Riving Knife Retrofit for Older Delta Unisaw?

[Spence Clark]

Hello:

I am new to the forum, and I am curious if anyone out there knows of an aftermarket riving knife for the older generation Delta Unisaws (I have a US built 34-814, right tilt).

I took a look at the blade height and tilt mechanism, and it appears that someone could easily machine a new arbor mount or retrofit the existing one to include a riving knife mount.

Any information or leads? Should I start a company?

Thanks,
Spencer

[phil harold]

Gary Katz has tutorial on how to build one on his site

google gary katz riving knife

[jacques nolin]

i cant seem to be able to find the tutorial by gary katz can someone give me a hint please thank you

[Curt Harms]

Hello:

I am new to the forum, and I am curious if anyone out there knows of an aftermarket riving knife for the older generation Delta Unisaws (I have a US built 34-814, right tilt).

I took a look at the blade height and tilt mechanism, and it appears that someone could easily machine a new arbor mount or retrofit the existing one to include a riving knife mount.

Any information or leads? Should I start a company?

Thanks,
Spencer

Here's the best option I'm aware of. ************ I don't have one but if you do a search you can find references. The difficulty retrofitting a riving knife onto a traditional-style saw is that the blade elevation mechanism travels in an arc. Saws designed for a riving knife from the get-go have mechanisms that travel in a straight line vertically. I hope this is what you have in mind.

Curt

[Jason White]

There's no such thing as a "riving" knife for your saw. Only splitters that look similar to riving knives.

However, you can come "close" to a riving knife with a better quality splitter that stays close behind the blade and is easier to take on and off.

I have the Shark Splitter set with quick-release (leestyron.com) on my cabinet saw and it is working out very well for me. $60 gets you 3 different height splitters that stay nice and close behind the blade. Well made and fairly easy to take on and off.

Jason



Hello:

I am new to the forum, and I am curious if anyone out there knows of an aftermarket riving knife for the older generation Delta Unisaws (I have a US built 34-814, right tilt).

I took a look at the blade height and tilt mechanism, and it appears that someone could easily machine a new arbor mount or retrofit the existing one to include a riving knife mount.

Any information or leads? Should I start a company?

Thanks,
Spencer

[Jason White]

Phil, I don't think that's quite accurate.

Gary took an existing riving knife (he called it a splitter, but whatever...) on a Bosch jobsite saw and modified it to sit below the top of the blade. The saw already had the mechanics in place to allow the splitter to rise and fall in height with the blade, just like a true riving knife does. Gary only modified the knife itself.

Jason


Gary Katz has tutorial on how to build one on his site

google gary katz riving knife

[scott spencer]

There's no such thing as a "riving" knife for your saw. Only splitters that look similar to riving knives.

However, you can come "close" to a riving knife with a better quality splitter that stays close behind the blade and is easier to take on and off.

I have the Shark Splitter set with quick-release (leestyron.com) on my cabinet saw and it is working out very well for me. $60 gets you 3 different height splitters that stay nice and close behind the blade. Well made and fairly easy to take on and off.

Jason

Jason - The ************ is more than a splitter...it sits as close to the blade as physically possible, and travels up, down, and tilts with the blade just like a riving knife. The biggest difference is that it travels in a slight arc instead a straight vertical path.

http://i6.photobucket.com/albums/y203/hewood/sawparts/Saw%20Blades/BR1.jpg
http://i6.photobucket.com/albums/y203/hewood/sawparts/Saw%20Blades/br3.jpg
http://i6.photobucket.com/albums/y203/hewood/sawparts/Saw%20Blades/br2.jpg
http://i6.photobucket.com/albums/y203/hewood/RT/rt001-1.jpg

[phil harold]

Phil, I don't think that's quite accurate.

Gary took an existing riving knife (he called it a splitter, but whatever...) on a Bosch jobsite saw and modified it to sit below the top of the blade. The saw already had the mechanics in place to allow the splitter to rise and fall in height with the blade, just like a true riving knife does. Gary only modified the knife itself.

Jason

My bad

sorry, I noticed this was wrong the other day when i wanted to make one for my left tilt Jet saw...

I would really like to see a picture or drawing of the B.O.R.K mounting system

[Paul Murphy]

I think Jason has a point with the ************. While it is a very nice splitter, it is not a true riving knife. I believe with the ************ if you set it with the blade low it will rise higher than the blade with an increase in blade elevation. If you reset the ************ at a high blade elevation, it will move lower than the blade upon reducing blade elevation.

As Scott said, the ************ is more than a simple splitter. I have never used one, but I haven't read any negative reviews.

I think the mechanism for the PM2000 might be worth studying. It has a pivoting lift arm like the traditional cabinet saws, and yet they have a riving knife listed as a feature. I would guess there is a follower link to keep the riving knife level through full blade travel, but haven't seen a PM2000 to check this.

Can any PM2000 owners provide details?

[scott spencer]

I think Jason has a point with the ************. While it is a very nice splitter, it is not a true riving knife. I believe with the ************ if you set it with the blade low it will rise higher than the blade with an increase in blade elevation. If you reset the ************ at a high blade elevation, it will move lower than the blade upon reducing blade elevation.

As Scott said, the ************ is more than a simple splitter. I have never used one, but I haven't read any negative reviews.

I think the mechanism for the PM2000 might be worth studying. It has a pivoting lift arm like the traditional cabinet saws, and yet they have a riving knife listed as a feature. I would guess there is a follower link to keep the riving knife level through full blade travel, but haven't seen a PM2000 to check this.

Can any PM2000 owners provide details?

The ************ has worked very well for me. Since the blade is on a swing arm, and the ************ is attached at the end of the swing arm, it does indeed travel a greater distance than the blade but it's not a large enough difference to make it problematic. I set mine to handle most common thicknesses....~ 3/4" to 5/4", and it doesn't require height adjustment anywhere near those thicknesses for most tasks. Even with rips or crosscuts to 3" it just means that the ************ rides a little higher than the blade, which is not a problem for those applications. I honestly can't remember the last time I adjusted the height of the B.O.R.K's knife, but could envision needing to lower it slightly for cutting a slot in 3" material, which is literally a 10 - 15 second task from start to finish, so I see it merely as a fact that's a non-issue.

If it'd be helpful to anyone, I could take a set of pics showing the knife height relative to the blade height at a few different blade height settings from low to high.

[Floyd Mah]

Interesting that you should raise this question now, as I posted a solution for the Delta Model 10 contractor's saw last week which probably is applicable to your saw. The link is http://sawmillcreek.org/showthread.php?t=112419 . The contractor's saw is also a right tilt, with the arbor raised on a lever arm. Assuming that the saws may have a similar mechanism, which I don't know, the riving knife can be implemented with Orchard Supply Hardware parts, pieces of your existing Delta splitter, and some metal-work.

The break-through step is to approximate the motion of the saw arbor using a linear travel of the riving knife tangent to the motion of the saw arbor. This results in a deviation of the riving knife about 1/4" horizontally from the saw blade, well within the intended function of a riving knife. Otherwise the my riving knife design follows the vertical motion of the arbor. Close attention must be paid to tolerances, since deviations of 1/64" or 0.3 degrees in the tilt will result in an unacceptable alignment of the riving knife. The few adjustments are very critical and took me a long time to master.

There is one part in my assembly which is a custom-made pulley, which I turned on a small lathe. I have an idea for a replacement part which uses off-the-shelf parts to make up the same function. Unfortunately, the riving knife of my design can't be made cheaply (mostly because of the time needed) but it is very suitable for a DIY project which you can tackle. I guess that our own time is much cheaper. Other ideas for contruction which I have come up with include making some of the parts from plastic casts or weld-up parts to simplify manufacture on a commercial basis.