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        Build Log Making scale pilots and replicating them.

#1 fuelsguy Oct 28, 2009 07:36 PM

Making scale pilots and replicating them.
 
3 Attachment(s)
Glenn Moore an I have been going down a very similar path on how to make pilots from light weight material and to be able to make multiple copies of the same pilot.
Since we have independently reached the same skill level it seemed worth while sharing this with the Forum.

As a sample here is my 1/9th scale pilot for a Hellcat I'm building
(http://www.rcgroups.com/forums/showt...6#post13417086)

The hope here is to describe a build of another master pilot, probably an RAF pilot and encourage other people to join in and share their ideas.

The foam pilot shown in the photos is 3" high and 2.5 inches wide across the arms for 1/9 scale.
The weight of this guy is 5 grams, or 0.17 oz.

The attractiveness of this is twofold, you get a pilot that meets your scale needs and is light enough to be used in any airplane and is reproducible for the next model or for a friend.
I have standardized on 1/9th scale for my WWII fighters as they are large enough to fly and look reasonably scale and they fit my Subaru.
Doing a 1/12 scale or a 1/4 scale pilot or crew member is the same process.
I will start on the build and paot photos tomorrow all being well.

Ivor

#2 WTFLYR Oct 28, 2009 09:07 PM

Nice job Fuelsguy. For the most part, if we want decent pilots, we have to make them. I was at the LHS yesterday, and saw a new vintage pilot there from great planes, which appeared to be the perfect scale for the WWI plane that I am working on now. At closer inspection, the Elton John sunglasses killed the whole thing. Vacuum and silicon molding are the 2 things I really need to do.

#3 portablevcb Oct 28, 2009 09:54 PM

I just get mine from Sparky, parkflyer plastics.

#4 J Morgan Oct 28, 2009 10:33 PM

This will be an interesting thread and fills a void. I have trouble finding pilots for my big planes. 1/9th is getting close though.:)

J

#5 CarreraGTSCS Oct 28, 2009 10:55 PM

I'm in.

#6 Guerrero Oct 29, 2009 12:57 PM

Me too!

#7 glenn7e Oct 29, 2009 01:28 PM

3 Attachment(s)
here is my contribution, one thing we have found is that the material for making the moulds is quite expensive but once you have a mould the pilots
can be produced at a very reasonable cost and the moulds should last a long time.
more later,
Glenn

#8 fuelsguy Oct 29, 2009 02:15 PM

6 Attachment(s)
OK, First, here's an overview my approach for the people who like to see the big picture before anything, here is what the process looks like speed-ed up.
1, Make a clay pilot figure and bake it, or if its air drying clay, let it air dry until itís hard
2, Make a silicone mold of the figure. This is done by cutting a cup like shape to fit around the figure, mixing some silicone mold material and filling the cavity between the figure and the cup and waiting until the silicone hardens.
3. Make sure you can extract the figure from the silicone mold. The silicone is very flexible and can be pulled a lot to help extract the figure. (Glenn uses a two part mold which is more complicated to do, but is a little easier to deal with once itís made, but you have a parting line on the final model to correct.)
4. Put the figure back in the mold and make a plaster of Paris support around the silicone mold, making sure you can pull the mold out of the support. The support is just to hold everything in place when casting a pilot.
5. Take the silicone mold out of the plaster of Paris support, remove the master figure and replace the mold in the support.
6, Mix up a small amount of expanding foam and pour into the mold and wait until the foam expands and hardens.
7, Remove the silicone mold from the support and then remove the pilot figure from the silicone mold
8, Paint to suit
9, install in your model or make another pilot.


I hope all this make sense,
I'll start getting into the nitty-gritty of making the master figure next post.

Ivor

#9 prunner Oct 29, 2009 02:52 PM

What is the expanding foam called? Where did you get it? Cost? I've always wanted to try making a whole pilot or even a bust, but am afraid I'd go all OCD w/ the carving. I'd really like to extend one of the Petes Pilots busts into a full figure. Thanks

#10 fuelsguy Oct 29, 2009 03:25 PM

The basic material I use for making the master figure is stuff called Super Sculpey. There are lots of other clay materials around so visit your local art supply store and chat to them.
I like Sculpey because it’s easy to mold in your fingers and stays soft until you bake it for 15 minutes.
The clay is relatively hard when you take some out of the box, but if you knead it for a few minutes it becomes pliable.
For the mold making I use a Product sold by TAP Plastics although there are lots of other suppliers.
The Silicone mold material is their Platinum Silicone System, it’s a two part easy to mix product. Expensive by my standards, but you can get two molds from a 1lb kit.
http://www.tapplastics.com/shop/product.php?pid=494&

The Plaster of Paris is available everywhere.

The expanding foam is again a TAP Plastics product. A two part mix, A and B, used in equal amounts and it produces approximately 30 times the liquid volume as foam. For these pilots the trick is to make just enough or you have foam expanding all over the shop!!! My 9th scale pilot is roughly 30 cc’s in volume so I only need 0.5 cc’s of each part. That down in the less than a teaspoon range. The foam is quite hard once it has set so taking the figure out of the mold is easy. The surface sets to a good skin that just needs a few touch-ups here and there.
http://www.tapplastics.com/shop/product.php?pid=79&

As far as making full pilot figures, this approach works just as well, all you need to do is make up master figures for the head/torso and then the hips and legs. It's not a big deal, just needs some practice in making the master figures. Sculpey is nice in that regard as you can make up a figure and if you don't like it you can mash it back into a ball and start again. Quite satisfying actually, and good practice.

All for now,
Ivor

#11 skylake Oct 29, 2009 03:53 PM

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Here are some of my foam pilots I have been making, and selling on my website smaller than yours mine are around 1/20 scale to fit my line of free flight models. I have a new set of WW2 pilots coming soon.

I have found the mold support is not needed using silicone molds, have you tried it without ?

#12 fuelsguy Oct 29, 2009 04:58 PM

Skylake,
Nice models, look very much like mine as far as finish and foam is concerned.

I built the support so I could try various pour compounds before settling on one. Foam is the best by far for the weight and the finish is OK. Glenn has been putting a coat of latex rubber on his two piece mold before the foam. It gives a slightly better finish but, IMHO, is not worth the effort in a full mold as it takes forever to dry the latex. I've seen commercial examples that seem to use a thick rubber compound but I haven't figured out what it is, but it still several time heavier than foam.

I'll try the no-support method this afternoon and report back.

Ivor

#13 skylake Oct 29, 2009 05:09 PM

I have been spraying a coat of Zinnser BIN primer on mine before painting it really helps a lot, strange stuff BIN primer. Get it at ACE hardware or Home Depot.

#14 jhspring Oct 29, 2009 05:48 PM

Guys, thank you so much for this thread. I buy Pete's and JustPilots busts, but for many of my planes I would like to have separate arms and longer torsos. My foam carving skills can best be described as marginal, so this looks like a great solution.

Cheers,
Jeff

#15 fuelsguy Oct 29, 2009 06:44 PM

Skylake,
I tried the no-support method and it looked OK but the result when I took the pilot out of the mold was a decidedly tubby pilot. There must be just enough give in the silicone rubber to let the foam push the mold out a little, or maybe its just gravity on the mold. Looks like I need the support, at least for the bigger figures.

Jeff,
Glad for the support. Tomorrow I'll get to the modeling the master pilot stage. I have thought about full body pilots, it's just a little more complicated to make the torso longer and create a lower body as a separate master and mold.
All of this does get you to the reproducible stage so you can have pilots for lots of models of the same scale.

Ivor


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