Regulating band saw speeds

That's a handsome looking machine you have there! However, wood cutting bandsaws sometimes have issues OTHER than just being way too fast for metal cutting.

The blade is typically pretty narrow, making it easy to cut circles and such, which is what they're designed to do. Metal cutting bandsaws typically have a heavier blade, at least half an inch front to back, and more teeth per inch. Verify that a metal cutting blade is available before putting a lot of work and money is that saw.

Another issue "may" be of concern. Check both wheels to see if they will track OK with the heavy big metal cutting blade, AND that the coolant that you'll want to use to prolong blade life won't affect the bottom wheel. Probably not an issue, but wood saws don't expect to be immersed in liquid while operating.

If everything looks good at that point, a jackshaft arrangement should work great. The support stand you have should make it a snap to gear it down.

At any welding supply you can get any width metal cutting blade you want I bought 1/4 and 1/2 for mine for $10 a piece. The tires or bandsaw wheels are no different on the wood or metal ones I have seen combo saws that use the same wheels and guides. I have used bandsaws in machine shops that run all day long with no coolant and in a home shop is not needed. If you dont tell the bandsaw it was meant for wood it will never know!!!!
 
Here's some more pic's of it if anyone is interested.

These are probably all over the place up north, but in South Florida you don't see too many of these if any. I have mixed emotions for buying this.. sometime I wake up and think.. Why did I buy this?? Other times I inspect it and think.. This is cool!! I must admit though.. I have little or no room in my garage..

I almost left the stand behind, but am now glad I didn't.. It is vintage of the same era. One owner.. Owned by an old man that died. He etched his driver license number on the motor and the cutting deck. He was born in 1919. Probably bought this when he was in his mid 20's. These pic were taken before I cleaned it up.

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In remarkable condition. Looks like it had little use or it was taken care of. It was given to the guy I got it from just recently, but he never used it. Said the blade kept coming off.. I wonder why?? :) He said if I didn't buy it, he was going to take the motor and throw the rest away. I gave him 75 for it. I probably could have got it for 50. I cringed when he told me he had all the old mans stuff, but threw most of it away because it was rusty. He didn't seem too mechanically inclined from talking with him.. He did make the wood cart underneth though...



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only thing that might be missing is a pulley guard on this side.
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Hard to make out, but you can see the old man's driver license number ending in 19 etched at the top of the motor.
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The tires were rotted. I used a heat gun and a sharpened chisel and they came off pretty good. I had to use a piece of fine steel wool with a litte acetone on it to remove rubber film and get the wheel surfaces shiny clean. I ordered a set of tires off ebay. The paint isn't real good, but should clean up better... I might leave it like that and just paint the stand. I want to move the motor underneath.

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If those are 14 inch wheels Grizzly sells the tires for them that is probably why the blade kept coming off great find it should work well for you.. Ray
 
I agree- beautiful find!

I used a cheap lathe countershaft I found on eBay, and hung it underneath the bandsaw to slow it down.

The stand is perfect- easy mounting motor, jack shaft, countershaft underneath to slow it down.
Don't regret it a minute- just utilize the opposite side of the stand for something else-
Maybe even turn the bandsaws to fit sideways, making more room to use on the other side?

What a beauty!

Bernie
 
Go on ebay they have the rubber repacement wheels. Use a treadmill motor and the smallest pulley you can find to reduce the speed, they work great , i have done several.As far as the blades go buy doaal blade material and silver solder your own to any lg. you want, using a simple jig. I like 1/4' WIDTH the best in either a 308-601 or a 309-047
 
If those are 14 inch wheels Grizzly sells the tires for them that is probably why the blade kept coming off great find it should work well for you.. Ray

Thanks, I know that's why they were coming off.. the 70 year old tires on it were down right ugly. See my post above.


I agree- beautiful find!

I used a cheap lathe countershaft I found on eBay, and hung it underneath the bandsaw to slow it down.

The stand is perfect- easy mounting motor, jack shaft, countershaft underneath to slow it down.
Don't regret it a minute- just utilize the opposite side of the stand for something else-
Maybe even turn the bandsaws to fit sideways, making more room to use on the other side?

What a beauty!

Bernie

Thanks. I will probably center the saw on the stand to make it as narrow as possible. The stand must have been some kind of kit that was available back then.. It is assembled with screws, nuts and these funky clamps:

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I am still looking for countershaft/jackshaft info to see what I can do.

I looked at another saw today.. an AMC, American made 14", but it was a piece of junk. The pot metal bracket that held the top wheel was broken. I was thinking about getting it for the lower stand/base and the motor, plus it had a cool on/off switch and a light. Could probably get it for 20.00.

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Go on ebay they have the rubber repacement wheels. Use a treadmill motor and the smallest pulley you can find to reduce the speed, they work great , i have done several.As far as the blades go buy doaal blade material and silver solder your own to any lg. you want, using a simple jig. I like 1/4' WIDTH the best in either a 308-601 or a 309-047

As mentioned in an eariler post, I already have new tires coming. Thanks for the blade info.. I like the idea of cutting them to size myself. I only plan to cut 1/4 mild steel and aluminum.

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The blades I purchased where cut, welded and annealed for $10 hard to beat that and they seem to be lasting just fine I use it all the time.. Ray
 
I also weld my own blades. I made a jig and use silver solder. It works great. I use 3/8-inch blade stock. Oh, if you weld your own you can some times find long blades on sale and cut them down to fit your saw.
 
Decided to go down and get the above mentioned bandsaw today. Actually the brand is AMT, made in Tiawan. Picked it up for 10.00. The upper wheel bracket was broken. Made of pot metal and also I broke the table brackets, also made of pot metal when I was loading it. Poorly made in my opinion. No big deal though because I got it for the base and motor.
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I plan on using the bottom base for my Power King. It is mounted on coaster wheels which make it easy to move around. Nice little light too. The Power King is 16" at the bottom and the base is 15 3/4, But I think it will work out okay. I'm thinking of putting a steel plate for strength between the base and the Power King unit. It was missing the side cover for the motor, but I can easily make one.

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The motor is a USA made unit by Dayton. I'm not sure of the horse power because it is hard to see the label.. motor looks good and runs smooth. Wiring is first class. The motor is mounted sideways and has some slots for belt tension. The box on the side is the cover for the pulley. Probably won't fit on the Power King.

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Nice quality USA power switch too.
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Even if the base doesn't work out, althought I would be surprised, I think it was worth the amount I paid just for the lamp, motor and switch.

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For reference, the reason that you can't regulate the speed of an induction motor by just turning down the voltage (that's what a variac does) is how the motor controls the current draw under normal conditions. A motor is also a generator. When a motor starts turning, it starts generating a voltage (counter EMF or CEMF) that opposes the voltage that's making it turn (EMF) . When the CEMF balances the EMF, the speed and current stabilize.

If you put more load on the motor, the speed is reduced and the CEMF is reduced. Without the counter effect, the current increases, adding enough torque to the motor to hold the new, lower speed and set a new balance. If too much load is added, the rotor will stall and maximum current starts to flow. If the control system (or operator) doesn't shut it down, the high current will generate high heat in the windings, burning out the motor. Running at reduced speed and high current, even though still turning, will over-heat the motor and eventually damage it.

VFDs control speed by changing the frequency and adjusting voltage and current for optimum performance. This is quite easy to do on a 3-phase motor, not so easy on single-phase. I'm using a jack-shaft on my bandsaw conversion. Much easier and cheaper.
 
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