Low Profile Cannon (Triple) [Deleted]

Kotori87 submitted a new resource:

Low Profile Cannon (Triple) - A stackable 50-round 3d printed cannon suitable for triples, quadruples, etc.

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how would you mount triples in a Lutzow?

 

These cannons are compact enough to fit in the barbette. I would suggest a turret-ring to hold three cannons together, with a servo for a 15-degree pivot mechanism. I'll see about getting an example picture soon.

 

I don't have a Lutzow, so how about a Deutschland example instead


A twin installation, with a turret-ring holding two cannons together. This was before I designed the stackable cannon, but was the inspiration.

And here are the details. The barbette (yellow) is fixed to the deck. Both cannons are held by a black turret ring, which fits and rotates smoothly inside the barbette. A lip on top of the turret ring prevents it from dropping down, while the white "millenium falcon" ring prevents it from jumping up and out of the boat. You can also clearly see how I achieved a 15-degree pivot. The wings of the "millenium falcon" ring protrude aft, engaging with a pin on the rudder servo. When the rudder servo moves to turn the ship to starboard, the pin moves the turret to port, bringing it on target sooner. A Lutzow could duplicate this installation with three cannons, or could use a separate servo for pivoting. Or you could omit pivoting entirely, but I think it's nifty.

 

These are for Fastgun right?

 

Yes.

 

Hey so, for clarity, could you explain the differences between the high and low flow solenoids? is this just in reference to the diameter of the in-flow tube? I am pretty sure I have low flow (strike solenoids with 1/16 tubing) on my current boat, but if High flow, by your definition, is the 1/8 tubing from the same solenoid, I'd definitely make the leap for the new boat I am building.

Also.... I have a friend who does printing, How do I explain to him how to stack together a triple?

Thanks!

 

Different valves have different internal flowpath sizes. It may not matter much if you're using 1/16" tubing, but once you go up to 1/8" id tubing the valve's orifice size makes a difference in gas flow-rate. A MAV-2 poppet valve has a very small orifice, while BC's combat gear solenoids have an enormous orifice. I originally designed my cannons just for myself, and I planned to use 1/8" tubing and the biggest solenoids I could find. After I posted this, I remembered that my original design is a real gas-guzzler that spurts a lot if used with smaller valves, so I changed a few internal dimensions to make the design more MAV-2 friendly. I have not tested the lower-flow version to see if it actually reduces the spurting, though.

 

Thanks Nick. I thought Kotori was digitally doing so and printing the triple as one big block.

Okay so I think I follow you. I'm using Strike solenoids and they can do high flow depending on the fittings you attach. I use 1/16 ID fittings because I have them available and just rolled with it.

 

Hey Kotori, could you tell me what metal hardware you used in that setup? ie: the magazine cap nuts, the gas fittings, and that threaded part to which the barrel/o-ring/nut attaches?
Links would be fantastic if you have them.

 

magazine endcap screw: 1/4-20 x .5in allen-head screw
magazine endcap seal: 008 o-ring

gas inlet: SP0-4 1/8NPT male to 1/8 hose swivel (or SP0-2 for 1/16 hose)
spring: from Strike Models
piston: injection-molded plastic piston from Strike Models, trimmed to height (I tried 3d-printed pistons but they tended to jam. I may have a solution but haven't tested yet)
breech magnet: a random 1/4" diameter neodymium magnet, glued into the prominent spot on the back side of the cannon

barrel fittings: I used a 1/4 compression thread hacked from a random hardware store fitting, same with the nut and compression ring. The threads were soldered onto a roughly 3/4" long length of 1/4" OD steel brake line (that was a mistake, very hard to solder) and then glued into the cannon. More recently, I have seen other people going the other way around, with the nut soldered to the barrel fitting, and the threads soldered to the barrel itself. These files include a spot for a 1/16" pin to help hold the barrel in place. I will see about getting some photos to help explain how to assemble the cannon soon.

 

wow, thanks for the details! that'll do the trick!

 

what is the length of the piston

 

I mostly use 0.5" rivets, so that'd be exactly 0.5" from the top of the piston to the top of the disk portion. Some of my earlier designs had shorter pistons though, and I don't remember if this one did or not.

 

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