Blade size for old bandsaw

[Dan Karachio]

Hello All,

Got an old Walker Turner 12" bandsaw. I found an old catalog online that seemed to list my saw as using a 85" blade. Bought one, but it was just a tad to big. Have an 80" laying around, but it is a tad too small. Came with an old blade and I tried to measure it's diameter and came up with about 82.5. Breaking out the old high school math I did various calculations in Excel (it has a Pi() function).

The top wheel has about 2 inches of vertical adjustment for blade tension, meaning the distance between the axis of the lower to upper wheel can range from 21.5" to 23.25." So, just about where do I want that with the right size blade? Near the top, in the middle?

The wheel diameters with tires are 12.25, so r = 6.125" The mean distance between the wheel hubs is about 22.5 - lets call it d. So 2PiR + 2d should get my blade size right? If so, that's 83.5. However, do I want the top wheel higher? It can go up to 23.25 max? If I make d 23" then my blade size is 84.5"

I don't want to keep ordering and returning blades, but maybe trial and error and lots of trips to the UPS store are the way to go?

[Wilbur Pan]

I went through the same process with my Walker-Turner bandsaw. I calculated the blade length with the top wheel about a quarter of the way up from the bottom of it's travel range, figuring that I would only want to add tension, if needed. In your case, I'd make d=22".

But don't sweat it too much. This isn't a precision engineering job. The range of useable bandsaw blade tensions is pretty wide.

[Raymond McInnis]

Hello All,

Got an old Walker Turner 12" bandsaw. I found an old catalog online that seemed to list my saw as using a 85" blade. Bought one, but it was just a tad to big. Have an 80" laying around, but it is a tad too small. Came with an old blade and I tried to measure it's diameter and came up with about 82.5. Breaking out the old high school math I did various calculations in Excel (it has a Pi() function).

The top wheel has about 2 inches of vertical adjustment for blade tension, meaning the distance between the axis of the lower to upper wheel can range from 21.5" to 23.25." So, just about where do I want that with the right size blade? Near the top, in the middle?

The wheel diameters with tires are 12.25, so r = 6.125" The mean distance between the wheel hubs is about 22.5 - lets call it d. So 2PiR + 2d should get my blade size right? If so, that's 83.5. However, do I want the top wheel higher? It can go up to 23.25 max? If I make d 23" then my blade size is 84.5"

I don't want to keep ordering and returning blades, but maybe trial and error and lots of trips to the UPS store are the way to go?

http://www.owwm.com/mfgIndex/detail.aspx?id=808&tab=3

dan, check the page linked above. (it leads to old walker turner manuals in pdf, that are downloadable.) if you don't know about owwm.com, with an old machine, i recommend that you join the conversations.

[Pete Bradley]

All you need is to have the top wheel carrier is between the stops when the band is tensioned. Within this range, tension is determined by spring compression only, not band length. Saws of this vintage usually had a workable range of about 2 inches to allow for blades being repaired. Looks like 83" would work fine.

Pete

[Frank Drew]

And don't throw away the band that's too long; it can be cut to length and rewelded.

[Dan Karachio]

Thanks all. I'm glad this isn't rocket science. I will go with an 83 and see what happens.

Oh, FYI, the original brochure I found listing the 85" blade was from OWM.