Saw question

[Angus]

I'm running into a problem I've never had before. When I'm doing the crosscut on large ( 3" plus) segments I'm getting a concave surface bad enough to show gaps between the segments. I'm using a dedicated sled on my table saw. I always run a thin kerf blade. Would a dull blade cutting exotics deflect enough to cause this? Nothing has changed in the sled or saw. I haven't crosscut anything this large in a while, I'm cutting bloodwood and yellowheart if that helps.

Any ideas would be greatly appreciated.

[chips ahoy]

Not sure but maybe a dull thin kerf blade and cutting too fast might cause some flex.


Mel

[AnthonyYak]

I thought you were where we went for this kind of info!!!

[gear jammer]

I question the trueness of the thin kerf blade. It's like the sawmills that have to hammer the circular saw blades to make them run true. They literally hammer the blade in a certain way. It was explained to me but I don't remember the specifics only that it is becoming a lost trade.

[Angus]

Thanks guys, yeah Yak I know but this one had me stumped and them fellers in the other forums scare me lol. I've always used a thin kerf because it's only a 1.5 HP saw and when I see the pile of dust from expensive exotics on the floor I get a nervous twitch. I don't have any good sharpeners within driving distance. Guess I'll go to a regular blade.

[Woodshop]

Thanks guys, yeah Yak I know but this one had me stumped and them fellers in the other forums scare me lol. I've always used a thin kerf because it's only a 1.5 HP saw and when I see the pile of dust from expensive exotics on the floor I get a nervous twitch. I don't have any good sharpeners within driving distance. Guess I'll go to a regular blade.

Yes a dull thin kerf blade will deflect in hardwoods and if dull enough so will a heavy kerf.  you will always get the best joint with a sharp blade

[robo hippy]

Thin kerf blades will deflect much more when dull. Pretty critical to keep them sharp. Too fast of a feed rate can add to the problem, but it doesn't sound like that is what is off here. I quit using them a long time ago. I keep several blades on hand then take most of them to get sharpened at once...

robo hippy

[Dusty Workshop]

If the regular blade does not yield good results you could also try a smaller diameter blade.

Is this only happening with these 2 species? Do you have any domestic hardwood of the same dimensions to test?

[Arlin Eastman]

I'm running into a problem I've never had before. When I'm doing the crosscut on large ( 3" plus) segments I'm getting a concave surface bad enough to show gaps between the segments. I'm using a dedicated sled on my table saw. I always run a thin kerf blade. Would a dull blade cutting exotics deflect enough to cause this? Nothing has changed in the sled or saw. I haven't crosscut anything this large in a while, I'm cutting bloodwood and yellowheart if that helps.

Any ideas would be greatly appreciated.

Angus

I am thinking there might be one of two choices

1.  The thin kerf is deflecting for sure at some height
2.  Last is the blade might only have a .001 at .75 of the wood, but at 3" it could be more.

It sounds like the blade is not completely vertical at 3" and you should check that out first

[Angus]

Angus

I am thinking there might be one of two choices

1.  The thin kerf is deflecting for sure at some height
2.  Last is the blade might only have a .001 at .75 of the wood, but at 3" it could be more.

It sounds like the blade is not completely vertical at 3" and you should check that out first

Arlin, it doesn't matter if the blade is completely vertical, but it is a perfect 90 degrees to the top of the sled. With that said I think you guys have hit on the problem. The sled is 3/4 thick, the stock I'm cutting is 1" thick. So theirs at least almost 2 inches sticking up out of the saw. I would think even a slightly dull blade in a sled type of situation would deflect.