DonStegall

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Though I completed the molds for the Smasher back in 2002-2003, I stopped making them as I started working on club pylon racing. I’m now getting back into full production of all of my fiberglass and composite parts. And I’m offering kits and parts in new configurations.

This is the Smasher. It has a bolt on tail. But it can be built with a conventional tail as the stab saddle is at 0 degrees to the wing and firewall. It uses the 66-012 airfoil with no modifications. Fully symmetrical.

I am now cutting 66-012 foam cores and very soon I will be selling sheeted foam cores using techniques borrowed from Bill Vargas and others.

I am making my plans for the wood bolt on tail user friendly and I will have plans for the conventional tail as well. I am going to do threads on building the wood V-tail and the wood conventional tail.

So I am offering the Smasher in these configurations (now):

Fiberglass fuselage, foam core, plans - $100 plus shipping ($25 in the US)

Fiberglass fuselage, sheeted foam core, plans - $150 plus shipping ($25 in the US)

Composite tail - $75 plus shipping ($15 in US, can ship 2 in one box)

I plan to have the molded composite wing done by June 1. The price will be very competitive.

vicman

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Looks pretty good Don.

DonStegall

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Thanks Vic.

I forgot that I had some pictures of a wood tail that I built when I was doing the prototypes.

When I do the thread on building a Smasher for 424 with a bolt-on V-tail I will show how to build one without the little points (vortex dissipators) that is easier to make. I have a jig design that is useful not only for this tail, but for any V-tail.

vicman

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What is the hinge made of? Is the carbon there to stiffen the control surface?

DonStegall

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The hinge is Kevlar. The carbon laminate was to prevent twisting of the elevators. This tail did not have it applied on the bottom yet. I was running 428 engines on the prototypes and was concerned about the balsa not being strong enough. I didn't want to take a chance on flutter. I lost one prototype to a tail failure. It was a foam core airfoil tail. But I don't know if it was the tail design or construction. So I went with the simpler tail for the first version of the composite.

On my composite tails I use CF on the inside of each skin of the elevators. It maybe adds $1 to the cost, but the elevators are extremely stiff.

This tail has been handed off to someone who may put it to good use.

vicman

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What wt Kevlar?

I just placed an order today for some 1.7 oz, shears, and cab o sil.

DonStegall

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It was 1.7 ounce ... Unfortunately it had been stuffed in a box and was wrinked up. Be careful of how you store the Kevlar. It has memory and will remember folds.

I use 1.8 ounce 1" Kevlar tape on my composite hinges now. Not full length like the one in the first set of pictures because it makes the hinge too stiff. I use it out on the ends where the control surface is cut out, and I adjust the stiffness of the hinge with the amount of Kevlar.

In the case of this wood tail, it worked fine. Because it was just the Kevlar and the slot was 1/8" wide. But on the composites, they have a layer of 1.4 ounce (glass cloth) on the outside, then a layer of 0.7 (glass cloth) on the inside. When I didn't use Kevlar I used an extra strip of 1.4 ounce cloth on the hinge line. This is not quite stiff enough.

Make sure you read Dave Norman's article at [link]http://www.nmpra.org/Documents/Skinned-hinges/Hinges.htm[/link] as there are other and better ways of doing what I did. I was cranking out those prototypes just to make sure the plane would fly well before making plugs and molds.

Glad you got some cabosil. Everybody needs some.

vicman

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I have done a few using Dave's method but they tend to break after a while. It's ok when I use covering but if I paint the plane I'm a little concerned about just the glass holding up.

Dave goes thru planes like I go thru Canadian Club and isn't worried about a plane living long enough to have the glass break down. [sm=bananahead.gif]

DonStegall

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Vic,

You're almost there then.

Lay up some Kevlar on some glass or marble and make a sheet to use on your hinges. Then use Dave's method. That way you won't have to deal with a bump on the surface.

But you can do it the way I did if you fair in the edges with some epoxy filler with microballoons and a little cab-o-sil.

daven

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WOOOO there a minute....

I've actually been good with planes, only lost one in the past 3 years and it was a Q40. Been a long time since I took out a quickie, heck, little AJ has wrecked more of my quickies in the past 5 years than I have

Vic, have you really had issues with the fiberglass laminate cracking?? Are you cutting it on the bias, or with the grain? I've done many quickies with the .010 on wings, and .005 on tails (with a layer of 1.4oz and .75 oz sandwiching the laminate) without ever a crack issue. When laminated, they get bagged at 22-23" of mercury.

I stopped using the Kevlar for a complete hinge as they tended to be a bit too stiff. OK with high buck servos, but not the ones most people can afford.

Maybe your cracked because of those "3D" type throws your trying to use for racing

vicman

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Wow! That got a quick response LOL.
I didn't use the sheet stock for my hinges I laid up two lairs, one of 2oz at the hinge and covered the whole tail surface with .75 oz. I did another one with the 2oz on the bias. They just seemed to be very fragile and want to pop a lot.
My plan this time around is to lay the kevlar down and glass over everything with .75oz. then cut the hinges in. I'm pretty optomistic on how this is going to come out but it's all experimentation at this point.
Like I said if I were using covering this would be a non issue since the covering would hold everything togeather like it did on my BuckShot but I also want to get to painting the model finished.

daven

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LOL is right

I've done hinges with a lot of materials, including neoprene scuba suit material, and every combination of glass and kevlar. Even did Carbon hinges (bad idea) once.

The fiberglass laminate has worked best for me.

If you are using Kevlar tape 1", be carefull of the sewn edge om the tape, it can leave a ridge on your tail. If you have that problem, just tell people you build turbulaters on your tail, and it makes it faster

djlyon

I've been using fiberglass laminate for 4 years now every sense reading Dave's method. I do it a little different but not much. I have 100% success with no failures except on impact

Denis

vicman

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I bought plain weave mat and will cut strips. We'll see how things go soon.
I wanted it for aileron hinges too.

Alabama Racer

I make my own fiberglass mat to use as hinge material. I lay up 2 layers of cloth, one on the warp & weave (90 degree orientation)
and the 2nd on the bias. I vacuum bag this with peel ply on one side. The texture left from the peel ply leaves a great
surface to glue onto the wing or stab. On the other side, I just use wax paper so that the 'glass/epoxy will not stick.
I vacuum this on a flat piece of wood, put it in my hot box to cure. After peeling off the wax paper and peel ply,
can cut my strips of hinge material to whatever width that I need. Have used 2 layers of 3 oz cloth and sometimes 1
layer of 3 oz and 1 of .75 ounce. Both methods seem to work well. I have not measured this to determine
its thickness. Have not had one fail yet, some planes with probably 50 - 60 flights.
brad

DonStegall

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I know the conversation has veered toward skinned hinges, but I'm going to post photos of the Smasher tail molds because some people asked to see them.

In terms of the skinned hinges, I have layed up fiberglass on a sheet of glass to make hinge material. I use 1.4 ounce, then 2 ounce on the bias, then 0.7 ounce on top. This seems to be about the right stiffness for a 1/8 to 3/16" gap. I think a single layer of 1.7 ounce Kevlar, possibly with 0.7 ounce glass cloth on top and bottom would be a good alternative.

luv to race

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I'm not trying to hi-jack the thread, so excuse my one comment here.

But skin hinges is so over-rated as a building method. Can anyone honestly say they are that good of a flyer to really determine it's faster? maybe on paper right Save the time and effort and just hinge your surfaces normally. Keep your bevels as small as needed, you only need at most 1/4" of throw on your surfaces.

We use a composite tails on my Vortex's. But I've done just as good of times with a wood tail and "standard hinging". And I can honestly say I couldn't feel any difference in airplane performance.

if you like to tinker...then do it. but if you're searching, stop searching. there is nothing to gain.

OH... DN builds some pretty good stuff. I go ahead and say his layup method is probably pretty solid..[8D]


Randy Bridge

djlyon

I have to agree with Randy whatever that means because he is several orders of magnitude a better flier than me. But I have found that my derivation of sheet fiber glass hinges is actually faster and easier to do than standard hinges. Go figure [X(]

Denis

luv to race

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It does look cool to the sport flyer though. I love that comment.. "hey buddy, you don't have ailerons?"..LOL...

Randy

garys

Randy's right. On both ailerons and elevators, the air is already turbulent by the time it gets to the hinge line, so it's really just a cool factor I will say, however, that when I was still building wook Q500's, I could probably save overall build time with skin hinges than with conventional, as I could save a lot of time during covering.

vicman

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Funny how this has turned. I was answering this question to someone on the phone just last night.
Reason #1, doing hinges is my least favorite thing to do bar none, I hate cutting them, I hate gluing them, I hate messing with them all togeather.
This unpleasant activity has led me to using all kinds of tools, materials, and methods and the skin via kevlar is just the latest chapter in my quest for a less anoying way of doing it.
Reason #2, If the fast guys are doing it there must be some decent reason. Plus it kinda makes sense.
Reason #3, If it looks good, it'll play good, and I'll feel good.

Thanks to those that share thier experience and ideas here. I really do listen, some of it just takes a little longer for me to understand.

luv to race

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All good points Vicman. If it's easier to do skin hinges, I say do it. But if someone is struggling with the concept, no worries. Do regular hinges. And just use the CA hinges, a little thin CA and have a nice day.

And the reason the "big boys" use skin hinges. Probably because they are all flying composite stuff, and that's the way the builders lay it up.

RB

DonStegall

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I've had a number of people ask me about carbon fiber in the Smasher fuselages. I finally realized that I haven't posted any pictures other than the primed in the mold fuselage.

Here is a fuselage without the primer. I'm no longer priming them in the mold. It takes an extra day and I have too many orders to waste the time. I will be making more sets of female molds from my male molds so I can make more than one a day.

This one has a void on the seam where the carbon fiber is. I will patch it before it goes out. I may use this one for myself.

I use 12K CF tow on all the edges because it makes them chip-free.

DonStegall

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I've had numerous requests to do a video of laying up a Smasher, like the series I did for the Stinger. Fortunately I'm so busy I don't have time to do that right now.

But I did take time to shoot a couple of photos before joining the one I laid up today. I'm having to lay one up a day to keep up. A happy problem.

The Smasher is split on the sides at the thrust line. I got this idea from Dan Kane and the fiberglass HurriKane. It has the benefit of having perfect registration between the wing saddle and the stab saddle. Plus I can put in the blocks for the wing hold downs, the tail hold downs, and the landing gear block as I am joining it wet. The only thing I have to do after taking it out of the mold is to put the firewall in.

jirvin

No longer racing myself but very much into composite construction.

Spends lots of time trolling in this forum as it is probably the most active for home composite builds

This link shows F5b techniques including:-
hinging with kevlar
use of joggle gaskets to avoid voids in the seam lines
painting in the mold

babelfish translation.......
http://66.163.168.225/babelfish/tran...ght%3deisvogel


Thanks for sharing you work on youtube

cheers jeff