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Thread: 14" bandsaw upgrade question - pulley selection

  1. #1

    14" bandsaw upgrade question - pulley selection

    I have a junky Harbor Freight 14" bandsaw that's basically been sidelined since I got a bigger one. I don't need it for resawing or cutting turning blanks, just for curves and general small bandsaw work. Still, I'd like to fix it up a bit. I have a list of things to do to it, but one that's confounding me is the motor and pulleys.

    junky saw.jpg

    The saw was originally set up for four speeds. It's got a step pulley on the motor and an intermediate step pulley between the drive pulley on the lower wheel. You tension the drive belt by pushing that intermediate pulley down. It's junk and slips under load. When I tried to tension it by prying against the pulley, it broke. I'd like to trash the whole multiple speed thing and go with a belt directly between the motor and the wheel pulley. I know I want about 3000 fpm blade speed. I can figure out the math easily enough, but I don't really know how to pick pulleys -- what size drive pulley should I select? Double pulley worth it? It has a 1hp 120v motor at 1725 rpm.

    Alternatively, I have a 1.5 hp, 220v 3450 rpm motor (and switch, wire, plug, etc.) just sitting around. I would like to use it, except it'd have to be a 2" motor pulley and an 8" on the wheel to get close to 3000 fpm. Could I get away with that if I used double v-belt pulleys, or would it slip too easily?

    Any thoughts or comments would be appreciated. Thanks in advance!

  2. #2
    Join Date
    May 2014
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    I have never seen a 14" bandsaw with double pulleys. A single pulley set -up is more than adequate to do what you are describing. Look for machined pulleys they will run smoother. A quality belt will help as well. The sizes you suggested are pretty close to the ones on my Delta ,maybe the 8" is a bit larger. hope this helps, Mike.

  3. #3
    Join Date
    Mar 2003
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    SE PA - Central Bucks County
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    If I'm not mistaken, HF made it multi-speed so folks could conceivably cut materials other than wood with it, but I agree that it's just not needed for woodworking. I'm truly interested in what you end up doing here as I actually have one of these things parked in the back of the garage bay behind the ZTR and some other things that I'm planning on fixing up one of these days to either use for scroll/curve cutting or to sell off. A friend moved across the country and gave it to me. Both motors were toast, but the machine is otherwise physically fine, other than a little surface rust on the table.

    For curvy, flat material work, the 1hp motor would likely be just fine and you wouldn't have to deal with all the rewiring, new switch, etc. Most modern 14" mass market band saws seem to have the ever-popular 1.5hp 120v motors on them, but I doubt you'd notice the difference of a half hp for scrolling.
    --

    The most expensive tool is the one you buy "cheaply" and often...

  4. #4
    1 hp should be plenty on a 14" saw. I've got that on my Delta 14" and it has never been under powered. Heck my 16" Jet only has a 1 1/2 hp motor at 240, and I've never locked the blade up, and it spends plenty of time resawing and cutting unsplitable firewood.

    Having a big bandsaw with a big blade for resawing and large scale work and a smaller one with a smaller blade for fine/detail work is really great. I only change blades now if they get dull, almost never for different operations.

  5. #5
    Join Date
    Sep 2016
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    Modesto, CA, USA
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    In general do not go under 2" diameter for vee pulley unless you are 1/2 Hp less. 3" is better. smaller pulleys mean more slip and shorter belt life.
    Bill D

  6. #6
    Looking at the original harbor freight setup the problem seems obvious. The middle pulley is only an inch or two below the pulley on the bandsaw wheel. It's maybe 1.5 or 1.75" and drives a 6" pulley right on top of it. No wonder the belt slips.

    There's an issue with using a larger pulley for the wheel: the sheet metal cover for the pulleys is roughly 8.25" wide and not particularly well centered or straight. An 8" pulley wouldn't fit without modification. All this pushes me toward just rolling with the original motor. I am not sure of the steps on the motor pulley for the HFT but I imagine I can use one spot on it with a new pulley for the wheel and get about 3000 FPM.

    A shame, I was hoping to be able to claim I'd hot rodded the thing by putting in a bigger motor.

  7. #7
    Join Date
    Sep 2016
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    Recommend 120 degrees minimum wrap angle on smallest pulley.
    Bill

    found this:
    Minimum center distances of pulleys should be equal to the sum of the pitch diameter of the larger pulley and one-half the diameter of the smaller pulley. This ensures the minimum wrap angle of approximately 120 degrees, which is generally sufficent for friction drives.

  8. #8
    Thanks, Bill. I appreciate it.

    I took the saw apart this afternoon. Going to put in new wheel bearings, new tires, replace some lost safety parts (I got the thing used for $100...), delete the riser block, get a new tension spring, a taller tension knob, a quick release, add new dust ports, a lamp, etc.

    The motor bearings made a little noise so I decided to take it apart and replace them. Ended up breaking the step pulley when I removed it (harbor freight loves their junk pulleys...). So I had to get another drive pulley too. $8 from amazon. No biggie. I do appreciate the thing using nothing but the most common bearings available (620x).

    I have a nice fat shopping cart at grizzly as lots of their (superior) parts fit the HFT saw. I'd place the order except I'm sure there's something I'm forgetting.

  9. #9
    Oh, yeah. The pulleys I ended up getting were:

    https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

    https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

    They say 6.75 and 3.25 but the useable diameter is actually 6.5 and 3.0, so that comes out to about 2900 FPM at the blade.

    ETA: The 6.75 was $12 when I ordered it. Now it's $55? That's amazon for you...

    Grizzly has a 6" (effective) pulley for ~$20. That'd be the one to get if you can't find a better deal elsewhere.
    Last edited by Bob Bouis; 01-06-2018 at 11:43 PM.

  10. #10
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  11. #11
    Join Date
    Dec 2006
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    Porter,TX
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    Like others said,over the yrs haven't come across double belt pulley system on BS which I have to say I have had maybe 10 BS(But why not?).Since its a HF maybe the pulleys have kinda glazed over and the belt also.Maybe give those belts a try that has the slots cut in them,which is for smaller dia pulleys.Can't remember that those belts are called,I get them at Auto Zone

  12. #12
    I got most of the stuff. Did a bit of work to the saw, going to put the quick tension parts on tonight-- but Amazon kind of forced my hand on the motor situation. The 6" pulley arrived a week late and turned out to be a 9" pulley. So I guess I'm going with the 220v after all. Maybe I'll paint the saw too...

  13. #13
    Hah, hah. The grizzly tensioner was a disaster. I mounted it where everyone else does, but either my saw has a different frame, my upper wheel carrier is different, or my blade is too long. So I end up with the wheel carrier being too close to the tensioner. The space is too tight and the whole thing is crooked so I can't adjust the lower spacer.

    It seems like the grizzly tensioner, if it worked right, would be more trouble to adjust every time you change the blade than it would be to just manually tension and detension after every use.

    Naturally the long knob grizzly provides isn't quite long enough to use by itself and have it clear the top of the wheel housing. So I'll end up having to buy a different handle anyway.

    Also, using the 9" pulley required me to cut about 1/2" of sheet metal off the stand on either side. Another pain in the butt.

    But otherwise it seems to work, I guess.

  14. #14
    Oh, and just in case anybody reads this and wonders WTF I'm rambling about, here's a picture from google images:



    So, what's happening is that I drilled the holes for the brackets too low on the frame of the saw. Also, the blade carrier on my saw sits way higher than that when the blade is tensioned. Then the assembly isn't centered well and one of the cross pieces is rubbing against the smaller of the two large black "spacers" that ride on the tension rod. The little one one has to be set a tad bit above the blade carrier so when you "detension" it pushes the blade carrier down (and actually tensions it backwards so the blade carrier moves down enough to get the blade off).

    You have to tension the blade then spin that thing down which is a terrible design idea as that spacer tends to get stuck against the larger spacer and there's no room to grab it much less tighten its set screw.

    I'm not sure that even if I had put the holes as close to the top of the frame as they'd go that it would work.
    Last edited by Bob Bouis; 01-27-2018 at 11:21 PM.

  15. #15
    Join Date
    Apr 2005
    Location
    Central MA
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    1,584
    So you bought some Grizzly parts to use on a Harbor Freight bandsaw and you’re upset with Grizzly’s design? Kind of seems like misdirected anger. All of the time and effort and money could have gone into finding and restoring a Vintage Delta 14” saw instead of trying to cobble together a frankenclone.

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