Marvel 612 Horizontal Band Saw Cutting Issue

[Janderso]

Hi,
I am not new to band saws but this old saw is in the middle of a refurbish for personal use. I love the old iron.
I was cutting a piece of cold rolled 2X2 square stock last night. This is the first time I have used this saw. Plenty of lubrication.
The hydraulic lowering valve is not sensitive enough (will be replacing it) so I had to lower the blade manually. It cut very fast and smooth with one big problem. The cut was angled a bit, dished out if that makes sense.
I have the roller/bearings fairly snug on the blade so I am thinking I had too much downward pressure causing the blade deflection?
Does this sound right?
I'll go back and check the adjustment of the concentric gadget.
This blade came with the saw, it's old but seems to cut well.
Could it be the blade?
I know if a chain saw blade gets dull it will dish out.
Thank you for your ideas.
Jeff

 

[markba633csi]

Hi Jeff yes it could be too much down pressure, this also happens if the blade is not tight enough I've found
Mark

 

[Dave Smith]

several things to check---is your blade tension enough?--do you have the correct width blade? Dave
*note--if the teeth of blade are riding on the metal of the large wheels then you have too narrow blade on--teeth should ride just off the wheel edge

 

[Janderso]

Dave, I'm at work right now but as I recall the blade does not overhang the wheel. It rides within the wheel surface with about an 1/8 to go. I have not measured the blade but it is approx. 5/8.
If it needs to overhang the wheel, the blade is too narrow.

 

[Janderso]

I just found a blade source on-line. This document from Lenox Bandsaw Blades- shows the Marvel 612-Olson 0100 having a 8' 10" blade with 3/4 or 5/8 width. Does that mean I can use either? It is a pretty hefty blade on this machine!!

 

[Dave Smith]

I think with the 3/4" wide blade you will have straighter cuts and the teeth will not wear on the one side---if the 5/8 " blade is still cutting good I would continue to use it unless you need totally straight cuts---if so then put the wider one on and keep the narrower one for a spare--Dave

 

[Janderso]

How do I know the correct tension? Do I let off on the tension when not in use?
It's been a long time since I have used this type of shop equipment. Having a ball.
My drill press came in today!
South Bend
Bridgeport
Grizzley
I'm getting there..
Thanks for the help!

 

[Dave Smith]

I usually just check with my thumb and finger that it is tight with tension and I never loosen it at all---Dave

 

[markba633csi]

+1

 

[Dabbler]

On my horiz bandsaw, I lightly tap the blade with a tiny hammer or other metal striker. when I get a resonant sound (kind of a 'ping!') then I know the blade is tight enough. Using a 3/4" blade, you can go pretty tight, which will help you get smooth and straight cuts.