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I have attached a couple of pdf files showing how I manufacture my torpedoes and I give the design freely to anyone that wants to have a go on the clear understanding that these designs are the subject of copyright laws and must not be used for commercial gain. Right that's the ****ty bit over, now for the fun part. The torpedo body is made form alum tube and thinned down so that it will float when the job is done.
The tails and caps are cast in resin but you can machine from ABS if you like. The firing tube is brass as are the seal holder and cap the "O" ring is neoprene. The loading valve is a popple valve from a cigarette
lighter. I use 1/16" brass tube for the blast nozzle but you will need to sleeve it down to stop the thing taking off.
Make the tail and valve holder a nice slide fit into the alum tube, make sure the inside of the tube is clean and grease free then coat the parts to slide in with some Dow Corning silicon sealant (bathroom seal is no good) make sure the parts are central and lined up and leave for 24 hours for the silicon to set. Once that is done you will need to crimp the alum around the resin(or plastic) parts. To do this I use a small pipe cutter and remove the cutting wheel and machine a small radius on the cutting edge
so that it squashes the tube rather than cut it. Next you will need to glue in the popple valve with a good quality adhesive (I use Devcon plastic welder, a two part epoxy for plastics).
The launch tube is brass big enough for the torpedo to slide in easily, the ejector can be brass or whatever takes your fancy and the locating pin is brass and must have a little pressure applied to it.
I use a little slice of silicone tube placed over the plunger sideways.
How it works---------you place the seal over the 1/16 tube , remove the torpedo cap and load up through the valve with cigarette lighter gas. Place the cap back on and slide the torpedo into the tube until the brass peg rides over the bayonet, when you then press on the ejector it forces the torpedo of the seal
and launches, the bayonet and seal are left in the ejector. They will be pushed out of the back when you load another torpedo which can be easily done while the boat is in the water.
Tomorrow I will post some photographs of the components for your assistance.
One last point, there is no mechanical restraint on these things and if the seal is not tight enough
the can shoot off when not expected so---do make sure your model has closing doors as a safety aid.
Have fun--be safe
The tails and caps are cast in resin but you can machine from ABS if you like. The firing tube is brass as are the seal holder and cap the "O" ring is neoprene. The loading valve is a popple valve from a cigarette
lighter. I use 1/16" brass tube for the blast nozzle but you will need to sleeve it down to stop the thing taking off.
Make the tail and valve holder a nice slide fit into the alum tube, make sure the inside of the tube is clean and grease free then coat the parts to slide in with some Dow Corning silicon sealant (bathroom seal is no good) make sure the parts are central and lined up and leave for 24 hours for the silicon to set. Once that is done you will need to crimp the alum around the resin(or plastic) parts. To do this I use a small pipe cutter and remove the cutting wheel and machine a small radius on the cutting edge
so that it squashes the tube rather than cut it. Next you will need to glue in the popple valve with a good quality adhesive (I use Devcon plastic welder, a two part epoxy for plastics).
The launch tube is brass big enough for the torpedo to slide in easily, the ejector can be brass or whatever takes your fancy and the locating pin is brass and must have a little pressure applied to it.
I use a little slice of silicone tube placed over the plunger sideways.
How it works---------you place the seal over the 1/16 tube , remove the torpedo cap and load up through the valve with cigarette lighter gas. Place the cap back on and slide the torpedo into the tube until the brass peg rides over the bayonet, when you then press on the ejector it forces the torpedo of the seal
and launches, the bayonet and seal are left in the ejector. They will be pushed out of the back when you load another torpedo which can be easily done while the boat is in the water.
Tomorrow I will post some photographs of the components for your assistance.
One last point, there is no mechanical restraint on these things and if the seal is not tight enough
the can shoot off when not expected so---do make sure your model has closing doors as a safety aid.
Have fun--be safe
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