Dummy pilots

[Piecost]

Hi George,

Can you tell the type of PU foam that you used?

Was it standard DIY aerosol stuff?


Tim

[dputt7]

Sorry MockwingF, I didn't understand most of that but what an amazing outcome.

[g_kandylakis]

Hi George,

Can you tell the type of PU foam that you used?

Was it standard DIY aerosol stuff?


Tim

Hi Tim, it was a very basic, stndard PU aerosol foam.

Same brand and type as this, only for hand application instead of a gun mentioned.

https://macon.gr/product/tekapur-standard-top-foam-enos-systatikou-afros-polyourethanis-genikis-chrisis-efarmogi-me-pistoli/

George

[Piecost]

Thanks George,

I will experiment with DIY foam

I attach a photo of a very nicely detailed resin printed 1:35 scale French pilot that I found on ebay. Inhave moulded him with 2 part silicon.

MockwingF, thanks for the explaination of the impressive modern technique for generating print files.

Tim

[Squirrelnet]

I like your resin pilot Tim, I'll be interested hear how you get on making a mould from him

I have tried again after the disastrous dolls house figure and bought a purpose designed resin pilot from an ebay seller called 3dclever. It's a rendition of Wilbur Wright but I'm more interested like George in the cap on backwards look of the pioneer aviators so I thought him suitable student pilot for a Deperdussin or infact a Bleriot. His arm's a bit high for the wheel but as I hope to do multiple moulds to create a full figure in foam I can lower it easily enough and he clearly has the confident look of a beginner to fly one handed !

3dclever do a small range of pilots in different scales but most are quite large and aimed at RC modellers. They do 1/12 which suits me and 1/24

[Piecost]

Success and sa monstrosity

I bought the cheapest can of "Soudal Gap Filling Expanding Foam", for about 8 quid, from the B&Q DIY store in the UK.

I taped and rubber banded my recent mould of the lovely ebay pilot and some old moulds of a home made pilot bust.

The can stated that the foam should be applied to fill only 1/3 of the void. So, I tried to do so; but it came out with such violance that it filled each mould.

I straped of the excess, like removing the froth from the top if a glass of European lager. To my supprise; after a while the foam shrank back into the mould hollowing out the bottom of the torso.

To my supprise; the middle pilot in the attached photo cane out really well. He only weighed 0.123g and his torso was nearly perfectly hollow. I am pretty happy with that for a peanut model.

One of the other pilots were less lucky and featured an incomplete head!

I am not sure why my experiments strayed away from squirty foam and concentrated on 2 part PU which required mixing. But, i did not have much luck with that. It foamed in the mixing cup rather than the mould so did not make a complete skin.

So, thanks Goerge and others for the tip. This turned out much easier than I thought.

[Squirrelnet]

That looks great Tim and very encouraged to hear it was more straightforward than you feared


The 3d printed pilot today and looks very promising.

He looks great in the Bleriot though his arm will need lowering..or maybe he's waving to crowd not sure

As both the Bleriot and Deperdussin have open cockpits it would be nice to do a full figure if I can so I may have to make a top half and bottom half mould or maybe even three top, bottom and right arm again not sure

[g_kandylakis]

Hi Tim,

I also struggled with 2-part foam and got very average results. That said, there must be tens of different foam makes and type for specific applications, so finding the correct one might take some time. The Czech guys make their pilots like that and they look amazing and are very light, so they must know better.

The spray foam proved good enough for me. The problem with imperfect filling has to do mainly with air pockets. You might try some ventilation holes or cuts to allow the air to escape and let the foam fill the cavity. Extrq foam (like flash in plastic parts) can easily be removed when everything is cured.

Also, no point to remove the excess, just let it cure and cut it afterwards. It helps with better filling too, since it solidifes first and forces the foam to expand inside the mold more.

It seems to work best if you fill the cavity with foam, by allwoing it to somehow flow through, by cutting a hole at the head top for example. When cured, you can cut adn sand to shape. You can also hollow out quite easily. Worst case, cut it in half, hollow out and glue back together...

Just some ideas.

[g_kandylakis]

Nice looking pilot, Chris.

About the arm, mold it as it is and decide later if you want to raise or lower it. Foam is flexible enough... I see little need for multiple molds. You can make more parts and cut accordingly. Air pocket prevention is more important, to allow proper filling of the cavity, as already stated above.

Back to my Batboat pilot, Mr. Harry Hawker, or at least a good look-alike of him.

Having received the STL file by Markus, I did some print tests on my FDM printer (courtesy of another german friend...) to setle on the proper size  for 1/20 scale, arriving to 65% of the original file size.

As it came out of the printer with all the support structure

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clened up, next to the existing dummy pilot
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3D print software allow you to scale up or down the STL file, to create different sizes of physical models.

This pilot does not look great, it was not printed with full detail and the highest resolution, but that was not the point of the test.


Now the file has been sent to a friend to be printed to the desired size with a resin printer which will provide much better results, since the STL file looks of very high quality.

More to follow when I get it and make a new rubber mold.

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George

Unrelated..

I just found out how to avoid double appearance of pictures when they are inserted in the message... Looks better

[Squirrelnet]

Made a start on the 1/12 Bleriot/Deperdussin pilot today. As I want a full figure if possible for the Bleriot at least I've decided it will be easier to do split around the top of the legs with some overlap to allow it to be joined.

The mould is cast into a takeaway container and I'm thinking I will split the mould along the line of the extended arm and then in a line across his chest sort of indicated by the 1/16" sq stick but in more of a quarter to one position

Only after I'd poured it did I think about mould release spray but good thing I didn't use it as looking it up, silicon release spray can act as a binder for silicon rubber actually sticking it to the part - no release is needed for the silicon rubber

Maybe I should have bought some lego to make a box to cast into as I could then make sure the mould stays in shape but I didn't think of that soon enough

[gravitywell]

This does NOT look dignified!

[MockwingF]

I'm building a peanut scale BD‑4, and for the pilot figure I used an original 1987 photo of Jim Bede (old.bd-4.org/gallery). I tweaked the photo with AI to add a headset and complete the lower body, then turned it into an STL using Makerlab's Image‑to‑3D feature and printed it in resin.
Now I'm getting ready to make the silicone mold — excited to see how this experiment turns out.

Markus

[Squirrelnet]

Love the BD4 pilot Markus he looks great

I had a first go at foam PU moulding today.

The pilot figure figure came out fairly easily, though I snapped his leg off which glued back on with some cyano

There a few small bubbles in the silicon but nothing to drastic so i thought I'd give it go with some foam. I was a bit concerned about getting the foam up his arm so I made a 90 deg turn for the applicator and started by squirting some in the first then quirting in the head and finally filling the rest ... lets see what happens when it dries

The stick on his head is so it vents to the outside, there's a similar arrangement at the end of his arm in an attempt to prevent trapped air pockets

[Squirrelnet]

Well that has worked very well, thanks for the thread George I couldn't have done it without the reference from your pilots

 As Tim has already said the PU foam is very simple though I'm glad I had air exits at the end of his arm and top of his head to prevent air pockets which seems to have worked well

Taping the mould together has worked too, in fact the silicon had slightly re-stuck itself along my parting lines and needed gentle encouragement to open again which has minimised the flashing

Untrimmed weight is 4 g for a 1/12 3/4 figure. As a guide my current 1/12 Dave Banks pilot is 5.5g painted and with magnets

[dputt7]

Mockwing F that is amazing technology, well done and thanks for sharing.
  Chris that all worked out all right you should be pleased