Saturn V builds - what would you different the next time around?

There have been many great build threads on various Saturn kits, and with the 50th anniversary of the Apollo 11 mission coming up, I bet folks will be building many more of them over the next few months. The list is long, and (luckily) growing, but many of them have a lot of features and challenges in common:

• Estes Saturn V 1/100 Kits # 2157 and #1969
• Estes Saturn 1B 1/100 Kit #2048
  
• Apogee's Saturn 1B at 1/70 scale
• Sirius Saturn V at 1:64 Super-Scale
• Others (LOC, Semroc, Dr Zooch, etc)

I am on my second Estes Saturn V kit (was #2157, now #1969), and wanted to take a minute to reflect and start sharing the things that I wish I had done differently on the first time build. And the things I plant to do differently the second time around.

Perhaps others can do the same, and share ideas and tricks on how to better build these beasts, and improve on both the process and the end result.

Here are a few of my current notes:

1. Do NOT prime the Estes BT-101 tube before applying the plastic wraps. Despite sanding off most of the primer (while filling the spirals), a fair amount of it remained on the tube. That increased the circumference by enough to cause wrap fitment issues.
   • Proposed solution: glue the wraps first, work to fill the exposed spirals afterwards. I might even bypass filling the spirals altogether, and cover the exposed tube with white vinyl wrap instead. TBD.
2. Fillet fin fairings from the inside! Despite careful curvature sanding, I still had the aft ends of the fairings bulge a bit after gluing, so I cut sliced them open (to relieve pressure) and glue paper half-moons on top to both hide the repair, and strengthen the fairing. This worked really well.
   • Proposed solution: This repair made me realize that I could have used the same aft fairing access holes for injecting internal fillets, since sanding the external ones is nearly impossible with the fragile plastic ribs everywhere.
3. Only use Epoxy for gluing centering rings, not Titebond or any other paper glue. Titebond shrinks a lot while drying, "pulling" the BT-101 around the location of the centering rings, creating ridges that are hard to hide afterwards. It can also "grab" the MMT while you are trying to insert it, if you are not careful. Epoxy all the way from now on.

Nice to haves:

• Go for clustered engine mount. I had upgraded my first Saturn V to a single 29mm MMT, but the next one will be a 5-engine cluster.
  
• Maybe an internal launch lug tunnel vs. stock two lugs glued to the outside?

a

I built my 2157 stock with the 24mm motor mount. For my 1969 I'm doing an interchangeable motor mount system:
1X29mm
4X24mm
1X24mm + 4X18mm
7X18mm
This will also be used in a scratch Aries/Fat Albert missile I'm working on. Beauty of it is that I only need to do one mount each that can be swapped between both rockets because each has a "mother" mount that they nest into.
BTW don't forget about the Estes 1/70 Saturn 1B. Cheers.

I took the scottdee fins and fairings and scaled them to fit the #1969 for my next build.

kuririn said:

I built my 2157 stock with the 24mm motor mount. For my 1969 I'm doing an interchangeable motor mount system:
1X29mm
4X24mm
1X24mm + 4X18mm
7X18mm
This will also be used in a scratch Aries/Fat Albert missile I'm working on. Beauty of it is that I only need to do one mount each that can be swapped between both rockets because each has a "mother" mount that they nest into.
BTW don't forget about the Estes 1/70 Saturn 1B. Cheers.

Click to expand...

Nice,
Do you mind sharing the design of your interchangeable mount?

a

afadeev said:

Nice,
Do you mind sharing the design of your interchangeable mount?

a

Click to expand...

Haven't started assembling the mounts yet, but here's a dry fit to give you an idea:

Mother mount is a BT-80 tube and 80-101 plywood centering rings. Two "F" size engine hooks to retain the mount.
Interchangeable mounts are standard BT-80 size. CRs are glued to couplers and coupler lengths are sized to match the length of the hooks.
Central bolt, wing nut, and washer for engine retention.

kuririn said:

I built my 2157 stock with the 24mm motor mount. For my 1969 I'm doing an interchangeable motor mount system:
1X29mm
4X24mm
1X24mm + 4X18mm
7X18mm
This will also be used in a scratch Aries/Fat Albert missile I'm working on. Beauty of it is that I only need to do one mount each that can be swapped between both rockets because each has a "mother" mount that they nest into.
BTW don't forget about the Estes 1/70 Saturn 1B. Cheers.

Click to expand...

Apogee makes the 1/70th Saturn 1B not Estes

BigRiJoe said:

Apogee makes the 1/70th Saturn 1B not Estes

Click to expand...

Not in 1967:https://www.spacemodeling.org/jimz/estes/k-29.pdf
Semroc also had a 1/70 version until recently.

To improve the problem of the centering rings being too small, I used the yellow wood glue for the centering rings and didn't have any problem with the BT pulling in (shrinkage) due to the CRs being too small. I had added a layer of ordinary photocopy paper around the edge of the CRs, tacking it in place with CA adhesive. This was done for each ring OD. Made them a whole lot more snug. The yellow glue should soak into the thin paper strip and make for a nicely bonded joint.


You will also notice I used a hole-punch to make provision for an internal launch rail. Don't forget to do the 3rd stage CRs as well (not pictured). I will puncture the transition later, after the wrap is added.

Another difficult part I found was that internal reinforcing ring in the tail of the main BT was seriously tight. After getting it into the BT, short of where it needs to be, then applying glue and sliding it up it stuck before it got to its final resting place. So it is a little short of target distance inside the BT. I can live with it where it is but it is a bit annoying for my.

I also think the CSM is lacking in detail so I will be adding to that with some card details an decals, to improve the overall look of the rocket. These are the decals I am looking at: https://www.culttvmanshop.com/Saturn-VApollo-196-scale-Apollo-CSM_p_1007.html

...I also think the CSM is lacking in detail so I will be adding to that with some card details an decals said:

https://www.culttvmanshop.com/Saturn-VApollo-196-scale-Apollo-CSM_p_1007.html[/URL]

Click to expand...

You might also check out StickerShock's 1/100 Saturn V decal/wrap set. It includes an SM wrap that should fit perfectly. (Considering Centuri had one way back in 1968, I'm amazed that 50 years later, Estes hasn't made an SM wrap and still directs modelers to simply paint it silver and call it good.) See https://stickershock23.com/product/saturn-v-estes/

I tried something different with BT-101 tube prep for my second build.
Instead of filling the spirals and spraying / sanding / etc multiple coats of primer and white paint, I glued the wraps and white vinyl wrap straight onto the naked BT-101.

The end result looks better than expected, see pic below.
Vinyl wrap came out a touch whiter than the plastic wraps, but nothing that a light coat of paint wont fix:


Everything is shiny due to the flash.
To make vinyl stick better, I had sprayed a light coat of glossy white paint onto the tube to seal the cardboard, and give vinyl backing something less porous to which to adhere. It worked.
The vinyl wrap seam was positioned to go under where the longitudinal wood tunnels will be glued next.

Also, I did not trim the 3D shapes around the front edges of the vacuform wrap. This had massively simplified and sped-up the plastic wrap application process, and also provided a nice edge to dove-tail with the vinyl wrap.

a

I participated in TVM's pay-in-advance to fund the Saturns, and so got one of the first Apogee Saturn V and one of the first Saturn IB. Not long after I got the kits I cleared one of my workbenches and started on the Saturn V. Decided to write a few words on RMR during assembly. Those posts have been reproduced here:
https://www.rocketryforum.com/threads/random-thoughts-on-the-apogee-saturn-v.77271/

Best -- Terry
...who will, someday, start work on the Saturn 1B...

Discovered 2 great products to help with the Saturn V (1969) build. One is DAP Platinum Patch, a VERY workable putty, available in white to help in cleaning up the interstage and fin fairing seams. Very workable for about a half hour, sets up in an hour, and is sandable the next morning. The other is GOOP sealant, and is VERY helpful with that troublesome fin area where the vacu-formed fin fairings meet the large body tube. It's almost a 90° contact point for the 2 materials, and GOOP gave me a strong & "material" bond there. The DAP was purchased at Home Depot, the GOOP can be found at sporting goods stores and other stores.