Gt-R - A 29mm MD Rocket - Build Thread - MIA

RAHagen said:

Chris, I thought I'd use your car as a target, you know so I got something to aim for. You wouldn't mind right?

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I'm just getting it back from the shop tomorrow, so not a good plan. Apparently, some fool can't back up the family van without doing $2000 worth of damage to his own car...the dreaded double insurance claim of shame. Besides my car is small, aim for the big orange Dodge, I'm sure the owner won't mind.

Anyhow, glad you have a DD scheme worked out. I mean what are you going to fly this with where single deploy would be good, an F maybe?

Haha I'm not actually sure. I haven't simmed it on anything smaller than a G. I'd probably have to adapt down to an E to make a single deploy viable.

Cl(VII) said:

Besides my car is small, aim for the big orange Dodge, I'm sure the owner won't mind.

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The Challenger isn't mine :cry:. A friend needed a truck so she could move, so I took one for the team and suffered through a weekend driving her car.

AlfaBrewer said:

The Challenger isn't mine :cry:. A friend needed a truck so she could move, so I took one for the team and suffered through a weekend driving her car.

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And you gave it back!?

Well, she knows where I live. I don't want to come home to find a rabbit boiling on my stove.

Plus, an orange Challenger is kinda hard to hide.

Peel ply came in today, I'm expecting the epoxy and glass to come in tomorrow.

Also got around to getting some pictures of the av-bay set-up.

Oh yeah!, that blue peel ply is awesome. The best part is it's super soft surface texture after release.

Nice e-bay man.

Nice project, looking forward to seeing it progress.

Glass and epoxy came in today, should be able to start glassing the tubes Saturday.

I think I've decided also to go ahead and attempt to make my own fins instead of buying them from PML. It'll be cheaper, and it'll help me get more experience with composites.

Got the tube glassed today!

let the shop warm up, cut the glass and the peel ply to size and went to work.

For a first try, I believe it turned out fairly well. There were a couple pinhole bubbles that I couldn't get out with my brush, but It should fill in with some filler primer or a finish coat of epoxy.

I'm letting the tube cure overnight and I'll try to get some photos of it without the peel ply tomorrow.

Lots and lots of bubbles.
Took the peel ply off this morning and found that I had a lot more bubbles in the wrap than I had first thought. The tube is still very sturdy so it should work fine for my purposes, but this is where my OCD shines the brightest: "I gotta get all the bubbles!"

Got some more composite work done today. I had time today to lay the finish coat of epoxy on the body tube to fill in some imperfections, and to make a fiberglass plate for the fins.

Thanks to the generosity of our local neighbors I was able to borrow some THICK steel plate to sandwich the fiberglass together, and to be extra sure that I had plenty of force to press the cloth down flat I put it in our 20 ton press. I'll get some pictures when I take them out tomorrow. Hopefully they'll come out nice...

Some photos of the press setup and finished body tube.

Okay so I'm coming up to something that I didn't expect... I opened up the press and took the fiberglass sheet out and It was as flexible as a piece of cardstock! I'm not really sure what is the problem.
A few possible reasons that have been brought to my attention are:
1. The fiberglass board was too thin
2. The fiberglass was still curing
3. The glass is not strong enough to create a solid fin by itself
4. The 20 ton press I was using pressed so much of the resin out that I was left with an overly flexible board and below average strength.

I was able to get the board to stiffen up a bit by setting it out in the sun for a couple hours but in reality it is still way too flexible to be used as a fin material. I was thinking that I might be able to use it as a sort of core for more FG/CF or maybe go ahead and use them as the fins and T2T them to the body tube.

Any and all advice on the topic is greatly appreciated!

How many layers did you use? Without any pressure a 6 layer laminate will give you a 0.06" thickness. I would try 12 layers.

SinfulDarkLord said:

How many layers did you use? Without any pressure a 6 layer laminate will give you a 0.06" thickness. I would try 12 layers.

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I used six layers. Overall the thickness came out to around .045". If I added six more layers it'd bring the thickness to around .09". I'm just worried that if I'm doing something wrong then I might end up with a 12 layer board of glass that is too weak to be used. Should I be worried about pressing too much resin out of the board?

RAHagen said:

I used six layers. Overall the thickness came out to around .045". If I added six more layers it'd bring the thickness to around .09". I'm just worried that if I'm doing something wrong then I might end up with a 12 layer board of glass that is too weak to be used. Should I be worried about pressing too much resin out of the board?

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Your not doing nothing wrong. Thing is when 6 layers is compressed down into a thinner laminate it is just more flexible. I would try 10 layers. It is actually a good thing to squeeze out as much epoxy as possible. It makes it more lighter by getting rid of the excess epoxy.

SinfulDarkLord said:

Your not doing nothing wrong. Thing is when 6 layers is compressed down into a thinner laminate it is just more flexible. I would try 10 layers. It is actually a good thing to squeeze out as much epoxy as possible. It makes it more lighter by getting rid of the excess epoxy.

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Okay that's good to know. Next day I can get time to work on it I'll add a couple more layers.

I would also suggest not putting it under a 20ton press Use a couple of weights and you will be good. I used a couple of textbooks when making mine and it came out great and really strong.

The more I think about it, the more I think the press wasn't the issue. I think I just didn't put enough layers in the layup. It's also very possible that It is more flexible because i forgot to alternate angles with the weave.
I'm going to go ahead and add a couple more layers with alternating weaves and see how it comes out.

Okay I've been talking with wfcook over PM for a a while now and he has agreed to make me one of his Fly-Away rail guides in 29mm for the Gt-R. Thank you wfcook! I'll be sending him a sample of the tube in the next couple days so he can have a point of reference for the guide so it fits properly.

Tube has been sanded and I'll be cutting it to size hopefully tomorrow.

Okay I finally got the tubes cut. Our chop saw can't cut even to save is life so I'll have to go back and square them.

I probably won't be able to get much more done on this in the next week or two. Our family is moving closer into the DWF area so for the next couple of weeks we'll be getting settled in and my (already slow) work pace will slow down a lot. Hopefully I can get all set up quickly so I can get back working on my rockets!

Cut tubes:

Okay, now that we are all-in-all moved I can finally get back working on Gt-R!

Today I got the av-bay finished for the most part. I still have to cut the coupler to length but I decided to wait till I get the nose cone.

Cut six more squares of fiberglass to add to the existing board. Should be able to get them laminated tomorrow before the temperature drops down again.

Me and the cold have a love-hate relationship... On the one hand, school has been cancelled, but on the other hand I can't due any composite work cause it's too dang cold!

RAHagen said:

Me and the cold have a love-hate relationship... On the one hand, school has been cancelled, but on the other hand I can't due any composite work cause it's too dang cold!

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Im in the same boat at the moment.



Doing these in the cold makes for a looooong wait.

Here are your fly-away rail guides around a segment of your nicely-glassed tube - I will ship them out as soon as I can get to the post office.

wfcook said:

Here are your fly-away rail guides around a segment of your nicely-glassed tube - I will ship them out as soon as I can get to the post office.

View attachment 257496 View attachment 257497

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Wow! Those look great! Thanks again for going through the trouble of making these! I'll make sure to get a camera pointed at the top of the rail so I can try and get it on camera.

Stand by a little bit - I am considering making them a touch shorter. Anyone who has opinions on the required length please chime in. I've done the hard part, though, so that would be a quick change.