Modifying a bandsaw to cut mild steel

[Brian Rupnow]

Well, I just completed a weekend project, and it went very smoothly. I pulled the motor out of the base of my bandsaw, and built a seperate hinged baseplate. Added a 3/4" shaft and a set of SKF pillow block bearings, and a 4 step pulley. Took the whole new base--motor, jackshaft, pulley and all up to my local hardware store and picked out a belt to fit from the motor pulley to the jackshaft pulley (I hate driving back and forth to the hardware store half a dozen times trying to get the right length belt). Mounted the hinged base back into the bandsaw base, and hooked everything back up. It works marvelous!!! My calculations showed that by adding a jackshaft and a second set of pulleys, it would reduce my blade speed from 677 foot per minute to approximately 250 FPM. I immediately grabbed a peice of mild steel and sawed it in half. Total cost?--$12 each for bearings, $3 for a 14" peice of shaft, $25 for a 4 step pulley, and $17 for 2 new v-belt pulleys. (the machine already had one jackshaft on it, and I needed to buy a slightly longer belt for the second drive).--So, about $70 and a day and a half of my "fabricating time"--which is pretty cheap when I',m working for myself.--Sorry, no pictures.
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[wareagle]

Brian, sounds like a success! If you are willing and able, please put up some pictures so that the others can see what you come up with. I'd certainly like to see!!

 

[Brian Rupnow]

Brian, sounds like a success! If you are willing and able, please put up some pictures so that the others can see what you come up with. I'd certainly like to see!!

Willing I am. Able--well, not so sure. Everything is reassembled and back in place in my miniscule "machine shop" area. I will attach a couple of "before" pics, and try to crawl inside my bandsaw for a couple of "after" pictures. These attached pics are 'befores".

 

[Cedge]

Bummer, Brian....
Now you've got to disassemble it all again to shoot the required photos. I know... its a bit of work, but it would have been easier had you done it right the first time...(evil grin)

Steve

 

[Brian Rupnow]

Yah, I know, I know. Actually, I was going to do a full blown thread with pictures and all on this modification, but I have never had much success photographing black.---and I paint all my machinery with black Tremclad paint. Why, you may ask?--Well, its because I am a veteran metal scrounger, and most of the steel I use is old enough to vote, and covered with rust. I clean it up with a 36 grit sanding disc on my big old Black and Decker angle grinder, but its still pretty ugly (Reference "lipstick on a pig" here---Yankee boys will know what I'm talking about.) Anyhoo--It goes like this--The base on my motor was 4" wide, with adjustment slots in the base to tighten the belt. I had a peice of 4" x 3/16" flatbar, and a left over 4" butt hinge (see finger pointing in bad photograph). I also had a peice of 2 1/2" x 2 1/2" x 1/4" angle iron. I cut the flat bar to 16" long, welded it to one leg of the butt hinge. Cut the angle iron to about 17" long (width of bandsaw base) and mitered the corners at 45 degrees, because this angle gets bolted to the OUTSIDE of the bandsaw base, and I hate gouging my shins on pointy peices of angle iron. The hinge was then welded to the angle iron. So--Now I have a peice of angle iron welded to the outside of the base (The base is open on 2 sides), and a long plate hinged like a tongue which can swing up or down inside the machine base. This allows the motor and jackshaft assembly to swing up and down, to tension the second belt, which runs from the jackshaft up to the lower bandsaw pulley.*** I positioned the plate so that it would keep the motor shaft end in the same relative position it had before I started changing things. I welded a peice of 1 1/4" x 1 1/4" x 5" long angle iron to the far end of this motor mount plate, to support the bearing closest to the 4 step pulley so that I didn't have to cantilever the 4 step pulley out too far from the side of the motor mount plate. (see pictures--it should show what I mean). This gave me everything I needed except that it wasn't rigid enough to suit me. the answer was to bolt a peice of plate from the far end of the motor mount plate (opposite from the hinged end) down to a crossmember in the original frame--AFTER THE SECOND BELT WAS TENSIONED.

 

[wareagle]

Thanks for taking the time, Brian! A job well done!!!! :bow:

 

[Brian Rupnow]

To make up or the rather ugly pictures, here it is modelled in 3D.

 

[Spin Doctor]

One guy I worked with used 2 Vega 4 speeds to get the speed ranges he wanted. He just happened to have them in the garage ;D

 

[Brian Rupnow]

Okay---I'm impressed!!! I have a very nice centerpost table that the legs would never stay on properly. Last night I made a cardboard pattern and cut out a peice of 1/8" mild steel with my bandsaw to fix it. The peice still has to be removed and edge filed for clean-up, but it does an outstanding job of keeping the table together. The saw worked just excellent---and prior to my reworking of the bandsaw I would have had to use either my sabre saw with a metal cutting blade, or a hacksaw to cut this peice out.