Band saw parts

[daniel_dsouza]

Hello all,

Our club sponsor recently acquired a Powermatic 143 band saw for us. His hopes were that we would be able to cut 1/8 aluminum sheets with it. However, the bandsaw did not come with a blade. While this particular model is no longer supported by Powermatic, there are blades that can be bought and used for it. However, I have absolutely no idea what I am looking for.

My questions are what qualities and specifications should I be looking for in a metal-cutting blade, what part would you suggest, and what suppliers and products should I avoid?

Thanks in advance,
Daniel D.

[sanddrag]

You're lucky, that's a very nice saw. There's an old rule of thumb that says you want 3 or more teeth in whatever material you're cutting. For 1/8" plate, that would be 24 teeth per inch. In reality, you can often get away with about 2 teeth in the material. For that saw, I'm pretty sure it uses a blade between 94 and 96 inches long, however you'll want to verify this.

Definitely spend the extra money for a "bi-metal" blade rather than just a carbon steel blade.

If 1/8" plate is your primary material being cut, you might want to look at something like a 1/2" x 0.025 14-18 TPI variable pitch anti-vibration bi-metal blade. This should give all around good versatility. If you're making only straight cuts, go for a blade that is wider (like 3/4" wide).

I think the bi-metal blades McMaster sells are Starret brand, which are very nice. However, I'm sure there's cheaper places to get bimetal blades.

[Retired Starman]

Any saw shop can make up the blades for you, so you aren't limited to buying them from a parts house or industrial supplier. They cut them from rolls of blade stock, weld and anneal them, any length you want in any blade width and teeth per inch. Look in your yellow pages for saw shops.

If you can't find one locally, you can order what you want from

Keenedge
http://www.keenedgeatl.com/

They are a small company outside of Atlanta, GA and do good work. Blades aren't very expensive. Call them up, tell them what you have in a saw, tell them what you want to cut, and they will figure out what you need, make it up and ship it to you, usually in one day or so.

Dr. Bob

[daniel_dsouza]

Thanks guys! This was great information.

Daniel D'Souza

[jspatz1]

We have used this online supplier and like them. You can specify the blade type, width, tooth pitch, length, and they will custom make it and ship it very quickly at a very good price. ==> www.probandsawworks.com

Opinions: Order a wide blade (3/4) for staight cutoffs through heavy material, AND a narrower blade (3/8) for curved/shaped cuts through thinner material. Go with a high TPI (teeth per inch) of 14-18 so you can cut sheet and thin stock without snagging. It will also cut thicker stock, just slower. If you are cutting aluminum almost exclusively as most FRC teams are, a plain high-carbon steel blade will last a long time for about 1/3 the cost of a bi-metal blade. For the cost of bi-metal you could buy a couple of different widths, TPI's, or spares and be well set.

[DonRotolo]

Don't worry about the saw manufacturer supporting the saw; the physical principles are the same regardless of the brand. The only issues would be spare parts; most can be fabricated by any group of FRC students. The saw is very much worth having, using and repairing - an equivalent would cost quite a lot of money.

In addition to the blade recommendations given already, you also need to consider the blade speed (given in feet per minute). Some online research will easily yield some recommendations for that, given what you'll be cutting. Too high of a speed - like that used for wood - will dull your blades quickly. Too slow is less of a problem.

I have also seen suggestions to use a very low-tooth-count blade for aluminum, since the teeth will not get clogged. I can't cite any experts, but some research for the cost of a blade might be valuable. Something like a 4-6 TPI skip-tooth blade was mentioned for aluminum.

[sanddrag]

Originally Posted by DonRotolo

I have also seen suggestions to use a very low-tooth-count blade for aluminum, since the teeth will not get clogged. I can't cite any experts, but some research for the cost of a blade might be valuable. Something like a 4-6 TPI skip-tooth blade was mentioned for aluminum.

I have used a 6 TPI blade for cutting 1" round bar stock, on my 14" Delta bandsaw which is intended for wood. It did seem to work fine. Finer teeth (higher TPI) for thinner stuff, larger teeth (fewer TPI) for thick stuff.

Any sort of lubricant seems to hep when cutting aluminum. WD40, A9, or blade wax stick.

[daniel_dsouza]

Originally Posted by Retired Starman

Any saw shop can make up the blades for you, so you aren't limited to buying them from a parts house or industrial supplier. They cut them from rolls of blade stock, weld and anneal them, any length you want in any blade width and teeth per inch.
Dr. Bob

Our teacher in charge of our club decided to take the above route and find a local store that might sell us a length of blade. It turns out that we have all the equipment for joining the ends of a blade! Thanks everyone for all your suggestions, we will use them when choosing our blade specifications. Thanks Dick Linn for your link to the manual, it will be invaluable when starting this thing up.

Thanks again.
Daniel D.

[Dick Linn]

Here's a good video showing how to uncoil and coil a bandsaw blade:

http://www.youtube.com/watch?v=2WUiEJEZMTc

[Dick Linn]

You can download a Powermatic 143 manual here:

http://vintagemachinery.org/pubs/detail.aspx?id=3630

Should use a 94" - 96" blade. Very nice saw, by the way. It has a lot of speed adjustment.