Zero Clearance Insert

[ldh]

IDH
I just went and measured my inserts from SS and in every one the hole is identical front and back, they are all 5/16 actually the holes are 41/128" which is 1/128" bigger than 5/16 but close enough. Also all my inserts have holes placed in the identical location. So I'm confused?????
Can you explain why you say each table is different so each insert has to be drilled in a different location?

Hi Ed,
Try measuring the holes using drill bits. I have found the factory inserts to be very close to the 5/16 and 27/64 measurement. I pulled a couple of my factory inserts from the wall and inserted a 5/16 bit in the in-feed side and a 27/64 in the out-feed side and shot a couple of pics for you. I sure hope it is not our dry weather here in AZ causing the holes to expand or your humidity in FL to cause them to close. Just kidding, let me know what you find.
ldh

[Ed in Tampa]

Hi Ed,
Try measuring the holes using drill bits. I have found the factory inserts to be very close to the 5/16 and 27/64 measurement. I pulled a couple of my factory inserts from the wall and inserted a 5/16 bit in the in-feed side and a 27/64 in the out-feed side and shot a couple of pics for you. I sure hope it is not our dry weather here in AZ causing the holes to expand or your humidity in FL to cause them to close. Just kidding, let me know what you find.
ldh

IDH
Okay here is what I found. All my SS factory inserts that are made from plastic have 5/16 holes at both ends and work just fine on my Shopsmith. These include the blank, those pre cut for the riving knife.

All the metal SS factory inserts like the one that comes with the 510/520, router, molding head cutter, drum sander have the larger hole at one end. I have no idea why. It isn't needed. Sorry for my previous post but all my metal inserts were buried and I only checked the ones I use all the time.

I have made ZCI for my SS out of wood and I have always only drilled my holes to be 5/16 and they have worked fine.

A 13/64 tapered hex slot screw is used to secure them to the table so 5/16 hole allows for plenty of adjustment

I have no idea why the holes are different, this is where we need Nick to run out into the factory and to bring back the official word.

[dusty]

IDH

I have no idea why the holes are different, this is where we need Nick to run out into the factory and to bring back the official word.
If Nick could go out and check would we find anything different than we find when we go out into our various shops? I think not. If he checked and found that there are different size holes, he might be able to explain why.

All I know for sure is that they are NOT all the same. Furthermore, I have some that have different locations for the blade that I can not explain. 2, 3, 4 and 5 from the left.

2438

Incidently, you can readily see that there are a couple different hole sizes. These don't seem to be an issue. I didn't even notice til this thread was posted. The ones I question are all plastic (as is the ZCI blank). The others are aluminum.

[charlese]

Hi - The plastic inserts with the offset slots came with your Crafter's Station. It is the only way you can saw a miter with the CS. I saved mine when sending back my CS. Thought they might be valuable for use with the MK V. I was wrong and therefore did not receive monetary credit for turning them in. Oh Well!

[reible]

Next question, are everyones metal inserts bowed?? When you tighten them do they flatten out?? Anyone care to go the next step with this information and guess why the holes are not the same?

Ed

[ldh]

Next question, are everyones metal inserts bowed?? When you tighten them do they flatten out?? Anyone care to go the next step with this information and guess why the holes are not the same?

Ed

I am no engineer, but for me I have found that when I make zero clearance inserts the crown (bow) of the insert needs be be down and the larger hole in the insert allows me to take the bow out and get a better fit. I think there is a natural crown in the SS made inserts and the clearance of the larger hole allows for the same best fit. The plastic inserts are so flimsy I don't think they have much of any crown. My shop made inserts work well for me so hopefully I am on the right track.

ldh

[doug45601]

I made a bunch of blank inserts out of 1/4" plexi-glass and drilled the same size holes in each end. Also made that drum sander insert shown in the shopsmith book.

Also believe that the "singing" comes from the slots between the blade teeth quickly closing the gap on rotations compressing the air thus causing the harmonic frequency, whistle or singing if you will.

Now ain't that a buch of crap! Well it could be true!

[Ed in Tampa]

The bow in the metal inserts is what Shopsmith calls coined and was designed into them so you could adjust the insert to be perfectly level with the table.
My instruction manual tells me to install the back screw and tighten slightly then to install the front. Now using my finger or a straight edge to check levelness you are to tighten each screw until the insert is setting level with the table surface. If it is too high at the front you tighten the front screw more, if it low in the back you loosen the back screw.
On the plastic inserts they are built level with the table but since they are plastic they can be shimed up or sanded down to make a perfect fit.

I still don't know why the holes are different in the metal inserts unless it has to do with this bowing or coining as SS calls it.

That is why I wish Nick was here he could go talk to the engineers at SS and find out why the holes are different.