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Cutting metal
JohnFol - 8/5/02 at 08:28 AM

I had an idea on how to cut metal accuratly and with little effort.
I aim to buy a chop saw (circular saw mounted like a mitre saw) so I can set the angles correctly and then use a metal cutting disk. What I can't find is anyone who can supply anything but wood cutting disk. Seems a reasonable thing to do .. .

David Jenkins - 8/5/02 at 08:51 AM

If you're looking for a metal cutting saw blade, then it probably won't work in a wood-cutting mitre saw - it will spin much too fast. If you ever go to a metal suppliers, have a look at their chop saw; you will see that the blade runs at 60 - 100 rpm (and usually has coolant running over the cut).

Many builders have used one of those gadgets that holds an angle-grinder in a similar frame. Quick and accurate enough, but I didn't fancy grinding dust over all my workshop tools (I used a hacksaw). Machine Mart sell these things.

cheers,

David

JohnFol - 8/5/02 at 08:55 AM

You cut it with a hack saw ?

Most impressed.

UncleFista - 8/5/02 at 09:06 AM

I cut all the steel for my chassis with a hacksaw, suprisingly easy and accurate as you like (or can be bothered )

David Jenkins - 8/5/02 at 10:08 AM

quote:
You cut it with a hack saw ?

Most impressed.


It's really not too hard, if you do each piece as you need it. You need a few things:

1. A really good hacksaw frame (not a B&Q jobbie). Get it from a real tool shop where real metalworkers buy their tools!
2. Good-quality hacksaw blades (bi-metal are favourite - cut well but not too brittle). Change the blade as soon as it's knackered.
3. Good stance and a relaxed attitude - a comfortable swing and about 1 cutting stroke per second (quite slow). Don't push down too hard, let the blade do the work. If both you and the metal are getting hot, you're over-doing it!
4. Clear marking out so you can see where you're going.

With practice you can cut near enough to the line so only a touch with the file is needed.

This suited my way of working - I've had a lot of practice - you may prefer the grinder mitre cutter!

David

ChrisW - 8/5/02 at 01:07 PM

I built the majority of my frame with a hack saw - the worst bit is cutting the double angles.

However, I have now invested in one of those angle grinder holders though and it's much easier (and just as accurate). £70 from Screwfix including the grinder! Bargain.

Chris

JohnFol - 8/5/02 at 02:48 PM

David, you mention professional metal cutters run at about 100rpm. What speed do angle grinders run?

David Jenkins - 8/5/02 at 03:27 PM

About 20 - 30,000 rpm!

...but I wasn't talking about them...

I was talking about putting a metal saw blade in a chop saw designed for wood.

Don't think about putting an angle-grinder blade in a chop saw for wood - too slow, and far too dangerous due to lack of protective guards.

Angle grinders don't have much of a guard, but it's enough to make sure that bits of a broken blade fly away from the operator (too bad about the bloke at the bench next door).

David

phil - 9/5/02 at 08:00 PM

QVC sell some things called do-all discs and on their tv demmo's they have one in a power devil mitre saw just like mine. the discs are i think about £24.99 for 2 plus a benck clamp for a drill.On the demmo's it looks quite impressive but then they are trying to sell them. Have a look on the web site under diy. May get one myself soon just to try them. hope it helps>>>> phil

XenoDraken - 5/6/02 at 06:57 PM

Hehehe I have done it. I took a very small miter saw for wood and fitted a steel blade. it works fine, and when I got into something that needed to be removed from the frame it deached from the base with ease. I built a very straight 4x4 frame with this abortionated thing lol. I have since purchased a nice 4.5 inch horizontal band saw but hey ya work with what ya got right?

Mike