Blue Tube warping

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Schuyler

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Well, I just got back from NERRF (which was awesome) where I learned a painful lesson about the airframe material known as "Blue Tube". I was looking forward to the first flight of a 3" diameter scratch built rocket I made from Blue Tube. Saturday morning I was busy working the registration table and then preparing my V2 for my level 1 cert flight. (Yes it was successful :)) Meanwhile my scratch built was sitting in the hot summer sun. After my cert flight I returned to find this rocket curving like a banana!

I tried turning it around hoping it would bend back the other way but no luck. Tim from Wildman kindly offered to let me put it in his air conditioned trailer hoping it would straighten out when it cooled. It didn't work. (thanks anyway Tim)

I spoke to a few people at the launch who were familiar with Blue Tube and I learned that this is a fairly common problem with this material.

And so, it never flew :(

DSC00277.jpg
 

madsen

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Thanks for the information. I have been watching much of the information being put out on Blue Tube since it was introduced a few months ago--"made from artilery shell material"--and the rest of the hype. It really sounded great. I was on the verge of ordering two 6" tubes for a rocket. You are the second person that I have heard of with a warping problem. I understand that it is a combination of sun/heat and humidity. Southern Arizona is normally not too humid--but it is always sunny--and very hot. All it takes is one thunderstorm--and it can be humid for days. I think I will pass on Blue Tube for the immediate future. It really sounded great a few months ago. This was probably a case of where a little more testing should have done. I understand that the seller is working on a fix for the problem. I hope that they are successful. The stuff sounds great. It is so strong--a tank can roll over it. Unforunately, 30 minutes in the sun--and it cannot stand on its own.
 

troj

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Randy, the guy behind this stuff, is aware of the problem and notified all the dealers right around LDRS. This is why it's not currently in stock anywhere -- he's working with the place that makes it for him, to make some changes to resolve this issue.

Last I heard, he had some samples back from the mill, but they've not yet been tested sufficiently.

-Kevin
 

sandmantoy

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Wow! Nice looking rocket too. When you get new products that just come out we are the next stage of working the bugs out. I would not have guessed it would warp that much. Kind of a step we must go through. Thanks for putting your experience on here. First I have heard of it. Makes me wonder what my other rockets are doing when they are sitting on the pad before flight. I bet there are others that warp some at least temporarily from sitting in the sun before flight. Humidity being a factor as well.

I am sure they will come up with a solution. I would bet sending a picture of your rocket and some data on flight conditions that you assessed from what you think caused it would net you some new tubing once it was fixed up. Might help fix the problem faster also.

I heard you guy's had some nice weather at NERRF too :D Congrats on you level one also :cool:
 

terryg

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Did it ever straighten out? I bet a full length coupler of another material would fix the issue. This would be a better solution then rebuilding it.
 

Schuyler

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Did it ever straighten out? I bet a full length coupler of another material would fix the issue. This would be a better solution then rebuilding it.
It's currently just slightly less warped than in the photo. That's an interesting idea. I also thought about cutting the tube a couple of inches above the top centering ring and replacing it with a phenolic tube. I don't know how well they'll line up though.
 

sandmantoy

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It's currently just slightly less warped than in the photo. That's an interesting idea. I also thought about cutting the tube a couple of inches above the top centering ring and replacing it with a phenolic tube. I don't know how well they'll line up though.
I think you would still have a warp problem below the phenolic tube. The full length coupler sounds like a good idea. To bad it will be adding weight to your rocket. I would just rip it apart and save what you can then build it again. A bummer no doubt and you will have better performance with your design in the end :pop:
 
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