Atlas Mercury 1/12 scale

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My Grand Dad worked on these out at Dyess AFB in Abilene, Tx. Well, just the Atlas missiles. Really takes me back seeing this, when I used to visit He always kept models of them in the room I stayed in. One of my earliest memories of rocketry.. Excellent build!!!

That is cool!

Love this build too!! Would love to build a large Atlas one day...and fly it on a 3-in-line cluster!
 
My Grand Dad worked on these out at Dyess AFB in Abilene, Tx. Well, just the Atlas missiles. Really takes me back seeing this, when I used to visit He always kept models of them in the room I stayed in. One of my earliest memories of rocketry.. Excellent build!!!

Thanks, Bojangles! I remember an assembly line picture of the Atlas, when I was growing up. I think this is the one. Looking at my model on the back porch reminds of this picture.

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That is cool!

Love this build too!! Would love to build a large Atlas one day...and fly it on a 3-in-line cluster!

Thanks, Marcus! I think my winter project will be figuring out how I can use a 3 motor cluster for this model. There is room in the outboard motor mount tubes for 8" long motors. It looks like G, H, or I motors will do. There are several design considerations to take into account. One consideration for me is that the outboard motors do little lifting so that the central K-motor has time to ignite. Things look safe with the G-motors. It is surprising how much altitude is added with 7" long H-motors according to RocSim. There is a 54 mm 5" long I-motor that will fit. Another consideration is to cant the motors so that the thrust line of action goes through the c.g. I don't know if I will do that, yet.
 
We launched the 1/12 scale Atlas Mercury again at Hellfire-20 on August 1st. The parachute opened late and never opened fully, so the main model had a hard landing with significant damage. The capsule landed with slight damage. I never got around to finding the c.g. of the full stack, so I launched only with the central K-motor. I did not have electronic parachute ejection and relied only the motor delay charge, which ends up firing late even after drilling the delay charge down the maximum amount with the CTI tool.

In disposing the damaged upper transition section I realized there was 5 pounds of lead there, so just pitching the lead in the trash can was not an option. I dissected the section with a jig saw and took the lead out. I found a metal salvage man in town, who took the lead.

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:(:cry::sad:

Gives new meaning to the term "Get the lead out."

I guess you always go with the biggest motor, shortest delay and most powerful ejection charge you can get with these big scale dream boats.

Future plans?
 
:(:cry::sad:

Gives new meaning to the term "Get the lead out."

I guess you always go with the biggest motor, shortest delay and most powerful ejection charge you can get with these big scale dream boats.

Future plans?

You are right, Daddy. Actually, "Getting the lead out" provided good practice for using a jig-saw on cutting the model. I found that a fine tooth blade for metal cutting worked good on cutting the "What's Up Hobbies" 10 inch diameter tube, which is 1/4" thick cardboard coated with a thin layer of fiber glass. The jig saw worked much better than my previous work with a hack saw (I may have tried a Zona saw, too.) I am contemplating repairing and rebuilding. The model seemed to hit broad sides on landing with damage on the aft-end, middle, and forward end. I took many pictures of the damage. A few pictures below show a general survey of the damage.

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Bummer, buddy. She really was a 'beaut, but that's rocketry for ya. Now you can go ahead and build the 3-in line cluster! And put an altimeter in for recovery redundancy!
 
Never did end up getting out to Hellfire when I was living in Utah. I was hoping to include it in a trip out their l there next year, but they start school super early out here in Alabama. If this is the caliber of stuff going on with you guys out there, then I'm doubly bummed.

Fantastic project. Too bad about the recovery issues. That same thing has got me worried about my first attempt at dual deploy with my 1/3rd scale Iris project I hope to fly next year. I'll definitely be relying on the experience and advice of the guys in my local club.
 
That was a neat build, sorry about the last flight damage, I've pretty much gone to all altimeter based ejection now, too many long/short delays and ez reload blow bys for me....


Hope you can rebuild it.

Frank
 
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That was a neat build, sorry about the last flight damage, I've pretty much gone to all altimeter based ejection now, too many long/short delays and ez reload blow bys for me....

I'm glad you built a big atlas, now I don't have to:) I might still do a missile version.... I was trying to think how I could do this using a foam built up structure, but if I tried clear fins I'm sure it would wind up too heavy, require too much nose weight, and then the structure would be too heavy for the foam.....Maybe I could go with foam fins but painted flat black ala the estes version.....

Hope you can rebuild it.

Frank

Frank, I'm going to try to rebuild it. I will definitely include electronic ejection, although it will be a back-fit of some kind. I used the jig saw with the fine tooth metal blade to cut back to the middle buckle area and remove it. I cut back in chunks and surveyed the damage as I went. I didn't even bother to draw lines. The circumferential cuts just followed the lines of the chrome mylar pieces. I cut around the long fairing with the jig saw and then easily cut across the fairing with the Zona saw (the Zona saw idea comes from Sodmeister). Cutting across the long fairing allows a new 10" diameter "What's Up Hobbies" tube to be telescoped in later. Luckily, I have more than enough What's Up Hobbies tube and couplers from the first build for the repairs. I then removed the fairing segment and simply peeled off the cardboard tubing. This will allow the fairing to be glued onto the new 10" diameter tube.

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Using the jigsaw I cut out the dent in the aft skirt. I was then able to look inside and survey the internal damage. The most damage appears to be in the quadrant between the 2nd and 3rd fin. Using a flexible light that I bought from the local auto parts store and a small digital camera, I was able to see that there was a crack in the wooden block used to mount the aft rail button. A good friend in our rocket club gave be some disposable syringes. I was able to attach a 1/4" diameter flexible tube to the syringe. On the first pass I put about 5 ml of epoxy around the wooden block. Later, on a second pass I put about 12 ml of epoxy on the side opposite of the wooden block.

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looking at this damage brings tears to my eyes. This was such a magnificent build!



Using the jigsaw I cut out the dent in the aft skirt. I was then able to look inside and survey the internal damage. The most damage appears to be in the quadrant between the 2nd and 3rd fin. Using a flexible light that I bought from the local auto parts store and a small digital camera, I was able to see that there was a crack in the wooden block used to mount the aft rail button. A good friend in our rocket club gave be some disposable syringes. I was able to attach a 1/4" diameter flexible tube to the syringe. On the first pass I put about 5 ml of epoxy around the wooden block. Later, on a second pass I put about 12 ml of epoxy on the side opposite of the wooden block.
 
looking at this damage brings tears to my eyes. This was such a magnificent build!
NJ Rick, you and me both. Of course, it won't look good as new. We will find out how good as the refurbishment progresses.

Nice to see you are rebuilding. Let me know if you need more syringes. We still have a bunch.

Joe, these syringes really came in handy. Thanks, again. I still have plenty.

I sealed up the hatch that I cut away. The details of the repair were not fancy, so I am just showing a picture of the final configuration. On the aft bulkhead I used aeropoxy and fiberglass cloth for a few repairs. It takes about 24 hours for the aeropoxy to cure, but it has extra strength. I completely covered the bulkhead in the area between fins 2 and 3 along with a few other small patches where the bracket holes showed cracking. The bracket holes will need to be re-drilled later. Fortunately, the wood tabs, which also had bolt holes for the clear plastic fins, showed no signs of damage. Only one of the four fins broke. There is considerable detail work (doo-dads, etc.) that need to be repaired, but that will come later. Photo's for the repairs just described are attached.

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Today I cut Fin #4 from a 12" square piece of 3/16" Lexan plastic (polycarbonate) that I bought from U.S. Plastics Co. The Lexan plastic comes with a thin layer of plastic on both sides that makes it easy to draw lines with a magic marker for the fin pattern. The plastic cuts easy with a scroll saw. With a little bit of filing I was to get Fin #4 to fit in its slot. With the broken fin replaced I can now stand the model upright in the downstairs furnace room. With the weather getting colder eventually I will need to move the model inside.

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I mounted a centering ring inside the 6" dia. parachute tube right above a coupler tube that was already there. This centering ring has a 5 inch diameter hole and its purpose is to be a ledge or lip to hold in place something like a piston with a big hole in it that will have an ejection charge holder mounted to it. An electrical wire will go through the parachute tube to the ejection charge holder. I had thought of just simply having a long wire go up the parachute tube to a small disposable ejection charge bag, but I like this idea better. I still need to make provisions for a compartment to hold the electronics in the annular space between the parachute tube and the 10" diameter air frame.

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OH MY !!!!!!

It broke my heart to see these pictures ,really a shame ,to say the very least.I don`t think too many people around could have done such an epic and down right beautiful build ,myself definitely included !!

I sure am glad you decided to try and fix her up ,it deserves it.I`ll follow your progress.

Cheers

Paul T
 
OH MY !!!!!!

It broke my heart to see these pictures ,really a shame ,to say the very least.I don`t think too many people around could have done such an epic and down right beautiful build ,myself definitely included !!

I sure am glad you decided to try and fix her up ,it deserves it.I`ll follow your progress.

Cheers

Paul T

Paul, thanks for checking in with your thoughts and support. Your sentiments echo my thoughts as I picked up the Atlas off of the Salt Flats at Hellfire-20. At the time I wasn't even sure anything could be done. Now, I am committed. Probably, my wife thinks I should be committed in more ways than one. I did have a disaster on my first Orbital Transport flight and I re-built it. It has gone on to fly more than a dozen flights and I plan to fly it again. Actually, I had a good friend at Hellfire-19 tell me that the parachute delay for the Atlas was a little too late and I agreed. I thought that I could get away with more flight at Hellfire-20 before using side boosters to increase the altitude. This should be a lesson for me.

I have assembled just about all the parts that I need as shown in the photo's below. As I mentioned previously, the 10" diameter tubes I already have in my inventory.

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I cut a 7 inch long piece from the 10" diameter tube (brown) using a jig saw. This will be the coupler to attach the 10" diameter air frame tube (white). The coupler tube will also house the compartment for the altimeter. The compartment will have an aft and forward bulkhead constructed from two centering rings. All my rebuilds go up in weight, so I am trying to keep weight down. The centering rings for this coupler are cut from 1/8" thick plywood. These centering rings are light weight and no structural strength. The objective is to make an airtight compartment. I cut four tabs from the coupler tube material to make small ledges to position the first centering ring. These tabs are epoxied in place first and then the centering ring is mounted.

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She's coming (back) along nicely! Glad you decided to rebuild!!

Thanks, Marcus! The encouragement does help. After I started the original build, I realized that the large 10-inch tubes were slightly out of round, but by then the out-of-round had already been built into the model. I am still fighting the out-of-roundness and had to sand the centering ring by file and Dremel tool (sanding drum) in order to get it to fit. I have now glued in the coupler tube using aeropoxy and cut a hatch using the Dremel tool with a cutting wheel and the Zona tube. I have test fitted the white air frame tube and it will fit on the coupler tube.

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I put in some side panels and bulkhead items along with an altimeter mount plate into the altimeter compartment before sealing with the top plate. I also drilled a hole into the parachute tube (or stuffer tube) for the wire that will eventually go to the ejection charge.

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Be sure to have it ready for Hellfire 21.

Joe

That's the objective, Joe. I'm making progress slow, but sure. Some days or weeks are better than others. I'm surprised that I got this far. There are several hard parts still left to do and then a lot of detail work later. I'm making parts and plans for the next hurdle now.
 
Sorry to see all the damage, and I'm glad to see that you're fixing it. Beautiful rocket!

In looking over the rocket, I was wondering... Could it be made modular? In other words, in the event of another bad landing, having parts that are attached to each other (e.g. with couplers), and only the top and bottom are directly attached to the stuffer tube in a removable manner.

I hope that this build gets to the point that it's reliable every time. Man that would be something to see out at a launch.

All The Best!
Jim
 
Sorry to see all the damage, and I'm glad to see that you're fixing it. Beautiful rocket!

In looking over the rocket, I was wondering... Could it be made modular? In other words, in the event of another bad landing, having parts that are attached to each other (e.g. with couplers), and only the top and bottom are directly attached to the stuffer tube in a removable manner.

I hope that this build gets to the point that it's reliable every time. Man that would be something to see out at a launch.

All The Best!
Jim

Thanks, Jim. During the first build I thought of making the model in 2 parts for the purpose of transportation. I cut the airframe for the second half yesterday and the old thought of two parts came back briefly. During the first build I asked Matt Johnson, who built a very similar model, what he did and he said that he made his model all as one piece. I decided to do the same thing. The biggest reason is that the 6" diameter parachute tube (or stuffer tube) goes almost the entire model length all the way up to the Mercury capsule. Since I like pistons for parachute ejection, I think that it is best to keep everything as one piece, otherwise there can be alignment problems. Hopefully, the alignment problems for the parachute tube will be resolved for this re-build.
 
I cut a 30" length of PML phenolic 6" diameter tube with the Zona saw to extend the parachute tube (or stuffer tube) to its original length. With the remaining length of the PML tube I cut parts for a 7-inch long external coupler (or sleeve) to connect the 30-inch length to to original tube. I cannot use an internal coupler tube, because I am using a piston. PML does not sell an external tube, so I need to construct my own.

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This is really making me thing about making one with a foam superstructure....but the missile only, lots of simple nose cone solutions for that one. My only quandry is how to do the fins. I could make them with foam and carbon to keep the weight light and paint them black like the estes version, I don't know how I would do this with lexan at this size and keep the weight low...

Frank

Maybe get the best of both worlds? Use a wood or carbon fiber frame and cover with clear Monokote or similar?
 
This is really making me thing about making one with a foam superstructure....but the missile only, lots of simple nose cone solutions for that one. My only quandry is how to do the fins. I could make them with foam and carbon to keep the weight light and paint them black like the estes version, I don't know how I would do this with lexan at this size and keep the weight low...

Frank

Frank, that would be cool, but also a challenge. I just weighed one fin and I get 10.5 ounces. Of course, there is the overall aft structure that holds the fin, also. These are 3/16" thick Lexan. Fins 1/8" thick would weigh about 1/3 less.

Dr. Zooch on his Atlas-Mercury does something similar to Estes using what some people call flame tubes. Once a design employs tubes with fins in the outboard motor positions, then a 3-motor Atlas is no longer possible, but that may not be a concern. I used clear fin-tubes on my small Titan Dyna-Soar propelled by a 24 mm D12. The clear tube and fins were acrylic bonded with super glue. The fin tube joint is weak and breaks often.
 
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