Full-length paper coupler tubes??

PML (phenolic) CTF-2.5-36, near the bottom of the 'Airframe' page.

Totally Tubular (paper) CPL-80-34:

Giant Leap Rocketry

click on High Power (rightmost button) click on Products on top frame click on airframes in left frame scroll down to Phenolic Coupler tubes

5" length for $2.09 36.5" length for $10.49

while your on that page, scroll down and check out the fiberglass and kevlar "socks", for seamless tube layups

Ed is a great guy to do business with, order fulfillment is very prompt and customer service is excellent. He has real pride in his work.

- iz

Andrew MacMillen wrote:

5" length for $2.15 36" length for $10.95

kraft only

4" for $1.00 34" for $9.00

I may use them but prefer paper. Even the "flexible" phenolic is too brittle for my needs, and I always have to slit a cardboard tube and glue it into the phenolic tube to make it durable enough.

from Giant Leap Rocketry, HPR -> airframes page at

They may call it "non-brittle" but in my experience it's only a little less brittle than the regular stuff, and still far more brittle than paper tubes.

I agree. Don't believe everything you read just because its on a website ;-)

I'm moving away from phenolic of any type and back to LOC tubes with a wrap or two of fiberglass. I've found that phenolic (from Giant Leap) will delaminate at the seams under stress. Isn't this exactly what the HPR strength of material test showed?

That said... I sure wish I knew where to get full length paper couplers. I'm pretty sure the Red Arrow full length l> >

I'm thinking that LOC/Barry should take note and start offering the couplers and stiffys full length!

BMS,

has 34 inch length coupler stock, from BT-5 to BT-80, including 24mm & 29mm. Totally Tubular may have better prices, but BMS is likely to get it there sooner, plus you could pick some cones, rings, & maybe an Edmonds kit at the same time. -- Richard Hickok

Isn't there an AT 2.5" OD tube that could serve the purpose?

Jerry

Do you really want a full length coupler or do you really want a THICKER TUBE?

You know what does work well? Butting them together as he says, wrap a masking tape seal around the external joint. Use 30+ minute epoxy at and near the joint. This type of butt-joint is VERY strong.

Tech Jerry

I'm surprised at you Jerry! Given paper couplers, I'd think that titebond would do just as well as epoxy here. Maybe better, since it will actually penetrate the paper where epoxy will likely just grap the surface. Unless you use a real thin epoxy like System3, West, etc.

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

I find that on butt joints in particular the epoxy works better. Time for a real test!

I think the problem is the thin layer of Titebond cracks easier than the layer of epoxy.

Jerry

Full length coupler -- very useful for payload and electronics bay construction.

Sounds like an expensive thing for a small market. That's always a problem.

Jerry

It is. That's how my altimeter bay kits go together. The section of body tube is the perfect place to put your vent holes and arming switch. I've never seen one fold up, even at speeds approaching mach 2.

Mike Fisher Binder Design

Gee I wonder who is going to spend the money to send him the samples since according to some here on rmr I am less than useless?

Hmmm?

And I wonder who is going to spend the money for several megabytes of storage space accessable freely forever?

Hmmm?

Us useless people want to know.

Jerry