Zero Clearance Insert for old saw

[DSWalker]

After reading a few posts about ZCI's I thought I'd show what I'm dealing with and get any suggestions you may have. I've watched several videos to get ideas, but thought I'd get your thoughts as well.

Saw is an old Darra James with a 12" blade. There is a huge gap on the right side of the blade and very little on the left. Existing insert is 1/4" thick. There is plenty of space on the arbor. Could I put a new wider flange on the back side of the blade and move it over to provide more room on the left side of the blade for a new insert? One issue if I did try that is that there is no support on that side for the insert to rest on. AS a matter of fact, the existing insert also only has 3 sides of support.

Should I just focus on a new insert that is much closer on the right side of the blade?

 

[Jeff]

How deep (thick) is your current metal insert that sits on that lip on the right? To the left of the blade there's no support and it looks like about 1/4" to the blade. Correct?

You can probably make your own custom fit zci with a 1/4" opening to the left of the blade. Does the blade tilt to the left or the right?

 

[zapdafish]

I dont see why you couldnt make a zci with zero clearaance all around the blade. I think the fence or material will always be providing downward support to the right of the blade so dont think you have to worry about lack of support on the fourth side. just make sure the fence is on the meat of the zci the first time you raise the blade through it.

how to deal with tilt, I dont know. I might revert back to your current setup.

 

[zdorsch]

That looks like something/someone may have modified it based off of the funky cuts at the ends of the blade.

I found this image that looks better on owwm:

Edit: I think the three sides would hold the insert and would focus on that side. The left side of the blade provides little space to fit.

 

[Gotcha6]

How much adjustment do you have in your trunnion and motor support? If you could shift the trunnion, it's not necessary that you use 1/4" material and a thicker piece could be rabbeted on the edges to proper depth. The big issue would be when making bevel cuts, how much does the blade go into the left side?

 

[DSWalker]

So I made one this weekend out of some scrape walnut. It is working great so far.

As suggested by Dennis, used a 1/2" piece and then rabbited the edge.

So far, so good.

 

[danmart77]

David that is a big improvement but I think there could be more glued on to the insert. Before I mention any ideas, the section of the wooden insert NEEDS to be secured on the edge where the blade is coming up in rotation. If you don't secure that with a device of some sort, it will go flying one day. Your shape is better than mine was but the insert needs to be held down with something.

My first thought on the metal insert was to fiberglass the insert and fit to the hole. Raise the blade and you will have a true "O" tolerance insert for small work. I had an old Rockwell TS with a 12" blade and this is what I had to do to make it safe for small stuff.

 

[DSWalker]

David that is a big improvement but I think there could be more glued on to the insert. Before I mention any ideas, the section of the wooden insert NEEDS to be secured on the edge where the blade is coming up in rotation. If you don't secure that with a device of some sort, it will go flying one day. Your shape is better than mine was but the insert needs to be held down with something.

My first thought on the metal insert was to fiberglass the insert and fit to the hole. Raise the blade and you will have a true "O" tolerance insert for small work. I had an old Rockwell TS with a 12" blade and this is what I had to do to make it safe for small stuff.

Very good point and I do recall seeing the 'clip' on the 'up side' of the rotation on many of the videos I reviewed. I'll figure something out to help get it secured.

 

[Jeff]

Very good point and I do recall seeing the 'clip' on the 'up side' of the rotation on many of the videos I reviewed. I'll figure something out to help get it secured.

My HDMW ZCIs have a steel split pin inserted in the end. The pin is about 5/8" l and 1/16" d. That keeps the insert from being lifted by the rotating blade.

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

 

[zapdafish]

that seems like an awful of space to the right of the blade, wondering why it was designed like that. Even if it tilts to the right, does it need so much?

 

[Gotcha6]

I've made inserts for my old "Kenmore" (aka Craftsman) saws from wood and just attached a wood cleat to the underside of the insert to mimic the clip. You could also drill & tap a small (10-24) hole in the flange and run a countersunk machine screw into it.

 

[DSWalker]

that seems like an awful of space to the right of the blade, wondering why it was designed like that. Even if it tilts to the right, does it need so much?

Doesn't need the space. The existing plate has clearly been 'hacked on'. Who knows what/why this happened in it's previous life.