculpting skill as seen in my recent...
  7. M

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

    Hello I want to carve an aerodynamic shape based on horizontal and vertical airfoil coordinates and a single cross section to ensure fit then extrapolating to every airfoil coordinate along the body. How can I extrapolate this curve? I have seen the Arnold Company videos where he uses...
  8. M

    Foam core composite motorcycle top box surface finishing advice please

    Project finished. Painted the box and painted some more then clear coat. Added a reinforcing rib to the bottom of the box to reduce flex at the mounting points. The locking mechanism broke because micro got into it so I replaced it. Project finished.
  9. M

    Foam core composite motorcycle top box surface finishing advice please

    I have been a bit lazy but progress is being made. Door and lock added, top and opening reinforced, box mounting holes and brackets made. The past couple days I have been filling with micro and sanding it with 180 on the random orbital sander to get it ready for some Rust-Oleum white pearl...
  10. M

    Foam core composite motorcycle top box surface finishing advice please

    Yes I have used similar vacuum cleaner vacuum bags on a previous project. I have removed the plug and now have a sense of the stiffness of the composite. When tapped with my finger I can hear the higher pitch due to the extra stiffness. The flat areas with only one layer as well as the load...
  11. M

    Foam core composite motorcycle top box surface finishing advice please

    Door cut, foam removed and tomorrow I'll remove the fiberglass.
  12. M

    Foam core composite motorcycle top box surface finishing advice please

    Yes I will do a female mold next project. The surfshop guy said there was cheaper resin I can use for mold making. Yes pointy end goes back, acting like a tail cone. I am thinking about the door now. I got some pizza to ensure the door is big enough.
  13. M

    Foam core composite motorcycle top box surface finishing advice please

    Thanks I had a read. Over the last couple days I prepared the plug and yesterday I laid a top and bottom layer of 400g carbon fiber twill. 0.6m x 1.0m on the bottom and 1.0m x 1.1m on the top. I trimmed a few corners to fit and stuck them on the bottom so as not to waste the material. The...
  14. M

    Foam core composite motorcycle top box surface finishing advice please

    Fiberglassing done for today. I am getting better at it. Tomorrow filling, primer and associated sanding. I have Honey Wax mold release but it is 4 years old I wonder if it expires. I will buy some pva release agent, primer as well as a "jenny brush" and foam surf board foam sander block. I...
  15. M

    Foam core composite motorcycle top box surface finishing advice please

    This is my first foam core composite project. An aerodynamic motorcycle top box and this is where I am up to. The foam layers were hot wire cut, stacked glued together and sanded to shape. I used some pastor stuff to fill low spots but I should not have. I then put layers of fiberglass on...
  16. M

    Plastic layers between foam ribs and carbon for removing foam for extra lightness

    Is there a formula for balancing the carbon fiber skin with the core material thickness for optimal stiffness to weight ratio? Or is it still an iterative process?
  17. M

    Plastic layers between foam ribs and carbon for removing foam for extra lightness

    Upon further research and the replies here I see I won't be able to use empty space in an attempt to reinforce the part.
  18. M

    Plastic layers between foam ribs and carbon for removing foam for extra lightness

    Oh that's very interesting, yes you have interpreted my post according to my intentions. Darn I thought I was onto something haha. Thank you for your reply.
  19. M

    Plastic layers between foam ribs and carbon for removing foam for extra lightness

    I just came up with an idea for removing the foam ribs in a composite mold for increased lightness. Step 1) Layup 1. Carbon fiber(s) layer (vacuum bag). 2) Plastic layer. 3) Foam rib, clay, whatever needed to get the desired shape. 4) Plastic layer. 5) Layup 2. Carbon fiber(s) layer (vacuum...
  20. M

    Core materials for resin infusion with best strength to weight ratio for use with compound curves

    Having worked with epoxy so far I know I want to avoid wet layups if possible. A skilled person may be able to do what you propose but I can imagine it turning into a sloppy mess in my hands haha. I have some materials go on now, I will order materials when I get to that stage of the project.
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