Propeller Development, Did I Tell You It's Made Out of Paper?

Discussion in 'Gallery & Designs' started by Gil, Jan 11, 2007.

  1. Gil

    Gil Active Member

    Hi All,

    I've been off developing parts for an in progress build and decided to give props a try. The following shows the results of those efforts. It's a facsimile of a Helix propeller used by Germany in the First World War. It's made out of cereal box cardboard, hard acrylic modeling paste and acrylic paints. The wood grain was accomplished by using clear shelf paper as a mask material. Works just like Frisket only much cheaper. One caveat is that the applied surface has to be sealed first, otherwise the shelf paper mastic will stick to the surface (can be removed with a gum eraser though). The real discovery is that clear shelf paper works great as a masking material with the mastic being just right to hold to the surface, yet is not strong enough to peel underlying paint when removed and the vinyl is pliable enough to adhere to curved surfaces easily.

    The cardboard layers were glued together with PVA and then soaked with nitrate dope (shellac or lacquer will also work). The resulting structure was then rough shaped by sanding and grinding followed by hand sanding. Hard acrylic modeling paste was applied to fill and countour the shape followed by sanding to shape. A light pumpkin base color was then applied. Masks were cut from the clear shelf paper and applied. The prop was then sprayed with a deep chocolate brown. The masks were then peeled off and any mastic gum removed with a gum eraser. Still needs a coat of clear matte acrylic.

    Another version using layered paper is in the works so the two can be compared. The painted version allows the color of the wood to be adjusted whereas the paper stack-up is limited to the color of the paper used. The trade off is that painting is not required other than sealing the finished product...,


  2. Gil

    Gil Active Member

    Forgot the Template!

    Here are the templates for the propeller stack-up...,


  3. cygielski

    cygielski Member

    Your techniques are fascinating to watch, even if my own model building is a little too primitive to use them fully. Congratulations on yet another great idea.
  4. cgutzmer

    cgutzmer Guest

    super! Thanks for sharing that idea. A good prop is hard to find :)
  5. rlwhitt

    rlwhitt Active Member

    That's remarkable. I would have sworn that was wood!

  6. Lex

    Lex Dollmaker

    I can't believe that's not wood! Even the textures look like it is.
  7. Bengt F

    Bengt F Active Member

    Paper Propeller

    Well done, Gil,

    This is the kind of artistry that makes you very humble . . .
    I have seen this laminating technique in R/C modelling on much larger aircraft models made from balsa or ply but this is applied in a much smaller scale in cardboard. I´ll try that myself some day for my Fokkers.

    You de man, Gil,
    Bengt :D
  8. rmks2000

    rmks2000 Member

    Very realistic! I would suspect that the paper version will require a few more layers to provide a smooth contour without the need for paste. I believe that there was a model mentioned on this forum in the past that used a similar method but I can't recall which one it was - perhaps a Camel from a Russian site?

    May I request that your templates be moved to the Parts Bin?
  9. SCEtoAux

    SCEtoAux Member

    I'm not an aircraft builder, but that is one sweet looking propeller.:yep: [​IMG]
    I've built a few whirlygigs just for fun. That propeller building technique looks like something to try out. Looks like it could be adapted for three or four blade propellers too.
  10. BARX2

    BARX2 Member

    Gil, what's the scale of the propeller? I'm guessing between 2" and 3", but I could be wrong. Thanks.
  11. EricGoedkoop

    EricGoedkoop Member

    Looks good, Gil.

    I've played around with this in the past; here's the business end of my Pfalz A.I from a few years back:

    This is 1/48th scale and the prop is alternating layers of cream brown card soaked and laminated with CA. It started as a rectangular bland and was carved to shape with a Dremel, then sanded and polished. It's convincing enough but would look better if I took more time to refine the shape - this is pretty clunky.

    Duplicates the wood layers of real props exactly
    CA-impregnated card polishes to a nice sheeen
    Nearly indestructible!​

    Takes FOREVER
    Fumes released from the blank as it's shaped with a Dremel are nasty
    A great deal of care and patience is required to achieve the proper shape​

    For what it's worth, I tried doing it with all sorts of different glues to get around the fume issue but nothing except CA gave the card enough strength to withstand being mangled into a propellor.
  12. Willja67

    Willja67 Member

    Very nicely done Gil. I also beleive that I've seen Eric Goodekoop post a similar method of constructing wooden props.

    Edit: Eric beat me by about 1 minute
  13. cgutzmer

    cgutzmer Guest

    if you can find that thread (I gotta run right now) and post it or pm it to me, I will combine both of these threads (given permission by both parties) into one pdf for the reserves.
  14. Zathros

    Zathros Guest

    That is the best propeller I have ever seen. It looks better than wooden ones. It seems that you have captured the scale "look" of the real one that using real wood often doesn't allow (the grain, etc.)
  15. EricGoedkoop

    EricGoedkoop Member

    Here's the bit about propellors from a build thread I did over at The Aerodrome:

    Again - these examples are not refined enough in shape to be accurate, but the technique is sound. It would no doubt be easier to achieve a better result in a larger scale.
  16. EricGoedkoop

    EricGoedkoop Member

    And let's not look too hard at the "spoked" wheels on that MoS L. This was before I figured out how to make decent ones.

  17. Gil

    Gil Active Member

    Thanks for the kind words

    Hi All,

    Thanks for all the positive support. As in any experimental development some paths just do not work and adjustments must be made. Capturing the look of the laminated wood grain was the intent and through a combination "begged, borrowed or stolen" techniques it was accomplished.

    Eric Goedkoop's laminated version was the original inspiration and continues to be. Thanks again Eric! The laminated version will have only five layers which is adequate to capture the wood grain effect, at least that's my thinking right now. Eric's scale at 1:48 makes for a fairly small prop but turned out beautifully. The prop pictured in this thread is 1:33 scale and measures 82 mm in length.

    The upshot of all this is that paper is a wonderful medium to create scratch built models. The really intriguing part is the flexibility of paper in its role as the core structural element with other low cost and available modeling materials.

    I'll make a .pdf file out of the template and place it in the parts bin after adding a few notes. Preservation of this type of thread is a very good idea so let's do that also.

    You should see the engine that goes behind it but that's the stuff of another thread...,

  18. cgutzmer

    cgutzmer Guest

    ok, it will be my next project - will be super easy now that eric made that post :) Eric, is the spoked wheel pdf I made up to date or do you have some new techniques? :D
  19. milenio3

    milenio3 Active Member

    Eric, I used your thread in the Aerodrome a few months ago for my Fokker E III. Although I didn't follow you step by step, the results I had were very good.
  20. EricGoedkoop

    EricGoedkoop Member

    Do you mean five bands of alternating color, or just five layers of card? I should think you'd need about 15 layers at 1/33 to reach the required thickness.

    p.s. Didn't mean to hijack your thread.

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