I posted last week about my plans to build a missile silo for my "secret rocket base." I really appreciate all the discussion, suggestions, and pictures.
Usually on a project like this I build at least one experimental prototype so I can learn from my mistakes and mis-steps, then start over on a second for the layout. So it will be this time. Missile Silo 1.0 will never make it out of my workshop, but I learned a lot. The missile here is a 1:48 model of a German WWII V2 rocket that is a foot long. The video is short, only showing the silo doors opening and the first few inches of the missile coming out: I was worried if I continued much longer I'd go over the 100 MB limit.
Left, the mechanism,is about 16" high and 7 inches wide and deep. Right: it takes about 90 seconds to fully raise. Right, missile fully raised and read for launch. Yes, the black platform the V2 sits on is a roll of electrical tape: anything to shorten the prototype test.
Here it is with the missile fully retracted below ground. I have removed a side brace so you can see inside better. I buy rulers at Lowes by the dozens for project work: good small wood and I don't even have to measure when I cut it - its already marked!
The drive mechanism. A can motor turns a 1/4 inch threaded shaft. The missile platform is threaded and rides up as the shaft spins.
The threaded shaft does not raise or lower itself: as the missile lowers the shaft goes up inside it. When fully retracted the top of the threaded shaft is about 1/2 inch below the tip of the nose cone.
I have a few kinks yet to work out. The mechanism is too slow: I don't want it to be too much faster - maybe twice the speed it is now - so it takes a while. That will require a bigger DC motor - the one shown is working hard - I originally used a smaller motor and burned it out. Other problems are that there is some wobble, and the door opening levers are visible. I know how to fix all this though, so my effort in making this prototype was worth it. Missile Silo 2.0 will hold a scratch-built Atlas type ICBM about 18 - 20 inches high, have all those improvements, along with a blinking warming light and a siren, and I expect it will work well-enough to go on the layout. The V2 will make it to the layout, by the way. It, too, will be in a silo, but above ground in what looks like a grain silo (the secret rocket base, when disguised, will look like a rural farmhouse, barn, and silo. The silo will clamshell open to reveal the missile inside, ready to launch.
I am also exploring an alternative silo design. Some one suggested using a power antenna for an automobile, and idea I had played with for a while but rejected because I thought it would be too fast to raise the missile. But I ordered one just to see. It might work well - certainly would be easy. Regardless, this project was fun.
