new air cylinder for swage press..

[Mauser 98K]

working on another air cylinder for my pneumatic swage press.. i thought a 3in cylinder would be enough, and it almost was, but it was just barely too weak to press the point forming punch home.. it like a smegging 1/16 inch going all the way to the stop when i was point forming my .30cal. this cylinder will give me an extra 700lbs of force and should give me enough to swage that extra 1/16 inch..

the end caps and the piston are just regular aluminum plate that i had laying around forever. the rod was another air cylinder that was a long bugger, about 3ft long but the bore was only 2 inches. i cut the rod in half to get a 12inch rod and threaded one end and cut a taper for a Jacobs chuck on the other end.. the tube is just a piece of 4-1/4ID 1/8in wall aluminum seamless tubing.. i turned the piston out today and will do the end plates tomorrow. i also still have to go and get some rubber O-rings for the seals.. should give around 2,000lbs of force for 125psi.. should be great being my arbor press i have been using for the swaging is just a 1 ton itself and im not doing nowhere near max force..

[jmorris]

You already have it cut and O-rings will work but you could have just bought a piston seal they work better for pneumatics and last longer IME. They make them in all sorts of sizes, I have some as large as 8" in diameter.

[Mauser 98K]

well im sort of on a very tight budget, the reason im making my own cylinder instead of buying one.. plus i can get a hand full of O-rings for 3$-4$ from my local maintenance supply outlet. i might see if they got the piston seals there, im going that way tomorrow. ill have to recut the piston if i went to a different seal design..

[jmorris]

I wouldn't change it now, just mentioning it for others or maybe a future project of yours. They keep you from having to make a piston at all. Just need a shaft with a shoulder and threads for the nut. Saves some work but you already have that part done.

[Mauser 98K]

it just screws on the rod with 3/4-10 threads, so no real big deal taking the piston off the rod.... but we will see how this works.. heck, i might need a bigger cylinder, im just hoping that 700lbs extra pressure will be enough to swage that extra 1/16 inch.

[jmorris]

There is also more than one way to "skin the cat" with pneumatics. You could have gotten the extra 700 lbs of force from the 3" cylinder with another 75 PSI.

You can make hybrid systems using 90 PSI shop air and a large piston to drive a much smaller hydraulic piston and get 1000's of PSI.

Not completely removed from the booster pump I made, as far as a change in volumes for a substantial pressure increase



Then of course you could add a lever arm into the equation and depending on where the fulcrum is placed have all sorts of mechanical advantages or distances of throw.

[Mauser 98K]

well the walls of the 3in was not that thick so i was getting paranoid with 125psi.. the bigger cylinder has 1/8in walls and i stepped up to 3/8 threaded rod to hold it together...

they didn't have the seals like you posted about so i went ahead and just used the O-rings.. i tested it out at 150psi and it held together so should be fine for 125psi.. but i was trying to stay as simple as i could on the entire design.. i can also use this setup im building to draw the jackets, it has a 5in stroke so should be plenty for that..

after i get the big cylinder to working like it should with the trimming ill add on 2 smaller cylinders, one will be for the ejection of the finished bullet, the trimmed jacket,and the seated core. the other will make it a all in one system and will be mounted behind the die plate. it will be set up with a shear plate that slides on the top of the trimming die that way the ram comes down and trims the jacket with the taper punch, the ram goes up and then the shear plate comes forward and takes off the waste material off the jacket, then the bottom cylinder comes up and ejects the trimmed jacket.. it will do this in about 1-2 seconds per jacket when trimming if i can get it to work out.. i got a PLC controller here that i can hook into the solenoid valves and program and turn it into a automatic system. i took logic controllers in college once so i know how to program ladder logic. but if i can get it to work like i want it i just put the jacket to trim in the die, push the button, and it does the trimming, the removing of the trimmed material, and the ejecting of the trimmed jacket on its own in about 1-2 seconds... it will be the same way with the point forming and the core seating operation.. i can also just put 3 valves on it and energize them in sequence and that would be a lot simpler..

but this is all a design in my head at the moment that im slowly bringing into the real world... we will see how it all works..

[jmorris]

You don't have to involve electronics to automate pneumatic systems, there are solenoids that are air operated as well as switches. So you can have an entirely closed system operating with just air.

Not unlike this video, if the cylinder contacted the switches at both extremes of its stroke.



If you wanted another pneumatic operation between, just add other solenoids and switches where needed.

[Mauser 98K]

swaged this about 30 minutes ago with the air press just to test it out. have not got all my die plates and the base for the press made yet and i just laid the plate on the press and held it in place to test it out.. this is a 130gr .308 varmint bullet.. did the trim, the core seating, and the point forming all with the press.. it takes about 120psi to do each operation too.. thinking on bumping it up to 130psi so it will make everything a little easier..

[jmorris]

Looks good. What is the required stroke length?

[uncle dino]

Fine job! Watching with interest..d

[Mauser 98K]

well the cylinder has a 5in stroke but im only using about 1-2 inches of it..