Bandsaw replacement motor help..

[Michael Menzli]

Thanks for that info Van. Was not aware of that. I got everything hooked up and have the saw simply hardwired to my circuit interrupt box for the time being. I plan on returning the current switch and purchasing one of those recommended . I can say I am pleasantly surprised with the change. I havnt noticed anything abnormal...with the saw vibrating even less than before. My only fear is how fast this bad boy starts. Its almost like this huge jolt of power. I know I sound very ignorant but cant think of how else to describe. Im assuming thats the 240 piece.

I did a quick 4 inch resaw on some sycamore. Everything was smooth as silk with no "bogging" or strain .

I did come across a minor issue. I discovered that the dang motor is 3450 rpm.. The original pulley had 4 "speed" settings. I currently have it set at the 1140 pulley (1750 rpm) and assume with the 3450 rpm this is simply doubled to 2280.. Is this correct? The blade Im using is a Timberwolf 3/4" 2-3tpi . Would I be okay to jump up to the next speed of (1670) 3340 ? Are there any pro's or cons to doing do? Ill be doing a majority of simple 6x6x3 or 6x6x4 bowl blanks and occasional pen and larger bowls.. I plan to do some resawing down the road..probably 8" high

[Michael W. Clark]

Yes, the pully combination speed at 1750 RPM would be increased by the ratio of the new motor speed to 1750 RPM (3450/1750=1.97) The "1140" RPM combination would actually be at 2247 RPM. As far as if this is the correct speed for what you are doing, others can probably answer that better, and in terms of blade speed. You'll have to back calculate your blade speed based on the speed of the pulleys and diameter (circumference) of the saw wheels.

For simplicity, put the belt on the pulley combination rated at half the speed of the combination you operated with the 1750 RPM motor. The 3450 RPM motor supplies less torque of a 1750 RPM motor of the same HP (but higher RPM), so using more reduction after the motor gives you better torque to turn the saw wheel. This gives you less stalling unless the blade slips on the wheels or link belt can't carry the load, as Van said. Think of it like 4WD low versus 4WD high. Same HP motor, more torque in low range (less RPM, more gear reduction).

Mike

[Van Huskey]

I would run it on the 1670 fpm pulleys to give you ~3200fpm, UNLESS this introduces too much vibration. For wood it is nice to be above 3000fpm in most situations.

[Michael Menzli]

Thanks guys.. Got everything up and running now. I went ahead and moved the belt up to the next setting. I didnt see any added benefit in moving it up really. I was hoping the feed rate may go up but it really stayed the same. I actually found it to be a little less overall as now when cutting I get a nice screech as it slices the wood vs. quiet with the slower setting.. So I will be switching that back.

So far so good. I havnt noticed anything substantial with the upgrade outside of this seeming more "efficient" persay. The saw seems to cut with less effort and I dont sense any bogging or slowing even if I force just a bit. No vibration and Id say maybe even less then the original motor..this motor seems quieter overall...

I did learn a lot which is always cool ...I can say Im a little more comfortable with 240 now but still have a ways to go. Thanks a ton for all the great feedback and lack of ridicule which I see at times. You guys have been great!

[Van Huskey]

I didn't go back through to see if you mentioned the blade you are using, the extra speed will NOT increase feedrate unless the blade has sufficient gullets to handle the increased chip load. So if/when you use a deep gullet aggressive blade for resawing or ripping you may retry the higher speed, probably with better results.

[Salem Ganzhorn]

I am not sure what the limiting factor is for cutting wood but I would use the lower speed set of pulleys for sure. The old motor was half the speed of the new one right?

Thanks for posting your info. Previously I thought about upgrading a BS motor but didn't because the higher HP 1750rpm
motors are more expensive then the 3450rpm motors. It is. I nice to hear a data point that it can work.
Salem

[Van Huskey]

I am not sure what the limiting factor is for cutting wood but I would use the lower speed set of pulleys for sure. The old motor was half the speed of the new one right?

Thanks for posting your info. Previously I thought about upgrading a BS motor but didn't because the higher HP 1750rpm
motors are more expensive then the 3450rpm motors. It is. I nice to hear a data point that it can work.
Salem

Optimum wood cutting speed is above the capability of most 14" saws, vibration due to wheel balance and lifting of the unglued tires. You will find larger old iron saws even above 9000sfpm! I find that optimum blade speed for wood cutting is 4,500-6,000 sfpm. Louis Iturra recommends "supercharging" a 14" saw to 4,000 sfpm but that may require tight urethane or glueing the rubber tires. In the end I think the best choice for this saw is the pulleys that give ~3200fpm but feedrate and finish will only increase with the correct blade. BTW finish also goes up with increased band speed.

[Michael Menzli]

Thanks for the followup Van.. Im using a Timberwolf 3/4" 3 tooth. I have resharpened it once so its not as new. I have installed urethane tires from Peachtree. Not sure how they compare to others but these seems legit and a nice upgrade..WAY better than a cheap rubber that came original.

Ill try and sharpen the blade a bit more and bump up the speed for giggles again.

I am satisfied Salem. There was some minor work involved but with some of the help on here it went very very smoothly. I will say the bigger motor was much heavier so I ended up with a floor jack to lift and stabilize it. I too was concerned about the 3450 but once I found I could get buy with my pulley options I pulled the trigger. This bigger motor as stated is just smoother overall with no "bogging" or binding. Just slides through the wood where the smaller may shut off intermittently... I did test it out on some 8" wet maple last night.(basically half a log) It was slow going but never skipped a beat or bogged for a second. Id feel real good about pushing it to 10" but the saw may not

[John R Hoppe]

Having worked in the electrical/electronics business most of my career, I find that it is better to get knowledgeable help than to "give it a try" and possibly have things go wrong. An electrical motor is an "inductive load" and as such can store a great deal of energy that is released when breaking the circuit (turning the switch off) and will arc across the switch contacts, quickly destroying a switch not designed for motor loads.

The OP's question needs to be set up correctly to work without possibility of electrocution or fire and to do that a secondary contactor or "Motor Starter" is needed to run that 3 HP motor. Since the motor requires 240VAC and will draw approximately 15 amps, you will need a breaker and circuit wired for 240VAC and 20 amps available to connect the saw. You will also need to find a motor starter rated for at least 3 HP at 240 VAC and with an operating coil voltage of 120 VAC. Next, the existing switch on the saw (assuming it is SPST with 2 wire connections that break the circuit) can be used to control the power going to the coil on the motor starter. In the drawing below, the 120 VAC is picked off of L1. The L1 and L2 wires are also connected to the contacts of the motor starter and will go through to the motor on the saw. The neutral wire is connected to the "ground" point on the motor, and also to starter coil as shown.

An even better solution would be to get a "magnetic switch" to use in place of the saw switch to operate the motor starter. A magnetic switch uses a relay to hold it's contact closed and a second contact to release. It is set up internally so that if power is removed and reapplied the switch will automatically open, preventing unintentional starting of the motor when the power comes back on.

In any case, if you are even slightly unsure of you ability to do this correctly, please hire a licensed electrician who has knowledge and experience with motors to set this up for you.