ZCI Sled

dusty · Post by **dusty** » Tue Jan 17, 2012 8:08 am

For a long time now I have been making my own zero clearance inserts (ZCI) for the Mark V. I have done this without incident until just the other day when I was attempting to extend the saw kerf to facilitate the Upper Saw Guard. It was then that something went wrong as I was lowering the ZCI back onto the blade to cut that area for the saw guard. The ZCI that I was working on was grabbed by the spinning blade and pulled out of my hands.

No damage, no injury except to the ZCI and my ego.

Never again. There has got to be a better, SAFER way to do this.

I think this might be the solution. Please comment. Let me know what you think.

[ATTACH]15818[/ATTACH]

What is not shown here is a method for securing the work piece into the cutout while the kerf is being cut and extended. I have not finalized my thoughts on that yet but I want to do this without spending money (no spring loaded hold down clamps which would work but there is an associated cost).

I have previously posted details for the ZCI. All I must do now is construct this sled to hold the ZCI.

This particular one was conceived for a 510/520 but the same concept could be used elsewhere.

sawmill · Post by **sawmill** » Tue Jan 17, 2012 8:42 am

How are you going to hold the insert in place. Will it be screwed or bolted to the sled?

dusty · Post by **dusty** » Tue Jan 17, 2012 9:00 am

sawmill wrote:How are you going to hold the insert in place. Will it be screwed or bolted to the sled?

Please reference comments above (original post). I have not determined that yet. I may have to build a concept version so that I can try a couple ideas.

I also need to determine how I intend to limit movement of the sled. The kerf that occurs when you lower the main table onto the blade needs to be extended 2" to the rear to facilitate the upper guard.

Actually, I intend to cut the original kerf back 2" and then push the sled back 2" to cut the extended kerf. Hope that makes sense.

robinson46176 · Post by **robinson46176** » Tue Jan 17, 2012 9:26 am

How about something very simple like this:
[ATTACH]15819[/ATTACH]
Or just make a batch of them out of wood scraps. Four should do it well.

.

dusty · Post by **dusty** » Tue Jan 17, 2012 9:33 am

robinson46176 wrote:How about something very simple like this:
[ATTACH]15819[/ATTACH]
Or just make a batch of them out of wood scraps. Four should do it well.

.

GOOD IDEA. Simple is often the best way.

claimdude · Post by **claimdude** » Tue Jan 17, 2012 9:36 am

dusty wrote:For a long time now I have been making my own zero clearance inserts (ZCI) for the Mark V. I have done this without incident until just the other day when I was attempting to extend the saw kerf to facilitate the Upper Saw Guard. It was then that something went wrong as I was lowering the ZCI back onto the blade to cut that area for the saw guard. The ZCI that I was working on was grabbed by the spinning blade and pulled out of my hands.

No damage, no injury except to the ZCI and my ego.

Never again. There has got to be a better, SAFER way to do this.

I think this might be the solution. Please comment. Let me know what you think.

[ATTACH]15818[/ATTACH]

What is not shown here is a method for securing the work piece into the cutout while the kerf is being cut and extended. I have not finalized my thoughts on that yet but I want to do this without spending money (no spring loaded hold down clamps which would work but there is an associated cost).

I have previously posted details for the ZCI. All I must do now is construct this sled to hold the ZCI.

This particular one was conceived for a 510/520 but the same concept could be used elsewhere.

Dusty,

I made a couple of ZCIs recently but the saw slot was the last detail so I just mounted the ZCI in the slot with appropriate screws and then lowered onto the saw blade to create the kerf.

Jack

mrhart · Post by **mrhart** » Tue Jan 17, 2012 9:37 am

What if you laid a couple cmall strips across the top surface bolted from the bottom. Wing nuts on top, easy off and on to make others. Strips positioned to hold the work but far enough front and back as to not interfere with your initial kerf cutting.

ss50th · Post by **ss50th** » Tue Jan 17, 2012 9:39 am

Dusty,
I just used a 1/4" straight router bit (on the router table) to extend the opening far enough to allow installation of the guard.

dusty · Post by **dusty** » Tue Jan 17, 2012 9:40 am

claimdude wrote:Dusty,

I made a couple of ZCIs recently but the saw slot was the last detail so I just mounted the ZCI in the slot with appropriate screws and then lowered onto the saw blade to create the kerf.

Jack

I do exactly as you have just described BUT the kerf that is cut this way does not provide for the upper saw guard. You do you use your upper saw guard - right?:rolleyes:

heathicus · Post by **heathicus** » Tue Jan 17, 2012 9:50 am

For holding the insert in the sled, what about a bar across the top to act as a clamp on the ZCI? Bolt it to one side of the sled, and cut a notch on the other end of the bar so it can catch another bolt sticking up from the sled. Use one of those big knobs to tighten the bar down to hold the ZCI, or loosen it so the bar can swing around for removal and insertion of the ZCI.

Does that make any kind of sense?

For limiting movement of the sled, you could make the runners longer than the table with stops on the bottom of them that would hit the table and limit both forward and backward movement of the sled.