Plasma Cutter - An Expert Please!

Hi All,
I'm semi retired & take in odd engineering jobs.
The latest to come up causes a bit of a problem, I cant do part of it
with my existing equipment!
The job wont make that much profit, so its not worth investing more than $1000 in equipment to do it.
It will come up with VERY short lead times and MUST be done on time, so I cant outsource it.
The jobs a bit difficult to describe, but...
Imagine a piece of a jigsaw puzzle. Some of the pieces are about 3 inches square and some around 25 inches square. Some of the edges are curves like a puzzle piece, and some a straight and meet in a 'V' Some of the pieces are 3mm thick and some 6mm thick. The accuracy required isnt that great, the example of a jigsaw puzzle would be about right for the accuracy and finish required.
The only idea that springs to mind is a manual plasma cutter and use a template to cut around.
But I've never used a plasma cutter. If it would do the job, its within my budget.
Will this work?
Many Thanks for any help or ideas
John
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A water jet cutter or wire edm would do that from a file in minutes - I know you don't want to outsource, but if you have a company nearby with the equipment it would be fast and easy
AWEM
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Andrew Mawson wrote:

CNC plasma will do the job as well and is a lot cheaper and more suitable to home shop use. You won't get one together for $1k since the plasma cutter alone is that much, but if you have time to build one yourself you can put one together for about an additional $2k past the plasma cutter and it will be a very useful and versatile tool to have. Likely having CNC plasma will open up new job possibilities.
Lots of good DIY CNC info, including plasma on cnczone.com
Pete C.
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After you get your CNC table built there is a host of other things you need like a bigger air compressor, a dust collection system. A seperate room for the monster that breathes out black dust instead of fire. Then there is the dreaded dross. Unless you have your cut speed down to the gnat's whisker you will have to deal with dross removal. If you are serious about a CNC plasma table I have seen the used Plasmacams go for about $6500.00 with the DHC, older machines without the height control for a lot less. It is likely you can get your parts cut for .03 cents an inch depending on material thickness. Steve
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You wont get the accuracy you want with templates and a hand torch. You need a computer guided machine- plasma, laser, or waterjet. Commercial versions of these run from $30,000 to a half million.
Job it out. Or else cut them oversize, and hand file, die grind, and sand to fit.
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wrote:

You can purchase the Campbell Hausfeld H7139 Plasma Cutter 115V from Grizzly http://www.grizzly.com/products/h7139 for $1000. There are not many other Plasma Torches you can get for this price. This one will run on 115v and has a built in air compressor so it doesn't need external air. The downside is that it cuts only up to 1/4" thick material. 6mm = .24" so you're looking at using the machines maximum cut capability for this thickness.
If you are primarily doing 3mm material and only occasionally 6mm this machine would work just fine.

Assuming the accuracy isn't that great you might be able to use this tool. Here is the long answer:
- A plasma torch is very easy to use. You place the tip on the material to cut, pull the trigger, and cut along the outline. It's fast, leaves clean cut quality (when used at the right speed) and takes very little practice.
- You would have to make templates to trace the torch tip around. There is no way you could freehand it with any kind of accuracy. But if you were to get a 3/4" sheet of plywood and make some wooden templates to trace with the torch it would be pretty easy.
- If you make templates you would need to take into consideration the size of the actual torch head to create your template a tad smaller so that the cut would be the actual size you want it.
- If your cut was a little off, you could finish it off with a hand grinder.
All of this assumes that you have fairly good hand/eye coordination and that you would consider yourself a generally "handy" guy.
I would also add that if you purchased a Plasma torch for this purpose you would find at least 100 other projects that you could use it for. It is my favorite metal working tool. You can see some stuff I made at http://pozadzides.com/john /. The tree is all free hand plasma cut.
Good luck,
John P.
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It will work - or reduce the work.
You make an oversized design and file to fit. Plasma isn't puzzle edge quality.
Water machine might - but that is very expensive and not fast to setup.
Martin
Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH & Endowment Member NRA Second Amendment Task Force Charter Founder
John wrote:

-
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I think that we all know that the plasma cutter is the tool that you need for this job. There is a lower cost alternative that might be able to meet your needs.
Download the demonstration movie at the following website and decide for yourself.
http://www.cut-like-plasma.com/info_cutting_thick_steel.htm
PS: I own both a plasma cutter and the Henrob torch. The plasma can do a better job but I don't knock the Henrob's abilities. The Henrob is more portable and doesn't require any electricity. It is also substantially lower cost than purchasing a plasma cutter.
--------------------------------------------- John Jan 13, 1:38 pm
Hi All,
I'm semi retired & take in odd engineering jobs.
The latest to come up causes a bit of a problem, I cant do part of it with my existing equipment!
The job wont make that much profit, so its not worth investing more than $1000 in equipment to do it.
It will come up with VERY short lead times and MUST be done on time, so I cant outsource it.
The jobs a bit difficult to describe, but...
Imagine a piece of a jigsaw puzzle. Some of the pieces are about 3 inches square and some around 25 inches square. Some of the edges are curves like a puzzle piece, and some a straight and meet in a 'V' Some of the pieces are 3mm thick and some 6mm thick. The accuracy required isnt that great, the example of a jigsaw puzzle would be about right for the accuracy and finish required.
The only idea that springs to mind is a manual plasma cutter and use a template to cut around.
But I've never used a plasma cutter. If it would do the job, its within my budget.
Will this work?
Many Thanks for any help or ideas
John
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