I already looked at the ones from Semroc. They are all standard wall thickness, and not the heavy wall.

Bill is right -
Not to step on his reply, I copied this from my "how to build" website -

When you buy body tubes, get the thicker "ST" (older Centuri style) tubing. The
Estes "BT" designated tube walls are thinner, nowhere near as strong.

ST-5 wall thickness is .013"
BT-5 wall thickness is .013" NO DIFFERENCE!

But at ST-7 and larger diameter (BT-20 equivalent and above) the ST Tube wall
thickness is .022"! At Series 10 size or ST-10 the thickness is .020" All larger ST
(Centuri) tubing stays right around the .020" thickness.

The Estes style (BT designation) stays at .013" thickness until they reach the BT-55 size.
The BT-55 is thicker at .021". All larger Estes BT tubes are at the .021" thickness.

Using the "ST" designated tubing, your models will be structurally stronger and
last longer. The ST tubing is less likely to dent, crimp and buckle.

From www.semroc.com
An 18" section of (thicker wall) ST-7 tubing is $1.60
An 18" section of (thinner wall) BT-20 tubing is $1.40

Personally, I'll pay the additional $.20 for the stronger tubing. The thicker tubing is great
for sport models. The thinner walled tubing is lighter and better for competition models.

Sorry the prices are from last year.

There is a definate difference between the BT (thinner) and the ST (thicker) tubes in the BT-20 (around 3/4" diameter) and BT-50 (around 1" diameter) sizes.
And more recently with body tubes being made from recycled fibers, the BT tubes seem to be even more prone to crimps, bends and buckling.
Side by side, pinch the open end of both tubes and you'll feel the difference in strength.

Nose cone, adapter and engine mounts aren't compatable between BT and ST tubes.
But I feel my sport models are stonger and less prone to problems.

__________________
Hans "Chris" Michielssen
Old/New NAR # 19086 SR

www.oddlrockets.com
www.modelrocketbuilding.blogspot.com
http://www.nar.org/educational-reso...ing-techniques/
Your results may vary
"Nose cones roll, be careful with that."
Every spaceman needs a ray gun.
Look out - I'm the Meister Shyster!

I recently bought a batch of Rescues, and now I have the back half of the Skywinder. Can someone please post the instructions for the 2077 so that I can rebuild this rocket.

The instructions are avaialble in the archived Estes instruction site. Right click on the link name and choose download linked file.https://web.archive.org/web/2022011...m/instructions/