Thread: Flawed wood on the TS --DUCK!

Robert

A lucky escape. (When's the next Lotto Superdraw so that you can buy a ticket?). Another reason why I am saving up for a thicknesser!

Regards

Larry

Larry.
I have a thicknesser, a 12.5" DeWalt, but decided that it would take too long to do the job. I may think otherwise next time.

Robert

Yes, we all have 20/20 hindsight. 6mm at 2mm per pass is only 3 passes. You could probably use the exercise to stay warm in Albany (I lived there for 6 years myself before spending 4 years in Kununurra. Much preferred the Albany climate).

Regards

Larry

Robert

I am still a bit puzzled about exactly how and why this accident occurred. You said that the void in the board was about half-way along an 1800 mm board, so, since the saw blade is about 350 mm from the front of the table, there must have been at least 500 mm of the board that was not yet on the table. Why were you using a push stick at that stage? I do not start using a push stick until the back end of the board is already on the table; otherwise the use of the push stick is liable to tilt the board up and cause kick-back. It seems to me that, so long as the board was held against the fence, and held down firmly onto the table, the presence of a void alone should not have caused this sort of accident. Where am I going wrong (as Bill O'Reilly would say)?

Rocker

Rocker.
I have just returned home from 3 days away working, hence the late response.
My practice is to use a pushstick as soon as the rear end of the work is close enough to the table to allow it. I had experienced some blade burning of timber in the changeover from hand to pushstick, when the work is stationary, and find the changeover to be quicker when done outboard of the table. Maybe I need lessons??? 500 mm outboard sounds to be too far so I guess the work was past the half way point.
I have not had problems with the work lifting but I will certainly give that some thought for the future.
It all happened very quickly and the end result was the timber in 2 pieces.
Looking at the pieces after the event it seems that the rear section seperated from the section at and through the blade. Having the pushstick torn out of my hand and thrown at the side of the shop behing me had the effect of distracting my attention from the work and precisely what it was doing at the time.
The cut section ended up behind the blade and out of harms way. The front, uncut section ended up over the featherboard and beside, but not touching, the blade. A section from between the two shattered and was flung back.

Robert, I can relate to your "near miss". See my thread of a few weeks back.

http://www.woodworkforums.ubeaut.com...&threadid=7103

Although my situation was somewhat different than you describe, it happened so suddenly that it was impossible to tell what actually happened.:confused: I have analysed my accident (by the way, in OHS, near misses are treated like accidents) and taken steps to avoid what I think happened from reoccurring.

I purchased the Board Biddies shown in the aforementioned thread and have developed an operating procedure that is safer than previous.

However, tablesaws (amongst other shop equipment) have the potential of doing serious damage to the unwary. As a matter of fact, I would love to see a Forum for this subject on its own - covering near misses and accident. I think the collective experience and wisdom of board members would go a long way to help all of us become more safety-conscious in our workshops.

I suspect that most of us have done things in the shop that, in hind-sight, were just plane dumb . And perhaps few will admit to this publicly. But anything we can do to reduce our potential for injury is a worthy objective.

Robert,

I wonder if the section of your board that suddenly disintegrated was bounded by a couple of oblique shakes (or cracks), thus forming a loose wedge-shape section that got jammed between the saw blade and the fence, causing the kick-back. I wonder, also, whether you were using a zero-clearance table insert; if not, a loose piece of timber might have got jammed between the blade and the edge of the slot in the insert, and caused the accident.

It seems clear from your account that, when the accident happened, your push-stick lost control of the board. With the traditional syle of push-stick, which only has about 25 mm pushing down on the board, that can easily happen, particularly if you start using it outboard of the saw table. I prefer the type of push-stick that is shaped like a bench plane, where at least 200 mm of the push-stick bears down on top of the board, holding it firmly down on the table. Obviously, this cannot be effective until the back end of the board is on the saw's table.

I am contemplating attaching a T-slot extrusion to the top of my table-saw's fence, so as to be able to mount movable featherboard hold-downs on the fence. If I can come up with a workable set-up, I will post pictures of it.

Rocker