[OP]
Member
Fellow Creekers,
I am working on a 36" 1959 Northfield bandsaw. It has been converted to belt drive. It came with a 2 HP single phase, which I intend to upgrade. The saw has 16" resaw capacity. I currently have two spare electric motors: a 5 HP Dayton TEFC single phase 1740 rpm and another 10 HP 3 phase 1700 rpm TEFC motor. Am leaning towards the 5 HP single phase based on the resaw capacity as the 10 HP would be an overkill... As always, thanks for any feedback...
Sal.
Contributor
Sal,
You get your hands on some awfully big bandsaws. I saw your other ones in the classifieds a while back.
Most 36" saws I see usually have a 5hp motor on them. 7.5hp might be perfect, but I think a 5hp will do the trick. I can't imagine slowing one down even while resawing 16".
Member
Quite a while ago I had a old crescent 30" with a 2hp DMD. No slowing it down but it was also a big motor for only 2hp.
[OP]
Member
Yeah, the bandsaws disappeared. I think there have been very good boys and Santa snatched the bandsaws for themOriginally Posted by Andrew Fleck
When I see old cast arn, cannot help it. This is the first 36" that I laid my hands onto though... This is definitely a keeper. Currently I have the Centauro 700 (a 27.5" cast iron beast) and a vintage Powermatic 141 and that is all.
Cheers,
Sal.
Contributor
Generally the 5 hp should be fine. Most old cast iron saws were direct drive and 700 RPM so they had lots of torque. Most 36" had 21" resaw capability but northfield made saws with both more and less. I would prefer three phase as the saw is hard starting but if the 5 hp is a stout frame quality motor you should be golden. Dave
Guest
One thing to think about is that in starting heavy loads; a little belt slip can be your friend. It can make it easier on the motor, with less chance of overloading the circuit.
Member
had a 2 hp! wow that pathetic. 5 hp is light for a 36" saw and the 10 would not be over kill by any means. I have 5hp on a 30" wadkin and at times is lacking.
jack
English machines
Member
Only 2hp that's what I thought. But that was a big 2hp, probably 16 inches diameter maybe more. Plenty tough. Lots of torque.
Contributor
I put a 2hp on my Delta 14" and my Bridgewood/ACM 20" has 5hp Marathon motor. Both are more than up to any task. Nothing worse than an under powered bandsaw! I think 5/7.5hp would be in the ballpark for a 36" bandsaw.
Member
Sal,
Hopefully the conversion to belt drive was done by somebody who knew what they were doing. Northfield sits the direct drive motors in babbit to get all of the adjustments fine tuned, the conversion could have potentially thrown everything out of whack...
What final SFPM are you shooting for? Will this saw be sat up specifically for resawing or general use? Are your wheels AL like most Northfield saws?
My 20" Northfield has a 900 RPM motor and thus is a bit too fast for solely resawing work, but it does work. The 2HP Crescent that Judson is talking about might be the version that had basically a flywheel as a lower wheel, so you could get away with a under powered saw...
A little more info would help for people to give you an educated answer.
Ben
Contributor
Most of the old 30" saws ran 900 rpm motors and 6700 fpm. Not too fast for resawing and much faster than a 20" wheel at that rpm. That speed helps with the feed speed and is a reason the old saws ran smaller motors ( in addition to the motors being huge cast iron frame ones ). Tanny used 900 rpm motors on their 36" ( 8400 fpm ) although most others used 700 which dropped the speed to 6700. It is not the size of the wheels but the resaw height that is relevant here. 16" means the saw was a special short version and closer to the 30" in height. 20" saws ran 1-2 hp motors with 10-12" resaw, 30" ran 3 hp with 15" resaw and larger saws ran 5 hp and higher. While I think the 5 hp will serve just fine, I like three phase enough that I'd be tempted to go with the 10 hp and a vfd to dial in the fpm to the application. Sal, you've done that before so it should be easy. Dave
Member
I run 5hp in my 36" Oliver, it works great. However, the speed was off as several of the guys mentioned when I changed out the 2hp to the new 5. No big deal on my saw, just different pulleys to get where I wanted. If it was me, I agree with David, 10hp and VFD. Soft start and variable speed would be pretty cool.
Oh, and when I was doing the motor change, several people told me that the old 2hp rated motors actually produced power more similar to a bigger motor by today's rating system.
Last edited by Steve Rozmiarek; 12-08-2013 at 11:29 AM. Reason: added more
Contributor
The three-phase motor would be my choice on a saw that size. Good luck,
Erik Loza
Minimax USA
Contributor
As a frame of reference, the 5 hp motor on my Oliver 116 DD is 19.6 FLA. Dave
[OP]
Member
Sal,
Hopefully the conversion to belt drive was done by somebody who knew what they were doing. Northfield sits the direct drive motors in babbit to get all of the adjustments fine tuned, the conversion could have potentially thrown everything out of whack...
What final SFPM are you shooting for? Will this saw be sat up specifically for resawing or general use? Are your wheels AL like most Northfield saws?
My 20" Northfield has a 900 RPM motor and thus is a bit too fast for solely resawing work, but it does work. The 2HP Crescent that Judson is talking about might be the version that had basically a flywheel as a lower wheel, so you could get away with a under powered saw...
A little more info would help for people to give you an educated answer.
Ben
I think the conversion was decent. They used pillow block bearings and a 11.25" double belt cast iron balanced pulley. I intend to use a 3.75" pulley which would give me a gear ratio of 1/3. With 1740 rpm, the SFPM is 5463. The fellow at Northfield suggested about 6000 SFPM for resawing. Below are some pictures.
First picture is the conversion. Secon picture is a brand new Dayton single phase 5 HP 1740 RPM motor. 3rd picture is a US Motors (Division of Emerson Electric) 3 PH 10 HP 1440 RPM motor. The last picture is the 2 HP 1750 RPM Century Electric Single phase motor. Notice how the 2 HP Century Electric dwarfs the 5 HP Dayton motor.
Now If I use the 10 HP, I will achieve 4521 SFPM. Is that adequate?
Thanks to all for the input,
Sal.
photo 1.jpgphoto 2.jpgphoto 3.jpgphoto 4.jpg
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