Big "F" Rocket

In the many years that I haven't been able to complete a high powered project I decided to go down to a mid powered rocket. Its no fun having a small rocket so I wanted to make a rocket that would be big and at the same time light enough to launch on mid-powered motors.

I came up with making a lightweight 3" diameter, 45" long, carbon fiber rocket. The design is simple consisting of 1 wrap of carbon for the body tube, balsa core with carbon reinforcement fins, and a plastic nose cone that is currently out of stock by estes rockets. The motor mount is paper tube with glassed balsa centering rings.

That covers the design and here is a picture of the design in rocksim.

Nice looking rocket, kind of has that Patriot look. Looking forward to seeing the results of your build and launches. You may even start a new trend, building the biggest rockets to fly the smallest motors. BTW that black background on the RockSim file makes it pretty tough to see the pic, or maybe it's just me getting old.

Nice but given your interest I am surprised you are not building small F powered Mach breakers. No shame in F's and G's!

SinfulDarkLord said:

In the many years that I haven't been able to complete a high powered project I decided to go down to a mid powered rocket. Its no fun having a small rocket so I wanted to make a rocket that would be big and at the same time light enough to launch on mid-powered motors.

I came up with making a lightweight 3" diameter, 45" long, carbon fiber rocket. The design is simple consisting of 1 wrap of carbon for the body tube, balsa core with carbon reinforcement fins, and a plastic nose cone that is currently out of stock by estes rockets. The motor mount is paper tube with glassed balsa centering rings.

That covers the design and here is a picture of the design in rocksim.

View attachment 261145

Click to expand...

When you say 'lightweight' do you mean 1k type carbon or ?

Kenny

With all that CF, isn't it overbuilt for F motors? Looks to me like a good L1 cert flyer. There are plenty of H motors in 29mm.

I thought this thread didnt post. It kept giving me errors and I thought it never made it. I'll quote your questions and comments in a bit.

First off I have made changes to the design. I went from three fins to four to add more stability. Reduced the span also to not make it too overstable.

Here is a picture of the new design.

mpitfield said:

Nice looking rocket, kind of has that Patriot look. Looking forward to seeing the results of your build and launches. You may even start a new trend, building the biggest rockets to fly the smallest motors. BTW that black background on the RockSim file makes it pretty tough to see the pic, or maybe it's just me getting old.

Click to expand...

Something is wrong with the image. It looks blurry on my end.

grouch said:

Nice but given your interest I am surprised you are not building small F powered Mach breakers. No shame in F's and G's!

Click to expand...

I will do that later on with glass instead of carbon.

KenRico said:

When you say 'lightweight' do you mean 1k type carbon or ?

Kenny

Click to expand...

It will be only one wrap of 3K 6oz carbon. The end result will be the rocket weighing in at half a pound. Thus it being lightweight.

jqavins said:

With all that CF, isn't it overbuilt for F motors? Looks to me like a good L1 cert flyer. There are plenty of H motors in 29mm.

Click to expand...

It will only utilized one wrap of carbon. This will make it light enough to handle those estes F motors.

Dont know why the images are uploading blurry. I dont think I'll be able to fix that. Sorry for the black background, but at night the bright white screen annoys me.

mpitfield said:

Nice looking rocket, kind of has that Patriot look. .

Click to expand...

The patriot as a totally different angle of leading edge and the outboard edge is way longer.... Speaking of fins, for a rocket that will launch of F motors, with low off the rail speed, I found them a little bit small.

Area66 said:

The patriot as a totally different angle of leading edge and the outboard edge is way longer.... Speaking of fins, for a rocket that will launch of F motors, with low off the rail speed, I found them a little bit small.

Click to expand...

He was only implying that it has the look of a patriot, not that it is one.

Since the motor is small and the fins are lightweight. All the mass is up by the upper body tube. I could go with smaller fins, but I like bigger fins, because it makes the rocket stand out more.

We have a local guy who has been building rockets since the 60's. He showed me pictures of a rocket made to be as large as possible and under the one pound weight limit of the time and fly on an F. It was made similar to a model airplane using ring frames and longerons then covered with silk. IIRC it was about 6 feet tall and 8 inches in diameter.
At an LDRS in Orangeburg there was a Mercury Redstone 6 or so feet tall on an H motor of the same construction but covered with Monocoat.

M

SinfulDarkLord said:

He was only implying that it has the look of a patriot, not that it is one.

Click to expand...

Like if I don't know .,.....it don't look like a Patriot ... that's my point.

MClark said:

We have a local guy who has been building rockets since the 60's. He showed me pictures of a rocket made to be as large as possible and under the one pound weight limit of the time and fly on an F. It was made similar to a model airplane using ring frames and longerons then covered with silk. IIRC it was about 6 feet tall and 8 inches in diameter.
At an LDRS in Orangeburg there was a Mercury Redstone 6 or so feet tall on an H motor of the same construction but covered with Monocoat.

M

Click to expand...

Truely amazing on what you can do with composites.

Okay so depending on whether or not estes has the nose cone available next week. There will be changes. For now some info on how this build is going to go down.

Since I find no real use wasting expensive epoxy on a mid powered rocket. I believe using regular hobby grade laminating epoxy to laminate the materials would be best. That is unless I can get my hands on another quart kit.

I found that making a 3 wrap 29mm glass tube of 3oz. glass will yield close to the weight of a paper tube. It should make for a sturdy motor mount.

I've placed the order for the balsa sheets, which two will be laminated with carbon and the other two will be laminated with 3oz glass. The glassed ones will be centering rings for the motor mount.

Next is the shock cords, along with the estes 29mm motor retainer and finally, the centering ring that will act as an engine block.

Now I wait for another payday, so I may purchase the remaining materials.

SinfulDarkLord said:

jqavins said:

With all that CF, isn't it overbuilt for F motors? Looks to me like a good L1 cert flyer. There are plenty of H motors in 29mm.

Click to expand...

It will only utilized one wrap of carbon. This will make it light enough to handle those estes F motors.

Click to expand...

I was unclear, sorry. By "overbuilt" I didn't mean to say it will be too heavy for F engines; I'm sure it'll be fine. I meant that it's stronger than it has to be, and plenty strong enough for a small H. If you just leave out the engine block and rely on the thrust rings on the engines, you'll have a rocket that can happily fly on F, G, or H motors.

jqavins said:

I was unclear, sorry. By "overbuilt" I didn't mean to say it will be too heavy for F engines; I'm sure it'll be fine. I meant that it's stronger than it has to be, and plenty strong enough for a small H. If you just leave out the engine block and rely on the thrust rings on the engines, you'll have a rocket that can happily fly on F, G, or H motors.

Click to expand...

Yes that is true, one of the club members got his level 1 on an Estes Ventris. Unfortunately I cant leave out the engine block, because the estes engines dont have thrust rings.

Besides my wallet will be happy with two motors instead of one lol.

Thanks to Codysmith I got the nose cone I was looking for (I dont have it yet). All is left is the parachute, which I'm still deciding on and the ACME Conformal rail guides from giant leap. Those I'll get on my next paycheck. I am trying to save as much money as possible. These times are a pain when it comes to money.

SinfulDarkLord said:

Yes that is true, one of the club members got his level 1 on an Estes Ventris. Unfortunately I cant leave out the engine block, because the estes engines dont have thrust rings.

Besides my wallet will be happy with two motors instead of one lol.

Click to expand...

Masking Tape

codysmith said:

Masking Tape

Click to expand...

Haha yeah that always fixes things. I'll think about it. Would be great indeed to not just launch it only on estes F motors.

Got to love it. If your wondering what those white strands are, their low melt fiberglass strands that keep the fabric aligned and from fraying.



I'll be making the tube tomorrow. I've decided to just use my expensive epoxy since I enjoy working with it. I'll later buy another quart kit when I get the chance.

Going to hold out on making the tube. Going to wait until I get the nose cone.

..?

shrox said:

..?

Click to expand...

..? yourself. What is it that confuses you, sir?

jqavins said:

..? yourself. What is it that confuses you, sir?

Click to expand...

Lol

shrox said:

..?

Click to expand...

Im assuming your wondering why I post-poned on making the tube? Honestly it might be awhile until I make it. My former teacher has requested it back and also their going to chop it down so I wont be able to use it. I may have to buy one for myself. Too bad public missiles only has them in 36". Maybe I can get two and just join them with a beefy coupler. This way I can make a 50" long tube instead of a 37" one.

Will keep you guys informed.

OK, now I'm the one who's confused. You haven't made the tube yet because your former teacher has requested it back? How could someone request that you give back something that a) doesn't yet exist and b) you're planning to make for yourself? And if said teacher is planning to (effectively) destroy it, why shouldn't he or she just get her own darn tube to chop down?

In any case, coupling a couple of PML tubes sounds like the easier way to go anyhow, but there is the weight of the coupler to consider. It doesn't have to be especially beefy though; as strong and stiff as the tubes themselves is really plenty. So, weight-wise, it's just doubling the wall thickness for a couple of inches along with a little epoxy. I know, some will say that a couple of inches isn't enough, but I believe it can be for a fully glued coupler if you make the joint up carefully.

• Make sure the coupler is nicely buttered with epoxy.
• Push the tubes together over it so there is some squeeze-out, ensuring that there is epoxy in between the tubes as if you were trying to butt join them.
• Use a piece of angle as a splint to assure the tubes are perfectly aligned. Secure the angle with two rubber bands or zip ties spaced on each tube. That is, four bands in total. Make sure the bands are pretty tight.
• Use something like a bar clamp or long rubber band to apply moderate compression along the length of the combined tube, i.e. keeping the "butt joint" tight.

Once the epoxy is fully cured, that's one tube, and just one inch of coupler on each side of the joint should be plenty.

jqavins said:

...Use something like a bar clamp or long rubber band to apply moderate compression along the length of the combined tube, i.e. keeping the "butt joint" tight.

Click to expand...

[video=youtube;OmCxtWrRQJ8]https://www.youtube.com/watch?v=OmCxtWrRQJ8[/video]