Riving knife on sale - highly recommended

[reible]

I think you need to call shopsmith again. No way should this be your problem. In fact when it comes to safety things shopsmith should bend over three ways from Sunday to fix their problem.

My three upper guards all work fine and as expected. If yours doesn't then perhaps they had a batch of "bad ones" and they should know about it.

Ed

My own experience with the upper saw guard on my 520 has been unsatisfactory. I think it is poorly designed. First, the riving knife with the pawls (part 199 on the upper saw guard) is not very durable. Just by tilting the table, the saw guard, which hangs off of the riving knife, will twist the riving knife slightly. My riving knife got a permanent bend in it when I put it in the "box of accessories" with something heavy on it. Despite careful efforts, I was not able to get mine back to dead flat.

So I ordered a new one at $46.64. Well, the pawls on the new one were VERY temperamental, by which I mean they did NOT slide up and down smoothly and would randomly stick on occasion (not because they were restraining a kickback), which was a safety hazard. I believe the stickiness was due to excess coating on either the riving knife and/or the pawls.

I called customer service. The advice I got was to press inward/downward on the edge of the pawls toward the riving knife body to loosen up the rivet. That did nothing and increased pressure just popped the rivet off. Another call to Customer Service, which told me it was my problem now. THAT HAS BEEN MY ONE AND ONLY LOUSY CS EXPERIENCE WITH SHOPSMITH, which has otherwise excelled at CS.

Ever since, I have used my non-through cut riving knife for all my cuts both through and non-through without any issues. Perhaps that's just luck. So I am not advising anyone to do the same.

[dusty]

BTW shopsmith has updated the information on the riving knife since I last visited the page. If you haven't visited it lately please do so. The link is:

http://www.shopsmith.com/ownersite/spec ... pn=RRXVTPR

This link might go away as it is for the special now going on.

I agree with shopsmith 200% on what they say. I know a lot of you don't like the guards and such but I do. I have no need to see where the cut is happening. If that is a major issue for you then it might be a good idea to rethink how you work. If you absolutely have to see then remove the plastic piece and keep the fingers that keep the work piece from kicking back..... I don't recommend this but it is much better then not using the upper guard at all.

I have micro-jig mj-splitters that I sometimes use with their grr-ripper or the shopsmith riving knife, that is also something that I like but it is quite costly. It is rare that I find I can not use one of these methods to do the cut.

I've got a lot of how to doing things posted here and I know I have posted how I like to use magic transparent tape to mark the cut line on the insert and then extend the mark to the front side of the work piece. I lift the guard and align the marks and then drop the guard in place and make the cut. If it a repeatable cut I use extensions on the miter gauge and set a stop. If someone want to review this I can attempt to locate the posts associated or redo it sometime soon.

I hate to disagree with Dusty but in this case I too have strong feelings.

Ed

I do not want a fight. I agree with you here in all respects except that I do not share your love for the upper saw guard. I hardly ever use mine and when I do, it simply reinforces my tendency to not use it.

The riving knife is another story. I have one installed all the time.

[reible]

Here is the link to the post I mentioned earlier in this thread. You can see here why I don't need to or want to look at the blade when I'm cutting.

http://www.shopsmith.com/ss_forum/viewt ... 3&p=189829

Ed

[ChrisNeilan]

Thru cut or non thru cut, i want a riving knife. When ripping narrow boards, the upper guard is in way and in my opinion creates a safety hazzard. I then use the riving knife. Wider boards is another story, and I always use the entire upper guard package, which of course does have a riving knife (or splitter if you will). Kick back is not your friend and as Dusty aluded to you have to be diligent in your setups.

[jms]

Great post - glad I read it.

I use the upper guard on every cut - true it's not the best design because you can't see the cut happening - but I've learned to trust my saw accuracy and measurements, and I just ordered the riving knife that's on sale for some dado work I have coming up.

[JPG]

I am 'unsure' how the riving knife will assist when making dado cuts.

[jsburger]

I am 'unsure' how the riving knife will assist when making dado cuts.

Since a non through cut is a dado cut no matter how wide that has been my thought since SS came out with this product claiming it is only for non-through cuts.

The way I learned, the spliter or riving knife was there to prevent the kerf from closing up due to wood stress. That would cause a kick back. It is the operators responsibility to keep the stock tight against the fence. It is called proper training/technique regardless of the discipline. Since I am not making a through cut how can the kerf close up?

I just read Ed's link so I guess SS got a lot of complaints about their reason for the riving knife was only for non through cuts like I stated above.

Now they have come up with another reason. If I put a flat piece of stock flat on the table how can it tilt? Only if it is cupped or twisted. I don't even want to get into this. "The workpiece could still rock or tilt slightly"??????? Really?

I guess it is the lawyers. If you use the riving knife you have no upper saw guard.

I bought one the last time they were on sale. I use it with my giant cross cot sled since I can't use the upper saw guard.

BTW, a high quality SHARP blade will go a long way to preventing kick backs.

[dusty]

I am not sure whether you were responding to my comments or not but----

the riving knife does not protrude out of the table as high as the blade and the work piece clears the blade only a fraction of an inch before it is retrained by the riving knife.

I have always had difficulty feeling like I understood the value of the riving knife. This image, I think shows why this discussion can be confusing. We each have our own comfort zone.

As for being designed only to be used for non-through cuts--- well I guess it works that way but I can lower the table a bit and I will be doing a rip cut with whatever protection the riving knife is suppose to provide (through cut or not).

Ed, note the "shallow "dado down the center of my table insert. That is my guide line. Note also that mistakes happen. The table insert was cut to be used with a thin kerf but has used with a standard blade.

[bobgroh]

My take on all of this:
1. Riving knifes are only recommended for non-through cuts because, with a through cut, the spinning blade is exposed on the top of the wood.
2. Kickback can occur through at least 2 mechanisms: the wood 'pinches' up after the wood clears the back of the blade and/or the wood at the back side of the cut rides up and the spinning blade catches the wood at the top of the blade and throws the wood backward (i.e. kickback).

It is true that you can use a riving knife for through cuts - I do it occasionally. When I do, I try to make sure the wood can't ride up (e.g. keeping down pressure with the pusher). Still I don't like doing it and the spinning and exposed blade is for Mr. Cautious Chicken guy (i.e. me) a bit nervous (which is not necessarily a bad thing).

Heck, some guys don't even use a guard of any kind! Or dust collection.

[reible]

Dusty I like your kerf idea. After you have used it a while how about a report back on how you have adapted to the idea.

Some one mentioned not having room for the upper guard when ripping thin stock. You need to make this "L" shaped piece to be able to use the guard. It is in the book. Online you can see it under "Ripping Narrow Stock"

http://www.shopsmith.com/academy/tblsaw ... /index.htm

Ed