Metal Cutter

The plasma cutters have become the standard way to cut metal. Twenty years ago, the Oxy-acetylene torch was the standard. The plasma cutter leaves a better edge with less cleanup, and is easier to use (lower skill). It is probably also lower cost per cut. I am still using Oxy-Acetylene, but that is an issue of money, and I already have the OA rig.

If you are cutting repetitive patterns, you would be best off using templates, of masonite or metal, allowing you to just trace the pattern with the plasma torch. A blacksmith I know uses a pattern and apray paint, and then she just cuts it out freehand, but this is artistic work, not assemblies with exact (or semi-exact) dimensions.

The only other technology that comes to mind is water jet cutting, but that costs a lot more than $1000. It does, however, do an excellent job, on a wide range of materials.

I am assuming that your patterns have some curves and complex shapes. If they are all straight lines, a shear could be used, but shears big enough for 1/4" plate are costly.

All told, especially in the thickness range that you mention, plasma is the way to go, with OA the second choice.

Richard

D&G wrote:

I agree with everything Richard Ferguson said. If you think oxyacetylene equipment is too expensive, then all the other stuff is completely out of the question. However, do you know that you don't have to buy the tanks. Most vendors give you a month's free demurage with the purchase of a tank of gas. If you are doing a lot of cutting, or if you can complete all the work in a month, the tanks won't cost you anything.

If we are talking about just a very few pieces, and you have to do it on the cheap, then band-sawing or sabre-sawing are tiresome, but viable options.

It is important for you to know that there is a learning curve with O/A cutting. You won't just pick up a torch and start making pretty steel valentines.

Depending on how big your patterns are, a jigsaw with a diamond blade might be the ticket. You can get a decent jigsaw for about $200 or less (e-Bay, flea markets, etc). The diamond blades are basically small round diamond files and cut in any direction. The throat depth of a cheap jigsaw (also sometimes called a scroll saw) is not likely to be much over 16", and the table size is probably going to be a foot or less in diameter. Cutting speed won't amaze you on steel either, but it should work. If you get a bit of skill in handling the piece you can cut intricate patterns very accurately...I've seen people cut Lincol out of a penny on the one I have, and leave him smoking a pipe...with smoke! :^) (mine's not a cheapie though).

If you want more power, a deeper throat or better cutting dynamics, you can get more expensive saws, but by the time you get a really good one you could buy a low end plasma cutter.

BTW - For thin softer metals (brass, copper, etc) you can just use a wood cutting blade in a scroll saw. They will break more often and wear out sooner than on wood, but for a few dollars a dozen, they are expendable and they do work for thin stuff (mostly 1/8" or less, but I've seen 3/8" brass cut that way).

-- Mike

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If you can get a copy of "Model Eng. Workshop", July 2003, a UK pub. Read the article "Improving the Conquest" (a lathe). Mr. A Sinclair suggest doing away with the compound rest all together for the sake of more stiffness, less chatter and better cutting off. The down side is when you want to advance the threading tool at 29 deg. However, I designed a threading tool holder that over comes this objection. Don Warner