Ye Olde Rocket Forum

Go Back   Ye Olde Rocket Forum > Work Bench > Scale & Sport Scale Rocketry
User Name
Password
Auctions Register FAQ Members List Calendar Today's Posts Search Mark Forums Read


Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 09-09-2018, 07:38 PM
scott_mills scott_mills is offline
Craftsman
 
Join Date: Dec 2013
Posts: 253
Default Body Tube source?

I would like to find a source for a body tube diameter of 12 foot at 1/100 scale which would work well for both space shuttle SRB's and the Falcon series . The size would be a 1.44" OD halfway between a bt 58 and a BT 56 . Does anyone know of a good source? Or has anyone had success making their own tube ?
Reply With Quote
  #2  
Old 09-09-2018, 09:46 PM
MarkB.'s Avatar
MarkB. MarkB. is offline
Surfrajettes Fan
 
Join Date: Feb 2008
Location: El Paso
Posts: 1,113
Default

This size is not presently available. It is one of three sizes missing in the old Centuri/Semroc system of Series tubing. There is no Series 14 (the size you want) or Series 17 (1.70 ID/ 1.74 OD) or Series 19 (1.9 ID/1.94 OD). As you note, Series 14 would be great for 1/100 scale, 144 inch rockets like Titan and Atlas. I'd be good for 1/10 Hawk sounding rockets and for 1/64 LRB on Shenzhous as well.

But nobody makes 'em.

Yet.
__________________
NAR 79743
NARTrek Silver
I miss being SAM 062

Awaiting First Launch: Too numerous to count
Finishing: Zooch Saturn V; Alway/Nau BioArcas; Estes Expedition; TLP Standard
Repair/Rescue: Cherokee-D (2); Centuri Nike-Smoke; MX-774
On the Bench: 2650;
Dream Stage: 1/39.37 R-7
Reply With Quote
  #3  
Old 09-12-2018, 03:24 PM
Jerry Irvine's Avatar
Jerry Irvine Jerry Irvine is offline
Freeform rocketry advocate.
 
Join Date: Jan 2008
Location: Claremont, CA "The intellectual capitol of the world."-WSJ
Posts: 3,780
Default

Look at BMS for a 38mm coupler.
Reply With Quote
  #4  
Old 09-12-2018, 11:59 PM
scott_mills scott_mills is offline
Craftsman
 
Join Date: Dec 2013
Posts: 253
Default

is it special order at BMS i couldn't find it .

C55-34 1.280x1.212x34 inch long T55 coupler stock $5.00
C60-34 1.592x1.524x34 inch long T60 coupler stock $6.00
Reply With Quote
  #5  
Old 09-13-2018, 12:51 AM
BARGeezer BARGeezer is offline
Avid Builder
 
Join Date: Nov 2017
Posts: 610
Default

Quote:
Originally Posted by scott_mills
is it special order at BMS i couldn't find it .

C55-34 1.280x1.212x34 inch long T55 coupler stock $5.00
C60-34 1.592x1.524x34 inch long T60 coupler stock $6.00


A 38mm coupler size would be a little too big for what you are looking for:

https://www.discountrocketry.com/mo...ler-p-2299.html

1.515" OD rather than 1.44". If no one makes this size then your best alternative would be to "cut down" the diameter of a slightly larger tube, like the BT-60. Calculate the difference in circumference of the smaller tube and the BT-60 using c = 2 x pi x r ( or d x pi). Mark a vertical strip on the tube equal in width to the difference in circumference and cut it out, trying to cut as straight as possible. An angle tool is very helpful. Use the strip as a glue tab and join the cut ends together. Saw a post on the net a couple of years ago showing this but can't seem to find it now.

Another option is to make your own custom sized spiral or convoluted tubes using kraft paper. However this would entail using a mandrel or tube that is the exact size you need to wrap around, so you would have to construct it or get lucky and find one that's the exact size. Way too complicated.

Last edited by BARGeezer : 09-13-2018 at 04:10 AM.
Reply With Quote
  #6  
Old 09-13-2018, 02:21 AM
DavidQ DavidQ is offline
Craftsman
 
Join Date: Aug 2011
Location: Washougal Washington
Posts: 375
Default

Quote:
Originally Posted by scott_mills
I would like to find a source for a body tube diameter of 12 foot at 1/100 scale which would work well for both space shuttle SRB's and the Falcon series . The size would be a 1.44" OD halfway between a bt 58 and a BT 56 . Does anyone know of a good source? Or has anyone had success making their own tube ?

If the OD is the important measurement, you could blend the two techniques. Start with a slightly undersized body tube, like a Quest 35mm (1.340 id and 1.387 od). Then use that as a core, and wrap your tube-making material around it. Kraft paper for taping off around paint jobs works well. The walls would be a bit thick (1.44 od to 1.34 id = 0.1 difference, or 0.05" wall thickness), but would be comparable to some of the heavy-wall tubes.
Reply With Quote
  #7  
Old 09-13-2018, 07:37 AM
MarkB.'s Avatar
MarkB. MarkB. is offline
Surfrajettes Fan
 
Join Date: Feb 2008
Location: El Paso
Posts: 1,113
Default

David's method has the advantage of being able to use the centering rings and possibly cones for the core diameter. You can built up the cones by "fiberglassing" using a worn out nylon stocking and using either finishing epoxy resin or polyurethane to fill the weave. Because the nylon is stretchy it will conform to the contours of the cone. Pull the stocking over the cone and then "paint" the resin or polyurethane into the weave using a cheapy brush. Repeat the painting until the weave is filled.

Apparently, a stocking in the trash does NOT necessarily mean it's being thrown away; it may be in there for discipline. So always check with SWMBO before using an old stocking for this technique.

Don't ask me how I know.
__________________
NAR 79743
NARTrek Silver
I miss being SAM 062

Awaiting First Launch: Too numerous to count
Finishing: Zooch Saturn V; Alway/Nau BioArcas; Estes Expedition; TLP Standard
Repair/Rescue: Cherokee-D (2); Centuri Nike-Smoke; MX-774
On the Bench: 2650;
Dream Stage: 1/39.37 R-7

Last edited by MarkB. : 09-13-2018 at 05:43 PM.
Reply With Quote
  #8  
Old 09-13-2018, 08:36 AM
tbzep's Avatar
tbzep tbzep is offline
Dazed and Confused
 
Join Date: Mar 2005
Location: TN
Posts: 11,610
Default

I have made custom tubes by cutting down larger ones and by inserting strips to make larger ones. Cutting down a larger tube is easier on smaller diameter tubes. If you pick the right size, you can use the strip you cut out as the backing material for the seam and it will already be conformed to the tube shape. You can still use centering rings and cones by cutting a notch to fit the backing strip. This is an easy step. This method should be slightly lighter than building up a tube, assuming gobs of glue aren't applied.
__________________
I love sanding.
Reply With Quote
  #9  
Old 09-13-2018, 02:03 PM
Doug Sams's Avatar
Doug Sams Doug Sams is offline
Old Far...er...Rocketeer
 
Join Date: Mar 2005
Location: Plano, TX resident since 1998.
Posts: 3,965
Default

Quote:
Originally Posted by MarkB.
Apparently, a stocking in the trash does NOT necessarily mean it's being thrown away; it may be in there for discipline. So always check with SWMBO before using an old stocking for this technique.

Don't ask me how I know.
That may be the funniest thing I've read in months

Doug

.
__________________
YORF member #11
Reply With Quote
  #10  
Old 09-13-2018, 08:23 PM
A Fish Named Wallyum A Fish Named Wallyum is offline
BP Mafia
 
Join Date: Mar 2005
Location: Ft. Thomas, KY
Posts: 8,596
Default

Quote:
Originally Posted by MarkB.
David's method has the advantage of being able to use the centering rings and possibly cones for the core diameter. You can built up the cones by "fiberglassing" using a worn out nylon stocking and using either finishing epoxy resin or polyurethane to fill the weave. Because the nylon is stretchy it will conform to the contours of the cone. Pull the stocking over the cone and then "paint" the resin or polyurethane into the weave using a cheapy brush. Repeat the painting until the weave is filled.

Apparently, a stocking in the trash does NOT necessarily mean it's being thrown away; it may be in there for discipline. So always check with SWMBO before using an old stocking for this technique.

Don't ask me how I know.

__________________
Bill Eichelberger
NAR 79563

http://wallyum.blogspot.com/

I miss being SAM 0058

Build floor: Centuri Design Contest F-150 Hurricane Estes - Low Boom SST Semroc - Gee'Hod, Shrike, SST Shuttle

In paint: Canaroc Starfighter Scorpion Estes F-22 Air Superiority Fighter, Solar Sailer II Semroc Cyber III

Ready to fly: Estes - Multi-Roc, Solar Sailer II Semroc - Earmark, Snake Jumper
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump



All times are GMT -5. The time now is 06:29 PM.


Powered by: vBulletin Version 3.0.7
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Ye Olde Rocket Shoppe © 1998-2024