Trying to Replace that Missing BT-60 (Semroc or Centuri ST-16) Rocket Body Tube? Look in the Bathroom...

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brockrwood

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On a lark, I tried using a toilet paper tube as a replacement for the lost payload bay on my Semroc Goliath.

Voila! New payload bay! Just look in the bathroom...

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JStarStar

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Also the size of standard paper towel rolls. And a 3-motor cluster of BT-20 (18mm) fits just right.
 

Rocketjunkie

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Paper towel and TP cores are way too flimsy for replacing BT-60. Unless you reinforce them with a layer of 1 oz glass or similar. An ejection charge will blow out the tube.
 

brockrwood

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Luckily, my TP core is used as a payload bay, with a balsa tube connector to connect the payload bay to the main tube. So, the "ejection charge will blow it out" problem should not be an issue. The "ugly as all heck toilet paper tube" problem remains. ;-)
 

boomtube-mk2

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It is only in recent years that this is true.
Inflation by reductions in size, today's TP is 3/4inch narrower than previously, and amount, same OD but a larger ID.
 

kuririn

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Well, you're on a roll
😁
On a lark, I tried using a toilet paper tube as a replacement for the lost payload bay on my Semroc Goliath.

Voila! New payload bay! Just look in the bathroom...
Great Scott!
That is such a Charmin observation.
This makes me flush with excitement.
No need to ply you for more information.
Now I can cheaply wipe clean my backlog of bt-60 tube repairs.
Heh.

Seriously, I've found that the TP and paper towel tubes are slightly larger than BT-60 size. So you may need a tape wrap or two. But they are an exact replacement for the BT-63 tube used in the old 1/70 Estes Saturn 1B.
And since that is an internal spacer/support tube and not a structural component it doesn't matter if it's flimsy or crappy looking.
😁
 

JPalmer621

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As a guy who works retail I will tell you that TP and paper towel tubes come a variety of diameters. I was looking to match a BT 60, took my nose cone to work and tried a variety of products before I found one that fit.
 

kuririn

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As a guy who works retail I will tell you that TP and paper towel tubes come a variety of diameters. I was looking to match a BT 60, took my nose cone to work and tried a variety of products before I found one that fit.
Probably in line with what this guy was saying about changes in recent years:

It is only in recent years that this is true.
Inflation by reductions in size, today's TP is 3/4inch narrower than previously, and amount, same OD but a larger ID.
 

JStarStar

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Years and years ago (about 50) i
made a Bizarro Bertha out of a wrapping paper tube, a plastic nose cone I got Easter Candy in, with fins out of scrap balsa and the motor mount out of a couple semi demolished BT-20 rockets. All put together the parts cost me about 50 cents. Everything fit pretty well without the motor mount or the parachute ever getting blown out.
 

brockrwood

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Years and years ago (about 50) i
made a Bizarro Bertha out of a wrapping paper tube, a plastic nose cone I got Easter Candy in, with fins out of scrap balsa and the motor mount out of a couple semi demolished BT-20 rockets. All put together the parts cost me about 50 cents. Everything fit pretty well without the motor mount or the parachute ever getting blown out.
How did she fly?
 

JStarStar

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Ok, I never would have entered any altitude contests but it flew fine. I flew it a dozen times or so before I took a 19-year sabbatical from rocketry.
 

MidOH

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My girlfriend actually commented on ''Where in the heck are you getting all of these rolls of TP without tubes in them? Some kind of Eco Green nonsense or something?''

Every bathroom has a tubeless roll, and half of the linen closet as well. They don't roll for nothing, on the TP holders. They warp and get all cattywompus.

I've been splitting the tube and using it as a lame inside coupler inside tubes to strengthen them ahead of the motor mount. It works OK if you use a ton of glue.
 

GlenP

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Another example of raiding the recycling bin for model rocket parts: I found an Amazon nose cone in the field near my house, and it was a perfect fit for a wrapping paper tube, so I scratch built this 24mm power upscale Centuri Excalibur, and used TP rolls a few layers thick to make my own twist-lock coupler. The 18mm Excalibur is the SEMROC retro repro kit, and the 13mm power is a cardstock downscale.


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cptcommache

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I've discovered that toilet paper rolls from Costco fit perfectly inside paper towel rolls also sold by Costco and are a great fit for a bt-60 nose cone. I basically make the entire body double walled and it feels really sturdy.
 

brockrwood

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Another example of raiding the recycling bin for model rocket parts: I found an Amazon nose cone in the field near my house, and it was a perfect fit for a wrapping paper tube, so I scratch built this 24mm power upscale Centuri Excalibur, and used TP rolls a few layers thick to make my own twist-lock coupler. The 18mm Excalibur is the SEMROC retro repro kit, and the 13mm power is a cardstock downscale.


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These are awesome!
 
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