Someone talk me out of it, .....quickly.

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well, I'm going to the work shed tomorrow and going through the boxes of tubes to see what this project will require in the way of new purchases.

At 1/23 scale with eight 3 in. dia. tank tubes the main airframe sections will require one large 11 in. dia. body tube ring section at 33 in. long.
That would be the biggest component.
Think it may be feasible even if I have to roll my own.

Thinking about one central 54mm for stability insurance with four 29mm outboards canted.
 
that is awesome!! In Walt's book he described riding the Saturn 1b as taking an elevator up to orbit...very smooth ride....Pete Conrad said the same thing....but then again..these guys were all test pilots and the word smooth might be a relative term.


Walt, Gus and Gordo, with the Apollo Pad Abort model.
NARAM 50.
 
All systems go.

Ok. I made a couple of fin templates based on preliminary calculations.
The 3 in. tube/tank upscale version of this project looks more feasible than the 4 in. version, for my building area anyway.
The standard 1/70th scale fin blows up from 2.4 in. along the trailing edge to about 7 in.

Maybe I should consider a slightly bigger fin size for stability, but then again, there are eight of them.

I think components can be made in my den workshop without having to move this project into my garage.
Of course final assembly will need something taller than my ceiling height.

So I'm going to give it a go.
Saturn 1B : 3X upscale from 1/70th
 
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Awesome!!! this is going to be fun to follow! From what I am seeing from your calculations....you may wish to call your den workshop Michoud....



QUOTE=MaxQ;1580812]All systems go.

Ok. I made a couple of fin templates based on preliminary calculations.
The 3 in. tube/tank upscale version of this project looks more feasible than the 4 in. version, for my building area anyway.
The standard 1/70th scale fin blows up from 2.4 in. along the trailing edge to about 7 in.

Maybe I should consider a slightly bigger fin size for stability, but then again, there are eight of them.

I think components can be made in my den workshop without having to move this project into my garage.
Of course final assembly will need something taller than my ceiling height.

So I'm going to give it a go.
Saturn 1B : 3X upscale from 1/70th[/QUOTE]
 
What about thin-wall 2.6" tubes (BT-80) to save some mass in the back, othersie thicker 2.6" tubing? Scale factor 1/26.92.... maybe call it 1/27 scale. S-IVB stage, 9.63" Dia., tail ring 10.00" Dia. Service Module 5.7" dia.

Overall height, 97.3" tall, a bit over 8 feet.

BTW - link to a 1/70 drawing with 1/70 dimensions:

https://www.georgesrockets.com/GRP/Scale/SATURN-IB/Sat-IB-70-100pct.gif

And link to the same drawing enlarged to 1/35 scale but still listing 1/70 dimensions (intended to be printed at 50% to get double the print quality since both are GIF files, unable to save them as PDF's).

https://www.georgesrockets.com/GRP/Scale/SATURN-IB/Sat-IB-35-50pct.gif

Sat-IB-70-100pct-t.jpg



Note that the Estes Saturn-IB Kit (and Semroc Clone) used oversized fins. If you used scale-sized fins, the launch CG would need to be at least as far forward as the middle of the interstage adapter to be stable. It is VERY easy to build the first stage too heavy, needlessly so, requiring the addition of a massive amount of noseweight to make it stable.

- George Gassaway
 
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Thanks George.
I'll rerun some scale calculations.

I have some 3" tubes for the tanks...but using 3" dia. tubes for those parts is making acquiring the main airframe and tail ring a little difficult to procure.
 
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For the sonotube's, take a tape measure to the store and check each one. Every one I have checked has been a different size and you might find one close enough to work with. You can also cut thin section out to get an exact fit (much like the process of making your own couplers).
 
I bought four 10" nominal diameter Quickrete tubes for fence posts about a week ago and noticed that they varied in diameter. Some could fit inside others.

Took my tape measure to a Lowes and found a 12" that was actually an odd size, not even size....about 11.5" dia.
Bought it - just in case I go that size/scale.

Looking at sources for various 3" and 2.6 " tank tube body tubes.
When I close on that, I'll start a build thread.
 
I bought four 10" nominal diameter Quickrete tubes for fence posts about a week ago and noticed that they varied in diameter. Some could fit inside others.

I mentioned this situation in another thread, but Sonotubes over a certain size (10" for example) are made in two sizes both of which are sold as the same diameter, one of which will slid inside the other. I believe this is done for shipping purposes. Most of the contractors we used to sell sonotube to just specified 24" not 24" plus or minus X, if a customer ordered twelve 24" tubes that is a stack on a flat bed 8' wide and just over 6' tall for twelve pieces (12' length iirc) but the nested ones could be shipped in half the space. Sonotube can also be bought as a special order with a PET plastic (I think) liner that makes the spirals disappear leaving a single seam down the length which can be turned away from the commonly viewed sides or ground off easier than the spirals. We bought Sonotube from the manufacturer by the semi-truck load in diameters from 6" to 48" and they were either 12' or 16' long. None of the many contractors we sold the tubing to seem to care that one of the tubes might be slightly over 24" and the other a small amount under 24" on the ID, typically we did try and make sure the tubes were either all inners or all outers as most of our contractors were only buying 1-6 pieces at a time. Sonotubes are also iirc sold in even inch diameters only like 6", 8", 10" etc. Most of the sonotube I dealt with over the years had a release coating sprayed in by the factory, I am not sure if thats the case with HD's Quikrete brand, if so it needs to be removed before gluing. Full length pieces of sonotube are generally sold by concrete suppliers, some construction equipment rental yards (Star Rentals, and Seco were two local ones for me), and some builders supply houses. I have seen two pieces of the same diameter sonotube joined end to end by cutting a piece and splitting it down the length then wrapping it around the two ends of the other tubes and then using clamps or tie wire to keep the "outside coupler" in place, some additional bracing was used as support of course.

Now back to the regularly scheduled thread.
 
I mentioned this situation in another thread, but Sonotubes over a certain size (10" for example) are made in two sizes both of which are sold as the same diameter, one of which will slid inside the other. Now back to the regularly scheduled thread.

Yes, I saw a lot of that this week. I also noted some tubes were out of round, and a few so terribly out of round to the point of being elliptical.
I've got a candidate Sakrete tube in both 10.5 " and 11.5 " depending on which way I go with the final scale up.

Eight tank tubes in the main airframe /fin can ..............need to find tubes.

Went over my body tube supply.
I only have a few (three or four) nice Loc P. tubes at 3" x 34" which would need to be extended to 38" to do the job, and I'd have to order more. Eight would run around $75-80.
If I go smaller scale - have some 2.6" Loc P. tubes - but they they would also need to be extended and I need more of those.

I have large cache of rough surface plotter paper tubes that my friends in graphic arts and architecture thought I could use.
These unfortunately are 3 1/8 to 3 1/4 inch diameter and won't allow for thru the wall fin placement unless the diameter expands.

Fifteen 3 1/8" x 30", and four 3 1/8" x 24".

Looks like I gotta start spending some money.
 
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Well, Bingo.
I was picking up plants for the back yard this afternoon and drove by a FedEx store.
Just so happened they had lightweight Scotch white mailing tubes.
3" dia. x 36"
Tolerances are very good, they are all identical.
They also had all that I needed - for a fraction of the cost of heavier alternatives.

These are thin walled, so they might benefit from a little reinforcement on the outside.
As George suggested earlier, weight savings in the aft end of this project doesn't hurt either.

The load bearing part of this project is going to be the larger central heavier motor mount that will run the entire length of the airframe, and the fins will be through the wall and attach to that (much like the other projects I've built).
So, think I'll break out the drafting pen, and start some cross section/templates.
https://www.staples.com/Staples-White-Mailing-Tube-3-inch-x-36-inch/product_468355
 
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Well, Bingo.
I was picking up plants for the back yard this afternoon and drove by a FedEx store.
Just so happened they had lightweight Scotch white mailing tubes.
3" dia. x 36"
Tolerances are very good, they are all identical.
They also had all that I needed - for a fraction of the cost of heavier alternatives.

These are thin walled, so they might benefit from a little reinforcement on the outside.
As George suggested earlier, weight savings in the aft end of this project doesn't hurt either.

The load bearing part of this project is going to be the larger central heavier motor mount that will run the entire length of the airframe, and the fins will be through the wall and attach to that (much like he other projects I've built).
So, think I'll break out the drafting pen, and start some cross section/templates.


https://www.staples.com/Staples-White-Mailing-Tube-3-inch-x-36-inch/product_468355

The 3" mailing tubes will also accept a standard 3" Loc coupler if needed.
 
Well, the cats out of the bag now.
The spouse saw this in the foyer.
Just shook her head.
Nothing seems to surprise her anymore.
I think I'm going to have a long list of Honey -Dos for awhile.

This is a comparison of the main Sakrete/Sonotube 11.5 in. dia. airframe "mandrel" with eight 3 in x 36 in. dia. tank tubes.
The 2.6 in. Loc P tubes are on the right for comparison.

DSCN8327.jpg
 
Trying to imagine the size of this thing and tasks ahead...here is a comparison of my 1/18th scale, 56 in. tall Apollo Little Joe II project next to this 1/23rd scale Saturn 1B.

Upscale Saturn 1B parts w 8.5in LJ-II.jpg
 
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