|Project by johnzo||posted 01-05-2011 12:47 AM||9218 views||15 times favorited||7 comments|
After seeing a lot of safety discussion about retrofitting a riving knife to a tablesaw, I decided to try to make one up for my 10” model G1023SL. I referenced some website photos of the popular $125 BORK model that
was designed to fit my saw as well as a few other brands. Since I threw away the restrictive safety splitter and pawl assembly almost as soon as I uncrated the saw about 10 years ago, I figured I should do something to preserve my remaining 10 fingers. I started out with a 1/8” thick mild steel bracket about 12” long. This bracket was basically a right angle with a 7/8” leg and a 1 3/8” leg which was just about what I needed to clamp to the arbor swing arm which raises and lowers the blade. My bracket (where it came from – I have no idea, since I save every scrap of metal I see) had a 5” long relief 2 1/4” from the RK end. This left a little over 1/4” to stiffen this relieved area. I then had to file this remaining 1/4” leg an additional 1 1/4” down to the 1/8” material thickness in order to form the bracket to the arbor swing arm. This resulted in a 45 degree upward bend of about 3/4” to conform to the arbor bearing projection and another bend to straighten the bracket toward the RK end. I thought about drilling & tapping a couple of holes into the beefy arbor casting because the hose clamp in the BORK kit looked kind of wimpy. However- after tightening a similar hose clamp, (it engages a large hole in the ASA casting and pulls the bracket into such an amazingly tight contact with the profile of the ASA), I decided to skip the extra drilling & tapping. It’s actually a brilliant application! I then mounted the saw blade on the arbor, positioned a 3/8” thick alum block to the end of the bracket and bolted the RK about 1/4” from the blade teeth. After assembling, found out that raising the saw blade (compare 1st photo to 2nd) causes the RK blade to rise too far above the saw blade which is why the BORK RK has a slotted attachment feature. I used tool steel (actually a dull saw blade) to make my RK from, so I will eventually be laboriously cutting a slot into the .o83” thick RK in order to accomodate this adjustment. Also had to mill the alum block thickness so that the RK aligned perfectly to the saw blade.
Final assessment: Not having seen the actual BORK retrofit parts, but re-creating a reasonable facsimile over the course of a week, I conclude I probably should have paid the man his $125 and saved myself a lot of trouble. The riving knife – after relieving a longer kerf in my zero clearance blade insert so that it fits, seems to work great at the single position I have it adjusted at. It’s certainly ridgid enough! Also, guess I’m glad I did it, since I do have way too much time on my hands – and not a lot of dough.
-- 70 is the new 50!