ZCI the very basic method(s) of making them

[reible]

Yes we are talking zero clearance inserts.

The most basic way to get one is to buy them from shopsmith. See:
http://www.shopsmith.com/ownersite/cata ... nserts.htm

Items C, D, and E.

If this is what you want then their you are.

If not go on to next post from me.

Ed

[reible]

If you are reading this post then I'm guess you just like reading posts or you want to make your own.

To make your own the first thing you will need is material to make them out of. Hardwood, plywood, MDF, hardboard, UHMW plastic or some such material.

If you are wanting to keep this simple then I'm thinking you want to buy material that is the right thickness. This gets to be tricky as finding things that say they are 1/4" X ? are often not really 1/4" at all. If you are looking for that thickness you best take something to measure with just to be sure when you head for your local materials store.

I use to use a product call Masonite but that no longer seems to be a product and I'm down to just scraps of it. I used that for router templates and zci mostly. If you look for "hardboard" you need to check the thickness as most of it that I have found is undersized.

MDF I can find in a true 1/4" thickness and again you will want to check this before purchase.

The UHMW plastic can be found in 1/4" some places, but it is a little flexible for my taste so I go to 3/8" or 1/2" but then that starts getting away from being a simple task.

Plywood is almost always undersized and while it can be used you will have to deal with getting it level in the table... It can be done but if you can find the other materials I'd forgo this option.

Hardwoods, if you shop for mill works area (moldings and the like) you may find some hardwood in the correct thickness that is wide enough.

So next is figuring out how much material you need. The 500 series inserts are about 3" wide and 13" long. The 505/510/530 series are 3" wide by 16". These are ruff estimates so make sure anything you buy is at least this size.

Now you can run off to shop for materials and I get started on the next post, OK?

Ed

[reible]

Are we having fun yet?

I'm going to use a term here which might not be familiar to all of you and that's OK it just another thing to learn. The term is "critical dimension". For our purposes here you can take this to mean this dimension is really importain to making one of these. In other words put your hatch away.

The only critical dimension is for the mounting the holes. If you get this to far off it will either not let you attach it or will cause some distortion in the insert. So why am I taking about this so early in the process? Well because if you do this wrong the part becomes scrap or goes in the bin to become something else. It also leads me into discussion of what is not critical.

If you have material in hand then it is time to brake it down to usable size. I'm going to assume you can do that. So let me say that you need to get a piece that is about the size on the insert you need. The width needs to be 3" or less, this is not critical, you could be as much as 1/8" off and even still have it looking good when you are done. The length was in the last post but 13"(can be longer but not less then 13") for a 500, 16" (is already a little long) for the 5++.

At this point I'm going to post a few pictures to make sure we are all on the same page.

First is one showing the shopsmith blanks shown as C and D on the shopsmith online posting I linked to before.
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This photo shows a 520 insert made out of "Masonite" material which I can not find anymore and as you will see in the next picture it looks a lot like the MDF material shown there.
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This is a replacement part for one of my sleds, it is made from MDF that is actually 1/4" thick. Sorry I don't have any pictures of an insert made form it.
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What you see here is an shopsmith blank insert and a UHMW plastic "blank" cut to size. We are going to take the blank an make it into something called a zci.
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Ed

[reible]

Since I'm working on a plastic that it hard to mark on you will see me using a invisible tape on the plastic so I can see my marks, you don't need to do that if you are working on a material that you can easily mark. Actually you may not see the tape, after all it is invisible.

Now we are going to use our caliper fingers to get things started. Your fingers if they are working properly can detect differences less the .001" so what you are now going to do is center real insert over our blank. Centered as in both width and length. If you use the metal insert out of your table it might be best as it will be accurate so far as distance between the mounting holes.

You might want use some double sided tape or just tape the parts together with making tape or use c-clamps. What ever it takes to keep them from moving while you are caring out the next process. You could put them in a vice or even use tight rubber bands to control them.

Now will come the time I will discuss several next steps for the marking of where the holes are going to be. The least accurate way but still an option is to take a pencil and trace around the inside of the hole. You need to keep the pencil vertical and depending on how good you do will be seen in how well the holes line up with the saw table. I think most people will be close enough doing it this way but there are better ways which I will also cover. After drawing the circle you can either eye ball the center point or use what ever method seems best to locate the center point.

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YES do both holes one after the other with out changing the position of either of the parts. Note, you will notice the bend or warp in the 5++ series inserts, that is to be expected they are made that way.

Some other options might be a center punch used for doing hinges etc or maybe a LARGE size hinge drill bit. My largest hinge bit is too small but I know there are larger ones to be had.

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What might be the best way to do this is with what are called transfer punches. I have a set of them and this is how I most often get my hole where they should be. Works will for marking gaskets, wood, and what have you. The ones I have are fractional and range from memory about 3/32" to 1/2" by 1/64" steps. They are just undersized by like .002" or so they can be used without sticking in holes. When I get this post about done I go get one to post a picture of it... if I remember.

If you have a set of transfer punches use them, and since you have them you will no doubt already know how to do that.

OK at this point I'm going to assume you have the two marks that correspond to the locations of the holes you will be drilling. If it is a pencil mark you will want to center punch it before drilling.

Going to take a little time off for supper then I try and wrap this up.

Ed

[reible]

I'm going to give just a few more moments to the transfer punches because they are really a handy item to have in your shop.

As far as cost, I don't recall what I paid but I think you can most likely find a set delivered to your house for less the $30.

First a shot of two of them:

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The two holes on the 5++ inserts are not the same size. So to do use the transfer punches you need a 27/64" one for the squared end and a 5/16" for the front end where it is rounded.

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Hope this little detour was worth it for some of you.

Ed

[reible]

Now with our holes marked it is time to go to the drill press and drill the holes. I'm going to let you figure out what size they are and I hope you all have a full set of twist drills up to 1/2" in your shop.

Make sure you do your drilling in a safe manner, no need to get hurt at this point in time making such a simple hole.

With the holes drilled it is time to make sure you have a fit. This can be done by checking with the insert you used to do the marking or check it with the table top. If the holes are not centered for width or are to close or to far apart you have officially in the danger zone. You will need to decide if it is a go or no-go situation at this point.

If it looks good then you need to counter sink the holes. You can do this by taking small cuts then checking with the mounting screws to make sure you are deep enough so the heads are embedded below the surface of the insert.

With the hole in place it is now time to do the rounding of the end(s). Again you will want to use the holes to align both the sample part and the new insert you are building. Once they are lined up it is time to draw the radius.

(Note that my shop is closed for the season so the pictures you will see will not have the hole in place.)
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Now comes a breve of options as to how to make the end round. There are more then I care to list but I'll point out at least a few of them.

The use of a hand tool such as the coping saw would work. You may like to clean up the cut with some sandpaper after but then again it is only an insert so some may not care to. This is the saw to which I was referring:

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If you have the band saw, jig saw or scroll saw attachments you can use them. If you want to use the table saw or hand saw to cut a line tangent to the circle then hand sand to shape. You can do the whole job with the use of the disk sander, belt sander, or strip sander or even a drum sander if you wish just take your time and don't get in a rush to remove material. My method of choice is a router but many other tools could be used. [Forgot to add that both ends of the 500 version gets the curve shape but the 5++ version needs to have the squared end trimmed to size.]

The end product should be something like these:
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One option which I don't have a sample of is the one with a cut out for the upper blade guard (5++). The ones you see will not except the blade guard but if you get them to this point you can cut them to fit your needs.

Just a couple more things and we are done.

Once you have one of these made check and make sure it fits. If so you may want to mark that one as a master and then use it for making others. A master is good for making routed versions.

Now for making the cut with the saw blade in to the zci I would suggest that you raise the table put the insert in place, check to see the table is locked in the proper location as well as the other normal checks like if you were going to do a sawing operation. Next mount the blade you are planning on using with this zci. Mount the rip fence so it covers the edge of the insert to hold it flat (you can also clamp a board over the table and insert to hold it in location). You will might not be able to have top guard in place so take all due caution as you lower the table into the blade. You need not lower the table all the way down if you now that most of the work you want to do with this zci is going to be less then full depth cuts.

I would have like to taken pictures of the whole process as I made one but I hope this will do for now.

Ed

[JPG]

That'll do Ed, that'll do!

[Gene Howe]

Excellent tutorial, Ed.

[mickyd]

Clear, concise, and too the point. Excellent work instruction!!! Now out to find material. Thanks Ed.

[bluekayak]

Thanks Ed. I am missing the inserts for both my dado blades and my drum sander. Now I have a starting point.

Thanks,

Jerry Floren
St. Peter, MN