Dave Campbell

Well, here's the first part out of my 1/2A racer mold. Like most newborns, it's a little ugly because I had to force delivery, it was almost a terminal miscarriage.

Even though I waxed the mold three times in a row and used PVA mold release, It stuck in one of the wing fillets and I had to get forcefull with it. The fuses are green (soft) with this glue for a day or two, so the standard 12hour cure time is too short for this mold.

The other problem was the speed bonnet. Being an idiot, I didn't povide any draft angle on the sides of the bonnet, so it has a perfect air-lock to hold it in while the rest of the body pops out.

The black lines in the wing fillet are carbon fiber, the ones in and around the bonnet are marker I used on the cloth to see where the stuff pulled to. This enables me to resize the cloth that goes into the bonnet and make it lighter.

The speed bonnet is hell-for-stiff and all that shape stregthened the nose a fair bit. The fuse as you see it in the pic has all the mold flashings and has not been trimmed or ground out or the mod release washed off. It weighs .8oz or 22 grams, and is useable-just has a few light ripples from where I flexed it before it got hard.

Isn't it nice to have a little success in life? I had a few problems making the mold, and was sure it wasn't going to work out. All the problems I had were from me trying to cut corners in the interest of saving time and effort (i'm pretty impatient).

I'm glad the first one's over with because the next ones will definitely be better. I just don't know how I'm supposed to sleep with this on my mind.. But then, the mold needs time to dry and I wouldn't fly in 15 degree weather anyway!

Dave

DICKEYBIRD

AWESOME job Dave! The talent on this forum never ceases to amaze me.

Dave Campbell

Thanks Dickeybird, but it was nothing you couldn't have done.

You'll probably get to see one of these things this year. I visit family in Hopkinsville, KY and a friend in Gray, TN every year, so I'll be in your and Matchless's neck of the woods when it warms up. Or, you guys could come to the Toledo show this April and stay with me. I live about an hour north.

Oh, one thing I forgot to mention was that the nose dimensions and shape worked out so that you don't have to cut the nose or motor mount lugs off to slip the engine in. That is, unless your name is Dickeybird and want to use a TD-they are too wide. This first fuse will probably be sacrificed in order to make a template so that later fuses can just be cut to the right hole shape as they will be laid out in marker.

Dave

Oh, BTW,... The Cyclons will fit <very Evil grin>, they will just have 1/4" of the front of the motor sticking out past the nose of the fuse. Can you say 150mph 1/2A?

Jeff Leavitt

Dave,

Nice job on the fuse.... Will you be offering the flourescent dye in the resin? That would really be great.... Paint adds a lot of weight and complicates things a lot. .8 oz. with the color in would be hot. Too bad my VA's are rear exhaust I'll need to cook up another engine, Maybe a Cyclon! Jeff.....

Dave Campbell

That depends. The powdered flourescent pigments I prefer to use have been discontinued and replaced by a smaller volume, pricier liquid that isn't as good. Honestly, I prefer opaques as they look nicer out of the mold. The orange Sliver fuse you got was nice by our standards, but to the ARF modeller that most people are, the little blemish on your fuse would be unnacceptable.

Honestly, I do my best to make every fuse I lay up as if it were for a plane I was taking to the NATs. They are not always photo-perfect, like the Russian airplanes I compete against in S400. I'm tired of dealing with the "I want it perfect, ready to fly and damn near free because I'm cheap and have only ever flown ARFs" mentality of guys in 400, so I'm doing things differently this time.

Since 1/2A guys are 'builders' above average abililty, I plan on providing no pigment option so that they can paint them and make them as pretty as they like-just like any Q40 or Q500 composite racer.

You really don't have to worry about weight. Just swapping component weights with a light, but not contest built Sliver, we are talking about an 8-8.5oz airplane. One of the things that attracted me to this project was that I didn't have to spend as much attention to getting the weight low. I have literally spent hours coming up with ways to take weight out of the Sliver over the years. They started out as 15oz airplanes when they came out, nowadays, I'm dissapointed if they don't come out nearer to 12.8-and I don't use the lighest RX and controllers on the market. I mention this because I found that during racing on windy days (20mph), the heavier airplanes (13.5oz seems good for all conditions) flew better. The light airplanes visibly hunted in yaw and I hesitate to say 'struggled', but went upwind with less purpose than downwind. On a calm day, the lighter plane ROCKS though.

You could fill, prime, paint, build with the HS-60's, a standard RX, 250mah nicad pack, and STILL be well under 13.5oz.

Dave

Dave Campbell

OH, BTW: I won't be making these for you guys at .8oz unless you reeeeeally want them that way. they would only go up to 1.3-1.5oz if I changed layups to something sturdier-much better for an out of state contest when you cartwheel the little sucker and bust the fuse off at the tail... That's the reason I use Kevlar in the 400 Sliver

This fuse has 2 layers of 2oz. cloth with the carbon in between. The layup I would probably do is two layers of 3oz. with the same carbon and a 1" strip of Kevlar on each side running lengthwise like a Sliver. Maybe it won't need the Kelvar-I hope not because it's a pain in the ***** to cut that stuff in neat strips without fraying, lay it in the mold without disturbing it, and get it in there without it sticking to everything but where it needs to go. See, this is another reason why I don't want to do dyed fuses-the transparent ones like the fluorescents hide no mistakes. Frayed Kevlar looks like crap but you'd never see it on a painted or opaque fuse.

Dave

Dave Campbell

Jeff: I fully intend to fly this airplane with the VA 049 MK II. The original 1/2A Sliver has a similar nose shape and 1/8" gap between the bonnet and exhaust was fine. You'll need an alminum blast plate to keep from cooking the glue thought.

Another thing is that the radial mounts add about 1/8" to the length of the motor, and the VA is pretty short for a 1/2A. I set the nose up primarily for the Norvel as it was adaptable to most other 1/2A's (I think you can even use the Norvel muffler). The VA's short length will push it even further toward the nose, possible making enough room for a muffler. The VA will need the lugs cut off to fit now that I think of it unless you mind a little prop to fuse mismatch.

OTOH, you could also cut a hole in the speed bonnet and run the VA with a 1/4 wave pipe?

Dave

matchlessaero

and a good lookin' little guy he is.

That is gonna make one good lookin' little plane!

YeeHaw!

Dave Campbell

For general interest:

Dave Campbell

For Jeff's amusement:

Dave Campbell

For MY amusement!

Dave Campbell

....and a little Deference to Dickeybird!

(Ooooh......! Look at it's brilliant shine! Be drawn to it's light! Be the Barstock, BEEE the Barstock!)

*ROFLMAO*

DICKEYBIRD