Don't mangle your zero clearance inserts

reftech · Post by **reftech** » Thu Jun 04, 2009 6:38 am

"5 points, uh oh no wonder my cuts are off:D . Just kidding. I need to get better at checking all lockdowns as well, just did not know there were 5.

dusty · Post by **dusty** » Thu Jun 04, 2009 7:06 am

tdubnik wrote:After generally mangling my own zero clearance inserts after using then a few times, I decided to come up with a way to set the blade in the same place every time.

I made a hardwood runner that fit snugly in the left miter slot and then attached a crosspiece that extended past the blade. I then set the table against the headstock bumper and locked it down. Next I extended the quill about 1/8 to 1/4 of an inch and locked it down. Then I cut the crosspiece to length by pushing the miter runner with the cross piece attached through the blade. Now I extended the quill with no table insert and set my zero clearance gauge so that the front teeth of the saw blade would rest against the cross piece when I released the quill. I now tightened the quill and raised the table above the blade.

I now inserted a blank table insert and locked it down. I turned on the Shopsmith and lowered the table to make the zero clearance cut. I then raised the table and removed the new insert. I checked the accuracy of my gauge by moving the table and then moving it back against the headstock. I extended the quill and let it come to rest against my zero clearance jig and locked it down. I reinstalled my new zero clearance insert and lowered the table to make sure it would come down with no interferance. As you can see, I shimmed the end of my jig with a couple of tape strips to get the setting just right. Now, when I install my zero clearance insert and use my zero clearance jig, I get a perfect fit. Since I am referencing from the miter slot and not the relation of the table to the headstock, I have not messed up another insert yet.

I'm going to make one of these but I have to spend some time thinking and playing with the Mark V first. Why? Because I am not sure that it works for all blades and arbor configurations.

Example: If after I have set up with a thin kerf blade and then I change to a wide kerf - will my settings have to be redone or do I need a set up gauge for the wide kerf as well.

Yes, this is academic. Oh ya, I do meed to recut a ZCI don't I. Hmmm.

BigSky · Post by **BigSky** » Thu Jun 04, 2009 8:26 am

dusty wrote:I'm going to make one of these but I have to spend some time thinking and playing with the Mark V first. Why? Because I am not sure that it works for all blades and arbor configurations.

Example: If after I have set up with a thin kerf blade and then I change to a wide kerf - will my settings have to be redone or do I need a set up gauge for the wide kerf as well.

Yes, this is academic. Oh ya, I do meed to recut a ZCI don't I. Hmmm.

As long as you continue to use the same arbor style the left face of any blade that you install will be in the same plane therefore the same gauge would be usable. Remember that the objective was to not destroy table inserts and changing blades may necessitate changing inserts too. I like it anyhow.

tdubnik · Post by **tdubnik** » Thu Jun 04, 2009 8:33 am

markfive510 wrote:As long as you continue to use the same arbor style the left face of any blade that you install will be in the same plane therefore the same gauge would be usable. Remember that the objective was to not destroy table inserts and changing blades may necessitate changing inserts too. I like it anyhow.

Since you are referencing from the miter slot to the left side of the blade itself, it shouldn't matter which arbor you use or even if it is positioned slightly different when installed. The two reference points won't change.

The blade thickness WILL make a difference in the ZCI itself. The reference points will be the same but the kerf will be different. I will probably use a different ZCI for each blade and have them clearly marked.

navycop · Post by **navycop** » Thu Jun 04, 2009 8:35 am

I have to make a ZCI (my first). But I am always hesitant about lowering the table onto the sawblade. I know (by your replies) that it has been done before and I am not reinventing the wheel here. But it still seems risky. I'll just have to remember the 5 locking steps first.

dusty · Post by **dusty** » Thu Jun 04, 2009 8:43 am

navycop wrote:I have to make a ZCI (my first). But I am always hesitant about lowering the table onto the sawblade. I know (by your replies) that it has been done before and I am not reinventing the wheel here. But it still seems risky. I'll just have to remember the 5 locking steps first.

You make a very good point. If the material that you use for the ZCI is too fragile it could break at the location of the holes where the ZCI mounting screws are. If that should happen, the ZCI could become a projectile. For that reason you want to lower the table very slowly so that the blade cuts its way through the insert without exerting too much upward pressure on the ZCI.

POINTS: Choose the material wisely. Secure the ZCI before cutting, Cut slowly and cautiously. Stand clear while making the cut. Remember, there are inherent dangers that come naturally with this hobby.

JPG · Post by **JPG** » Thu Jun 04, 2009 9:47 am

dusty wrote:I'm going to make one of these but I have to spend some time thinking and playing with the Mark V first. Why? Because I am not sure that it works for all blades and arbor configurations.

Example: If after I have set up with a thin kerf blade and then I change to a wide kerf - will my settings have to be redone or do I need a set up gauge for the wide kerf as well.

Yes, this is academic. Oh ya, I do meed to recut a ZCI don't I. Hmmm.

It should work with ALL insert/blade PAIRS. The insert MUST be unique for each blade(kerf/blade thickness etc.) Any variation re arbor/arbor type is compensated for by the quill adjustment. Attention must be paid to any blade non-flatness(wobble/set) so as to align to the same tooth!

Ed in Tampa · Post by **Ed in Tampa** » Thu Jun 04, 2009 9:57 am

dusty wrote:You make a very good point. If the material that you use for the ZCI is too fragile it could break at the location of the holes where the ZCI mounting screws are. If that should happen, the ZCI could become a projectile. For that reason you want to lower the table very slowly so that the blade cuts its way through the insert without exerting too much upward pressure on the ZCI.

POINTS: Choose the material wisely. Secure the ZCI before cutting, Cut slowly and cautiously. Stand clear while making the cut. Remember, there are inherent dangers that come naturally with this hobby.

I use the edge of my fence to hold down the ZCI over it's entire length as I make my initial cut. Of course you have to insure the blade will not hit the fence but that is fairly easy to sight check. If you do not trust your eyes you can use an aux fence attached to the fence and just place the aux portion of the fence over the ZCI.

dusty · Post by **dusty** » Thu Jun 04, 2009 10:44 am

tdubnik wrote:After generally mangling my own zero clearance inserts after using then a few times, I decided to come up with a way to set the blade in the same place every time.

I made a hardwood runner that fit snugly in the left miter slot and then attached a crosspiece that extended past the blade. I then set the table against the headstock bumper and locked it down. Next I extended the quill about 1/8 to 1/4 of an inch and locked it down. Then I cut the crosspiece to length by pushing the miter runner with the cross piece attached through the blade. Now I extended the quill with no table insert and set my zero clearance gauge so that the front teeth of the saw blade would rest against the cross piece when I released the quill. I now tightened the quill and raised the table above the blade.

I now inserted a blank table insert and locked it down. I turned on the Shopsmith and lowered the table to make the zero clearance cut. I then raised the table and removed the new insert. I checked the accuracy of my gauge by moving the table and then moving it back against the headstock. I extended the quill and let it come to rest against my zero clearance jig and locked it down. I reinstalled my new zero clearance insert and lowered the table to make sure it would come down with no interferance. As you can see, I shimmed the end of my jig with a couple of tape strips to get the setting just right. Now, when I install my zero clearance insert and use my zero clearance jig, I get a perfect fit. Since I am referencing from the miter slot and not the relation of the table to the headstock, I have not messed up another insert yet.

I have been challenged by this thread and I am going to run with some thoughts brought about by the conversations here.

I sorta built one of these for my own use and while doing so got side tracked onto a project to build a new "Auxiliary Table" for use with the Sliding Crosscut Sled.

My thought now is do build the Auxiliary Table so that it fits right up against the left side of the blade. By doing this the Auxiliary Fence doubles as "the gauge" while serving its purpose along with the cross cut table.

dusty · Post by **dusty** » Thu Jun 04, 2009 11:34 am

First task was to develop a miter bar to be used for this sled and the gauge.

I had a plastic Shopsmith bar for the gauge but needed to cut one for the sled. I had no hardwood suited for this task but was pressed (by myself) to do with what I had. I cut a piece from another gauge I had in the shop (I think it might be poplar).

The bar was just a little bit sloppy so I devised a way to expand it. Devised is not the right word. I copied the method employed by Shopsmith on the plastic bar from a finger board using a small brass screw in a bandsaw kerf. Photos attached.

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