Author Topic: Mercury Atlas 1/45.5 Flying Model (Read 17549 times)

rocketguy101 · « **on:** 09/02/2013 02:57 pm »

I have always wanted one of the Estes Mercury Atlas model rocket kits, but did not want to pay the ebay prices for the out of production kit...during some discussion on a model rocketry forum, I found out that Semroc produced the tubes that would combine to make a 1:45.45 scale model, plus they made the balsa cone!

So I bought a set of David Week's drawings from realspacemodels and started modeling the rocket in a 3D CAD program to figure out the various parts, and figure out the modifications required to make the model fly.

So my results are shown here, along with the drawings I created from the CAD for my shrouds and other naughty bits...

rocketguy101 · « **Reply #1 on:** 09/02/2013 03:00 pm »

Next I started the construction...

First the motor mount and then slotting the main tube for the fin tubes...

rocketguy101 · « **Reply #2 on:** 09/02/2013 03:04 pm »

The nacelle shrouds were produced from the 3D CAD (SolidWorks) "flat pattern" sheet metal feature. I was pleased with how they turned out. I discovered that I needed to trim the ribs more carefully to prevent wrinkles. That forced me to do more filling and sanding, but the finished product turned out nice...

I also discovered that glue should not be applied past the line marked with the red arrow to allow the fillet to form properly between the nacelle and the body.

I built a little jig to space the ribs, and to place them at the proper angle inside the nacelle.

rocketguy101 · « **Reply #3 on:** 09/02/2013 03:08 pm »

Adding the various external lines, fairings, vernier motors...you can see my messy fill job on the nacelles. I used Elmer's wood filler.

rocketguy101 · « **Reply #4 on:** 09/02/2013 03:12 pm »

The part I dreaded most: the LES tower! I used wooden dowels and a "draw plate" to reduce their diameter to 0.04" Then it was a matter of cutting to length, gluing in place on top of wax paper, and having to force myself to walk away and let things dry!!!

rocketguy101 · « **Reply #5 on:** 09/02/2013 03:15 pm »

The LES motor was produced from a 1/4" launch lug with some balsa end pieces I turned on a lathe. Cardstock bands are glued to the tube.

The nozzles are paper shrouds.

I left the aero spike off since I know it will break off during the first flight (that was my experience with my Mercury Redstone kit model

)

rocketguy101 · « **Reply #6 on:** 09/02/2013 03:19 pm »

I used a cardboard ring for the aero shoud to make a base on the nose cone to attach the LES tower. I coated it with CA (super glue) an then sanded a bevel on the outside diameter.

I also applied CA to all of the paper shrouds and nacelles. When it hardens the paper is like plastic and you can sand it. It is very tough.

rocketguy101 · « **Reply #7 on:** 09/02/2013 03:22 pm »

I decided to paint the model before gluing the LES tower, since it is red and the Mercury capsule will be flat black. So applying primer covered my filler sins...

Prior to painting, I glued a piece of corrugated styrene to similate the inter stage adapter...

rocketguy101 · « **Reply #8 on:** 09/02/2013 03:26 pm »

Now decision time: do I paint the Atlas all silver? I decided to paint it with the frost pattern (I call it "T -0").

The capsule is flat black with some red and white details.

rocketguy101 · « **Reply #9 on:** 09/02/2013 03:28 pm »

Now the tower is painted and attached. I added an eyelet to the nose so I can make a harness to attach the parachute. It will descend with the tower pointing upward to reduce damage during recovery (this Mercury will not splash down in water

)

rocketguy101 · « **Reply #10 on:** 09/02/2013 03:32 pm »

I built slip-on fins from Lexan. Someone (luke strawalker) suggested I add the nozzles, which was a nice touch

rocketguy101 · « **Reply #11 on:** 09/02/2013 03:36 pm »

Now flight pictures!!! The model flies on a D12-3 motor which has turned in several nice flights. The rocket flies straight, although the tower has cracked on a couple flights when the nose landed on a dirt road.

Davp99 · « **Reply #12 on:** 09/02/2013 04:12 pm »

Real Nice Job Dave

Silmfeanor · « **Reply #13 on:** 09/02/2013 04:31 pm »

Looks good! Looks like a good replica, but making if flyable adds a nice touch.

rocketguy101 · « **Reply #14 on:** 09/02/2013 04:40 pm »

Thanks! I will confess my heart was in my throat at the first launch...that was several month's worth of work sitting on the pad. Now that she has a few dings, it is a little easier to fly.

rocketguy101 · « **Reply #15 on:** 09/02/2013 04:43 pm »

Now that I have the MercAtlas, I can fly my "Man in Space" collection...we missed out flying right after the 44th anniversary of the Apollo 11 landing due to rains making the flying field too soft to drive on, so I made a photo montage of some previous flights....

Bubbinski · « **Reply #16 on:** 09/05/2013 02:30 am »

Very nice rocket build. I haven't flown a model rocket in almost 20 years. Time to change that.

clongton · « **Reply #17 on:** 10/18/2013 01:26 am »

rocketguy - is that a kit or scratch build?

rocketguy101 · « **Reply #18 on:** 10/18/2013 01:29 am »

Quote from: clongton on 10/18/2013 01:26 am

rocketguy - is that a kit or scratch build?

it is a scratch build...the plans are in the pdfs in the first post. parts from Semroc. it started when some folks on The Rocketry Forum were asking about the OOP Estes kit, and if anybody made the special tubes.

clongton · « **Reply #19 on:** 10/18/2013 03:33 pm »

David - there is no .pdf.
Just the .jpg