Need Opinions on this Bandsaw Guide Bearing Set-up

gunner66 · Post by **gunner66** » Fri May 20, 2011 1:08 pm

Hello everyone:

A couple of years ago, my friend replaced the upper and lower blade guide bearings on his mid-1980's bandsaw - using just a single 627-ZZ bearing at each location. The original bearings were 7mm ID x 22mm OD by x 10mm Wide (at least on my own bandsaw that uses the the WC-77037-1 bearings).

The 627-ZZ measures 7mm x 22mm x 7mm wide. He put a couple of washers on the shoulder screw to position each bearings so it would be centered on the blade. He uses the saw quite a bit at his business and says it cuts and tracks just as it had before (note: he had a 1/2" blade mounted). His take is that as long as the guide blocks are properly spaced, the blade is centered on the bearing and the loss of the 3mm of width over the original bearing doesn't matter.

I have not seen this arrangement in any posts here (I have seen the posts where twin 627zz bearings are being used at each location when these bearings are changed). Am I missing something here as to why a single 7mm wide bearing should not be used? Thanks for your opinions in advance.

peterm · Post by **peterm** » Fri May 20, 2011 2:29 pm

FWIW, I agree with your friend, the loss of 3mm does not matter.

JPG · Post by **JPG** » Fri May 20, 2011 3:05 pm

Ditto! With the single bearing only a fraction of the bearing width is bearring against the blade. I doubt the blade was more than 2mm thick. I would agree with the inclusion of the washers so the blade would be centered.

Now as for the 2x7mm it does have a potential problem. The 'offsetting' of the center of the 'pair' 2 mm from the center of the original 10mm bearing requires realignment and possibly lengthening the mounting bolt.

The tangential path of the blade should determine that 'centering'. With the single 10mm bearing, there was +- 3mm margin for error. The 2 bearing pair needs to be dead on.

hdtran · Post by **hdtran** » Fri May 20, 2011 8:42 pm

Correct, the blocks keep the blade from drifting off of the bearing.

For my next bandsaw trick in 2012 (after next year's refund of an overpayment to the Feds

), I'm thinking of the Carter bandsaw stabilizer (see http://www.carterproducts.com/product.a ... &cat_id=14 ). Using this, you can apparently use a 1/4" blade as if it were a 1/8" scrollsaw... (watch the video).

JPG · Post by **JPG** » Fri May 20, 2011 9:02 pm

hdtran wrote:Correct, the blocks keep the blade from drifting off of the bearing.

For my next bandsaw trick in 2012 (after next year's refund of an overpayment to the Feds ]http://www.carterproducts.com/product.a ... &cat_id=14[/url] ). Using this, you can apparently use a 1/4" blade as if it were a 1/8" scrollsaw... (watch the video).

Yep! Look at that blade 'WANDER'! I guess beauty IS in the eye of the beholder.

BTW Just what is correct? Who was discussing guides?

horologist · Post by **horologist** » Fri May 20, 2011 9:26 pm

hdtran wrote:Correct, the blocks keep the blade from drifting off of the bearing.

For my next bandsaw trick in 2012 (after next year's refund of an overpayment to the Feds ]http://www.carterproducts.com/product.a ... &cat_id=14[/URL] ). Using this, you can apparently use a 1/4" blade as if it were a 1/8" scrollsaw... (watch the video).

I think you would be better off with a scroll saw.

1. Safety, I don't often get nervous watching woodworking videos but this one made me cringe. Reckless or careless behavior with a scroll saw can get you a nasty cut, but sawing like this can have your thumb off before you even think to pull your hand away. I had a shop teacher who rapidly swung 2" x 2" square maple blanks through a bandsaw. It cut them just fine, he then asked us how much trouble we though the saw would have in removing our fingers.

2. Safety. See above.

3. While this is a remarkable performance in sawing tight radius curves for a bandsaw it is decidedly a mediocre performance in the scroll saw world. Even the cheapest scroll saw will create tighter radius cuts.

4. Surface finish. The surface of that reindeer was pretty rough, a good scroll saw blade will leave a surface that requires little further treatment.

The bandsaw will certainly cut a lot faster than a scroll saw but how beneficial will this be when you are trying to follow a complicated pattern?

Troy

billmayo · Post by **billmayo** » Fri May 20, 2011 9:30 pm

hdtran wrote:Correct, the blocks keep the blade from drifting off of the bearing.

For my next bandsaw trick in 2012 (after next year's refund of an overpayment to the Feds ]http://www.carterproducts.com/product.a ... &cat_id=14[/url] ). Using this, you can apparently use a 1/4" blade as if it were a 1/8" scrollsaw... (watch the video).

I find that using the 2 7mm wide bearings for the upper and lower guides provides me with the same stability as the Carter setup and a lot cheaper. Yes, it take a little longer to get the blade to track between the upper and lower guide bearing sets. I started using a very thin round shim between the bearings when cutting metal on a dedicated bandsaw. It allowed better blade tracking when cutting metal. I have a bandsaw that I just use for metal cutting as the metal cuttings embeds in the tires over time.

damagi · Post by **damagi** » Fri May 20, 2011 9:52 pm

billmayo wrote:I find that using the 2 7mm wide bearings for the upper and lower guides provides me with the same stability as the Carter setup and a lot cheaper. Yes, it take a little longer to get the blade to track between the upper and lower guide bearing sets. I started using a very thin round shim between the bearings when cutting metal on a dedicated bandsaw. It allowed better blade tracking when cutting metal. I have a bandsaw that I just use for metal cutting as the metal cuttings embeds in the tires over time.

Could you post a picture of this?