Sheri's Mercury Redstone

At this point, the plywood cores were sandwhiched between styrene sheets and bonded with CA. The bevels on the leading edges of the fins still had to be dealt with though. This was easily done with the application of a solvent type of plastic cement. I used Plastruct. This welded the leading edges together and healed all gaps.

I do have a question for Sheri at this point.

I was looking ahead and one of the things coming up soon is to cut the little piece that fits between the fins and the rudders from the styrene. The instructions mention a template but I have not yet found it. Is is a paper job or another piece of styrene?

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So the bevel on the leading edge of the fins is created by bending the two pieces of styrene together?

Interesting approach!

-Kevin

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Sheri said:

The fins on the Redstone are an important detail I was really wanting to recreate versus just cutting out a plywood fin shape and gluing it on.

Once they are built up they are a nice looking scale fin.

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Agreed. A slab of plywood would give the basic shape, and that's about it. This approach takes more work, but it gives the right profile to the fin.

When we did our big Redstone, the fins and the escape tower took more time than the rest of the rocket did.

-Kevin

troj said:

So the bevel on the leading edge of the fins is created by bending the two pieces of styrene together?

Interesting approach!

-Kevin

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I cannot testify (yet) as to how well they perform but they are much easier to put together than I thought they would be. More important, they look good.

troj said:

When we did our big Redstone, the fins and the escape tower took more time than the rest of the rocket did.

-Kevin

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:y:

You had to remind me about the LES!

I still need counciling for the one I put together on my Zooch Little Joe.

Sheri said:

Here's a few pics for encouragement:

I got these a few weeks ago from a customer that built the Redstone. His turned out better than mine do.
He added the rivet details to the capsule as well as others!! The Instructions tell how to add the rivet details if desired.

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Now is NOT the time to be promoting feelings of inadequacy in the customer...:eyepop:

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John and Sheri,

That technique may be just what I need for my Doorknob. What happens to the root and tip edges when the styrene gets folded in?

troj said:

I've not seen what Sheri is including for tubes, so I'm going to assume it's comparable to what LOC use
-Kevin

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Sheri's kits usually come with thick & sturdy ULINE shipping tubes.

Sheri said:

or the manufacturer!! :shock: I get that feeling everytime someone sends me a pic of their model!!!

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I'll fix that for you when I post some more build pics. You'll feel like queen of the universe.

judo said:

John and Sheri,

That technique may be just what I need for my Doorknob. What happens to the root and tip edges when the styrene gets folded in?

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Sheri can probably answer this better than I can but here's what I have.

The root edge is a non issue. The tab from the core protrude past the styrene and the styrene will fit flush against the BT.

I can't tell you about the tips yet because I have not gotten there yet and I do not remember what I read. The instructions are at the shop and I am not.

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I finally unwrapped the resin capsule to take a look at it. I'm not doing anythign with it yet but it sure is purty. I can take care of that!

The Redstone had another little detail between the fins and the rudders. This kit builds that "thingamabob" out of styrene as well. The template must be cut from the plan that is provided. It is then laid on the styrene to trace the outline four times. I scored the styrene with a razor knife and steel rule. I found this much more difficult that cutting the fins themselves.

The thingamabobs were test fitted onto the fins and it was found that in each case, my cutting left something to be desired. All kit all right towards the bottom but each had to have the top opened up a bit more. When they all fit, CA was used to cement them to the fin cores. When the CA had dried, solvent cement was used to joint the platic to that of the fins.

I think that Sheri has a few of these kits out there and I have never heard of the eye bolt failing. No doubt that a forged or welded eye bolt is stronger, but why would you over build when you are already well within the strength limits for that task?

I think it is fantastic that you are sharing your build experience with everyone. I am sure that you are getting more advice and support than you ever imagined.

Really, if the eyebolt fails during recovery, I think you have bigger problems than a failed eyebolt!

Great build BTW!

With the thingamabobs in place, the rudders came next. They were formed from the pieces of styrene that were cut from the fins a few steps before and assembled in a similar manner. I held each piece flush against the bottom and inner edges and used the razor knife to score a line. Half were scored on one side and half on the other. The plastic was then gently bent to form the angle using the plywood core as a straightedge.

After bending, the styrene rudder tabs were glued to the plywood cores with CA. When the CA had set, solvent cement was used to join the edges along the angled leading edges and the joint with the thingamabobs. The results were much less than perfect and almost all of the problems were with the thingamabobs. I had not gotten them as well as the other pieces.

Before capping off the rudders, I needed to clean them up a bit. I used a sanding board to take down the excess material and get the edges of the styrene to line up with the edges of the cores. I then used liquid solvent cement to glue on scraps of styrene to the outer edges, leaving plenty of overhang. When I tried to remove the excess material, though, I found that the joint between the plastic pieces was not handling the abuse. This was rectified by putting a small amount of CA on the tips of the rudder cores and then solvent welding the edges of the plastic.

With the tips re-applied and now holding firm, I trimmed the excess material by first scoring around the perimeter with a razor knife and then using the sanding board to remove smaller humps. There were a few gaps and bulges but I figured that the fairing process would take care of that.

I like the way the fins are built, the finished product really looks very close to scale. I don't mind shaping fins, but I really enjoy building fins that use the structure to form the shape. Very nice fin design Sheri, I have to build one of these.

From a distance, the fins looked pretty good, certainly better than most things that come out of my shop, but there were some flaws that bothered me. A few places had gaps between the pieces of styrene. I applied Squadron green putty to the offending area and let the fins cure for a few days.

When the few days were up, I went after the accumulated good with a will using sandpaper, sanding sticks and a little jewelers file to get into those tight corners. A frequent scrubbing of the file with a wire brush was a must as was the brushing away of the dusty by-products. I got it to the point where I thought that painting would make them look "perfect".

Teusday's are my days off and I normally like to get a lot of work done on important things like rockets but...

...today the poopy dog got sprayed and I have an outraged dog, a traumatized teen girl and a tired wife that are demanding my attention.

Hopefully, I might get some more done latter.

Another question for Sheri:

I test fitted the motor tube today and found that I did a bad job of placing the forward centering ring. It is too far forward. When I slide in the motor tube it just barely intersects the forward ring by a very small fraction of an inch and that is with it barely contacting the rear ring, let alone having it prodtrude any.

I thought about splicing on an additional length of motor tube and using another piece of tubing and an external coupler but then the tube would not fit through the holes in the CRs. My current consideration is to splice the tubes with an internal coupler, formed from another piece of motor tube but with a vertical slit in it. It would still be hollow so gas could pass through. I think this should work unless there is something I am missing.

What are your thoughts?

Why not purchase a longer piece of motor mount? Assuming it's standard rocketry tubing....

-Kevin