cutting sheet metal straight....

[Possum]

I need to cut some thick sheet metal in strips as straight as I possibly can. I have the Micromark metal band saw, its small but works well but I've never had any luck in sawing perfectly straight lines with it. so looking for ideas.

Is it possible to use a wood band saw like a Ryobi and put a small toothed blade on it and slow it down with a variac and cut with a wider blade to get straighter metal strips?

Is there such a thing as a table saw like blade and fence setup that will cut perfect metal strips?

am I scrrewed?

[trevorus]

Why not buy the stuff in the size you need? You could probably get it at a hardware store. It would be as cheap/cheaper than buying a blade and variac for said saw.

[Possum]

...

doesn't come in precut sizes, exotic expensive material.....

[SkinnyWire]

I have a couple of small band saws that I use to cut wood spacers. Nine tenths of the battle is setting the doggone things up so the blade is square with the table and the blade tension and guides/bearings are properly adjusted. Getting all that done and setting the guide blocks as low as possible (as close to the material being cut as possible) all help produce a straight cut.

I'm not a machinist, but I'd say you need a 1/4", 24TPI blade if you can get one that fits that saw. That, proper setup, and not forcing the material through the blade too fast and causing the blade to walk is probably your best bet, followed by a bit of de-burring.

I haven't tried this yet, but I've also read that you can use a stone to round the back of the blade a bit to cause less drag through the material. I was going to try a fish hook sharping stone for that. You can find a description of the procedure on the net.

I spent an evening last week balancing the upper wheel on my - shall we say, inexpensive - saw. Didn't quite get it perfect, but it does the job on the spacers.

[John_H]

I had a couple metal cutting blades made for my Sears bandsaw. As long as you know the length most saw sharpening shops can handle it. They're 1/4 x 18tpi carbon steel. It works fine for small stuff.

[lexluthier72]

be careful though....most wood cutting bandsaws have an open winding type motor, and if metal shavings get in there....watch out....you will have a pretty cool "afterburner" effect the next time you start it up...
-Erin

[trevorus]

doesn't come in precut sizes, exotic expensive material.....

Want to let us in on what it is?

[Possum]

...

some good ideas to try. the micromark bandsaw has limited types of blades, they don't tell you what size those blades are in length, maybe I can find a wider blade somewhere else, that would sure help cut straighter. I'm cutting ferrous material 1/8" thick, I tried making a fence guide but that doesn't help much.

[Rosewood]

Do you have a miter saw that you could use a cutoff disc on?

[Possum]

..

I found a place that custom makes band saw blades, about half the price of the micromark blades. Cutoff saws are too thick and waste too much material...

[bobbybunante]

accurate sheet metal working.

What is the material you are cutting and what guage is it?
Is this a one time project or will it be on going?
If the material is less than 20 guage, I'd recommend a Dewalt nibbler. About $150 - $200
Mark your piece and the nibbler cuts it like a pair of scissors.
The only other way to get precise dead on accurate pieces is to take your stock to someone with a sheet metal brake. They can mark it off, score it and snap it off at exactly the dimension you need.
I'd still get a pair of nibblers (or they could be called electric shears, depends on who you ask) if you do any regular sheet metal working (20ga or lighter)and I'd scrap the band saw idea band saws are way too unpredictable.

[David King]

If it's ferrous you're going to be stuck with slow and steady. Get the blade tension up as high as you can and make sure the blade guides are doing their job of keeping the blade straight. If you have lot to cut then find a shop with a water jet or laser and get them to do it over lunch hour. Hopefully someone there will be into guitars and pickups.
Maybe call Lonny Gilbertson (SE 8th and Belmont). He'll know who to call.

[jonson]

guillotine.

my local guys who do my laser work have no trouble shearing 1/8 or 3mm mild ferrous for me in 3/16 or whatever widths I require. a good industrial sheet metal guillotine will handle that for you, so contact your nearest sheet metal shop that's doing heavy work.

[Possum]

thanks...

didn't think about lasers, what kind of edge finish does it leave?
Is there someone you can recommend that has a website and does email?

[jack briggs]

Why not shear it?