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View Full Version : holding down your zero clearance throat plat?



Benjimin Young
01-12-2007, 10:21 AM
My General cabinet saw has two parts holding down the stock clearance place, a simple spring clip behind the blade and a screw at the front of the blade.

All of the designs for home made plates I have seen do not address if and how you should fasten them to the table (not to be confused with leveling screws).

My question.
Are your home-made plates fastened to the table in any way and if so how?

Ben

Jim Becker
01-12-2007, 10:25 AM
All of my shop-made ZCIs have a finish nail inserted at the rear that catches under the lip of the table so that the back end cannot lift as the blade turns toward the front of the saw. Holding it down in the front isn't required for most contractors' style and cabinet saws, but some machines that use thin metal likely will need that due to the low weight of the insert.

Garry Smith
01-12-2007, 10:35 AM
I use leveling set screws in my inserts and fit them fairly snug when making them.
When the humidity drops the inserst become looser. I then just use maskiing tape on the side to snug the insert in the cavity and if needed readjust the leveling.
http://www.superwoodworks.com/images/Holders/TableSawInsert2.JPG

Al Willits
01-12-2007, 11:21 AM
I got the Woodcraft ZCI for my Delta and found the leveling screw interferes with the original hold down screw hole on the saw, ended up drill and tapping a 10-24 screw hole and making another hold down hole on the saw, in hindsight, next time I'll buy the blank insert or make my own...more learning curve.
Al

glenn bradley
01-12-2007, 11:25 AM
I leave a little tail at the back of my wood inserts and pare it down with a chisel to make the rear "tab". Jim's finishing nail idea is good as well and I may try that for my next batch.

Jim Becker
01-12-2007, 11:40 AM
Glenn, the "nail idea" came directly from the OEM insert...it has a similar structure at the back of the piece.

Kyle Kraft
01-12-2007, 11:45 AM
Roger that, Jim. My OEM insert had a 3/32" roll pin driven into the end. I simply did the same with my homemade one.

D.McDonnel "Mac"
01-12-2007, 12:17 PM
I make my ZCIs like Garry with 4 allen screws to level and then I put 2 in the side to snug it in the hole. Tape would work but the allen screws are probably a little quicker.

Mac

Brad Hammond
01-12-2007, 12:24 PM
finish nail and leveling screws here too.

Garry Smith
01-12-2007, 12:26 PM
I make my ZCIs like Garry with 4 allen screws to level and then I put 2 in the side to snug it in the hole. Tape would work but the allen screws are probably a little quicker.

Mac
That's a good idea Mac. I will add that to mine also.

Sam Chambers
01-12-2007, 2:27 PM
All of my shop-made ZCIs have a finish nail inserted at the rear that catches under the lip of the table so that the back end cannot lift as the blade turns toward the front of the saw.Same here. My saw didn't come with a factory insert, so I bought a phenolic after-market one to use as a template. I made a batch of them from some 1/2" MDF, routed them using a flush trim bit at the router table, used some short screws as levelers, and a finish nail in the outfeed end. It works great, except that on my left-tilt Unisaw, the blade doesn't drop far enough below the table surface to cut the zero clearance slot in the insert. So, I start with one of the outside blades of my 8" dado set, get the slot started, then change blades and use my Forrest WW-II to cut the rest of the slot.

Jim Becker
01-12-2007, 3:59 PM
The pin in the back is particularly important with a ZCI because with the "tight" clearance to the blade there is a greater chance of the blade lifting the rear of the insert if there is an anomaly in operation. The pin that slips under the edge of the saw table keeps it from lifting and being thrown at the operator.

Bruce Wrenn
01-12-2007, 10:29 PM
Same here. My saw didn't come with a factory insert, so I bought a phenolic after-market one to use as a template. I made a batch of them from some 1/2" MDF, routed them using a flush trim bit at the router table, used some short screws as levelers, and a finish nail in the outfeed end. It works great, except that on my left-tilt Unisaw, the blade doesn't drop far enough below the table surface to cut the zero clearance slot in the insert. So, I start with one of the outside blades of my 8" dado set, get the slot started, then change blades and use my Forrest WW-II to cut the rest of the slot.Wouldn't it be nice to use just the blade that is going to be used in ZC insert, instead of outer blade from dado set first. I have almost got the little bugs worked out of a jig to do this. This jig also allows me to cut slot in back of ZC insert for a splitter that actually lines up with the blade. What a joy it is to see an idea become a reality. But if it doesn't work, I have to remember my son's favorite saying " The only difference between the word CHAMP, and the word CHUMP is U." Somedays I'm a champ, and other a chump!