ZCI on a sliding compound miter saw?

Jim O'Dell

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Between Aledo and Fort Worth, TX
With my kick back using my cheap, but so far dependable, Ryobi miter saw, it got me to thinking about it's eventual replacement (and that it may have moved to the top of the equipment list :eek:). Are any of the SCMS units out there zero clearance insert capable? I need to start doing some more serious research, and saving, but hadn't seen this in my window shopping before. My front runners from the casual search are, in no particular order, Makita 10", Bosch 10", Hitachi 10", and I wasn't happy with the DeWalt 10" I played with, but won't count it out. I grabbed the handle and made the cutting motion. The plastic blade guard took a nice smooth section right off my hand! (no power, static display) So I figure the handle placement and how I intuatively grabbed it, may not be a good match. I really liked the Hitachi setup and the way it felt, again on a static display, but the new design sure kills the reason I built the box bay window on the shop!! :D Haven't really played much with the Bosch or the Makita yet, but both have their loyal following. Wouldn't rule out the Ridgid completely, but it's not on my radar scope at the moment. Anything else I need to look at? I know Festool is coming out with a new one, but I already know it will be out of range pricewise.
Thanks for any insights you can give about the XCI capability on these units! Jim.
 
Jim,

I have a 12in single bevel CMS from DeWalt. I just replaced the kerf plate with a shop made ZCI from MDF. It did a good job stopping tear out on the bottom of a scrap piece of pine. Unfortunatly I had trear out on the back side of the wood-- the part that rests up against the saw's fence. From my understanding of your kick back incident, this is where zero clearnace would be helpful. I am, as a temporary measure, going to double stick tape a thin (1/4in) sacraficial fence along the saw's fence. This will ineffect create a zero clearance fence. The double stick carpet tape I use is pretty tough stuff, so I'm not worried about it holding. This should both prevent chip out on the back side and prevent kick back like what you experienced.
 
I use them whenever I can. Grab some 1/4" hardboard or whatever is appropriate. If you're gonna make one, may as well make a few:

make six.jpg

Double tape the original to a bandsawn blank to use as a pattern:

dbl tape sm.jpg

Use a pattern bit to shape:

pattern sm.jpg

I leave the original on each one long enough to use as a drill guide:

drill guide sm.jpg

Here's my worn throat plate and a new one ready for a cut:

worn zci sm.jpg

There you go; nice and clean:

new cut sm.jpg

I use one for 90* x 45* bevel cuts but draw the line at compound miters. I just don't do enough of the same compound cut to make it worth it. Others might during a large project.

For tearout at the rear I make a small bed with a fence. The trick here is to set the depth of cut on your saw so you don't saw the little guy in half on the first cut. This jig is bolted to the original fence through a couple convenient holes in my original fence.

CMS mini fence.jpg

If you have no holes; clamps or double stick tape will do. This effectivly gives me a ZCI at the bottom and rear of the cut although I use this primaily for small cuts to avoid "launchers". Another "launch" cure is to keep your blade in position once the cut is complete till it is fully stopped.
 
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On my Hitachi CF8B, I've used a ZC insert in the base fever since the saw was new - about 15 years ago. For the past ten or more years, I've been using BB plywood fence faces that slide along the aluminum extrusions (aftermarket) of the 'main' fence. In effect, this also provides a zero-clearance for the fence as well. The plywood inserts are expendable, and do get eaten away as various miter angles are used, but loosening a few bolts and sliding them over to the center again then closes any gap and returns them to "ZC".

I do this mainly to minimize tearout at the back of cuts, but it also does a very efficient job of preventing kickbacks, or flying short cutoff pieces, too.
 
Glen,

A few days ago I just made a master pattern for both my TS insert and CMS insert. I used 3/4in MDF for the master pattern. I can batch cut 3 inserts at a time using this pattern.... So now I have a stack of extras:D. I dont' need to put any screw holes in the inserts for my TS, but using the CMS origonal inset for a drill guide is a good idea. :thumb:
 
On my Hitachi CF8B, I've used a ZC insert in the base fever since the saw was new - about 15 years ago. For the past ten or more years, I've been using BB plywood fence faces that slide along the aluminum extrusions (aftermarket) of the 'main' fence. In effect, this also provides a zero-clearance for the fence as well. The plywood inserts are expendable, and do get eaten away as various miter angles are used, but loosening a few bolts and sliding them over to the center again then closes any gap and returns them to "ZC".

I do this mainly to minimize tearout at the back of cuts, but it also does a very efficient job of preventing kickbacks, or flying short cutoff pieces, too.

Jim, I'd be interested in seeing a few pictures if you have some!!

Good ideas guys. And thanks for the pictures Glenn. What brand miter saw do you have? I'm guessing a Delta, but I can't tell for sure. Jim.
 
Jim, I'd be interested in seeing a few pictures if you have some!!

Good ideas guys. And thanks for the pictures Glenn. What brand miter saw do you have? I'm guessing a Delta, but I can't tell for sure. Jim.

Jim,

Glen has a DeWalt. I think I have the same one....... the Yellow didn't give it away? :rofl:
 
Yeah, Sean's got it. I think we both have the same little DW703. Mine has been a little workhorse. It may be due to it's squat build but everytime I take a few moments to check the stops, etc. for accuracy. . . they're still fine.
 
Jim, I'd be interested in seeing a few pictures if you have some!! ...

Okay, Here you go. First, a pic of the front:

front.JPG

Then one of the back - note the tear-out on the plywood:

back.JPG

And another of the back, showing the full length of the extrusion (ignore the piece of dowel. It's just resting there between cuts...):

back2.JPG

And finally, a shot showing the extrusion's profile, along with a blank (½" BB ply) for the base ZCI.

insert.JPG

Hope this helps.
 
Jim D.,
That is a sweet setup.

Glenn,
The extrusions are a fairly common item today, Several companies - Kreg, Rockler, Woodhaven, etc. - are using that or a very similar one for bandsaw fences, router table fences, etc.

Back when I bought mine, Mark Duginski was selling it - thru his affiliation with Jeff Farris at the time, if memory serves. I bought it from Mark himself at a woodworking show in Southern California.

I've replaced the plywood faces many times over the years. Now, with the big saw cabinet, I make them three feet long, and replace them when they get down to about 18 inches. Swinging the saw thru 45° each way will take about half an inch off each fence, but a 45° will take a couple inches at a time off the left one.

The overall system with the extrusion and the plywood face does eat up about ¾" of crosscut ability, but I've seltom ever missed it since 99.9% of my cuts are in stock narrower than a foot It'll still cut just over 11" - lacks about an eighth of an inch from crosscutting a 1 X 12.
 
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