Saturday I added some tubes to my mortar launcher. When I built it many years ago it only had one tube on each plate. Lighting the fuses was a pain, and best done with two people. Even then you only had two shells going up at a time, with long spaces in between firing.
So Friday after work I stopped at my local old fashioned auto parts store and bought a 10 foot stick of 2" exhaust tubing. Saturday morning I cut 6 19" pieces, prepped and welded them tot he plates, and then prepared a new method of firing the shells.
I got some nichrome wire, wrapped short lengths around the fuses and connected the ends to some primary wire. As I only had enough primary wire for 4 circuits, I paired the shells up.
When the day had turned to night, I gathered the tribe and we sat a safe distance away from the battery of mortars. One by one I touched the wires to a voltage source and each time a pair of shells ignited and headed skyward. Only one of the eight shells failed to ignite, later found to be an open in one of the wiring connections. I borrowed a lighter from one of the smokers, and lit the fuse the old fashioned way, and got the last shell off.
My plan is to add at least 8 more tubes, maybe 12, for an even 20. I also will be building a wiring buss, with a switch panel, fitted with pushbutton switches, as carefully slipping the bare ends of wire into the end of an extension cord can be tricky in the darkness.
Why the fuss with the steel tubes you ask?
Well, these mortar shells come with cheesy cardboard or fiberglass launch tubes. They are dangerous, prone to falling over just as the shell fires (not good), or the tube fails during the explosive action of the launch (also not good). Since discovering the 2" mortar shell many years ago while living on the local Indian reservation, I have been obsessed with them. I have even found a local supplier who can get them in bulk, rather than in the consumer "kits" offered at the July 4 holiday.
So the steel tubes are durable, and a larger platform offers a safer method of firing the shells, as well as making the firing of them more convenient. Also, the tube in the kits are only about 12" long. Knowing that a similar sized cartridge in a gun performs differently in a pistol with a short barrel, as opposed to a rifle with a long barrel, I went with a longer tube, for more velocity, and a bit higher launch. The 19" figure of the original tow tube came from them being leftover scrap after a repair job at work when I worked at the electric utility vehicle maintenance shop.
And I can sit and watch them too, rather than running away while ducking as each one launches.
So happy Pre Fourth Of July everyone!
Last edited by Racer X 69; 06-23-2019 at 06:39 PM.