Winter Scratch Build

I've started working on a new rocket after our last launch of the year was shot down by high winds. It's a clustered engine rocket, with the engines seperated in individual tubes. One of the questions I have been pondering is to use balsa with paper skins or plywood for the fins. They seem somewhat skinny and breakable to me for balsawood and 1/8 plywood doesn't seem to hurt the stability much.
Here are the plans and a picture of what I have so far
John

Boy, I like that. Seems like a good candidate for a ring on the bottom. Just my :2:. Keep us posted. Heres a pic of one I built.Kinda sorta like that.

Scott,
You may be right about a ring on the end, but for now, I'm sticking with the struts to hold the back end together. You've got a pretty nice collection of scratch builds in your temple. Did you coat the aft end of the Bad Boy with something to get that plastic look or switch from balsa to plastic as you built it?
John

Now that is a Scratch build!!!! Very nice! :wink:

Madison Alum said:

Scott,
You've got a pretty nice collection of scratch builds in your temple. Did you coat the aft end of the Bad Boy with something to get that plastic look or switch from balsa to plastic as you built it?

John

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Thanks. No plastic on the Bad Boy. Just paint. Dont know if you seen them, there is some build pics in the gallery also of the Bad Boy.
So, hows it comming?
You got a name for it yet?
I like your paint sticks.

Here's the progress I made over the holiday. Next up is fin attachment. I've decided to go with paper reenforced balsa wood. Then a bit of wood filler on the nose cones, some ducting holes, attachment to the main body, a few incidentals and then sit and wait for the weather to get warm enough to paint. I don't expect to progress much over the next week, as work is once again encroaching on my life.
John

Rings are cool, but personally I love the no-ring look on this. Very cool design! :clap: I am building an Allegro and went with 1/8" plywood on the fins. Once bevelled the weight isn't as bad as I was thinking it would be, and they're pretty big. A good compromise is 3/32 plywood, but I couldn't find it locally, and for some reason was in too much of a hurry to order any. I think I would go that route. Basswood is a pretty good alternative too. :2:

Well, I papered the fins last Monday, pressed them between 2 old shelves for 3 days, with wax paper to keep them from sticking. They seemed a little damp still when I took them out, but looked nice and flat. Yesterday, I went to trim the edge of the paper prior to superglueing the edges and 2 of the 3 were really warped. I am trying the spray them down with windex and press them again suggestion I found in the forum and hopefully they will come out in good shape.
Don't know if I used too much glue to add the paper, or just didn't let them sit long enough with pressure on.
Is it a good idea to cut the wax paper down to the shape of the fin to get more air around the fins, or should that not make that much of a difference?
Maybe this coming weekend I'll be able to get the fins on.
As you can tell, this build is not one I am doing in a couple of days.
John

Well, patience is not one of this grasshopper's virtues. Since I have a couple days of vacation this week, it's time to add the fins. The windex and pressure did a pretty good job of straightening out the fins, even though it's only been a couple of days.
Here is my build so far.

Very nice... I see the ejection gas port in the pictures.

Is she 18mm or 24mm? Any engines you thinking for a launch?

It's built for 18mm motors. C6-5 is the smallest that will get it in the air safely. If it survives the first couple of launches. I may have to try my hand at some clusted composite motors. Haven't tried that yet.
John

Next step complete. Will need some sanding and some epoxy inside the main tubes to hold it all together, then add the block on the back end of the main tube. This is not coming together perfectly square/round/symetrical, but I think it will be OK.
John

Madison Alum said:

Next step complete. Will need some sanding and some epoxy inside the main tubes to hold it all together, then add the block on the back end of the main tube. This is not coming together perfectly square/round/symetrical, but I think it will be OK.
John

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Ohhhhh, its OK alright. Nice looking scratcher.
Whats your plan for the launch lug(s).
Be interesting also , how hot (or cold) the ejection gas will be , and how many particials will get in the top tube.
On mine, the way its designed,its a baffle in it self.

Scott,
I kicked around the launch lug location some. It seems the rocket would be more secure on the pad to put them on the main body, but looking at the Rocsim info, I'll need to keep this on a rod for as long as possible, so I'm putting them on one of the motor tubes.
As for the ejection gas, I planned on using a kevlar chute protector and hopefully the 3 ejection charges will push out the chute and not blow the legs off. I am using epoxy inside and out for attaching the motor tubes, so hopefully the rocket will remain intact.
John

That's looking very sharp!

Here is the latest. Doesn't look much different than last time, but I've got wood filler on the nosecones and struts and finished putting the block on the back of the main body tube. Also managed to snake the shock cord through the eye bolt in the block (would have been a lot easier to attach it before putting the block in place, but I didn't want to get epoxy all over the cord and based on my complete lack of patience and skill, I figured putting it on afterwards would be best). Next up is the launch lugs. Have a 24 inch chute and a nomex chute protector coming. Then finalize the nose weight, wait for a good day and take it for a spin. The good old Connersville soccer field will be plenty big enough for the launching this rocket, and the surrounding fIelds are empty, making even more room. If it survives, I'll paint it in the spring.
John

Hope everyone had a great Christmas. My daughter gave me a Corona with booster, which I will be working on soon. Today, however was a great day to fly some rockets which had been waiting for some good weather. Sarah and I took her Mean Machine, her scratch built min diameter 24mm rocket and my Tripod 4 out to the local soccer field and shot them off. Pics aren't the best, as I just missed (late) the Tripod, just missed (early) the 24mm gold rocket but managed to capture the Mean Machine once.
John

COOL!!!!!!!!!!!!!!!!!!!!!!!
Bet ya felt real good seeing the Tripod coming back under chute.
I love that feeling when a scratcher pops the chute and comes home to Daddy.

Madison Alum said:

Pics aren't the best, as I just missed (late) the Tripod, just missed (early) the 24mm gold rocket but managed to capture the Mean Machine once.
John

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So you did not get the rocket, you caught the shadow of the rocket.

Nice build, BTW.

Got some primer on the Tripod today. Will need some sanding and repriming due to some runs. Shows off the defects pretty good, but I'll be flying it later this month if the weather cooperates. Then it'll be time to figure out a color scheme.
John

Tried painting the Tripod today. Was almost done applying the red when I noticed that the nose was looking kind of bare on the end. Went back to add some more paint to the nose and the stick I had the rocket on snapped. Broken fin, dirt and grass in the paint, nice flat spot in the nose cone. Time to regroup. Bummer.

Doesn't sound too bad. I like the color so far! Can't wait to see the finished paint scheme.

A little sanding, a little glue and some more red paint and she's done, except for some clear. Ready to fly again, hopefully to land on something softer than tar.