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Estes Saturn V Build - Kit No. 2157
I decided to start the new Estes Saturn V build, kit no 2157. It looks like it will be a great build, and of course most of the time will be spent on the painting when I get to that step.
I marked up the main body and third stage tubes as required and built the engine mount and centering rings. I also built the optional cradle for holding the body during assembly. Now I'm ready to insert the mount into the main BT. It's suppopsed to recess to 3 3/8", and was wondering if anyone has modified this step to decrease the depth. I plan on using Aerotech 24mm RMS motors so I don't have to rely on an Estes D12 to get this thing off the ground and I could add nose weight if necessary. I'd just rather not have the motor recessed the full 3 3/8" into the main BT if I don't have to. Also does anyone have any glue recommendations for the vac-formed parts. Estes recommends Plastic Weld Cement (Plastruct), Testor's Plastic Cement #3502, Tenax 7R, and Testor's or Tamiya glue pens.
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I plan ahead that way I don't have to do anything right now. Oh by the way, I'm not here just for the "olde" rocket discussions. |
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A popular modification is to move the mount back and fly with the F-1 nozzles attached. Additional nose weight, larger fins, clear fins or a combination of these is always necessary to compensate. Too bad there is not a gas with negative mass we can put between the stuffer tube and the outer airframe. Bill |
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For vacu-formed wraps I use DAP rubber cement (the stringy, amber stuff that smells like hell). For the fins I SPARINGLY use Tenax 7r.
I'm sure there are other adhesives that work, but this is how I roll. Remember: always test the adhesive on a piece of scrap material! Have a fun build! Jeff
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Never trust an atom. They make up everything. 4 out of 3 people struggle with math. Chemically, alcohol IS a solution. NAR# 94042 SAM# 0078 |
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Thanks!
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I plan ahead that way I don't have to do anything right now. Oh by the way, I'm not here just for the "olde" rocket discussions. |
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If I didn't have to deal with additional fins I might actually consider that... But for this build I may just cheat the mount to between 2 3/4" and 3" instead of 3 3/8". For flight I can compensate with nose weight, and for display I can cut down the spacer ring to make sure the F-1 Nozzles display correctly. The main reason I'd like to do this is to reduce the chance of burning of the inner wall of the rocket by the Aerotech RMS motors... I still need to do some research and do some thinking though before I go ahead and make the change...
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I plan ahead that way I don't have to do anything right now. Oh by the way, I'm not here just for the "olde" rocket discussions. |
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Having never built a Sat V, I thought your measurement on how much the motor mount was to be recessed was a typo, but after reading further, I see that's not the case. 3 3/8" seems like a lot to me. At what point does the Krushnic effect come into play?
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Dave Fire is the leading cause of fire. Was once SAM#0132 |
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I would hopefully always launch this rocket with enough of a stand-off from the blast plate to not allow a vacuum build-up, which I think is what causes the Krushnic effect with recessed motor mounts, although I've never seen it happen and am not all that familiar with it. What I am really concerned about is just the burning of the inner lining of the main BT from the RMS motor exhaust. If I recess the mount just a little less I think I can reduce the possibility of that inner burning. Actually I see it a lot on one of my TLP kits, where the mount is recessed and the engine exhaust has charred the inside of the BT.
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I plan ahead that way I don't have to do anything right now. Oh by the way, I'm not here just for the "olde" rocket discussions. |
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I have a build thread on my Centuri Saturn V here we discussed adhesives there. This model is similar to the current Estes Saturn V.
I noticed this thread on RP, the poster mentions some problems with the third stage reduction wrap not fitting the paper shroud correctly. I have not started building my 2157 yet, but I want to check that out. ps: I tried flying w/ an F motor, and did get a little scorching on the bottom. |
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Go ahead and pull the mount back to the bottom and add a little weight to the capsule, plenty of room in there. Just keep the cg at 17.5" from the bottom of the bt and you're good to go.
Randy www.vernarockets.com |
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Thanks Randy. I think if I recess it 2 1/4" it should eliminate any serious interior burning. I built the Sat V kit 2001 a few years back and I set that one up with a trippe 24mm mount, also recessed to 2 1/4" and that one has flown with no interior burning so I think that's probably a good compromise placement. I've never launched that 2001 version with an RMS motor though...
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I plan ahead that way I don't have to do anything right now. Oh by the way, I'm not here just for the "olde" rocket discussions. |
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