Band Saw question

PeteH · Post by **PeteH** » Wed Sep 02, 2009 11:45 am

I’ve been thinking of getting a vertical bandsaw. To save space and money (metal-cutting bandsaws are pretty pricey), I’d prefer to use the same saw for wood and metal. I know that different blades and different speeds would be needed. I’m strictly a hobbyist, so time spent cutting isn’t an issue for me.

Has anyone modified a regular “wood” bandsaw by (A) putting in a reducing gearbox or (B) substituting stacked pulleys for the regular pulley arrangement?

And if you did it, were you satisfied?

Thanks…

Steve_in_Mich · Post by **Steve_in_Mich** » Wed Sep 02, 2009 2:41 pm

Yes I have converted wood cutting bandsaws to metal cutting also using both of the options you mention - they are okay for some metal cutting operations but as I started to work with a bigger variety of materials I looked to variable speed drives as a means of powering my bandsaw/s. I used a motor driven hydrostatic unit by Ghram (sp, I'd have to check the spelling) which worked better than gear boxes and belt changes but the hydraulic units are noisy. I next went to DC motors for variable speed on my bandsaw/s with some belt changes for the extremely slow or fast speeds. Along the way I acquired a couple of bigger bandsaws in my shop that already had some wood and metal cutting capability and 3 phase motor driven. I then turned to variable frequency drives to gain still more latitude in speed adjustment. It was a progression that started in the early 70's.

Post by **gwrdriver** » Wed Sep 02, 2009 3:27 pm

Pete,
Yes, I am in the process of doing this. A while back I picked up a virtually new Delta #28-245 14" vertcal wood cutting bandsaw for relatively cheap. This is still a made-in-USA cast iron machine and has decent bones, except for the blade big wheels which are aluminum (although on ball bearings.)

In proceeding with a conversion the first thing I did was figure what size pulleys, gear reduction, final rpm, etc, were required in order to end up with something within the blade speeds I needed. There were dozens of possible combinations. I then began monitoring eBay and quickly picked up a new NEMA C-face 90-degree reduction gearbox for a pittance. I already had a Dayton 3/4hp/1725rpm C-face motor. I then pieced together a pair of 3-step V-pulleys which most nearly gave me the range of blade speeds I needed and luckily everything worked out so that I have a range of speeds I can live with.

I am currently in the process of completing a belt slacking mechanism. The motor/gearbox assembly is bolted to a pair steel angle brackets (with bronze bushings) which in turn slide on a pair of drill rod "ways." Belt slacking and change is achieved by moving the motor/gearbox chunk (and thus the driving V-pulley) forward or back by a leadscrew down the middle if the ways.

The key item in any bandsaw is the blade guide and in order to end up with a tough and long-lived guide some alterations to this one will be needed, and if I decide to go to a ball-bearing guide there will need to be a complete replacement. I am not yet to that part of the project. I'll try to get some photos posted if I have time.

mechanicalmagic · Post by **mechanicalmagic** » Wed Sep 02, 2009 3:29 pm

Pete,
I put a variable speed drive from a washing machine on my Delta 14" band saw. Cut steel just fine. Never had an issue with the saw. (The drive was another story.) When I re-mounted the saw, I went back to a single speed, and I cut Alum, Brass and Plastics, as well as wood. The main reason I didn't bother with a slow speed; I bought a 4x6 H/V that I use for Steel and other stock.

Dave J.

Ken Schroeder · Post by **Ken Schroeder** » Wed Sep 02, 2009 10:42 pm

If you can find an old Delta Rockwell 14" combination band saw you would have what you need. They have a 2 speed gear box for high and low speed plus multi grove shivs. I picked up one for $50.00, or rather stole it for that.

pkastagehand · Post by **pkastagehand** » Thu Sep 03, 2009 11:29 am

Ken Schroeder wrote:If you can find an old Delta Rockwell 14" combination band saw you would have what you need. They have a 2 speed gear box for high and low speed plus multi grove shivs. I picked up one for $50.00, or rather stole it for that.

I worked at a place that had one of those back in the early 80s. Seemed to work pretty well. I didn't know if they still produced that saw or not.

If there is room underneath or behind a jackshaft assembly to get other pulleys would slow it down.

Paul

tomc · Post by **tomc** » Thu Sep 03, 2009 12:13 pm

What is a good speed to shoot for when cutting aluminum?

Tom C.

jim314159 · Post by **jim314159** » Thu Sep 03, 2009 1:45 pm

Pete,

I'm in the middle of this exact project now on a Delta 28-250 that I picked up from craigslist for next to nothing. I did the math and decided to go with a 3 phase replacement motor and a VFD (which are also incredibly inexpensive these days).

The sorts of steels you'll be cutting will determine exactly how low you want your SFM to go, but with a VFD and a smart sheave/pulley choice on the motor, you can have an excellent metal saw that's still useful for wood at the top end of its range without a lot of investment in shafts or gear reduction. And it's a fun project to mount the drive in the saw base and program and wire variable speed controls etc.

I'd recommend ball bearing guides just to prolong your blade life, and make sure to look at Frank Ford's pages on his vertical BS modifications for some great ideas on gravity feeds, stops, stock holders, etc. He's the Thomas Edison of metal shops.

Cheers,
jim

Post by **Harold_V** » Thu Sep 03, 2009 2:59 pm

tomc wrote:What is a good speed to shoot for when cutting aluminum?

Speed is a non-issue with aluminum, but you will be limited by the power available. Gearing down will multiply torque, so that may determine how fast you can run the blade. Needless to say, thickness of the material you can saw will dictate overall performance, as will blade selection.

Harold

Post by **Harold_V** » Thu Sep 03, 2009 3:05 pm

jim314159 wrote:I'd recommend ball bearing guides just to prolong your blade life

The best choice if one intends to do contour sawing is the solid guide. Bearings require a greater distance between support points, allowing more flex of the blade when attempting to make turns in the cut. I think I'd use that as a guide for deciding on which type would serve one's needs best. As much as I like bearings, I use the solid type on my DoAll. The sides of the blade do get somewhat abraded, but that is rarely the cause of a blade replacement.

Harold

spro · Post by **spro** » Thu Sep 03, 2009 9:56 pm

When you start with good meat to begin with it's worth modifying or leaving alone. I like the Deltas for their cast frame and relative abilty to accept upgrades. Many many times different reductions were done to wood bandsaws to slow the speed for steel yet they were so good enough for wood there had to be a convenient transition from one to another. I went thru this and have still my 1st with it's large washing machine pulley on a jackshaft mounted under the base and all the stepped pulleys matching for others speeds. It worked well for what it was. Then there are limitations in guides and blades to seriously cut thru metal stock.
All considered you don't want to remove its ability to what it would do very well. Cut smooth without too much fuss, fast and light and contour wood.

spro · Post by **spro** » Thu Sep 03, 2009 10:38 pm

Something HV said which may not seem to make sense needs to be explained. Solid as not opposed to yet different than bb guides. See the way it goes you have your wheels and slack or whatever adjusted so that your blade can ring a low base note then back it off and adjust your side guides in. Where does it want to ride? If it wants to ride forward slightly you better have some stock there for it to eat or depending on the frame and alignmentit may be right. You don't want it Always riding to the rear. Then the guides come in for support and are adj as the table to the relation. Then if you think of it the support across the side of the blade at two points is closer with solid guides than bbrgs . Consider the solid finger has its imperfect contact 1/2-3/4" patch of contact whereas a bbrg must be away the contact area by 1/2" and only at 1/16" have the direction of the blade in its grasp.
Ballbearing guides are great and no other for the back bearing.
The other things which happen is inadequate adjustment or a blade is changed. Where a solid bronze or something solid guide gets eaten a new blade can have its outset/most productive edges beating hss bbrg guides and be destroyed. Because there is always a certain backset required for guides, for different blades which some bandsaws lack.