Tablesaw Blade to Fence Alignment

[Eric Bong]

I recently cut a lot of melamine particle board for a project. It bothered me how much "spray" was coming off the back side of the blade and into my face. My dust collector does a good job with the dust that is generated on the down cut. It seems that the back left side of the blade is also cutting the piece on it's way up. I checked the following things:

1. Blade to miter slot alignment. Blade was off by .002" with the back side tilting to the left.

2. My fence tilts .010" to the right from front to back.

I had always read that your fence should tilt away from the blade slightly to avoid binding on the back of the blade. I don't think that .012" is very much tilt. I'm nervous about moving the fence any closer to the blade. I'm also pretty confident that my measurement techniques are accurate. Are there any thoughts on what I might be missing?

Thanks

[Chris Padilla]

Personally, I try my best to get both the fence and blade dead-nuts parallel to the miter slots. I think the effort is well worth it.

I use other means to prevent binding (like a splitter).

[Chris Tsutsui]

I'm in agreement with above.

Fence set dead parallel to blade, and if it's a fraction of a hair off, then just make sure that it's a fraction of a hair off with the fence tilting away from the blade..

If your work piece is held firmly against the fence during it's whole travel then there's no burn marks and no binding after the saw makes its initial cut.

The saw blade you choose may affect the amount of dust kicked up. I actually had success cutting particle board melamine with a Freud Diablo Glue Line Rip blade with standard kerf... I imagine that I am supposed to use a high tooth count melamine blade, but maybe with all those teeth that it would kick up more dust and slow down the feed rate?

Anyways, I also try to not have my head in-line with the saw blade and keep your self out of that "danger" zone when possible.

[Bob Wingard]

+1 on using the miter slot for alignment ... it is the only stationary point of reference.

I don't "toe" my fence out by any specific amount ... the number is meaningless ... I adjust it until the scraping of the teeth rising at the rear goes away

[Howard Acheson]

Basically, your blade should be set parallel to your miter slot. It should be within 0.003" at most. With a little care, you should be able to get it to 0.002".

The fence should be set parallel to the miter slot also. With certain blades like the Forrest WW II the fence should be kicked out about the thickness of a playing card if you are experiencing burning when ripping.

Of course, your splitter should be exactly in line with your saw blade.

[Chip Lindley]

++1 on aligning the blade and fence exactly coplanar with the miter slot. Check your blade for runout on the arbor. Any amount of wobble will act to cut wider than the kerf at some point, causing more dust, regardless of how exactly your TS is calibrated. Also, consider an overarm blade guard with dust collection. Guards like the Biesemeyer, Exaktor or Excalibur earn their keep by capturing dust above the table instead of being thrown on you, the operator.

[Eric Bong]

Thanks everyone for your responses. I did adjust the fence to be completely parallel to the blade and miter slot. I did still get some spray. I tinkered with the fence until I minimized the the amount of spray but I still get some. The blade and fence are within a couple thousandths. Honestly I'm not convinced that I can repeatably measure any closer than that. I think I need to look at the fence next. It looks like the portion of the fence that sits behind the table bows toward the blade slightly (.005").

[Jim O'Dell]

The definitely correct the fence as that could be dangerous if it does indeed bow toward the fence. But you will get some cuttings thrown at you on a perfectly aligned set up. It is the nature of the blade spinning toward you. Make an over head guard that hooks up to your DC and 99% of that will be gone. Jim.

[glenn bradley]

I'm another who tries for dead-on parallel; I'll live with .001". I align the blade to the left miter slot (the one I run my gauge in) and then the fence to the same miter slot. My old contractor saw would only align just so much so when I had to err, I would err with the fence away as you describe. Your overall difference of .012" (over a tenth of an inch???) is too much for me though. YMMV.

[Mitch Barker]

Melamine, seems like a coarse particle board, so maybe it has a tendency to break off particles as the blade wizzes by.

Btw, 0.012 is a bit more than a hundreth of an inch.

[Jim Neeley]

As for preventing kickback, we align either neutral or with the rear of the rip fence slightly farther from the blade than the front.

As for sawdust, keep in mind that both sides of the back of the blade can cut, so rear-cutting (dust) increases with increasing misalignment either way.

[ian maybury]

I've experienced the annoying reality of the upcoming/rear of a blade throwing dust in my face too!! (mind you I should have had the top guard on at the time) Irrespective of toe in or out it's probably an inevitability that some dust is still going to get caught in and carried around in the blade gullets - to be flung out tangentially perhaps all the way around the blade.

A personal pet theory (still to be tested) is that (hopefully it wouldn't result in a lot of noise) if one was to arrange for a good strong flow of air across/through the teeth it might well prove effective at clearing this dust out of the gullets. One way of achieving this would be to place the extraction outlet to suit - presuming there was enough clearance to permit this along with blade tilting etc...

ian

[Bret Huggard]

... With certain blades like the Forrest WW II the fence should be kicked out about the thickness of a playing card if you are experiencing burning when ripping.

Is there something special about the Forrest blade that this is true where it is not the case with other blades? I am just wondering as I am trying to diagnose my burning issue while ripping.

Thanks

[Cary Falk]

I try to get my blade and fence within .001" of the slot also.

[glenn bradley]

Is there something special about the Forrest blade that this is true where it is not the case with other blades? I am just wondering as I am trying to diagnose my burning issue while ripping.

Thanks


My Forrest doesn't require anything different than my Freuds, Lietz or Amana's(?). Some woods (cherry, maple, beech) are prone to burning a bit more than say, walnut or mahogany but, burning is generally an alignment issue. It can be a feed rate or blade tooth count issue as well in my experience and burning is something no one wants. I learned early on to use the proper blade for the job; 24 - 30 teeth for ripping, 60 - 90 teeth for crosscuts and the 40 - 50 tooth blades for general purpose.

[Steve Baumgartner]

I believe that Forrest blades get their smooth cut by having only a very small relief on the sides of the teeth, so that the teeth deliberately have a scraping cut against the sides of the kerf. This rubbing makes them get hot, hence more prone to burning if things aren't perfectly aligned.

Regarding the OP's question, I think that even a perfectly aligned blade will throw a certain amount of dust off the top. Most of the dust is flung out of the gullets inside the cabinet, but some part is carried all the way around. The blade acts like a narrow blower, causing a draft that sucks some dust out the top. Both of those effects can be reduced by strong dust collection inside the cabinet. Finally, the rising teeth at the back scrape one side or the other of the kerf unless everything is absolutely perfect, generating some dust that flies off the top. The scraping may not be great enough to cause noticeable marks, but it is happening. As others have noted, the only way to completely eliminate top dust is to have a collector guard above the blade that sucks it up.