Author Topic: Unspiking (attempt #4) (Read 4105 times)

rampa room artillery · « **Reply #30 on:** May 24, 2008, 07:56:11 AM »

Dont damage the back of the bore. I agree you can tap it and turn it out, but what if the cup turns ? well make a home made toggle bolt that can handle some strength and use a slid hammer. i have seen a guy remove the rifled bore out of a cannon that way.

rick bryan
3rd va. co B
N-Ssa

Chilachuck · « **Reply #31 on:** May 24, 2008, 06:35:21 PM »

Getting the cup to turn means it's at least a little loose, right? And it's not going to spin freely, not with that rough a bore, so he'd gain a little.

How'd they make those cups, anyhow?

Did they drop in anything like a bit of rock salt to encourage rust formation to lock the cup in better?

Squire Robin · « **Reply #32 on:** May 25, 2008, 12:36:04 AM »

Made up a long drill extension and drilled a 6.4mm hole, the cup self centred.

The drill went in precisely 1/2" then stopped. I have hit something hard, probably the back of the cup. Either a hard case of steel or compacted rust behind it.

Half an inch sounds like it should take a screw thread.

What do you reckon?

Squire Robin · « **Reply #33 on:** May 25, 2008, 01:27:53 AM »

OR...

...use the incredible push you get from BP.

Drill in another 1/8" using carbide to break through behind the plug.

Thread the hole.

Make up a screw in cartridge containing 50 grains of best black so it shoots behind the obstruction.

Take it out in to the countryside, aim into the ground, light the fuse, stand behind a tree.

dan610324 · « **Reply #34 on:** May 25, 2008, 01:34:35 AM »

thread it M8 and screw in an long enough threaded bar of high quality , then try to use an hydraulic jack outside the muzzle to pull it out

SLEEPY BEEPER · « **Reply #35 on:** May 25, 2008, 05:39:13 AM »

Sounds like a thread and pull is the next step. Maybe a 10 MM thread and a bottoming tap? In cases like this. Getting some pull on it and hammering on it(or a slide hammer). Seams to work better then just a straight pull. If that doesn't work. Then try a carbide cement drill. They seam to drill through anything. This is the most interesting post in a long time. I'm sitting at the end of my chair in anticipation.

dan610324 · « **Reply #36 on:** May 25, 2008, 07:23:30 AM »

slide hammer is an good idea, but you need an long threaded rod and an very heavy hammer

cannonmn · « **Reply #37 on:** May 25, 2008, 01:30:33 PM »

Quote

you need an long threaded rod and an very heavy hammer

What does the cannon weigh? Use it as the slide hammer. You rig up block and tackle to hoist the cannon a bit, inside of an A frame or H frame, if you don't have a forklift handy. Anyway, if you get a rod attached to the cup, just rig the cannon vertically up in the air a bit with chain somehow attached to rod, and chain fixed to hard point above cannon such as the frame I mentioned. Slack the chain but rig it so the chain will be taught and stop the cannon in falling before it hits the ground (we put pallets under such rigs so nothing bashes the floor.) Your weight release can be as simple as a piece of rope that you cut to let it fall. The sudden force applied works better than slow but greater force, such as hydraulic, usually.

Squire Robin · « **Reply #38 on:** May 25, 2008, 11:16:40 PM »

I had a close call dropping a cannon once, think I will start by threading the blockage M10, applying a preload of a few tons then giving it a tap with a somewhat lighter slide hammer

Double D · « **Reply #39 on:** May 26, 2008, 04:20:49 AM »

Did you tell the wife she needs to park her car some where else than in your shop...nope don't do that, it wouldn't work in my house either.

kevthebassman · « **Reply #40 on:** May 26, 2008, 06:45:56 AM »

Some more armchair quarterbacking for you..... Why not try and get your hands on some dry ice, or preferably liquid nitrogen, pour it down on the blockage, then try shattering it? I've seen a piece of 1" stainless steel round stock shattered like so much glass after a bath in liquid nitrogen.

dan610324 · « **Reply #41 on:** May 26, 2008, 10:43:14 AM »

that would probably make the cast iron cannon even more fragile then the barrel block , I wouldnt do it .

cannonmn · « **Reply #42 on:** May 26, 2008, 02:33:53 PM »

Quote

Why not try and get your hands on some dry ice, or preferably liquid nitrogen, pour it down on the blockage, then try shattering it?

Good idea but i don't think you would ever be able to cool the steel cup sufficiently, since it is in contact with the relatively "hot" cannon. There's no way to thermally insulate the cup from the cannon.

If all else fails, get a machinist with a big lathe to swing the cannon in it and just bore out the cup. The worst that could happen is that the torque would loosen the cup so it spun and could not be held so it could be cut. But very likely the cutter would stick in it, and if the lathe kept turning while the boring bar was backed out, the cup may come with it. If not, at least it will be broken free from the rust and a lot easier to remove.

Double D · « **Reply #43 on:** May 26, 2008, 03:55:12 PM »

I don't think that cup is going anywhere until you get what ever is down the vent is cleared. My guess is that the vent spike attaches to the cup.

I think you need to get a better look at what is ever is down there. You need to determine if the spike was put down the vent and riveted in place via the cup. You also need to determine that the cup is smaller than the bore and wasn't put in place via explosive welding or a at least explosive swaging

Can you rig up a small TV camera on a pole and look things a bit closer?

Terry C. · « **Reply #44 on:** May 26, 2008, 04:00:55 PM »

Don't know if the bore diameter and depth of this tube will allow it, but here is a method I use to remove bearing races from blind holes.

Using a stick electrode, run several beads of weld inside the flange of the cup. Be careful not to let the electrode drift out into the bore. The more weld you can get inside the cup, the better. Just make sure that you don't burn through or you could weld the cup into the chamber

As the weld deposit cools, the stress will cause the cup to contract.

I've had bearing races that were pressed in with a heavy interference fit, literally fall out of their bores.

BTW: You can weld electrodes end-to-end to get to the bottom of the bore (be sure to wrap the bare areas so that the electrode doesn't arc on the tube), but four feet is about the practical limit on how long you can go.

Squire Robin · « **Reply #45 on:** May 29, 2008, 12:17:29 PM »

This gets worse by the minute

I drilled 6.4mm, then opened it out to 8.5mm, then put in a 10mm tap and there was nothing there to cut.

Thought maybe the vibration on the long extension had put me oversize.

Put in an 11.7mm drill, turned it by hand, down it went. Put in a 1/4 BSP tap and there was nothing there to cut.

After drilling there was no swarf. It's like it's made of cheese.

Thought, maybe it's rusted out behind, hit it with an iron bar next to the hole and it's solid as a rock.

This is getting spooky. Think I may try getting it up on the drill press and drilling the touch hole. See if it comes through where I think it will come through.

cannonmn · « **Reply #46 on:** May 29, 2008, 12:35:10 PM »

What I'd do at this point is put some 3FG powder in the space behind the hole you put in it, so as to fill up the entire space behind the cup, while the cannon is in a safe place to fire it vertically. I'm guessing there isn't room for more than an ounce or three of powder, if there's a larger space than that, use cannon grade powder. "Vertically" is to keep the powder in place by gravity. The roughly 1/2 inch hole you have in it now will keep from allowing any really high pressures to build up, but you might get enough of a kick to dislodge that cup. Then you can stick a rod in the hole with some spring-loaded fingers that will lock in place and give you a way to pull it the rest of the way out.

You could use larger grained powder if the hole were smaller, but it is really large right now for confining powder gas.

Ignite the charge with quickmatch or electric match.

Be careful.

cannonmn · « **Reply #47 on:** May 29, 2008, 12:43:58 PM »

Come to think of it, you could put the electric match on the end of a long wood dowel to insert it in the hole in the cup after the powder is in. When you ignite the powder the dowel will help build up a little more pressure, plus making the placement of the electric match much easier. Tape the electric leads to the wood dowel at intervals. The wood dowel will of course be launched skyward, so have everyone under cover when it comes down.

SLEEPY BEEPER · « **Reply #48 on:** May 29, 2008, 12:46:14 PM »

Are the drill chips magnetic?

Squire Robin · « **Reply #49 on:** May 29, 2008, 12:54:21 PM »

I do have the chance to give it a pop this Sunday, but only one pop. I don't have a mop or a worm for it and I'd rather like to keep my hands in their old familiar place, attached to the ends of my arms

I was thinking more like half a pound of blasting powder behind 3 pounds of wet grass in a paper bag.

That might well loosen the rust up a bit.

Squire Robin · « **Reply #50 on:** May 29, 2008, 01:05:14 PM »

Quote from: SLEEPY BEEPER on May 29, 2008, 12:46:14 PM

Are the drill chips magnetic?

Well, I just scraped some rust off the 1/4 BSP tap, searched for a magnet, found an electric motor with magnets inside, and it does pick most of them up.

I think the back end has to be a thin skin of metal over a whole mess of rust.

SLEEPY BEEPER · « **Reply #51 on:** May 30, 2008, 10:25:53 AM »

More arm chair advice. Or something to think about anyway. In the old days. A chipper would have cut the plug in half with a hammer and chisel. Probably in under 30 minutes.

Squire Robin · « **Reply #52 on:** May 30, 2008, 01:46:16 PM »

Quote from: SLEEPY BEEPER on May 30, 2008, 10:25:53 AM

More arm chair advice. Or something to think about anyway. In the old days. A chipper would have cut the plug in half with a hammer and chisel. Probably in under 30 minutes.

When can you come do it?

MINOR SUCCESS

I have a touch hole

Got it up on the drill press, a 4mm cobalt HSS drill got me in another 1/4" before it hit something hard and went instantly blunt. I sharpened it and tried again then it broke.

Made an end cutting electrode and sparked it. Took hours, think it went through some rust, that slows it down.

Tip burnt out, made a new one, just about to give up for the night when the note changed. Noises coming out the bore, looked down it, showers of sparks and burning metal inside. Then the kerosene I was using as dialectric caught light with a bit of a whoomp. Didn't stop me looking though

I can now shoot blanks. Alle-blooming-luyah, Yippee etc

kevthebassman · « **Reply #53 on:** May 30, 2008, 02:34:58 PM »

It's a start! Keep at it, I'm sure you'll get that sucker out if you keep at it long enough.

Squire Robin · « **Reply #54 on:** May 30, 2008, 02:42:59 PM »

The service charge is 2 1/2 lbs of coarse powder, 6 pound ball.

Don't want anything like that much, I'm thinking 1/2 lb of blasting powder, 3 lbs of wet grass clippings, maybe a couple of Celotex wads to keep it all in place.

There will be a movie, Sunday afternoon

Shooting is so much more fun than metalwork, but not having a worm or a mop for it I guess there's only a chance for one shot. Better make it a good 'un

GGaskill · « **Reply #55 on:** May 30, 2008, 03:13:51 PM »

I can't believe a skilled artificer such as you couldn't make a worm and sponge between now and Sunday.

KABAR2 · « **Reply #56 on:** May 30, 2008, 04:38:59 PM »

Ummmm................ Squire.................. By blasting powder do you mean cannon powder? or Fg powder? Or do you mean BLASTING POWDER?

Double D · « **Reply #57 on:** May 30, 2008, 05:05:57 PM »

Hey might mean Fa.

cannonmn · « **Reply #58 on:** May 30, 2008, 05:29:37 PM »

Quote

By blasting powder do you mean cannon powder? or Fg powder? Or do you mean BLASTING POWDER?

I suspect he means something like what I use for blanks, no. 2FA blasting powder. Blasting powder is a cheaper type of black powder made with sodium nitrate instead of postassium nitrate. The grains are really course and odd-shaped, like fine gravel. It is normally used for blasting rock in quarries, where it will push large chunks of rock when desired and not waste energy shattering them when that's not desired. It is a low explosive, like black powder.

Tropico · « **Reply #59 on:** May 30, 2008, 06:11:27 PM »

I been following the story of this cannon for a few years., it has been pretty exciting at times., but now., Ön with the movie !!!
I believe Congratulations are in order Squire Robin .., Here's to you sir !