Thread: After-market Table Saw Zero Clearance Inserts

Originally Posted by RoyG

In the past, I've tried making my own zero clearance inserts from MDF, and from HDPE, and haven't had much success. The insert MDF is a bit fragile...

The trick is to make the MDF insert from 16mm MDF and rebate the edges to the correct thickness. I made a couple for my mitre saw this way and they are rock solid.
https://www.youtube.com/watch?v=pGp7amw7LLg

I haven't made any for my TS yet because I haven't worked out a way to cut the slot to accommodate the riving knife.

start with making the blank, taking off riving knife and raising the blade up through the blank to cut slot.

Then remove blank, Put old insert back and use the table saw fence to position the new blank with the slot over the blade. Then carefully extend the slot. I use a jig to hold the blank during this process. Depends how brave you are.

Refit knife.


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Originally Posted by jack620

The trick is to make the MDF insert from 16mm MDF and rebate the edges to the correct thickness. I made a couple for my mitre saw this way and they are rock solid.
https://www.youtube.com/watch?v=pGp7amw7LLg

I haven't made any for my TS yet because I haven't worked out a way to cut the slot to accommodate the riving knife.

Thanks for that info. The video shows pretty much what I did to make my Zero Clearance Inserts. My MDF attempts were done using 10mm MDF I think, but I found that if the MDF was set flush with the table saw surface, the MDF quickly started to get cut up when sliding work pieces across the table. The MDF Inserts worked OK, provided you used the set screws to set the top surface of the Insert just a tad below the surface of the tablesaw - but doing that starts to defeat the purpose of having a zero clearance insert.

Cutting the slot for the Riving Knife was easy enough. I used a small 3mm straight plunge cut router bit in the router table. Set the fence, and a couple of stops to mark the limits of the slot, and carefully plunge the work piece down over the bit. It's only a very small router bit, so to avoid stressing it too much, I do the cut in a few passes. If you use this approach, the slot for the riving knife doesn't have to extend right through to the back end of the insert, which makes the back end of the insert much stronger.

I've decided to order a couple of the Phenolic inserts from Leecraft and see what happens. I'll also get a couple of their Phenolic Sheets while I'm at it to make future inserts.

Thanks,

RoyG

Originally Posted by jack620

I haven't made any for my TS yet because I haven't worked out a way to cut the slot to accommodate the riving knife.

This is how I have done it in the past:
Remove the riving knife and lower the blade fully below the table.
Lower the overhead guard fully onto the table - this is both for safety and to hold the insert down
Turn on saw and slowly raise the blade through the insert.
Turn off saw, lower blade fully again and flip the insert over front to back.
Turn on saw and raise blade again.

You should now have enough space for the riving knife.

Originally Posted by elanjacobs

This is how I have done it in the past:
Remove the riving knife and lower the blade fully below the table.
Lower the overhead guard fully onto the table - this is both for safety and to hold the insert down
Turn on saw and slowly raise the blade through the insert.
Turn off saw, lower blade fully again and flip the insert over front to back.
Turn on saw and raise blade again.

You should now have enough space for the riving knife.

I have tried this approach, but this approach alone does not create a slot wide enough to allow the riving knife to tilt with the blade. If the slot for the riving knife is too narrow, the narrow slot will force the riving knife out of alignment with the blade when the blade is tilted.

RoyG

Originally Posted by RoyG

I have tried this approach, but the above approach alone does not create a slot wide enough to allow the riving knife to tilt with the blade. If the slot for the riving knife is too narrow, the narrow slot will force the riving knife out of alignment with the blade when the blade is tilted.

RoyG

Yes tilting is an issue, that I haven't quite solved...maybe some magic with a big V-bit and a router...but we don't tilt the big rip saw at work so I haven't really bothered.

You just make two cuts with the blank against the rip fence. One vertical, one at 45 degrees. The poke out the remaining bit with a chisel.


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Another option from O/S is here, http://www.highlandwoodworking.com/z...roatplate.aspx, select model JT-7 & JT-8.

They are the same price $26.99 (u.s), and when going through the order process they do ship to Australia, but you have to ask for a quote manually from them.

Thanks


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Bah! HDPE chopping boards are buyable from the bigger kitchen supply companies. Chefs use them and butchers get it in massive blocks as UHMWPE.

Cheap!

If you are interested, you can make your own with milk cartons. Cartons here (the opaque ones) are HDPE. Process: Save a heap of cartons. Take off the labels and clean them. Chop them up a bit with a knife and put all the bits into your wifes best blender and chop it all into particles. Heat her wok up with oil until it's good and hot (use canola for the high flash point), dump the plastic in. It will "melt" into a blob at the bottom. Lift out the blob and put it into a cake tin. shape it flat and let it cool. Shape and cut as needed.

Bonus - your wife will be very pleased you are finally in the kitchen!

* HDPE wont melt until you get it to 500° (I think). The wok will make it goopy and workable.

Originally Posted by meherenow7

Another option from O/S is here, http://www.highlandwoodworking.com/z...roatplate.aspx, select model JT-7 & JT-8.

They are the same price $26.99 (u.s), and when going through the order process they do ship to Australia, but you have to ask for a quote manually from them.

Great minds think alike ..... I ended up ordering the inserts through Highland Woodworking last night. I gave up on Leecraft due to their you must live in the USofA mentality.

The manufacturer (Leecraft) was happy to ship to the Shipito address in the US, but they wanted a Credit Card issued by a US or Canadian Bank (kept saying that my Ausie issued Credit Card was invalid), and they also wanted a US phone number for the contact. A close examination of their trading terms & conditions says that only Credit Cards issued by US or Canadian Banks are accepted. I could have paid Leecraft via Paypal, but would still have hit their North America only brickwall with them wanting a US phone number.

So, Highland Woodworking it is. I should have them in a week or so. I'll let you know how they go.

Regards,

RoyG

I doubt that plastic milk bottles are HDPE they may be medium density PE, if they were HDPE they would be harder

Originally Posted by Evanism

HDPE wont melt until you get it to 500° (I think). The wok will make it goopy and workable.

From Wikipedia

For common commercial grades of medium- and high-density polyethylene the melting point is typically in the range 120 to 180 °C (248 to 356 °F). The melting point for average, commercial, low-density polyethylene is typically 105 to 115 °C (221 to 239 °F).

So be careful - molten plastic can cause 3rd degree burns and catch fire.

Originally Posted by Evanism

Bah! HDPE chopping boards are buyable from the bigger kitchen supply companies. Chefs use them and butchers get it in massive blocks as UHMWPE.

Cheap!

If you are interested, you can make your own with milk cartons. Cartons here (the opaque ones) are HDPE. Process: Save a heap of cartons. Take off the labels and clean them. Chop them up a bit with a knife and put all the bits into your wifes best blender and chop it all into particles. Heat her wok up with oil until it's good and hot (use canola for the high flash point), dump the plastic in. It will "melt" into a blob at the bottom. Lift out the blob and put it into a cake tin. shape it flat and let it cool. Shape and cut as needed.

Bonus - your wife will be very pleased you are finally in the kitchen!

* HDPE wont melt until you get it to 500° (I think). The wok will make it goopy and workable.

That's doing it the hard way. And around here they are HDPE (2 inside the triangle).

Here's how I do it:
I have two sheets of Aluminium, 1/4" x 12" square, and about 5lbs of lead ingots in each of four tin cans.

Set one of the Al sheets on a lower rack in the oven. Use only the flat sides of the bottles and array them on the Al, roughly 1.5 x desired thickness (to allow for gaps). Put a stack of washers or coins in each corner of the Al about 10% thicker than your target thickness (to allow for cooling shrinkage). Upon this, place the second sheet of Al, then the lead ballast in each corner. Set the oven at about 380F (190C) and cook for an hour or so. Allow to cool in the oven for a few hours.

If you're concerned about spilling over the sides, place a large sheet of Al foil under everything.

The chopping boards are simpler though.

Cheers,
Joe

Hi Roy,

Just wondering if you would be able to tell me how many inserts you ordered and how much they are charging you for Shipping to Oz?

Thanks.