Tablesaw Splitter

[Greenvilleguy]

OK, I'll confess -- I rarely use the upper saw guard; but I do use a splitter. I used to make my own, but now I just use an MJ splitter like Dusty.

Please don't think I'm recommending you follow my bad habits and stop using your upper guard, but there are times when it's in the way. That's a good time to use a splitter.

For those not familiar, here is a picture. That little piece of plastic is all you really need to keep the wood from squeezing back together behind the blade and causing a kick back. It also helps keep the cut straight.

[ATTACH]1155[/ATTACH]

[chrispitude]

Something I've been wondering... does a zero-clearance insert hinder or defeat dust collection?

- Chris

[greitz]

About the zero-clearance insert and dust collection- someone once mentioned that they drilled an extra hole at one end of the saw kerf in the insert to help with dust collection. Sorry, I forget whether it was the front or the back. Haven't tried it yet myself.

Gary

[termite06]

Okay, you folks are much more diversified users than I am. I am convinced. I may want to use my Shopsmith without the upper saw guard but with the riving knife.

Is that what I will have if I remove the plastic guard. It is held on with just a bolt and nut.

No, it is not. I will also have kickback pawls along with the riving knife.

In some circumstances, kickback pawls are also going to be in the way.

If my imagination serves me well, we are now down to a totally exposed sawblade and I would think a zero clearance insert. I guess it is time to build a zero clearance insert with a riving knife. In otherwords an MJ Splitter.

This riving knife from sawstop could cut bevels & moves up/down with the blade. Page 4
http://www.sawstop.com/SawStop_Brochure.pdf
I might try making one from sheet metal this week.

[Greenvilleguy]

Something I've been wondering... does a zero-clearance insert hinder or defeat dust collection?

- Chris

This is an interesting question. I haven't noticed any difference. It would seem that the sawdust would be trapped in the gullets of the blade until the gullet cleared the insert underneath the table. I would think that might marginally improve dust collection. Since all the suction from dust collection is through the insert and the insert is usually covered by the work, the only way for dust to be "sucked" is from the gullets underneath the table.

I'll be interested in others thoughts.

[Ed in Tampa]

Yes a true riving knife does move up and down with the blade. The Shopsmith upper blade guard assembly can be made into a true riving knife if you simply cut off all the blade guard, antikick back pawls and the metal that sticks above the saw blade. The resulting riving knife needs to be exactly the same height or slightly shorter.

If you do that you will not be able to mount the upper blade guard again. Therefore I suggest you buy another riving knife and cut it rather than your present upper saw guard assembly.

I think doing this is actually cheaper than buying a MJ splitter. Plus you end up with a true riving knife (one that moves with the blade) and it is metal which I would think insures a longer life than a plastic one.

Yes a zero clearance insert does restrict dust collection. If I have my normal insert in and using my upper blade guard assembly I have really good dust collection. If I use a zero clearance insert I begin to see dust on my table top. If I use my zero clearance with my Sharkguard (which has an upper vac port) I see no dust. If I don't use a blade guard and either the normal or a zero clearance insert I have to sweep the floor.

Again cutting the Shopsmith riving knife is fairly easy. A sabre saw with a metal cutting blade, a metal bandsaw, a recepocating saw with metal cutting blade, a hack saw, a grinder, cutting torch will all do the job fairly quickly and easily. Just insert the riving knife into the holder making sure is fully seated. Then with a level settting on your blade draw a line across the riving knife marking the height of the blade. Next cut on the line staying a little on bottom side, when finished sand the edges to remove any burrs.
You want to riving knife to be exactly the same height of the blade or a little lower. It can not be higher so error on the lower side!
Ed

[dusty]

Ed;

Is the only reason the riving knife must be lower than the top of the blade so that I can make something other than a through cut?

We use a riving knife so that the kerf does not close on (pinch) the blade and with this sort of cut a riving would not be needed (or so it seems to this old man).

Please explain why the blade must as tall or taller than the riving knife.

[Ed in Tampa]

Ed]must be lower than the top of the blade[/U] so that I can make something other than a through cut?

We use a riving knife so that the kerf does not close on (pinch) the blade and with this sort of cut a riving would not be needed (or so it seems to this old man).

Please explain why the blade must as tall or taller than the riving knife.

Dusty
Yes the riving knife must be just equal to or lower than the blade to permit non through cuts, that is true. However it is not true that a non through cut can not close the kerf and pinch the blade. I have seen wood pinch the cut close on many non through cuts.

But the biggest reason is if you don't have to remove the riving knife to make a cut you also don't have to reinstall it. Many times we remove the knife and get lazy and don't reinstall it.

I'm guilty of doing it. If I'm really into what I'm doing and if I take the riving knife off I will catch myself making through cut before I put the riving knife back on. So by being able to keep the riving knife in place is just one more of insuring it will be there when you need it.
Ed