Why is a trapped bevel rip unsafe?

[cgallery]

With a narrow rip bevel, the ability to keep a shoe on top is gone, I have to push from the rear as I mentioned before, this is more hazardous.

I agree. A narrow bevel rip on a fence-tilted blade would be problematic. I will mention that I've seen blades tilted into sacrificial fences (forming a triangle with blade in contact with the fence) and stock shoved through without problem. But I can't imagine good cut quality as there is no way to control the stock under the blade. And regardless, thin bevel rips with a fence-tilted blade gives me the willies.

The more I think about this issue, the more I wonder if a blade tilting AWAY from the fence isn't more dangerous in one regard: The splitter or riving knife is defeated when the blade is tilted away from the fence. If the stock drifts away from the fence for whatever reason (reactive wood, stock that wasn't straight to begin with, operator error), the stock will ride higher on the blade.

That is, the "advantage" sighted for a blade tilted towards the fence is a disadvantage for the blade tilted away. Maybe.

[JoeSpackle]

The reality of a bevel cut on wider stock using a right tilt saw is that there is a potential for the part to lift producing the potential for what I call push back not kickback. The part is captured under the blade, and that rather prevents the part form lifting but it can still catch and try to push back at you.

The problem of course is how do you work a bevel cut on a right tilt saw at a distance greater than the available width to the left of the blade?

The safest is to do a two stage cut and use the standoff fence I showed in the other thread. Set properly there is 0 chance of a dangerous push or Kick back. I use that setup on a very regular basis and to date it is the safest and easiest way to make a bevel cut on any saw that tilts right.

Joe

[Russianwolf]

here's a video I found on kickback.
http://www.youtube.com/watch?v=sVpGi...eature=related

on the bevel cuts, what he is saying in the video is still true. The teeth will lift the piece, and once contact is made with the fence, one of four things will happen.

1) piece self destructs into tiny bits as the blade chews it up.
2) piece bends the blade
3) piece damages fence
4) piece goes the only other direction it can, back at you at something near 300mph.

Having taken a kickback from a small piece of wood in the stomach and having to dig a 1/4 chunk (not a splinter) out of myself several days later when I realized that what I had was more than a scratch, I know how even an innocent looking kickback can be not so innocent.

[cgallery]

here's a video I found on kickback.
http://www.youtube.com/watch?v=sVpGi...eature=related

on the bevel cuts, what he is saying in the video is still true. The teeth will lift the piece, and once contact is made with the fence, one of four things will happen.

But the question is, is it MORE likely with the blade tilted towards the fence than tilted away, and why?

[pecker]

There is an alternative way to cut bevels described here:
http://www.cjohnhebert.com/Bed.htm

Although it requires more setup time, it works quite well and is very safe if you follow all his instructions...particularly the part about the rabbet which allows the waste piece someplace to go.

[bthorne]

I seem to remember that Nahm did a two-episode series devoted to the table saw a couple years ago, and did discuss a couple safety issues w/ bevel rips.

Two things he said that stood out to me:

If the blade is tilted toward the fence and you want to bevel two opposite edges of a board, when you bevel the second edge of the board, the point of the first edge can slip up under the bottom of the fence slightly. This may increase friction or cause the board to get stuck, making the operator use more force on the board (not good), or allow the board to twist, leading to kickback.
All of these problems are alleviated if the blade is tilted away, as the acute angle on the first bevel is riding higher on the fence and can't get stuck under it.

The second thing he mentioned is that if the blade is tilted toward the fence, the offcut is then lying on the top of the blade (actually touching those rear teeth), and can be caught and pushed back toward the operator. If the blade is tilted away from the fence, the offcut is under the blade and is more likely to vibrate to the outside away from the blade.

Finally, for me - I just don't like a blade tilted toward my fingers / push stick, so I move my fence to the opposite side of the blade anyway.

[niki]

Personally, I think that a bevel rip is not more dangerous than a "normal" 90° ripping.

In the EU they teach in schools to rip bevels with the blade tilted toward the fence but a Riving knife and a "Short/Low fence" are more than recommendation...

If you don't use a riving knife (splitter is ok but only if your blade is at "full height") or not using the short fence - don't even try this method ((I would recommend not to try even normal ripping without RK and short fence)....

As for Featherboard, it helps me to control long workpieces so they are pressed to the fence.

Saying that, I think that a bevel rip with the blade tilted "out of the fence" will give smoother cut on the "visible side" of the bevel and, if you bevel cut both sides, the first bevel will not enter below the rip fence (the apex is at the upper side)...

So, here is the way thart the HSE (UK equivalent to the USA OSHA) is showing to make bevel cuts...



And here is how I do it...

[Carlos]

I love that roller jig in the last photo. Where did you get the wheel/arm part?

[niki]

I love that roller jig in the last photo. Where did you get the wheel/arm part?

I posted it here
http://www.bt3central.com/showthread.php?t=25123

As for the parts, well, I live in Poland so I cannot advise...

Regards
niki