Tablesaw burning cuts

jmoore65 · Post by **jmoore65** » Tue Jan 08, 2008 9:35 pm

I have a 520 (510 recently upgraded) recently purchased used.

When ripping with the fence or crosscutting with the miter, the cutoff side of the wood is being burned by the blade. The teeth area of the blade appears to be the culprit (it's a Sears 5/8" combo blade).

Given the burn when using the mitre or fence - I'm assuming it's not a fence alignment problem.

I've also tried this with and without the splitter - same result.

Thoughts and info on what the likely culprit causing this problem is - and ways to fix it would be most appreciated.

Jim

a1gutterman · Post by **a1gutterman** » Tue Jan 08, 2008 9:49 pm

Hi Jim,

If you try another blade and the problem goes away it seems like the blade is the culprit. If the blade swap doesn't work, both your fence and your miter guage might need aligned.

Personally, I would assume that my alignments might be off and check them first. Especially if I did not have an extra blade hanging around.

jmoore65 · Post by **jmoore65** » Tue Jan 08, 2008 9:56 pm

Tim,

I can see how an out of alignment fence could cause this - but am not clear on how the miter guage could do this...

Given the path of the miter guage is restricted to the slot in the table, I don't see how the word would burn.

I could believe that the blade might not be parallel to the table - but a check with my (cheap) combination square says that looks not to be the problem.

Jim

a1gutterman · Post by **a1gutterman** » Tue Jan 08, 2008 10:04 pm

Hi Jim,

I am not saying that this is the case for you, but if the blade is not parallel to the slots in the main table the miter gauge is not exactly perpendicular to the blade (and just because the scale says it is doesn't make it so), you could be forcing the cut material against the side of the blade causing the burning. But if you checked the alignment with your square, like I think that you meant?

I could believe that the blade might not be parallel to the table - but a check with my (cheap) combination square says that looks not to be the problem.

and it shows as square, that may not be the problem. Do you have a spare blade that you can try?

8iowa · Post by **8iowa** » Tue Jan 08, 2008 10:16 pm

Jim:

Assuming mis-alignment is not the culprit, try lowering the speed. I often saw at the "M" and "N" settings on the dial with good results.

The combination blade does a lot of things well. However the 24 tooth rip blade and the 60 tooth crosscut blade will do better for their respective purposes. An advantage of the Shopsmith is that blade changes are quick and easy.

a1gutterman · Post by **a1gutterman** » Tue Jan 08, 2008 10:20 pm

8iowa makes a good point, I would add that in my experience, different woods will burn at different speeds.

jmoore65 · Post by **jmoore65** » Tue Jan 08, 2008 10:28 pm

Hmmm...speed. I'm cutting MDF - maybe I have the speed too fast?

I do have a SS ripping blade - and a Diablo 80 tooth blade.

I'll try slower speed and different blade permutations tommorrow.

I can see how the miter could be misaligned to cause the wood to go through the blade wrong. If the miter bar isn't running parallel to the miter slot, you'd get the wood going through at an angle vs perpendicular to the blade.

Or - I could just be too tired to think about this right now...

Jim

paulmcohen · Post by **paulmcohen** » Tue Jan 08, 2008 11:20 pm

jmoore65 wrote:Hmmm...speed. I'm cutting MDF - maybe I have the speed too fast?

Jim

MDF is very hard on blades, I use a carbide blade when I cut MDF or the blades dull very fast. A dull blade could cause burning.

What is recommended is a TCG (triple chip grind) blade where one tooth is ground flat on top, while the next tooth (and the one preceding) is ground with an angle at each edge and a flat center, which delivers a lower edge tear out. Another important benefit of this tooth design is that the blade will last longer since there are no sharp angles on the tooth (like an ATB grind) to break or chip. A 10 degree hook angle is used to reduce force needed to feed wood into the blade. These blades work very well with table saws, and excel at cutting MDF (medium density fiberboard), which is often a substrate (base material) for laminates.

curiousgeorge · Post by **curiousgeorge** » Wed Jan 09, 2008 1:34 am

Maybe the blade just needs cleaning.

jmoore65 · Post by **jmoore65** » Wed Jan 09, 2008 10:24 am

> Maybe the blade needs cleaning.

It almost certainly needs cleaning now. It was pretty clean when I started. Maybe it was/is dull?

I swapped out blades - for my SS rip blade - worked fine. I also reduced speed to M/N.

I guess the 5/8 arbor could be at fault - but looks pretty hard to damage easily.

Anyhow, now I can finish cutting the MDF sheet into shelves for my Mom's cabinet.

Thanks for the help,

Jim