# Making A Zero Clearance Table Saw Insert



## pollys13 (10 Apr 2016)

Hi all,
I'm making a zero clearance table saw insert, see attached. I'll bring the blade up from under to cut the slot. Though to do this I'll need to remove the riving knife. What I'd like to know is, how do I make a continuation of the slot for the riving knife to rise?
Cheers,
Peter.


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## Jacob (10 Apr 2016)

Any of the usual methods would do. Simplest would be to run it into the TS blade. You could close the gap (if necessary) with a glued-on closing piece or something.


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## blackrodd (10 Apr 2016)

Jigsaw with a metal blade.
Rodders


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## deema (10 Apr 2016)

If your lucky the insert is symmetrical, a lot are. Just rotate the insert so it's upside down and back to front and re- plunge the blade up through the insert plate. You should find that the riving knife now fits into the slot. 

I'm sure your probably doing this, but it's worth mentioning, Plunge the blade up with the fence holding the insert down.


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## pollys13 (11 Apr 2016)

deema":1y53hl1j said:


> If your lucky the insert is symmetrical, a lot are. Just rotate the insert so it's upside down and back to front and re- plunge the blade up through the insert plate. You should find that the riving knife now fits into the slot.
> 
> I'm sure your probably doing this, but it's worth mentioning, Plunge the blade up with the fence holding the insert down.



" If your lucky the insert is symmetrical, a lot are. Just rotate the insert so it's upside down and back to front and re- plunge the blade up through the insert plate. You should find that the riving knife now fits into the slot. " I'm not quite following you on this, you mean original plate or ZCP I'm making. Could you explain to me so I grasp what you mean? Good tip to use tablesaws rip fence to hold it down.


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## deema (12 Apr 2016)

Remove the riving knife and place the insert you are making into your slot. Move the fence over the insert but ensure it will be missed by the blade. Try to get it as close to the blade as possible. 

Raise the blade up through the insert all the way. Lower the blade and turn off.

Now as you are looking at the table insert turn it length ways upside down. So, turn in the same direction as the saw blade makes. The insert will be upside down and the groove cut by the saw blade will realign with the saw. Now bring the blade back up all of the way with the fence positioned back holding the insert down.

If the table slot is symmetrical you will have an insert that allows the blade and riving knife to be fitted with the new insert fitted.


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## MattRoberts (16 Apr 2016)

Is that a piece of aluminum you're using for the insert? If so, be incredibly careful of you use the tablesaw to continue the cut without the riving knife installed!


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## Bodgers (31 May 2016)

If your slot is asymmetrical (as it is on my Axminster TS200) a track saw is your best friend.

I raised the table saw blade with the fence over it, and the knife removed, and made the main cut then removed the new insert and plunge cut, using my Dewalt tracksaw, the remaining riving knife bit.

I think if you want the cleanest looking result it is the best way. Jigsaw, coping saw methods can look a bit ropey if your clean up isn't 100%.

BTW - I made my last insert from red Acrylic - machines well and looks like a factory item when finished.





Sent from my MI 3W using Tapatalk


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## Lons (1 Jun 2016)

Bodgers":r5vezc4l said:


> BTW - I made my last insert from red Acrylic - machines well and looks like a factory item when finished.



What thickness acrylic did you use Bodgers? The insert on my SIP 01332 is quite thin, can't remember what I measured it at but can't be more than 2 or 3 mm. I thought about acrylic but felt it would be too flexible unless I used 6mm and routed the edge to drop it down into the slot.
I might have to reconsider in light of your post.

cheers
Bob


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## Steve Maskery (1 Jun 2016)

Personally I wouldn't use acrylic for a ZCI. It is very brittle and shatters on impact, so if anything goes wrong when you are sawing, you can easily end up with a destroyed throat plate. I don't see what advantage acrylic would have over a piece of plywood. MDF is OK but ply is better. Just make sure it is flat and not doing impressions of a poppadum. 

I rough cut the plywood to the size I want, use DS tape to stick it to my original throat plate and flush-trim to size. There is a narrow gap between the TCT edges of the router cutter and the guide bearing and I have to make sure that the bearing is wholly on the steel whilst the cutter is wholly in the wood. 1mm either way and either it wont cut or the cutter gets ruined on the steel. If there is a bit of wood still to finish, I adjust the height of the bit, remove the steel and flush-trim the ply to itself.

The ply is a tad thinner than I need, so I mark on the underside where the supporting lugs are, drill pilot holes for small countersunk screws (but I don't fit them yet), which I will use to adjust the plate for level, but before trying it for size I drill a couple of 1" finger-holes, nicely rounded, so I can lift it out easily.

Once I'm happy with the fit, I move the fence right up to the throat, dead flush, replace the old throat plate,and cut a slot about 1/2 way along the ZCI. This is the area that will take the riving knife. Stop the saw, remove the workpiece and cut and fit a small sliver as a plug to close the back end, behind the RK. Fit and adjust the levelling screws. Install the new ZCI.

Lower the blade completely, move the fence up right next to the slot, wedge it in place if necessary, switch on and carefully raise the blade. Job done.

NB
If you later lower the blade, the ZCI is no longer strictly ZC. It will be ZC at the sides, but not at the front, directly in front of the teeth. That might matter if you are cutting MFC, for example.

ZCIs do wear, so it's worth making a batch rather than just one.


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## MattRoberts (1 Jun 2016)

I wish it was easier to make an insert for my SB10 - the throat is an irregular shape, so it's a bit of a pain


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## Jacob (2 Jun 2016)

The cheats way is to fix a large piece of ply to the table top (clamp at one edge etc) and raise the saw blade through it.


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## MattRoberts (2 Jun 2016)

I'm a stickler for keeping maximum cutting capacity! I don't even like using thick ply for jigs


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## Bodgers (16 Jun 2016)

Steve Maskery":aw7fyx6a said:


> Personally I wouldn't use acrylic for a ZCI. It is very brittle and shatters on impact, so if anything goes wrong when you are sawing, you can easily end up with a destroyed throat plate. I don't see what advantage acrylic would have over a piece of plywood. MDF is OK but ply is better. Just make sure it is flat and not doing impressions of a poppadum.
> 
> I rough cut the plywood to the size I want, use DS tape to stick it to my original throat plate and flush-trim to size. There is a narrow gap between the TCT edges of the router cutter and the guide bearing and I have to make sure that the bearing is wholly on the steel whilst the cutter is wholly in the wood. 1mm either way and either it wont cut or the cutter gets ruined on the steel. If there is a bit of wood still to finish, I adjust the height of the bit, remove the steel and flush-trim the ply to itself.
> 
> ...



Don't doubt what you are saying about acrylic, but I ended up settling on it after experimenting with plywood and MDF.

Plywood just isn't workable on the TS200 plate. You have to recess the thickness on one side of the plate down to about 3mm and at this point, even with have decent birch ply you run into delamination and instability problems.

My second attempt was with MDF and I used this for about 6 months. Ultimately though, this ended up in the bin as it just wears out and feathers very quickly.

To answer the question about the thickness I used - I used 6mm. And I also epoxied a small piece of it to the underside of the TS200 table on the right side of the plate hole to act as a support, as for whatever reason, Axminster decided the right side of the plate should be in supported.

Not sure if there are different grades of Acrylic, but this stuff does seem very tough...


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## Lons (17 Jun 2016)

Bodgers":2ooxqszk said:


> Don't doubt what you are saying about acrylic, but I ended up settling on it after experimenting with plywood and MDF.
> 
> Plywood just isn't workable on the TS200 plate. You have to recess the thickness on one side of the plate down to about 3mm and at this point, even with have decent birch ply you run into delamination and instability problems.
> 
> ...



Thanks Bodgers. There are only 2 grades of acrylic easily available though some others are manufactured. I.E. cast and extruded and are easy to tell apart if you look closely as cast is glass clear while there are extrusion marks visible in extruded acrylic. Most stable is definitely cast as extruded is slightly softer and more affected by climatic conditions. Cast is more expensive btw.

I still haven't done anything about mine  but I have some 6mm tufnol SRBP so might just route the edge down to thickness to fit as it's very rigid and if that doesn't work I have 6 mm Perspex and polycarbonate to try. ( Good job the stuff doesn't deteriorate with age as I've had mine since I was in the industry 25 years ago :lol: )

cheers
Bob


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## Steve Maskery (17 Jun 2016)

Bodgers":2piux4qv said:


> My second attempt was with MDF and I used this for about 6 months. Ultimately though, this ended up in the bin as it just wears out and feathers very quickly.



If you got 6 months out of a ZCI, I'd say that was pretty good. As I said, they do wear, and if you lower the blade they are no longer ZC at the front anyway. You have to think of them as disposable. But if you are happy with your material and it performs well for you, then that is all that matters!


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## AndrewR86 (20 Dec 2020)

pollys13 said:


> Hi all,
> I'm making a zero clearance table saw insert, see attached. I'll bring the blade up from under to cut the slot. Though to do this I'll need to remove the riving knife. What I'd like to know is, how do I make a continuation of the slot for the riving knife to rise?
> Cheers,
> Peter.



Sorry for opening an old post.
Did you get a new zero clearance insert made? I’ve got the SIP 01332 and looking to make a new insert myself.

thanks in advance.


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## DBT85 (20 Dec 2020)

I made one for my SIP 01446 a few weeks ago. 

Put the new insert in the hole and raise the blade without the knife, then put the old insert in, put the new insert over the blade and snug the fence up. You can now with extreme risk extend the hole but not go all the way. Alternatively you can, once the fence is in place, run the insert through the blade as normal and then insert a spline in the cut end to stop it flapping about.


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## AndrewR86 (20 Dec 2020)

DBT85 said:


> I made one for my SIP 01446 a few weeks ago.
> 
> Put the new insert in the hole and raise the blade without the knife, then put the old insert in, put the new insert over the blade and snug the fence up. You can now with extreme risk extend the hole but not go all the way. Alternatively you can, once the fence is in place, run the insert through the blade as normal and then insert a spline in the cut end to stop it flapping about.



what material did you use? 
How did you get it the right thickness?? I’m measuring anywhere from 3.2 to 3.6mm depth around the ledge so struggling to find the right material without a load of work to get it down to the right thickness.


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## DBT85 (21 Dec 2020)

AndrewR86 said:


> what material did you use?
> How did you get it the right thickness?? I’m measuring anywhere from 3.2 to 3.6mm depth around the ledge so struggling to find the right material without a load of work to get it down to the right thickness.


I made a template from a bit of spare 9mm MDF and then used it and a template bit in a router on some 18mm MRMDF. I then used a router to take the outer 15mm or so down to about 3mm to actually slot in correctly. I then put grub screws in the existing threaded holes in the table for leveling.

I did the first one with no router table and that alone was enough to make me want one  

It's a PITA to make inserts for if I'm honest.


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## Fidget (21 Dec 2020)

AndrewR86 said:


> Did you get a new zero clearance insert made? I’ve got the SIP 01332 and looking to make a new insert myself.



I made one for my Itech 01332 (same machine) out of Valchromat, bought a couple of A3 size bits from The Bay.

I cut it roughly to size then stuck the original plate on with double sided tape and used a template follower bit on the router table to trim it to size. Marked the mounting holes while it was still taped. Then I used an ordinary router bit in the table to gradually thin the edges down until it fitted snugly in the slot. Drilled and countersunk the screw holes and put another larger hole in so I could lift it out. Then put it in the slot, clamped it with the fence and raised the blade, turned it over length for length and did the same again which nearly cut a slot long enough for the riving knife. If I remember correctly I had to use a small file to make it about 3 or 4mm longer so that the riving knife didn't foul the slot at full height. This one is about 2 years old now, I made two so I have a spare

HTH


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## Dr W (21 Dec 2020)

If you're using plastic, I'd definitely go for Polycarbonate (aka Lexan/Makralon) rather than Acrylic (Perspex). Readily available on the usual auction site for a few quid in A4 sheets, with a range of thicknesses to suit your insert slot. Polycarbonate cuts cleanly and is very strong, whereas Acrylic tends to chip and shatter. You may get a bit of melting and bubbling around the edges of the cut but that can be sliced away cleanly with a sharp knife.


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## AndrewR86 (21 Dec 2020)

DBT85 said:


> I made a template from a bit of spare 9mm MDF and then used it and a template bit in a router on some 18mm MRMDF. I then used a router to take the outer 15mm or so down to about 3mm to actually slot in correctly. I then put grub screws in the existing threaded holes in the table for leveling.
> 
> I did the first one with no router table and that alone was enough to make me want one
> 
> It's a PITA to make inserts for if I'm honest.



nice. Never thought of the grub screw idea, good thinking.
Thanks...was hoping there would be an alternative approach but looks like that’s the only option!


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