Gotta love QT from PML

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Indeed! I’m one of those not using QT anymore. Yes, it’s great to work with, BUT it is not as durable as FG, and it also suffers from differential heating resulting in body tubes bending when on the rail waiting for launch in a hot sun.
Both of you are ridiculous ...bending on the rail? Really!! T***************************88
 
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I would have used more gentle language but in all my flights here in Texas in the how summer sun I don't think I've ever experienced that. It's never gotten soft in the heat, the big issue is how much it shrinks in the cold. I still have some QT out in the garage (in Texas) that is probably 20 years old and it's still straight.


Tony
 
Both of you are ridiculous ...bending on the rail? Really!! T***************************88
Thanks for your tolerance! It’s not stupid when you have experienced it. It was with QT, as I’ve never used BT. I should add that it was a long 54 mm body tube for a dual deploy hybrid - about 2 m long.
 
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I would have used more gentle language but in all my flights here in Texas in the how summer sun I don't think I've ever experienced that. It's never gotten soft in the heat, the big issue is how much it shrinks in the cold. I still have some QT out in the garage (in Texas) that is probably 20 years old and it's still straight.


Tony
It’s not getting soft that’s the issue - it’s thermal expansion of the sunny side. It is possible with a long narrow diameter QT tube (54 mm x 2+ m). It didn’t occur in a fibreglass body of the same dimensions. This is from personal experience, not made up. It probably wouldn’t be noticed in a 4” diameter body of the same length.
 
LOL..
Rail buttons are better!? What?? And red is better than blue. Make sense? No.
Not everyone shares your enthusiasm for QT or linear rail guides!? Who gives a rat's aft portion what other people like?
Won't hold up at Mach? They know that, they tell you that, it's no secret.
Holy Cow!

It looks like you, @AfterBurners, should probably step back and reevaluate some of your life choices because a large percentage of experienced people don't like what you like.

Wow..just..Wow.
 
Thanks for your tolerance! It’s not stupid when you have experienced it. It was with QT, as I’ve never used BT. I should add that it was a long 54 mm body tube for a dual deploy hybrid - about 2 m long.
LOL..
Rail buttons are better!? What?? And red is better than blue. Make sense? No.
Not everyone shares your enthusiasm for QT or linear rail guides!? Who gives a rat's aft portion what other people like?
Won't hold up at Mach? They know that, they tell you that, it's no secret.
Holy Cow!

It looks like you, @AfterBurners, should probably step back and reevaluate some of your life choices because a large percentage of experienced people don't like what you like.

Wow..just..Wow.
No kidding right?!! LOL
 
I have better things to do than argue with certain people on this thread. I was simply making a point that I enjoy the QT that PML offers that's all. I wasn't trying say its better than one material or another, but a nice compromise to card board and wood and it's easier to work with. We all know that. Anyway you guys have a great day!
 
Many people mentioned the problems with QT and cold weather. I just want to mention the reverse, Ive seen QT deform in direct sunlight. So if you are out on the field, and you have your rockets lying down on a tarp, be wary of that.
 
Qt certainly has limitations but also it has its place in the world. When I was a teenager trying to break my way into high power rockets before I could afford fiberglass kits which by the way have gotten a ton cheaper since 2004 it was a great way to build bigger kits stronger than paper tubes but not as expensive as fiberglass. To that point j flew a PML endeavour for my level 2 cert on a j250 at Midwest power in November it was 35 degrees outside and my endeavour was built in 2003. That same day I flew my explorer to get my level 1 certification. I also flew my 1/4 scale patriot twice that day all of these rockets were built in 2003. Certainly qt has limits but they let also give more people access to rocketry especially kids
 

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I confess: I like quantum tube for some rockets. And I’ve flown it past mach. It can be done. Be particularly careful with preparation for epoxy.
I have reinforced my qt rocket with a phenolic coupler and I'm gonna try to fly it on an L850 in February
 

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I have reinforced my qt rocket with a phenolic coupler and I'm gonna try to fly it on an L850 in February

The worst failure I’ve had with a QT rocket was at LDRS 27. I flew a Sudden Rush on a K2045. At burnout the phenolic coupler broke, causing the chute to come out into the airstream. That blew all the panels out of the chute. The QT, fins, fin attachments, and everything else other than the coupler and chute were undamaged. But the coupler failure was almost certainly contributed by the airframe flexibility as well as phenolic’s brittle nature. If I could find a g10 coupler to replace the phenolic coupler that’s how I’d build a rocket like yours.
 
This is PML’s Mini BBX with quantum tubing and fiberglass fins. JB Weld PlasticBonder is easily the best glue for it. 7698E04D-C059-481D-AA33-61C3510A57FE.jpeg
 
Spent some time this weekend working on the Spitfire. Nose cone is done with nose weight and bulk plate and piston is done. Right now its just primer and paint. Took the day off from work. It's two-fold. It's a mental day off and dropped my truck off at the shop to look get the clutch looked at. It use to make a weird noise when I would step in the clutch and engage it in gear, If it's out of gear no noise with the clutch engaged? Well when I took it in there was no noise whether it was in gear or not...so who knows but figure I would get it checked out and take the day off. Hope you guys are doing well...
 
Spent some time this weekend working on the Spitfire. Nose cone is done with nose weight and bulk plate and piston is done. Right now its just primer and paint. Took the day off from work. It's two-fold. It's a mental day off and dropped my truck off at the shop to look get the clutch looked at. It use to make a weird noise when I would step in the clutch and engage it in gear, If it's out of gear no noise with the clutch engaged? Well when I took it in there was no noise whether it was in gear or not...so who knows but figure I would get it checked out and take the day off. It might be a throw bearing? I'll probably head out in the garage and work on the Spitfire. Maybe play a few games of pinball?? Hope you guys are doing well...
 
Wait,what is Quantum Tubing? And why is it good?
Quantum tube is essentially polymer plastic tubing that public missiles started using to design rocket kits. It has some advantages because it allows rocketeers to build larger rockets with a material that is easy to work with and flexible for a budget price. However it doesn't handle impact particularlly well and it is a very temperature sensitive material. It shrinks significantly and becomes brittle in cold and soft in heat. All that said I have successfully built and launched a four inch diameter quantum tube rocket on a 75mm L motor twice successfully both times below freezing temperature so inspite of it's limitations it can be used to build a viable rocket
 
I hate pistons..never ever had good experiences there.
Quantum tube is fun and easy to work with....however
it's really not good if you like to push hard. It was a really cool shred

gotta build me another one....
 
I hate pistons..never ever had good experiences there.
Quantum tube is fun and easy to work with....however
it's really not good if you like to push hard. It was a really cool shred

gotta build me another one....
Yeah I removed all my pistons too unpredictable in varying temperatures I like the concept though and not having to worry about chute burns.
I have successfully pushed my quantum rocket to little over 600 mph and I plan to go supersonic once I get my level 3 but again it is reinforced. I kinda just wanna see how far I can push it
 
consider myself a fiberglass master but purchased a PML kit to try QT for the first time

did bluetube a while back for similar reasons, was nice enough to work with but I definitely see why it is waning in popularity
 
Yeah I removed all my pistons too unpredictable in varying temperatures I like the concept though and not having to worry about chute burns.
I have successfully pushed my quantum rocket to little over 600 mph and I plan to go supersonic once I get my level 3 but again it is reinforced. I kinda just wanna see how far I can push it
I pushed a little too hard. Probably could have given you a shred speed but the altimeter didn't like the sudden deceleration when it got to ground level :>
 
I have used QT for a couple of custom rockets over the years with phenolic pistons- no problem with the fit as long as you're willing to do a LOT of sanding to make the piston fit. Lived in FL at the time, so cold weather was never an issue. I agree with Steve that phenolic couplers aren't my favorite with QT- I would typically use Blue Tube couplers.

Currently building a 4" dia. QT rocket which will have four deployable landing legs as well as side pod "retro rockets" firing for 8 seconds during descent. Curious to see how it holds up to the landing- although I have reinforced those internal stress points with Blue Tube coupler material. I'm calling it "Delta Super Heavy Lander" and will paint it like the Delta rockets.
 

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