Very nicely done. I never thought of using EMT as a mandrel. I've always used paper or phenolic tubing except for the 38mm mandrel I had one of my machinist buddies make from schedule 80 aluminum pipe.

Thanks Warren,
I used 1 1/4" for this. Did a 29mm also, used 3/4" for that one.

I learn from observation. Keep up the pictures. I really enjoy them.

38mm is a very easy size to get, 1.5" OD tubing. Alreco has tons in stock, if you make cases you want .083" wall thickness, otherwise I've sure he has .062 and .125 there.

Edward

Hey guys,

I got the fins cut, airfoiled and stuck on the tube.

Heres a back veiw picture.

Heres a picture of preping for the fillets.

I got my fabric, peel ply, breather and bagging all cut out today, going to do 3 layers of cf. I bought one of the Fiskars rolling cutting wheels, Wow what a nice job this tool does, highly recommend it. I'll post more pictures later.

Hey guys,

I got my fabric done yesterday on the fins. I did 3 layers of carbon fiber, first layer 1/2 way up both fins, and 2 layers tip to tip. This was my first attempt at doing the whole fin can at once.
#1- vaccum bagged and picture shows breather soaking up extra epoxy.

#2- Picture of the gauge, held at 17 Hg.

#3-Just after removing bagging, breather and peel ply materials.

#4- Trimmed up the extra fabric. I airfoiled the G10 alittle to sharp, so I enend up cutting into the wing just a bit.

#5- Veiw form the backend.

#6- Got this Idea from Jim Jarvis, sanded a shallow groove in front of the fins and the back of the fins, so I wouldn't have a bump on the airframe, worked out well. Kinda hard to tell from picture though.

I will say the hardest part about this whole process was getting the bag on with just one pair of hands. I just need to give her a thin skim coat and polish her up, very pleased with the results, thanks to all the information I've learned form this website. Thanks guys!

Very nice David! "Grom" huh? I'm currently having a piece of 4" airframe turned down in three steps to accomodate 1, 2 and 3 layers of tip to tip without increasing diameter. It is slated to fly at BALLS this year.

Hey,
Yeah whats a grom, hehe. I edit my post to "groove". Thanks Warren, sounds like you got a nice project going.

Hi,
I got the fin can all polished. I add a thin layer of epoxy before doing any sanding, or you won't get those little dust particles off there. Then start with 320, 400, 600, 1000, 1500, and 2000. Then use some 3M polish which gives it that wet look.
Finished picture gleaming in the sun.

That looks really nice. You sure you want to fly it?

Pretty impressive from a DIY perspective. I've ogled Mongoose kits, but I bet you were way more cost effective.

Thanks Steve, this rocket was going to be for the MMM contest, but I don't want to put a tail cone on this one, so I think I'm going to build another bird for the contest. Yes, tons cheaper to build yourself, I think I got about $60 in this rocket, eventually when I have the means to track this, I'm thinking a "J" would be cool. I'm also working on making it the booster for my 2-stage 29mm that I built, turning it into a 3-stage, but that's a ways down the road. Although a free Raven at LDRS would be awesome, nothing wrong with a guy that dreams, right? hehe.