Using an FP2 as a lathe...

[ballen]

I needed to true the drive wheel of a 175 x 300mm (7" x 12") bandsaw that I restored a year ago. My lathe has a 250mm= 10" swing but the wheel is 300mm = 12" in diameter, so the lathe is not large enough.

But I realised that I could do this on my FP2 vertical head. It was even convenient, because the wheel shaft is 25mm, which meant I could just hold it in a 25mm collet.

Turning it worked well. Tool-holding was certainly rigid! On the last pass I reproduced the crown (about 0.2mm = 0.008" in diameter) on the wheel.

Here is a short "action video" of this process.

Cheers,
Bruce

 

[climb-101]

I had to make a new wheel for my 38" oliver bandsaw not too long ago. 38" diameter, 3" wide where the blade rides.

i ended up bolting the wheel down on my rotary table and using an endmill to cut the center disk out of some 3/8" aluminum. i then got some 1/2" alum flat strap and milled a 3/8 wide 1/6" deep grove and modified a large radius bender and rolled the outer section in 2 parts. the groove located the flat strap onto the center disk so i could clamp and weld. then it all went back onto the rotary table on the bridgeport so i couild get it the right diameter. I will see if i can find some pics.

 

[thanvg]

Nice one Bruce!

You could even do in on the horizontal spindle for better lathe emulation :P

 

[ballen]

You could even do in on the horizontal spindle for better lathe emulation :P

Good point, that would also be a more rigid setup. If I touch up the other wheel, I'll do it like that.

Cheers,
Bruce

 

[ballen]

I had to make a new wheel for my 38" oliver bandsaw not too long ago.

Nice work! I'm curious, is this a wood-cutting bandsaw, with rubber tires on the wheels, or does the blade ride directly on the aluminium? If the blade rides on aluminium, does it wear away the aluminium?

Cheers,
Bruce

 

[Markusfu]

truing bandsaw wheel

great idea- thanks

Markus

 

[climb-101]

it's a 38" saw built by oliver for boeing back in the 40's for cutting steel. I have a copy of the original sales slip and an original brochure from Oliver. when i call oliver the guy there said he had never herd of them making a steel cutting saw and after checking the serial numbers he said boeing ordered 2 and that's a first for him.

when i picked up the saw the lower wheel was cracked in a few areas, the outer rim was cracked because of the brake actually pressing on the rim to slow it down. also the was a crack just below the rim where some one tryed to lift the machine under the table with a forklift and hit the wheel with a fork. I asked the guy at oliver about a replacement and he said he wasn't sure if they can even get a 38" wheel, and last wheel that was a 36" was over the $2k mark. I figured i could make one out of some flat sheet and role a new hoop. The wheels have a rubber the goes on them and is crowned. i will see if i can find a picture of the whole thing, it's size is impressive. i was walking around on the table of it to clean the dust off it. it runs a 10hp motor through a reeves adjustable belt drive so the blade speed is adjustable. it runs a 20' blade also up to 3.5" wide.

you can kind of see it on the right side in the back ground. the plywood on the wall is 4x8 sheet on end so it kind of gives you reference of how tall it is. If a few people are interested i can start a thread on it and how i did the wheel.

 

[ballen]

The wheels have a rubber the goes on them and is crowned.

OK, then the fact that the wheel is aluminium instead of cast iron or steel doesn't matter. My wood-cutting bandsaw uses crowned rubber tires, but I wasn't sure if this approach was also used on metal-cutting bandsaws.

..it's size is impressive. i was walking around on the table of it to clean the dust off it.

Yeah, I would enjoy seeing a photo of it, perhaps with you or someone else standing on the table to appreciate the scale!

Cheers,
Bruce

 

[ballen]

I have put the bandsaw back together. First up was TIR of the drive wheel running under power but not under tension, this was 0.04mm = 0.0015". Then I measured the TIR of the free running wheel, spinning by hand. It was about 0.10mm = 0.004". I decided this was good enough to leave as-is for the moment.

I then checked that the wheels were planar. This was hard to measure, I ended up making a tester from a long aluminium woodworking straightedge with two 123 blocks clamped to it. The reward was finding that the wheels were indeed planar to about as good as I could measure, around 0.1-0.2mm (0.004-0.008").

I then adjusted the tracking with the blade guides removed. This was nice and predictable, as I shifted the angle of the free wheel, and (surprisingly) not very dependent on the blade tension.

Next step, I put the blade guides in place with the bearings behind the blade retracted, and tweaked the tracking again. Then moved the rear bearings into place, and squared up the rear face of the vice.

Then I got a nice surprise. I made my first test cut, expecting that I would have to tune the angle of the blade guides to remove left/right lead and get a square cut in the vertical direction. To my surprise it was dead on. My first 100mm = 4" square test cut was less than 0.1mm = 0.004" out of square in either dimension. This job is done.

Maybe in a few years I'll take the bandsaw to bits, and sandblast and paint it. But it's hard to get motivated to do that. The saw has a built-in coolant pump and catch pan and I use it with a water-soluble oil flood coolant, so it's always a bit grimy. I guess I've gotten accustomed to that. It's one of those tools that works well, and I use almost every time I'm in the shop for more than an hour or two.

Cheers,
Bruce