Carbon Fiber

I am planning to order some parts from Commonwealth for a 38mm minimum diameter build. I am going to use an ACME fin can so I am not concerned abour reinforcing the fins, but I would like to use CF to reinforce the body tube. As i am a bit new to this type of construction, can someone please tell me if the CF sold by Commonwealth (found at the following link) is what I should be using to reinforce the body tube? Thanks.

https://www.commonwealth.net/cgi-bin/info.pl?prodcode=AHUNIC1003&url=bm/unic1003.htm

Josh

thats unidirectional CF, it only strengthens in one direction, its best to use bidirectional on a tube, the unidirectional is good for fins with the fiber direction going perpendicular to the root of the fin.

carbon fiber

thats the stuff I used for min diameter rockets.. I got it before the war started and it was only about $28/yard. I should have gotten more than 3 yards at that price! Carbon aerosleeves are a good alternative, they look much easier.. because carbon fiber is very stiff, its hard to wrap around a tube and stay wrapped, especially on smaller tubes.. so after its wrapped you have to go back and keep checking on it to push down the bubbles where it starts to peel off. And with the aerosleves you dont have to worry about the seam.

Brian:

Thanks for the info -- I think I'm better off just glassing the tube.

Josh

Originally posted by Brian Barney
I got it before the war started and it was only about $28/yard. I should have gotten more than 3 yards at that price!

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Maybe the war is over?? AVT composites has the ~6oz 2x2 twill for $34. It's $58 at aircraftspruce. Shop around a bit.

If I'm going to glass a 38mm body tube for a minimum diameter rocket, what weight cloth should I use? 2 oz? 6 oz? Thanks!

Originally posted by JJI
Brian:

Thanks for the info -- I think I'm better off just glassing the tube.

Josh

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I do a lot of CF stuff. CF over tube is very strong and light, and if you do it right looks very sexy. It's easiest done using CF sleeve. Check out Aerosleeve.

Soller Composites is great also.

The Aerosleeves tutorial says you should use a metal mandrel. Will a LOC body tube be good enough for maintaining shape, or do I need something additional inside to make sure it doesn't collapsed? As you can tell I'm a bit confused. Thanks for the help.

Originally posted by JJI
The Aerosleeves tutorial says you should use a metal mandrel. Will a LOC body tube be good enough for maintaining shape, or do I need something additional inside to make sure it doesn't collapsed? As you can tell I'm a bit confused. Thanks for the help.

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Just checked my Legacy kit. It's about the smallest tube LOC offers in a kit. It'd handle sleeve lamination just fine, glass or CF. Just don't squeeze the tube hard enough to crimp it. Feel the tube before you put the cloth on so you know how strong it is.

You could slide the tube over a piece of PVC (or a rake handle -- I did that on my last tube) and lay that across a couple things that'll hold it where it's comfortable to work, about waist high.

A mandrel is necessary when the tube is weak (LOC's are not) or when you're making a composite tube without a paper tube under it. A metal mandrel is great if you can get one the right size. I use 34" coupler stock tubes for mandrels because they're exactly the right size. I made a 38mm minimum diameter bird by putting sleeve over Estes-quality BT60 using no mandrel, but then I didn't use heat shrink tube or tape either. Laminating with sleeve by hand doesn't take much practice before you can judge how hard you can squeeze.

Great suff, thanks!

I ordered two yards of 1.5" CF sleeve from Soller.

Thanks for everyone's input.

Josh

Did you order? A mandrel is not airframe tubing but coupler tubing... I would say for 38mm 2-3 layers of a medium weight (5-6oz) CF would be a good strong airframe. You could also do a LOC or PML tubing with one layer of CF, but then you may have trouble getting that fin can on.

PML tubing alone is good to speeds over mach and used on there 38mm MD cirrus dart kit.

Lastly, personally I cant put on of those acme fin cans on a MD rocket. They are super heavy and not very aerodynamic, but if you arent looking for extreme performance then go for it. The airframes and fins (attached) of my 54mm bird (entire rocket minus alt bay and nose cone) weigh about the same as one of those fin cans...

But the alt bay and nose cone are pretty heavy, then you add a 7 pound motor and you got one heavy rocket. Love it when the motor is 3.5 times the weight of the rocket though

Instead of starting another thread, I thought I would just add my inquiry to this thread:

I am looking at using a sleeve for my 54mm minimum rocket, and I was wondering what the best way is to pick these sleeve?

My tube is roughly 2.125" outer, so reading the following two material specs, which would be best?

Nominal Diameter: 2.00 in (50.8 mm) @ 45° braid angle
Minimum Diameter: 1.00 in (25.4 mm) @ +32% length
Maximum Diameter: 2.25 in (57.2 mm) @ -18% length
Fabric Weight: 7.5 oz/yd2 (254 g/m2)
Thickness: 0.011 in (0.28 mm)

...or...


Nominal Diameter: 2.50 in (63.5 mm) @ 45° braid angle
Minimum Diameter: 1.25 in (31.8 mm) @ +32% length
Maximum Diameter: 2.90 in (73.7 mm) @ -18% length
Fabric Weight: 11.9 oz/yd2 (403 g/m2)
Thickness: 0.018 in (0.46 mm)


What are my intensions? Just to build a light, but strong rocket. I am not an altitude junky, or a speed freak, it is hust that I tend to build too heavy (fiberglass) and I want a light. strong and sexy rocket...and maybe hit 1.5 - 2 miles if I should feel so inclined

Also, I see that Soller Composites also offers a 50/50 Carbon/glass in which the glass is purple...would I loose to much strength and gain too much weight at the same time just for a colors sake?

Johnnie

I would go with the 2.5 simply because its not stretching the CF. When you have a sleeve that you need to stretch to fit, the strength is decreasing because the weaves in the fabric are spreading apart. When you have a sleeve that you actually need to condense in order for it to fit, the strength will be greater because there is more carbon fiber per in. squared than if you stretched it.

Originally posted by chicagonative17
I would go with the 2.5 simply because its not stretching the CF. When you have a sleeve that you need to stretch to fit, the strength is decreasing because the weaves in the fabric are spreading apart. When you have a sleeve that you actually need to condense in order for it to fit, the strength will be greater because there is more carbon fiber per in. squared than if you stretched it.

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What you say makes total sense...I guess I need to stop looking at this project from a $dollar$ standpoint, and get what my project really needs. At 69" total length, I would guess that 3yds would work well.

I am divided over the 50/50 CF/glass and the 100% carbon fiber...it's not really so much the weight thing, as it is the strength issue.

Thank you for your input.

Johnnie

is this to laminate a tube, or making your own tube from scratch over a mandrel? If it is to go over a mandrel, you want to wrap afew layers of mylar over your mandrel, I made a 54mm tube out of carbon and the pro 54 cases wont fit, the ID is 2.130 and its too tight. my hypertek fits great, and the aerotech cases seem to fit just fine. I ended up having to use a flapperwheel and a long time to open it up .005-.010" so the L730 case would fit, and even then its still really tight..

If your making it just laminating a tube phenolic or paper, the glass/carbon will be plenty strong, glass alone is enough to break mach+ but I dont know if you will be able to see the dyed glass very well as it goes clear when its wetted out.. i have seen kevlar dyed mixed with carbon, and that keeps its color well.

No, I will be laminating an existing Loc Precision tube, with glassine peeled...

I actually searched many of the threads here on TRF for Carbon threads, and ran across yours...and many others:

https://www.geocities.com/brian77223/rocket/tomrocketpics.html

https://uscomposites.com/

https://www.rocketryforum.com/showthread.php?s=&threadid=12793&highlight=carbon+tubes

https://www.rocketryforum.com/showthread.php?s=&threadid=14984&highlight=carbon+tubes

https://www.rocketryforum.com/showthread.php?s=&threadid=17771&highlight=carbon+tubes

A little more recent…

https://www.rocketryforum.com/showthread.php?s=&threadid=23810&highlight=carbon+tubes


Just a few in the the minutes that I searched...

Thank you for posting,

Johnnie

Carbon sleeve stretched to its maximum diameter will be weaker than using it at its nominal diameter. But even at that point it's stronger than the "proper" diameter of glass sleeve, which is stronger still than wrapped glass cloth. When it's pulled over LOC tube, which is tough to begin with, it's going to be near bullet proof. I'd put any thickness of CF over paper up against twice the thickness of glass over paper.

I can pull 1.5" light CF sleeve over 2.56" (BT80) tube. Actually I have to work it on over a nose cone, like a woman putting on panty hose, but I can do it. And I will be, for a scale model of the ARCA Demonstrator B. Glued onto paper, the "weakest" this stuff will be is way more than it'll need. Consider: we use CyA painted onto things to stiffen and toughen. Epoxy is tougher. If you painted the peeled LOC tube with epoxy alone, it'd make one tough tube. In fact, I did this with my LOC Legacy after incorrectly peeling the tube. It's quite a bit stronger now. If you epoxied even the weakest cloth over the tube the epoxy would have all the more surface area to grab, and be stronger yet.

If you want the pretty of CF, the strength of CF and more heat resistance than anything else, but the cost of glass, look into "basalt" sleeve from Soller. If I didn't have a boatload of CF stock still and could justify it, I'd buy a bunch of this stuff. CF/glass looks pretty neat. I haven't used any. I have used kevlar/CF. Very hard to cut and sand. I used the last of my kevlar sleeve making ejection mufflers glued over the end of motor tubes rather than laminate with it.

Originally posted by Johnnie
No, I will be laminating an existing Loc Precision tube, with glassine peeled...

I actually searched many of the threads here on TRF for Carbon threads, and ran across yours...and many others:

https://www.geocities.com/brian77223/rocket/tomrocketpics.html



Just a few in the the minutes that I searched...

Thank you for posting,

Johnnie

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My Tom Cloud memorial rocket He was a really cool guy, I talked to him online alot, he showed me how to wrap tubes out of glass, and then Tony (Tfish on the forums) showed me how to make molds and hand layed up cones. I only flew it once on an I300, the kevlar cord untied on its way down from the drogueless desent and the fin came down from 8300 feet with no damage at all. I now have an I435 case that I can send it up on, just havent gotten around to it yet. its stout, im pretty sure I can drive my car over the tubes without damage, I can stand on it. I could have made it alot thinner, but it was my first complete composite tube, i made it as thick as a normal phenolic tube so that the nosecone shoulder fits well. My 54mm rocket is only about .030" wall thickness all carbon, I havent flown it yet.

Originally posted by DynaSoar
Carbon sleeve stretched to its maximum diameter will be weaker than using it at its nominal diameter. But even at that point it's stronger than the "proper" diameter of glass sleeve, which is stronger still than wrapped glass cloth. When it's pulled over LOC tube, which is tough to begin with, it's going to be near bullet proof. I'd put any thickness of CF over paper up against twice the thickness of glass over paper.

I can pull 1.5" light CF sleeve over 2.56" (BT80) tube. Actually I have to work it on over a nose cone, like a woman putting on panty hose, but I can do it. And I will be, for a scale model of the ARCA Demonstrator B. Glued onto paper, the "weakest" this stuff will be is way more than it'll need. Consider: we use CyA painted onto things to stiffen and toughen. Epoxy is tougher. If you painted the peeled LOC tube with epoxy alone, it'd make one tough tube. In fact, I did this with my LOC Legacy after incorrectly peeling the tube. It's quite a bit stronger now. If you epoxied even the weakest cloth over the tube the epoxy would have all the more surface area to grab, and be stronger yet.

If you want the pretty of CF, the strength of CF and more heat resistance than anything else, but the cost of glass, look into "basalt" sleeve from Soller. If I didn't have a boatload of CF stock still and could justify it, I'd buy a bunch of this stuff. CF/glass looks pretty neat. I haven't used any. I have used kevlar/CF. Very hard to cut and sand. I used the last of my kevlar sleeve making ejection mufflers glued over the end of motor tubes rather than laminate with it.

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Thank you for your input doc, I remember when you were first posting about carbon sleeving etc. Good stuff!

As it turns out, I may end up getting the 50/50 carbon/Purple glass sleeve for this rocket. I'll just make up for the extra weight with a bigger motor if needs be.

Johnnie