Just curious, how do you like to gauge the tension on your bandsaw blades? Do you go by feel, use the indicators on the machine, or a special tension gauge. Also who releases the tension when finished, or are you like me and leave the blade always in tension?
Oops, wrote this much earlier today and forgot to click "Post Reply"...
I wrote about tension recently.
I had a small mishap with my bandsaw blade. It’s an expensive carbide one from Laguna. I was able to get it running straight side to side, but not front to back. It cuts, but “thunks” pretty bad when the bent spot comes around.
I have bent a couple over the years. I've tried straightening but always end up getting a new one from the box. I buy 8 or 10 Lenox spring steel blades at a time from a local bandsaw blade shop. The box will last me for years (I sharpen each blade several times.)
I have a few carbide but the rarely use them for type of bandsawing I do, mostly...
I use a commercial bandsaw blade tension gauge. It guarantees the proper tension. A bit pricey these days. These are extremely easy to use, no math needed.
As I mention in the message above, it's easy to make your own tension gauge but does need a bit of easy Young's Modulus math to get the numbers.
The commercial gauge dials are calibrated to eliminate the need for the calculation.
At one time I had 5 bandsaws so having the gauge was handy, especially when changing to a different type/size/thickness of blade.
I usually use it once for a particular size/type of blade and make a mark on the highly inaccurate indicator marks on most bandsaws. Also, the stock tension springs are often too weak.
Some other methods are iffy, things like the flutter or finger deflection rely on experience and are best done AFTER setting the tension properly with a gauge.
Some points:
- The tension too high can break blades and damage the bandsaw in several ways.
- Tension too low can result in poor and unsafe cuts. I've seen a low-tension blade actually bow and come out of the side of a tall cut during trimming a thick blank. Imagine what that could do to the hand if supporting the wood in that spot! As shown in my bandsaw video, I cut a LOT of thick wood on my bandsaws.
- If the saw has never been properly tensioned, doing so may reveal some adjustments needed, in particular if the wheels need to me made coplanar.
Having the tension right is so important I think turning clubs should buy a tension gauge and loan it to users. They are incredibly simple technology. I've taken my gauge to friend's shops and checked/adjusted their tension.
I leave the blade tensioned unless I plan on using the bandsaw in the next few days. I know some who NEVER detension. That can be harder on the saw and the tires but maybe not too hard.
When I release the tension, I put this on the bandsaw table so I can't forget to retension before use. I stole this idea from someone years sgo.
I think the bandsaw is the 3rd most useful thing in the turning shop after the lathe and and sharpening station.
JKJ
