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Bluegrass Rocket
12-16-2008, 09:53 PM
Thought I'd throw this out there, does anyone know of a source for a body tube that slides ON THE OUTSIDE of a BT-5 sized tube? The Estes .541 o.d. size. Thanks in advance for any help.

sandman
12-16-2008, 10:09 PM
Yes, it's a T-5+ body tube.

The I.D. is 0.559 and the O.D. of the BT-5 is 0.544".

The only place I've seen them is Totally Tubular.

http://www.wooshrocketry.org/misc/tt.htm

Good luck.

Mark II
12-16-2008, 10:22 PM
Or you could roll your own, using cardstock or something similar.

Mark \\.

micromeister
12-17-2008, 08:57 AM
ditto what Sandman posted;
BT-5's are .518" ID .544" OD with .013" wall.

Totally Tubular's T-5+ is listed at .559" ID, .589" OD with .013" wall comes in 34" lengths.

Ya might want to try BMS and ASP both sell Totally tubular tubes so if they don't have them them may be able to get the T-5+ quicker then you might trying to order direct.
Hope this helps.

Bluegrass Rocket
12-17-2008, 12:28 PM
I'm no expert by any means but, the SEMROC tube page, as well as, any of the old ESTES catalogs on Ninfinger show .541 as the O.D. of BT-5 tubing. The Centuri BT-5 size was .543 O.D. I'm just throwing one more wrench in the gears. ;)

jbuscaglia
12-17-2008, 01:25 PM
I'm no expert by any means but, the SEMROC tube page, as well as, any of the old ESTES catalogs on Ninfinger show .541 as the O.D. of BT-5 tubing. The Centuri BT-5 size was .543 O.D. I'm just throwing one more wrench in the gears. ;)

They used to be .541, but they changed to .544 OD. I don't remember exactly when the change happened, but it's been a number of years. IIRC, the ID is slightly larger as well and newer mini motors are a really tight fit in older BT-5 tubes.

Mark II
12-17-2008, 01:33 PM
I have often felt recently that there ought to be a BT-8 or a BT-15 or something, a standard tube size that is between BT-5 and BT-20. Realistically, I'm not sure how much demand there would be for it, but there have been times when I really could have used it.

Rolling your own tube is actually not that hard. Take a length of BT-5 and slip it over a 1/2" dowel. If it is too loose, built up the dowel with one or two wraps of printer paper. Glue it on, and then wrap it with a layer or two of wax paper (if you can) or spray it with triple-thick clear glaze (get an even coat). Then get some kraft paper, available in the mailing supplies section of many stores, or else a roll of banner paper (from the school supplies section). Take a piece and trim it to the width that will match the length of the tube you want to make, and test-wrap it around the mandrel you made to see how long of a piece you will need in order to get the wall thickness (or OD) that you want. You then roll it on like a window shade, but tightly! To get it started, what I have done is to take a long strip of regular scotch tape and lay it along the length of the mandrel, sticky side up, and then tape the ends down with more scotch tape just beyond the boundaries of the section that I will be wrapping. I stick the end of the paper onto that, so that when I'm done with the wrap, I can just cut off the taped-down ends and then slide the mandrel out of the tube. For glue, I just use regular old white glue, spread thin with a squeegee, and I only spread it on for a couple of inches at a time onto the section that is about to be rolled.

It may help to build up the tube out of several short lengths of paper, instead of one continuous piece. Not only does it make the rolling easier to manage, but between pieces, you can take the tube and roll it over a smooth surface several times with a little bit of downward pressure, to compress the layer that you just rolled.

It's a lot more work than just placing an order, but you'll get your tube a lot faster! It will never have the quality of a commercially-made spiral wound paper tube, of course, but depending on your needs, it may be good enough. If all you have is a one-time need for a short piece, it may be economically feasible to roll your own. For longer lengths, or for multiple tubes, though (especially for a set that is uniform in dimensions), buying the commercially-made kind will be much cheaper, of course.

Mark \\.

Bob Kaplow
12-17-2008, 01:55 PM
Thought I'd throw this out there, does anyone know of a source for a body tube that slides ON THE OUTSIDE of a BT-5 sized tube? The Estes .541 o.d. size. Thanks in advance for any help.

The old MPC T15 should work. I'm not sure if it's still available from Quest at the moment or in any of their current kits.

Mark II
12-17-2008, 01:57 PM
They used to be .541, but they changed to .544 OD. I don't remember exactly when the change happened, but it's been a number of years. IIRC, the ID is slightly larger as well and newer mini motors are a really tight fit in older BT-5 tubes.
The difference from vendor to vendor may reflect differences in the parameters specified when the tubing was ordered. All of the tubing is, for all intents and purposes, the same size, although some vendors' tubing may have a slightly thicker wall. Semroc's Series 5 tubing has a 0.543" OD, because it was meant to be identical in size to Centuri's ST-5 tubes. Semroc also sells BT-5 tubing, which has an OD of 0.541", which is identical in size to Estes BT-5.

The difference between a tube with an OD of 0.541" and one with an OD of 0.544" is only three one-thousands of an inch, after all. It is very difficult to tell the difference by sight. All of Semroc's "Series #" tubing, from 5 to 20, as well as some of the sizes in their heavy-wall Large Tubing ("LT") series, are meant to match the sizes of Centuri and FSI tubing. Their "BT" series of tubing, on the other hand, matches the sizes of Estes tubing. While there may be very little perceptible difference between ST-5 and BT-5, there is a more noticeable difference in the wall thickness between ST-7 (OD: 0.759") and BT-20 (OD: 0.736") and between ST-9 (OD: 0.998") and BT-50 (OD: 0.976"). But these are all model rocket tube sizes that were long ago established as standards for the industry.

Mark \\.

gpoehlein
12-17-2008, 02:22 PM
Here is the technique I use for making my own tubes. You can use any size mandrel for the inside diameter with this method - for a BT5+ just use a BT-5 for the mandrel (you might put a layer of tape around the tube if you want a loose fit).

Cut several strips of paper from 1/4 to 1/5" wide. I use 20 lb bond paper for smaller tubes. One good source is cash register tape - you can get it at any office supply store and the lengths of the strips can be as long as you like.

Take one strip and wrap it around the mandrel in a spiral, with the edges touching but not overlapping. Secure both ends of the strip with masking tape. Start a second layer spiralling in the opposite direction from the first and tape the end in place. Open back out. Mix a 50/50 mix of white glue (I use Elmers) and water and brush it on the inside of the strip. Wrap the strip around the first layer, again trying not to overlap or leave any gaps between the windings. Once the second strip is glued in place, repeat the process with a third strip, this time going in the same direction as the original strip. After the third layer is glued in place, you can cut the ends straight with an Xacto knife and a cutting guide - simply roll the tube under the knife and press with the flat edge. You can either leave the tube on the mandrel to dry or slip it off to dry. The resulting tube will be just about as strong as an Estes tube, and the wall thickness will be somewhere between 0.10 and 0.13 (Estes is 0.13). If you need an extra strong tube, a fourth layer can be added - wrapped the same direction as the second layer.

Greg

Mark II
12-17-2008, 02:41 PM
OK, here is a breakdown:

BT-5..(ID: 0.515"; OD: 0.541") - Estes, Semroc, FlisKits, Custom, Sunward
T-5....(ID: 0.518"; OD: 0.544") - Apogee, ASP, BMS, Totally Tubular
ST-5..(ID: 0.515"; OD: 0.543") - Centuri (OOP), Semroc

Tubing that will slip-fit over BT-5/T-5/ST-5:

T-5+...(ID: 0.559"; OD: 0.585") - Totally Tubular
T15.....(ID: 0.550; OD: 0.590") - Quest

The only Quest kits that I can think of that might have used T15 were the Aurora and the Space Shuttle Intrepid (for the glider bodies on both kits).

Mark \\.

Doug Sams
12-17-2008, 02:48 PM
The old MPC T15 should work. I'm not sure if it's still available from Quest at the moment or in any of their current kits.Buzz McD gave me a bunch of that stuff a few years ago. I've used it for HPR launch lugs (with a wrap of glass) and also used it in a cluster accidentally thinking it was BT-5 :( Fortunately, I was able to work around that fubar with no ill effects.

Doug

.

gpoehlein
12-17-2008, 04:03 PM
Actually, there is another supplier of T15 - you might try Sky High Hobbies:

http://www.skyhighhobbies.com/mpc_minirocs_rocket_kits.htm

The Minirocs Parts Assortment contains four T15 tubes (as well as 4 nose cones and 4 motor tubes). You might give them a call and make sure they still have some in stock.

Greg

Bluegrass Rocket
12-17-2008, 09:03 PM
Hey guys, thanks for all the information. That T5+ tube is what I would be looking for. Is it still possible to get it from Totally Tubular? I think I've read somewhere in this forum that it is hard to get a hold of this place. Any advice? Thanks again.

micromeister
12-18-2008, 08:28 AM
OK, here is a breakdown:

BT-5..(ID: 0.515"; OD: 0.541") - Estes, Semroc, FlisKits, Custom, Sunward
T-5....(ID: 0.518"; OD: 0.544") - Apogee, ASP, BMS, Totally Tubular
ST-5..(ID: 0.515"; OD: 0.543") - Centuri (OOP), Semroc

Tubing that will slip-fit over BT-5/T-5/ST-5:

T-5+...(ID: 0.559"; OD: 0.585") - Totally Tubular
T15.....(ID: 0.550; OD: 0.590") - Quest

The only Quest kits that I can think of that might have used T15 were the Aurora and the Space Shuttle Intrepid (for the glider bodies on both kits).

Mark \\.

Mark:
Where did you get this information? I just looked again at the 2008 Estes Catalog and my old desk ref stand-by from the 1992 estes cat. both show BT-5's as .518"ID, .544OD. Perhaps semroc, flis and sunward are making the BT-5 a little tighter:)

Mark II
12-18-2008, 10:39 AM
Mark:
Where did you get this information? I just looked again at the 2008 Estes Catalog and my old desk ref stand-by from the 1992 estes cat. both show BT-5's as .518"ID, .544OD. Perhaps semroc, flis and sunward are making the BT-5 a little tighter:)
Estes Industries 1973 Custom Parts Catalog (http://www.ninfinger.org/%7Esven/rockets/custom_estes/no_diagram.html#bt).

Mark \\.

micromeister
12-18-2008, 11:24 AM
Estes Industries 1973 Custom Parts Catalog (http://www.ninfinger.org/%7Esven/rockets/custom_estes/no_diagram.html#bt).

Mark \\.

Wow! I just I really hadn't paid that much attention, seems Estes changed to .544" OD in 1991.