Wood to steel cutting bandsaw

[jmc]

A short video

Dec 13, 2013 - YouTube

Speed "sounds" about right. Good job.

Another way to calculate your surface feet/minute without calculating all of your gear reductions is to time (in minutes) how long it takes to hear, say 20 of the clicks caused by your blade defect. Then measure your blade length. Say it takes 1/3 minute for 20 revolutions of a 4 foot long blade, the surface feet/minute would be 80 feet in 1/3 minute which is 240 feet/min. Sorry if this was obvious.

 

[Zick]

A short video

Dec 13, 2013 - YouTube

Well done sir!

:thumbsup:

 

[ericher69]

Speed "sounds" about right. Good job. Another way to calculate your surface feet/minute without calculating all of your gear reductions is to time (in minutes) how long it takes to hear, say 20 of the clicks caused by your blade defect. Then measure your blade length. Say it takes 1/3 minute for 20 revolutions of a 4 foot long blade, the surface feet/minute would be 80 feet in 1/3 minute which is 240 feet/min. Sorry if this was obvious.

Was thinking of double checking with your method but the laser rpm meter is pretty accurate. I came up with 468.75 fpm which is still too fast (I think) but will call Lenox Tech Service on Monday.

Thx

 

[ericher69]

Well done sir! :thumbsup:

Thank you!

I will update the thread as I work on this.

 

[the old grind]

Yes, 470 sfm is way high, but to my ear it sounds like your going at about half that now. Weld click rhythm sounds familiar, reminds of hearing a longer blade at ~220 sfm (DoAll w/24" throat). Just to be different, I'd have 'tach-ed' a wheel and compared its circumference to blade length.

I've been faking it on a wood bandsaw (boocoo sfm) using a HFT metal blade on alum only. Noise is horrendous, and parts heat up quickly. That said, I'd be surprised if the steel cut in the video generated much heat or was very hard on the blade, two signs of too high sfm. Not to challenge the OP's math/method, but in the trade we often rely on 'reading the chip' as a backup to recognizing proper speed adjustment. What I mean is that if the cut looks good, and it ain't broke, a further 'fix' might not be needed.

Might want to cut a few more ferrous pieces. Keep 4-6 teeth min in the cut with choice of blade pitch if its fixed vs variable (10-14, etc) for clean cuts and cool running ('goals'). (looking for a speed reduction method myself...) Thanks for posting and for the video!

 

[ericher69]

Yes, 470 sfm is way high, but to my ear it sounds like your going at about half that now. Weld click rhythm sounds familiar, reminds of hearing a longer blade at ~220 sfm (DoAll w/24" throat). Just to be different, I'd have 'tach-ed' a wheel and compared its circumference to blade length. I've been faking it on a wood bandsaw (boocoo sfm) using a HFT metal blade on alum only. Noise is horrendous, and parts heat up quickly. That said, I'd be surprised if the steel cut in the video generated much heat or was very hard on the blade, two signs of too high sfm. Not to challenge the OP's math/method, but in the trade we often rely on 'reading the chip' as a backup to recognizing proper speed adjustment. What I mean is that if the cut looks good, and it ain't broke, a further 'fix' might not be needed. Might want to cut a few more ferrous pieces. Keep 4-6 teeth min in the cut with choice of blade pitch if its fixed vs variable (10-14, etc) for clean cuts and cool running ('goals'). (looking for a speed reduction method myself...) Thanks for posting and for the video!

I know what you mean about "it sounds right" for proper speed of 220 SFPM.

Maybe I am just used to the screaming 1600+ SFPM that the saw use to run on wood!

Anyway I will cut a few more ferrous pieces and will try and remember to keep 4-6 teeth in the piece at all times; seems unnatural to me to turn a flat piece on end to cut on the flat side but it is probably better for the blade.

Blade is 6/10 variable pitch Lenox Diemaster II 0.035x3/4x125"

Chips look good to me (I'm no expert) but I have inspected the teeth and no signs of damage.

Will make another video revisiting the above mentioned.

Thanks

 

[the old grind]

Your conservative infeed suggests, to me, care regarding the pitch vs thickness aspect. (You do want to cut across the smaller dimension as shown.) Nice work!

General stuff:
If a v-block isn't handy to stabilize round stock use vise grips to keep it from rotating. (parting-off on a homeowner lathe can make threading seem easy) Always cut angle stock with the 'v' up. Tubing, whether square or round, requires patience to get through the near & far sides without feeding too fast thru' the middle & perhaps ripping teeth off. Use the v-block for square & rectangular tubes.

These work for chop saws too, with the exception that any rectangular or flat would be cut edge-up where height capacity allows, and the wheel needs dressed once in a while. Here the band saw has it's edge for the big & wide, and I'd use the 8-10 pitch blade up to several inches thick. (IMO Lenox variable pitch are tops ..)

btw: That 4-6 (teeth) is a minimum and has much to do with feed pressure/tooth. Fine-toothed blades as we'd use on a hacksaw (16-32 tpi) are for small stuff. They can clog with chips in thick stock (esp alum, etc), require more feed pressure, and run hotter.

 

[ericher69]

Your conservative infeed suggests, to me, care regarding the pitch vs thickness aspect. (You do want to cut across the smaller dimension as shown.) Nice work! General stuff: If a v-block isn't handy to stabilize round stock use vise grips to keep it from rotating. (parting-off on a homeowner lathe can make threading seem easy) Always cut angle stock with the 'v' up. Tubing, whether square or round, requires patience to get through the near & far sides without feeding too fast thru' the middle & perhaps ripping teeth off. Use the v-block for square & rectangular tubes. These work for chop saws too, with the exception that any rectangular or flat would be cut edge-up where height capacity allows, and the wheel needs dressed once in a while. Here the band saw has it's edge for the big & wide, and I'd use the 8-10 pitch blade up to several inches thick. (IMO Lenox variable pitch are tops ..) btw: That 4-6 (teeth) is a minimum and has much to do with feed pressure/tooth. Fine-toothed blades as we'd use on a hacksaw (16-32 tpi) are for small stuff. They can clog with chips in thick stock (esp alum, etc), require more feed pressure, and run hotter.

Old grind;

Thanks for the positive reinforcement that I am doing it right.

I never like forcing any tool but prefer to let the blade do the work; good way to break stuff or get injured!

My Princess auto 4x6 horizontal came with a 32tpi band (that broke twice) before I made the switch to the Lenox band; yes I am very very impressed with the quality and difference in cut ability with a high quality, proper tpi and feed pressure. Really woke the saw up!

The original band would gal up and heat up ++. The material being cut was also very hot to the touch afterwards; not so anymore.

 

[ericher69]

A slow motion cutting video

http://youtu.be/m2dm5Aeb0Hg

 

[ericher69]

Did some more work on this saw tonight.

Fabricated a permanent mount that leaves me the option to use all 3 pulleys on the motor giving me the ability to still effectively use the saw for wood;eek when needed. Rigid mount made out of 1-1/2"x1/4" wall

Motor mounted

1-1/2"x1/4" wall square tubing drilled. Base plate drilled and tapped to accept 5/16" bolts with lock nuts.