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Blade recommendations for a Powermatic 14 inch bandsaw?
- Thread starter gi_984
- Start date
- Joined
- Dec 27, 2014
- Messages
- 658
A band saw is like any other tool, the quality of the cut has more to do with the skill of the user, than the precision of the tool. There is probably no other tool that is more mis-understood and abused than a band saw. 90% of the stuff I read on the internet about band saw adjustment and usage is garbage.
I have an 18" saw that is about three times the size of your new saw, I can put a 2" blade in it, but 1 1/4" is really the practical limit for a saw that size.
A 3/4" blade is pushing your saw a bit, and there is really no reason to use a blade that wide in a saw that small unless you are cutting really thick stock, or cutting fat tube. I had the same saw in a different color and gave it away. It was a nice machine, but I could not get full tension on wide blades with out twisting the casting, and have the wheels go ever so slightly out of alignment.
A 3/8" blade will cut every bit as straight as a 3/4" blade. In fact, you can pull the side guides out of the machine an it will cut straight provided your feed speed is properly matched to your rake, and the tpi and gullet are matched to the material. The side guides are for making curved cuts or bringing the blade back into the cut line, they are not for keeping the blade straight during a straight cut. If you need the sides guides to cut straight, the machine is not properly set up, or there is operator error. I used steel guides in my machine for years before I invested in ceramic guides with no issue, and I still use a steel guide behind the blade. The rear guide should be considered a wearable part that needs to be dressed or replaced at need. If you must use a roller rear guide, do not use one whose axle is perpendicular to the blade - it will wear a groove in the race and twist the blade each time you start a cut. A proper back guide should have its axle parallel to the blade so the blade skims the side of the race and wears the race back evenly. I prefer solid to roller guides on the side. Stuff tends to get between the roller and the blade since you adjust them to zero clearance, solid guides allow dust and small debris to pass by.
The wider blade does a better job of absorbing the shock of tooth impact, the more teeth in the material, the greater the impact pressure on the blade. Too many teeth and chip removal becomes and issue. Use a 0 rake tooth for steel and other hard metals, use a positive rake for brass and other soft metals.
I would just toss a 1/2" variable tooth in for general shop work, and buy an assortment of tpi's and rakes for specialty work when a quality cut is needed. Since it will be a rare day that stuff does not go from saw to mill/lathe, I would get a 3/4" 0-rake for large tube, and a 3/8" hook tooth for brass in a couple of different tpi's. Brass and cast iron tend to clog up the gullet if you have too many teeth in the work.
A final note. Always detention the blade after use, always. The easiest way to ruin a band saw is to leave it under tension. My big saw has a level for quickly doing this. It can be a hassle to turn the crank down, put a piece of tape with a pen mark next to the tension scale so you can return it to the same spot.
I have an 18" saw that is about three times the size of your new saw, I can put a 2" blade in it, but 1 1/4" is really the practical limit for a saw that size.
A 3/4" blade is pushing your saw a bit, and there is really no reason to use a blade that wide in a saw that small unless you are cutting really thick stock, or cutting fat tube. I had the same saw in a different color and gave it away. It was a nice machine, but I could not get full tension on wide blades with out twisting the casting, and have the wheels go ever so slightly out of alignment.
A 3/8" blade will cut every bit as straight as a 3/4" blade. In fact, you can pull the side guides out of the machine an it will cut straight provided your feed speed is properly matched to your rake, and the tpi and gullet are matched to the material. The side guides are for making curved cuts or bringing the blade back into the cut line, they are not for keeping the blade straight during a straight cut. If you need the sides guides to cut straight, the machine is not properly set up, or there is operator error. I used steel guides in my machine for years before I invested in ceramic guides with no issue, and I still use a steel guide behind the blade. The rear guide should be considered a wearable part that needs to be dressed or replaced at need. If you must use a roller rear guide, do not use one whose axle is perpendicular to the blade - it will wear a groove in the race and twist the blade each time you start a cut. A proper back guide should have its axle parallel to the blade so the blade skims the side of the race and wears the race back evenly. I prefer solid to roller guides on the side. Stuff tends to get between the roller and the blade since you adjust them to zero clearance, solid guides allow dust and small debris to pass by.
The wider blade does a better job of absorbing the shock of tooth impact, the more teeth in the material, the greater the impact pressure on the blade. Too many teeth and chip removal becomes and issue. Use a 0 rake tooth for steel and other hard metals, use a positive rake for brass and other soft metals.
I would just toss a 1/2" variable tooth in for general shop work, and buy an assortment of tpi's and rakes for specialty work when a quality cut is needed. Since it will be a rare day that stuff does not go from saw to mill/lathe, I would get a 3/4" 0-rake for large tube, and a 3/8" hook tooth for brass in a couple of different tpi's. Brass and cast iron tend to clog up the gullet if you have too many teeth in the work.
A final note. Always detention the blade after use, always. The easiest way to ruin a band saw is to leave it under tension. My big saw has a level for quickly doing this. It can be a hassle to turn the crank down, put a piece of tape with a pen mark next to the tension scale so you can return it to the same spot.
Hi Joshua. I never said I was going to use a 3/4 inch blade. The Lenox tech support guy suggested that for just straight cutting with their "Classic" blades. I'm sticking with the 1/2 blades in .025 for general contour cutting. This seems to be the best overall thickness and width for this saw. I don't know if it could properly tension a .035 blade. The casting on this US made Powermatic is very stiff. Not sure what they changed (i.e. lighter & cheaper construction) besides the color when production went across the pond. I suppose you could cut heavy stock if needed in a pinch but that is what the horizontal saw is for. I'm curious which model 18 inch saw you have? Does it have a air blower on it? I almost bought a DoAll ML in good shape for $800. Had a chance to buy a Grob for cheap also but needed some repairs. I passed on both because I just couldn't squeeze either into the shop. Would take up too much room. I plan on upgrading my sandblasting cabinet with a longer model, adding a surface grinder, and belt/disc sander so floor space is at a premium. The Powermatic is a "just right" size for my shop and will do everything I should need for the work I do. Just ferrous and some aluminum.
I've never heard about taking the tension off the blades when not in use. Thanks for the tip.
I've never heard about taking the tension off the blades when not in use. Thanks for the tip.
- Joined
- Dec 27, 2014
- Messages
- 658
Hi Joshua. I never said I was going to use a 3/4 inch blade. The Lenox tech support guy suggested that for just straight cutting with their "Classic" blades. I'm sticking with the 1/2 blades in .025 for general contour cutting. This seems to be the best overall thickness and width for this saw. I don't know if it could properly tension a .035 blade. The casting on this US made Powermatic is very stiff. Not sure what they changed (i.e. lighter & cheaper construction) besides the color when production went across the pond. I suppose you could cut heavy stock if needed in a pinch but that is what the horizontal saw is for. I'm curious which model 18 inch saw you have? Does it have a air blower on it? I almost bought a DoAll ML in good shape for $800. Had a chance to buy a Grob for cheap also but needed some repairs. I passed on both because I just couldn't squeeze either into the shop. Would take up too much room. I plan on upgrading my sandblasting cabinet with a longer model, adding a surface grinder, and belt/disc sander so floor space is at a premium. The Powermatic is a "just right" size for my shop and will do everything I should need for the work I do. Just ferrous and some aluminum.
I've never heard about taking the tension off the blades when not in use. Thanks for the tip.
Sorry if I offended, it was not my intention. My folks were professors, and I tend to lecture too much. You do have a great saw, my brother who I gave mine to is very happy with it.
I special ordered my bandsaw about 25 years ago from Laguna tools (they import Italian saws). I wanted the sturdiness of a big saw with a smaller foot print, so we started with an 18" multi-speed metal saw, removed the blade welder, swapped out the table, downsized the motor to 5hp 1ph, and made some other changes that I can't recall. I had to add a dust collection port and modify the chip sweeper. A blower might have been one of the things left off when I ordered it. It takes a 177" blade and weighs in the neighborhood of 500lb or 600lb if I recall correctly - it is much easier to move than my 14" planer, but much harder to move than my 10" cabinet saw.
After my experience with my previous two saws, I took the plunge and shelled out some pretty large bucks - it is by far the most expensive machine I own. It has cut everything from sheet metal to cast iron engine blocks with no complaint. Mostly it gets used for face cutting veneer from wide boards. I have an arrangement of weights and pulleys to assist moving the work through the blade and hand feed it to ensure correct feed rate through hard/soft spots. I usually cut a .060" piece from something about 10" wide, face the board on the jointer, then take another cut. The veneer is consistent enough that I can lay it up and put it in the vacuum press right from the saw.
leaving the blade under tension prints the tires. Often the tires will return to round after it has been run for a few minutes, this is probably the most common source of vibration. It can also deform the column, the wheels, and the axle mounting points.