Level 2

I think I'll call it ELP 201.



View attachment DSC00466.JPG

This is just dry fit. I'm waiting on some good epoxy to put it all together. The fins are going to get a layer of fiberglass just because, and the transistion is paper so its going to need some glass on it.

Stormbringer said:

This is just dry fit. I'm waiting on some good epoxy to put it all together. The fins are going to get a layer of fiberglass just because, and the transistion is paper so its going to need some glass on it.

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FWIW, I would probably give the fins 2, if not 3 layers of FG. Although you have already constructed a smaller version of this rocket, (quite nicely at that) you're upscale is going to see much more impulse and fin flutter (due to the tubes) may come into play. You might also want to beef up the fillets on the fin-tube transitions.
Beautiful design....looks like it's going to be a real whistler.
_______________________________
-Chris

Those fins must be one of the coolest I've ever seen. Did you cut the tube in half and glue it on each side of the fin, or did you make the fin out of two peices and glue them together with the tube in the middle?

The plywood is glued to the tube. These are 1/4" plywood on a 29 mm tube. The small version flies real nice, I'm hoping the larger model does just as well.

The fins are based on the FSI viking rockets.

Finally all the parts came in. Here's the first layer of glass (6 oz.) going on. I should have put a fillet in first, I'll do that on the other side.

Looks good......Just curious though why you didn't carry the FG out to the edges of the fin?
Also, it still isn't too late to put fillets on the FG side of the fins anyways. It will still add more strength as well as aerodynamic consistency. J/M 2 cents.
Nice start......
Keep the pics comin.......
__________________________
-Chris

I'm going to lay another layer over the whole fin, I just thought that this would help stabilize the tube. After working with it some today I realized that I should have wrapped the tubes first and then attached the plywood and then layed glass over the whole thing.

Stormbringer said:

I'm going to lay another layer over the whole fin, I just thought that this would help stabilize the tube. After working with it some today I realized that I should have wrapped the tubes first and then attached the plywood and then layed glass over the whole thing.

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LOL..Ya know.....I was gunna say that in the beginning, but you had them all glued up already, and it wouldn't have helped very much to make mention at the time.
Actually, you're still ok though. As long as you epoxy in your fillets like you mentioned, and glass (I'd still do 2 layers, though) them, you'll be plenty strong. Heck, if ya wanted you could still glass the I.D. of the tubes with some wax paper and a balloon.

And just so you know, there are 4 other people here (more family rocketheads) reading your thread, that are completely blown away at your fins. In fact you may have started a new project for us.
So with that I say thanks .....
Please keep the pics comin'.....ya got us hooked now.
__________________________
-Chris

This is the transistion/electronics bay. I put one layer of glass on the inside and it has 2 layers of 6 oz on the outside right now. I think I'm going to add a layer of 2 oz and see if it makes it smoother(is that a word?).

This took longer than I expected.

What would have been the proper way to put these fins together?

Can you lay 2 layer of glass at the same time?

Do one layer need to be sanded before the next one?

Shouldn't the fins been vacuum bagged?

Stormbringer said:

This took longer than I expected.

What would have been the proper way to put these fins together?

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Glass the tube, then glue it on and put glass across the fin and tube

Stormbringer said:

Can you lay 2 layer of glass at the same time?

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yes you can lay up to 5000 at a time

Stormbringer said:

Do one layer need to be sanded before the next one?

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if you let it completely cure. You can either put them on one after another, let the epoxy get a little thicker (sometime called the leather stage) or let it cure and sand

Stormbringer said:

Shouldn't the fins been vacuum bagged?

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no, they can be but, no

Thanks for the info.

Tubes with putty, how exciting, more sanding.

couple of new pics.

Those are some awesome fins you've got there!

One layer of glass bonding the fins to the motor tube.

Is one enough? The smaller version is just surface mount but all I've flown it on is D & E motors.

I will let some with more experience with glassing then I of which I have none give their expert advice..But, I think 1 layer should be fine..

I would guess that the one layer of glass inside will be more than enough.

Truthfully, as I look at what you're building with (plywood and LOC style paper tubing,) I'd have just used wood glue throughout without and glass and not given it a second thought. I know it would hold together great and withstand some abuse.

That said, if you think you've got it all stuck together as well as you would if you were using wood glue, I'd be satisfied.

I glued the fins to the motor tube with probond wood glue and then used the epoxy and fiberglass on the inside. I will lay some fillets on the outside around the fins and that should tie it all together.

In my humble opinion, it sounds like one layer should do

those are some messy fillet's...lol. but they'll do. a trick to getting solid glass fillets on the inside of your tubes (without cutting your fin slots to the back of the BT), is to lay your strips out normally with the rocket verticle, and then sliding down a medium like wax paper (though it usually sticks for me...maybe i just buy the cheap stuff) or a cheap plastic drop "cloth"...its in the painters section of wal mart or any other store like that. and its cheap, like a dollar for 20sq ft... anyway, you take a good section of drop cloth and roll a balloon inside of it, then put it in between your BT and MMT (with fin tabs on either side) and blow it up with some air pressure...then tie it off and let the epoxy cure up,

ps. sorry, they're good fillets and they'll work, but im just saying there's a more efficient way of doing it, thats all, im not knocking you at all, in-fact, those are some seriously nice fins...you should hear that sucker whistle from a mile away...

Yeah, this was the first attempt at glassing the inside.

So I need to:
spread some epoxy,
put the glass on
then some wax paper
then blow up a ballon on the inside
??

couple of pics of the outside fillets.