Apogee 1/70 Saturn V help

[ChrisPeek]

I am building a Apogee 1/70 Saturn V. I don't see anywhere in the instructions where is says how from from the end of the engine tube to mount the rear engine mount disc. Am I just missing something?

 

[OverTheTop]

Flick an email to Apogee and I am sure they will sort you out. Great customer service.

 

[David Schwantz]

What ever it is, just make sure to leave enough MMT to attach your choice of retainer.

 

[mikec]

The OP appears to be long gone, but for the benefit of future generations: per Apogee, the dimension being asked for is 0.5 inches. And the aft centering ring is 3.40625 (3 and 13/32) inches from the bottom of the body tube.

IMHO the kit would greatly benefit from the inclusion of a single drawing of the whole stack that shows the critical dimensions and the correct orientation of all of the wraps. As it is, you have to watch 2+ hours of videos and pluck these details out when they go by, and some of them are obscure even if you do that. I managed to attach the top wrap incorrectly because I had glazed over on the videos by that time.

I also question two things about the video instructions: the use of thin CA to adhere the wraps and the use of Fix-it epoxy clay to, well, do anything ever. I'm not saying the videos are flat out faked, but I sure couldn't reproduce anything about them in this regard. YMMV. I ended up using double-sided tape to attach the wraps, but the method Tim shows for this didn't work at all with the tape I had -- I attached the tape to the tube first, not the wrap. And that was marginal. And the Fix-it is, to be blunt, unusable for any rocketry purpose, in my experience.

I appreciate that Apogee was trying to make the kit light, and it is impressively light, but using thin balsa and vacuform for the fin fairings was a bad tradeoff between weight and durability. I managed to crack one of the fairings just painting the rocket, and I think the chance of there being no damage on landing is not great.

 

[Steven]

I've had success in using thin CA on both the Apogee Saturn v and Saturn 1b. It requires learning a technique in distribution of the adhesive so as not to melt the wraps. For the wraps I taped them around the joint itself, then began wicking the CA around the top and bottom of the wrap finishing off with the joint itself. He uses epoxy clay to strengthen the flimsy outer details by molding the clay into these areas. I've also used the clay to fillet the joints of the fins to the body tube as well as adhering the fin shrouds of the Saturn V as instructed. It works.

 

[prfesser]

I've had success in using thin CA on both the Apogee Saturn v and Saturn 1b. It requires learning a technique in distribution of the adhesive so as not to melt the wraps. For the wraps I taped them around the joint itself, then began wicking the CA around the top and bottom of the wrap finishing off with the joint itself. He uses epoxy clay to strengthen the flimsy outer details by molding the clay into these areas. I've also used the clay to fillet the joints of the fins to the body tube as well as adhering the fin shrouds of the Saturn V as instructed. It works.

Thick CA worked much better (for me; YMMV) for attaching the wraps. If memory serves I taped the wraps in place and ran a very small bead of thick CA at the tube-wrap joint. Thick CA seemed not to dissolve the wraps the way that thin CA did.

 

[Steven]

It's all in the application.

 

[mikec]

What type of thin CA did you use? The type Tim is clearly using in the videos (BSI thin with the blue label) caused the wrap material to crack every time I used it.

As for the Fix-it, I'm not sure what technique could possibly work. I found it too sticky and stiff to do anything with no matter how much alcohol I used. I'd love to see a detailed photo of what a fairing joint looks like using this stuff. Mine ended up looking really bad; I tried filling them with spackle. The fit of the vacuform was not especially impressive and some of them ended up with pretty large gaps.

 

[bguffer]

I used Bob Smith Gold for the wraps back in 2007, and still holding just fine.
https://www.rocketryworks.com/super-gold-thin-oderless-foam-safe-cyanoacrylate-glue/
Due to own fault, single time i launched it, came in hard, and wraps stayed attached. When i finally repaired it in 2014, used Bob Smith Gold again on bottom wrap that need replaced, and still holding just fine in 2022.

Bob

 

[bguffer]

Appears i attached the fin fairing balsa to the tube/wrap with a thicker crazy glue.



Video also shows me applying fixit epoxy clay to strengthen the fin fairing wraps.

Bob