I have a 14 " bandsaw wirh 6" riser driven by a 1/2 hp motor at 1725 rpm. I have a chance at a 1hp motor at 3450 rpm. If I use the 1hp motor and half the diameter of the pulley so that the blade speed stays the same will I lose any advantage of the 1 hp? I other words will the gain be the same as using a 1 hp motor at 1725 rpm and the same pulley diameter?
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Band saw hp and speed
- Thread starter Wayne Spence
- Start date
Yes, for the same blade speed, doubling the HP will double the available torque on the the driving wheel. Dennis
My sense is you'd get a lot more power and torque both.
I had an old Delta 14" years ago with a riser that had been added but the motor was still the original smaller unit ..It may have been 1/2 HP I don't recall, but it could have been 3/4.
Anyway it was too wimpy and would bog down when resawing big stock. I stepped up to 1.5 HP and it was much much better.
I would think you'd notice a substantial improvement even at 1 HP.
If halving the size of the motor pulley means you will need a real small pulley though, you may have issues with transmitting that new power. There's a way to figure out that stuff but I don't know it ..I've always just gone by eye ..but belts with too tight a pulley wrap relative to their length and the diameter of the other pulley can be a big pain in the neck.
I had an old Delta 14" years ago with a riser that had been added but the motor was still the original smaller unit ..It may have been 1/2 HP I don't recall, but it could have been 3/4.
Anyway it was too wimpy and would bog down when resawing big stock. I stepped up to 1.5 HP and it was much much better.
I would think you'd notice a substantial improvement even at 1 HP.
If halving the size of the motor pulley means you will need a real small pulley though, you may have issues with transmitting that new power. There's a way to figure out that stuff but I don't know it ..I've always just gone by eye ..but belts with too tight a pulley wrap relative to their length and the diameter of the other pulley can be a big pain in the neck.
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I made the change to a 3450 motor on an older Delta. I had to use a larger upper pulley even after using very small pulley on motor. I built a new "belt house" out of wood to accommodate the larger upper pulley. I used powertwist belt. Definitely lots more power.
Second Thoughts
Checking the motor drive pulley which I should have done initially I find that going down to 2 inches from 4 inches might be too much so I have scrapped the idea. Thank you for you comments. I did buy the motor , dirt cheap, now I have a motor looking for a tool.
Checking the motor drive pulley which I should have done initially I find that going down to 2 inches from 4 inches might be too much so I have scrapped the idea. Thank you for you comments. I did buy the motor , dirt cheap, now I have a motor looking for a tool.
bandsaw motors
if you want to get the skinny on your questions regarding speed and rpms call the guy at iturra designs in flordia. this guy is a bandsaw guru.
i already had a 1hp lesson motor on my saw and bought this guys pulley system to increase the speed of the blade. man what a difference
if you want to get the skinny on your questions regarding speed and rpms call the guy at iturra designs in flordia. this guy is a bandsaw guru.
i already had a 1hp lesson motor on my saw and bought this guys pulley system to increase the speed of the blade. man what a difference
bandsaw motor
Wayne i see you too are in denver. if you want to see my saw or look at this guys catalog drop me a pm and we can make arrangments.
Wayne i see you too are in denver. if you want to see my saw or look at this guys catalog drop me a pm and we can make arrangments.
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Jointer would be a good place. Or you could use it with a mandrel, slow it down and sand/buff/grind with it. Bit of overkill at 1HP, but my JET buffer has a 1725 1Hp on it, and my electric bill doesn't seem to suffer. They even sell a 3450 version, so someone must use it.
Wayne, I don't quite understand why going a 2-inch motor pulley would be a problem, but even if you kept the same pulley, you would get the same max torque as with the smaller slower motor and the advantage of higher cutting speed. Alternatively, you could pick a pulley diameter in between 2-in and 4-in and get some benefit in both cutting speed and torque.
By the way, Horsepower is proportional to the product of torque and RPM, so for a given max horsepower you can trade off max torque for RPM as you like by proper choice of pulley sizes. Dennis
If you can increase the distance between the driving and driven pulleys, you can reduce the arc-of-contact discount factor for the small sheave. Alternatively, an outside idler can restore the arc of contact, but it will shorten the belt life because of increased stress range.
Dennis and Joe
I thought, no other reason, that the contact area with the belt on the smaller sheave would have less power, maybe more slippage and more belt wear. In regards to increasing blade speed I thought that was a no-no. Is it safe to double the blade speed or increase it by half?
I thought, no other reason, that the contact area with the belt on the smaller sheave would have less power, maybe more slippage and more belt wear. In regards to increasing blade speed I thought that was a no-no. Is it safe to double the blade speed or increase it by half?
Bandsaw blades are reasonably tolerant of being operated in a range of speeds (linear feet per minute) but they can't be all over the map. The speed set by the original configuration will likely be a decent compromise for overall performance.
The issue I've had on a couple of occasions with a drive pulley that was too small for the rest of the drive train was with vibration and belt "hopping", both undesirable.
A two inch pulley is kinda small, but if you have one laying around it would be worth trying it just to see what happens. If it runs smoothly then you're home free with more power and the same blade speed you started with.
If it hops around or is generally a pain, you could try a three inch, which would increase your blade speed but might smooth out the drive train. You may like or not like the cutting characteristics of the new blade speed.
Nothing wrong with experimenting, so long as it's not totally out of the ballpark. Resaw blades are the most finicky in my experience, and will complain if the speed, tension, tooth set, or the feedrate is out of whack by too much.
The issue I've had on a couple of occasions with a drive pulley that was too small for the rest of the drive train was with vibration and belt "hopping", both undesirable.
A two inch pulley is kinda small, but if you have one laying around it would be worth trying it just to see what happens. If it runs smoothly then you're home free with more power and the same blade speed you started with.
If it hops around or is generally a pain, you could try a three inch, which would increase your blade speed but might smooth out the drive train. You may like or not like the cutting characteristics of the new blade speed.
Nothing wrong with experimenting, so long as it's not totally out of the ballpark. Resaw blades are the most finicky in my experience, and will complain if the speed, tension, tooth set, or the feedrate is out of whack by too much.
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I believe that woodcutting bandsaw blades will work well over a range of around 2700 SFPM up to approximately 3400 SFPM, but it is best to stay in the middle of the range. The acceptable range depends on the type and size of blade, blade thickness, and also the bandsaw wheel diameter. Generally, speaking a speed of 3000 SFPM is satisfactory for all woodcutting blades.
Regarding power delivered to the load, it is the same as the motor's rated output power minus any transmission loss. A single stage v-belt is fairly efficient and as already mentioned, you need to pay attention to minimum and maximum belt wrap angles for best efficiency and longest belt life. Slipping is not an issue as long as the belt is not worn out and is properly tensioned. A belt might slip if it is seriously under tensioned. It will also slip when it has worn to the point that it is running on the bottom of the pulley rather than running on the sidewalls.
At this power level, transmission loss is not normally a big deal, but if you want the greatest efficiency, poly-v (a.k.a. micro-v) belts and sheaves can give efficiencies in the range of 95 to 98%.
As far as using a 2 inch diameter pulley, that is a bit small, but it depends somewhat on the spacing between the two pulleys since that affects the wrap angle. Something else not mentioned is the maximum rim speed (usually given in FPM) and maximum pulley angular speed in RPM. The first number is related to how fast the belt wraps and unwraps while the second number relates to the maximum rated safe load due to the moment of inertia of the spinning mass of the pulley.
Regarding power delivered to the load, it is the same as the motor's rated output power minus any transmission loss. A single stage v-belt is fairly efficient and as already mentioned, you need to pay attention to minimum and maximum belt wrap angles for best efficiency and longest belt life. Slipping is not an issue as long as the belt is not worn out and is properly tensioned. A belt might slip if it is seriously under tensioned. It will also slip when it has worn to the point that it is running on the bottom of the pulley rather than running on the sidewalls.
At this power level, transmission loss is not normally a big deal, but if you want the greatest efficiency, poly-v (a.k.a. micro-v) belts and sheaves can give efficiencies in the range of 95 to 98%.
As far as using a 2 inch diameter pulley, that is a bit small, but it depends somewhat on the spacing between the two pulleys since that affects the wrap angle. Something else not mentioned is the maximum rim speed (usually given in FPM) and maximum pulley angular speed in RPM. The first number is related to how fast the belt wraps and unwraps while the second number relates to the maximum rated safe load due to the moment of inertia of the spinning mass of the pulley.
2 inch pulley
wayne a 2in. motor pulley will give you exactly the same blade speed with the 3350 motor as the 4 in.did with the 1725. will give the power you are looking for. GO FOR IT..
wayne a 2in. motor pulley will give you exactly the same blade speed with the 3350 motor as the 4 in.did with the 1725. will give the power you are looking for. GO FOR IT..