Question on a metal cutting bandsaw

[LordAthens]

We aquired a metal cutting bandsaw (a Delta) on the cheap. Used *very* little.

I've noticed that when cutting wider pieces (3" x .125 mild steel strap for example) it's cutting a mild half moon or angle on the piece. It will start straight, start curving in and then sometimes it will start to straighten out, other times it just keeps cutting at an angle.

I read through the instruction manual and it doesn't mention anything about fixing this type of situation.

For what it's worth, I'm cutting on the slowest speed as recommend on the pulley guide and I have the blade guides as close to the workpiece as they will allow.

Thoughts? I know little about bandsaws.

[MF Steve!]

Sounds like a stretched out blade to me...

[LordAthens]

Brand new (also Delta) blade. I thought the same thing and put a new one on tonight. At first, I adjusted it per the instructions which is just tight enough that it doesn't slip. After I got the same results, I tightened it up a half turn, then another half turn with the same results.

[Cebby]

Too much pressure on the blade? (onto the workpiece)

[LordAthens]

I'll check but I don't think so? The only weight is the weight of the "head" itself, which I believe I have set as "light" as possible. There is a rod with a spring on it that connects to the head and I have the spring pulled as tight as possible (it's on a cantilever, so it's trying lift the "head").

I'll try holding the head up and letting it cut slower next time I make a cut.

[hyperbuzzin]

What is the TPI (teeth per inch) of the blade?
For thinner material, you don't want too few, and for thicker material, you don't want too many.

Also, slow isn't always good. Bump the speed up to the next level and see what happens.

[aman-fred]

we have an old saw at work and for the first year I was there I tried and tried you get good straight cuts.. New blade old blade high tpi and low tpi I can't get it.
curious to hear if you get it.

[machinerguy]

Hey Brandon,
On a horizontal, cut-off bandsaw, your problem is likely caused by the blade being out of square with the table. This is usually adjusted at the blade guides. They're the roller bearing holder things. A guide bearing could be shot too. Think, if the blade is not perpendicular to the work, it will cause your symptom exactly.
Hope it helps.
Mike

[LordAthens]

Quick update;

I checked the blade to table and it's square. I would assume the bearings are fine as the saw was nearly brand new when we bought it. The guy used it for one small project at his engineering firm.

The blade on it is a 24tpi. I changed it to the "middle" speed and increased the band tension a little more. This go around I was cutting .250 x 3" mild steel for a pair of rear frame tie-in's and it cut perfect.

I'm not sure if it was the changes I made or the different stock I was cutting. I suppose the real test will be the .125" when I get a chance to do so.

[limegreentj]

you just gotta make sure the blade is tight enough