Cutting tapered pipe?

Last Summer the owner of the green house in town-two mi. down the highway from me stopped me and asked me if I wanted to build him two cannons--His last name is Cannon and He and his wife put up one of those nice thirty ft. aluminum flag poles and now he wants to put a civil war type cannon on each side of the pole. He came out today and I showed him my plans and he was happy with what I thought up. I bought some thirty ft. tapered street light poles years ago from a salvage/junk yard and we both think they will work.

I am open for suggestions on how to saw the tapered pipe and get it straight--one end is eight and the other is seven inches in diameter . I tried that trick I saw on those car restoration shows where they take tape and go around the pipe but did not work very good--got the cuts crooked--any suggestions--I can hardly lift the small end and the big end is worse--won't fit in the saw so have to spin them as I cut it--Thanks

We agreed on a six ft. barrel


I had two different kinds of wheels out back in a snowbank so
I brough them up with the loader and he chose the ones in front. They are 32 inched tall--I wish they were ten inches taller..

wrap something around it that has a straight edge, ie sheet metal, cardboard, etc, that's at least a foot wide. The ends may not match up exactly, because of the taper, but when you get close, tape it together and run your sharpie along the edge. Cut on the line. I've used large hose clamps but they're not wide enough to stay straight. steve

By sliding a sleeve over the small end and centering the exposed end of the pipe you can mark it with a sharpie. The sleeve could be a piece of sheet metal or even cardboard..HTH.Sam Womer (PA)

Take a sheet of tin about 24 inches log and 10 inches wide, wrap it into a cylinder that is straight, not tapered. tape it so that its inside diameter is the diameter at which you want to cut the pipe. Run it up the pipe until it is snug and stable. At the end of the tin towards the small end of the pole, make the gap between the cylinder of tin and the pipe equal all around. this will force the end that is in contact to be perpendicular to the tapered pipe centerline! Jim

If we were in the shop, we would set it up on V blocks. In the field, I would eyeball it and use a porta- band or a cut off wheel.

They make something called a pipe wrap. It's a roll of basically gasket paper. You could use some 1/8 garlock paper on the small end and mark the large end. Sheet rock tape also works in a pinch.

Good luck. It looks like a neat project. I'm sure we would all appreciate the result.

Stan Coryell
Mickleton, NJ

First off is either end tru? If it is take a tape measure mark of where you want the cut. Just start with the tape and go around it marking the length that you want to make the cut. Do it every inch or two at most. That should give you a good line to cut from but that would also give a line to make sure that collar others have sugested is fitting up to your marks equual. Would give you a second check in getting it true. Just a way to double check so you don't acidently cut wrong.

That it is only going to be yard art, I would use the straight sleeve slid down and centered, then mark it, cut it carefully with the hand grinder and a cut off wheel.

Then true it with a flap disc until it looks good.

Another thought, to give it a more realistic look, make heavy wall bushing to weld into the end of the barrel. That can be made straight and true.

Weld it in and blend the welds, it will look perfect even if the end of the taper is not!

We've got a couple of lathes at work that you could chuck it up in, then indicate it true....

Now that you've got it cut to rough dimension with the chop saw, go back with the tape trick and establish a straight line. Use a sharpie marker to make the line, step back, and make sure it's straight. If it isn't, carb cleaner and a rag to clean off the mark, then try again. Keep trying until you're satisfied with the line.

Now get out your angle grinder and a cutoff wheel. Trim the tube, leaving the line. Switch to a flap disc and fine tune things up to the line.

Steve and Leroy have good ideas. I would make sure big end was square and measure from there. Torch, plasma, or cut off wheels to do the deed. Reinforcing band of flat bar wrapped on the end plus a couple along the length. Cool project.

Since you know the taper on the pole measure the length and determine the amount of taper per foot. Set the pole on a level surface and block up at one end, set the other on the chop saw at the same elevation. Now shim at the chop saw at one half the amount of taper you determined for your length. If the pole is 20 ft long and the taper is one inch that is 1 inch divided by 20 ft. = .05. So if the cut is to be at say 5 ft. the taper will be .25 of an inch or a quarter inch. Half of that is .125 or one eight inch. That is the shim to correct the end cut. This is of course based on the poles being straight with no bows or bends.

I've cut off a lot of well casing drilling wells.I would pull my belt off,wrap it around the casing,through the buckle and pull it tight.I would eyeball it and tap it around until it was level,then draw a line around it with soapstone.Then torch it,or cut it with the gas cutoff saw if it was handy.

(quoted from post at 21:58:20 01/09/23)
I had two different kinds of wheels out back in a snowbank so
I brough them up with the loader and he chose the ones in front. They are 32 inched tall--I wish they were ten inches taller..

Click to expand...

The most common field artillery pieces were mounted on carriages with 57" wheels, 14 spokes, tapered, and all wood except for the center bushings, the hub bands, and the tires. These pieces were 6 lb guns (Model 1841), 12 lb guns (Model 1841), 12 lb Napoleon gun-howitzers (Model 1857), 3" Ordinance Rifles, and 2.9" and 3" (10 lb) Parrot Rifles.

Prairie Carriages (1st and 2nd models) used 42" wheels; pack carriages used 36" wheels. The most common tubes on Prairie Carriages were the 12 lb Mountain/Pack Howitzers (Model 1841).

One very obscure carriage used 48" wheels; this was the carriage for the Woodruff gun, a small, light, and decidedly oddball piece whose main claim to fame is that Genl. Benjamin Grierson took a 6-gun battery of them with him on his famous raid through Mississippi (the subject of John Wayne's [i:d08a5c531c]Horse Soldiers[/i:d08a5c531c]. Those 48" wheels were spindly, more buggy wheels than artillery, and, when Grierson reached Baton Rouge, it is said that no two wheels were alike, all having been repaired or replaced [i:d08a5c531c]en route[/i:d08a5c531c].

THABKS to all who commented--will try suggestions on the second one---

I should make him the battleship Iowa--wouldn't have to cut them then!1

If it were me, I would put it all away and wait for spring. It sure looks cold. Stan