# Make Your Own Zero Clearance Insert: DeWalt DWE7491RS Table Saw



## Tool Agnostic (Aug 13, 2017)

*MAKE YOUR OWN ZERO CLEARANCE INSERT FOR A DEWALT DWE7491RS TABLE SAW*

*Introduction:*
This procedure shows you how to make your own zero clearance inserts for a DeWalt DWE7491RS table saw. 

The design is simple: Match the basic pattern, but use a bolt to rotate a scrapwood cam in place, with another screw to lock it down. This approach lets you make as many inserts as you want, without cannibalizing parts from original DeWalt inserts. In addition, I think my solution is faster and easier than the one above, but it is quite similar.

*CAVEATS:*
* I wrote this procedure for an inexperienced woodworker. It looks much more complex than it really is, because I wanted to include every possible detail for a beginner to follow. It is designed to be relatively easy. 
* I have NOT tested this procedure. 
* I do not own a DeWalt table saw. My goal is to encourage someone to make their own inserts, rather than buying them.


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## Tool Agnostic (Aug 13, 2017)

*Parts:*
* An original DeWalt DWE7491RS table saw insert to use for a pattern.
* Board, the same thickness as the zero clearance insert above.
* Small piece of scrapwood to serve as a cam. This will be the cam that holds the plate down. The exact size doesn't matter, but maybe 3/4 x 3/4 x 4 inches long, something like that. It must be wider than the T-nut below, and also thicker than the length of the T-nut. The T-nut should not protrude from the scrapwood cam. 
* Small bolt. This will be used to rotate the cam in place.
* 1/4 #20 T-nut. Like this: https://www.rockler.com/tee-nuts-select-size
* Flat head screw, 1/4 (#20)
* Set screws. I use M6x8 set screws, but any set screws will work.

*Tools:*
* Paper
* Pencil
* Blue or masking tape
* Glue - Nearly any kind will do. Wood glue, CA (super) glue, epoxy, or even white glue. I do NOT recommend polyurethane (Gorilla) for this use.
* Sharpie marker pen
* Sharp point (nail) for marking.
* Jigsaw, bandsaw, scrollsaw, table saw or any other cutting to make the rough shape.
* Router
* Router pattern bit
* Thin double-stick tape for router pattern matching
* Small hand saw or a file or a Dremel tool or other small cutter/sander/grinder to shape tabs.
* Handheld drill or drill press.
* Socket wrench or driver, plus socket to turn bolt.
* Hammer to tap in the T-nut.
... and several drill bits, see below. Consider buying a brad point bit set or sets, metric and/or imperial. A forstener bit set is also nice to have. IMPORTANT NOTE: The drill numbers below are for identification only, not size:
* Drill 1 to match the finger hole.
* Drill 2 for the set screws. I found that a 5 mm drill bit works for M6x8 set screws. Test the drill bit on scrap to make sure that the set screws will thread snugly in the holes.
* Drill 3 large enough to leave clearance around the bolt head to turn it with fingers or a socket. A flat bit would be best, such as a forstener, brad point, or spade bit, but you can use a regular twist drill if you must.
* Drill 4 one size larger than bolt shank threads. The bolt should slip through this hole.
* Drill 5 to match bolt shank threads, so the threads engage lightly. Test the drill bit on scrap to make sure that the bolt threads easily. You will not need a "tap" for this. 
* Drill 6 for the 1/4 (#20) screw, one size larger than the screw threads, so the screw threads do not engage.
* Drill 7 for the T-nut. It could be the same as the Drill 6 above.
* Drill 8 - to use as a countersink for the 1/4 (#20) screw. Make sure it is wider than the screw head. This could be a simple twist drill bit. 

*IMPORTANT NOTES:*
* Read all instructions first, to make sure you understand what you are going to do.
* I suggested a 1/4 (#20) screw size because it is common and will work fine. Use what you want that fits.
* I suggested M6x8 set screws, but any set screws will work.

*PROCEDURE:*
0. Lower the table saw blade fully, and unplug the saw.
1. Cut the rough shape out with a jigsaw, bandsaw, or whatever. 
2. Flip the original insert over and tape it to your board. 
3. Mark the finger hole for later drilling.
4. Use the router and pattern bit to copy the shape of the original insert. Be sure to include the tabs at the end!
5. (Drill 1) Remove the original insert and drill the finger hole in your insert where you marked it.
6. Use a small handsaw, a file, a Dremel tool, a grinder, or whatever to shape the tabs for a snug fit. Keep testing the board until it is perfect. (You may have to adjust it later after you add the set screws.)
7. Tape the paper to the original insert and mark the locations of the set screws and the cam lock.
8. Move the paper to your insert. Use the nail or pencil to transfer the locations of the set screw holes and the lock cam to your insert.
9. (Drill 2) Drill the set screw holes now. You can insert the set screws if you wish, but keep them inside the insert plate. Don't let them protrude yet.
10. (Drill 3) Use the flat bottom bit to make a _stopped_ (partial) hole at the back of the cam area. The hole should be slightly deeper than the thickness of the bolt head, deep enough to clear the bolt head plus a small additional gap, approximately 1/16 inch. The remaining wood can be pretty thin. Be sure that this hole is far enough in front of the blade kerf that it will not interfere with the blade or saw mechanism, on the blade side where the back of the locking cam would normally be. Flip the bolt upside-down in the hole to test the head, ensuring that it is below the surface of the insert with extra clearance.
11. (Drill 4) Drill a hole all the way through the center of the flat hole you just made. Test the bolt to make sure it slips easily through the new hole, with the head resting on the bottom below the surface of the plate with room to spare. 
12. (Drill 5, kinda) Hold Drill 5 next to the bolt protruding from the bottom of the plate. Wrap tape around the drill bit to mark the depth to match the bolt protrusion. 
13. (Drill 5) Use the "bolt size" drill bit to drill a stopped hole near one end of the scrapwood piece. Stop at the tape.
14. Thread the bolt through the insert, and gently tighten it in the hole in the scrapwood (cam). Check the following:
15. CHECK: Verify that the bolt doesn't bottom out in the hole with the scrapwood too loose against the bottom of the insert plate. If so, (DRILL 5) drill the hole slightly deeper and check again.
16. CHECK: Verify that the scrapwood "cam" rotates easily when you turn the bolt head. If not, loosen the bolt very slightly until it does.
17. CHECK: Verify that the bolt head does not protrude above the top of the insert. If it does, go back to step 10 and drill the flat bottom hole slightly deeper (Drill 3).
18. Put a very light coat of glue down in the hole. You want to avoid "squeeze out". Thread the bolt through the insert and into the hole. Tighten the bolt in the hole. Do the following checks again:
19. CHECK: Verify that the scrapwood "cam" rotates easily. 
20. CHECK: Verify that the bolt head will never protrude above the top of the insert. (IMPORTANT: If this check fails. STOP NOW and quickly remove the bolt before the glue cures. Go back to step 10 and drill the flat bottom hole slightly deeper (Drill 3). You may need a new bolt and you may have to e-make the scrapwood cam, too.)
21. Allow time for the glue to cure. 
22. Turn the board over and rotate the cam so that it extends beyond the front of the insert. Tape the cam down to the insert so it doesn't move.
23. (Drill 7, kinda) Hold Drill 7 next to the scrapwood cam. Wrap tape around the drill bit to mark the depth to match the scrapwood cam. 
24. (Drill 7) Drill a hole through the "bottom" of the scrapwood cam for the T-nut. Stop drilling when you reach the bottom of the insert, at the tape marker. If you drill slightly into the bottom of the insert, don't worry about it. Be sure the hole goes through the scrapwood cam.
25. Swing the scrapwood cam out of the way and look for the drill hole mark on the bottom of the insert. If there is no drill hole mark (really!), make sure the scrapwood cam is pointed forward and use the hammer and nail through the hole to make the mark.
26. Use the hammer to tap the T-nut in the bottom of the scrapwood cam.
27. (Drill 6) Swing the scrapwood cam out of the way and drill a hole through the bottom of the insert for the 1/4(#20) screw.
28. (Drill 8) Gently drill a countersink in the top of the insert for the 1/4(#20) flathead screw. The head must rest below the surface, but it must also rise up high enough to pinch and remove when you unscrew it. Drill a little bit at a time and test it. Swing the scrapwood cam out of the way and poke the bottom of screw with your finger to test it.
29. Remove the 1/4(#20) screw.
30. Rotate the scrapwood cam so that it is underneath the screw hole. Insert the 1/4(#20) screw. Wiggle the scrapwood cam to line up the T-nut and tighten the screw. Perform the following checks:
31. CHECK: Verify that the screw head is below the surface of the insert.
32. CHECK: Verify that the bolt head is below the surface of the insert.
33. Use the Sharpie marker to draw an arrow on the top of the bolt, pointing to the front of the insert plate. This will help you align the cam when you can't see it.
34. Remove the 1/4(#20) screw.
35. Swing the cam out of the way and drop the insert into the saw. Adjust the set screws until the edges of the insert match the top of the table saw. 
36. Verify that the scrapwood cam will swing under the front of the table. Use your fingers or a socket to rotate the bolt until the arrow points to the front of the insert. If necessary, trim or sand the scrapwood cam to fit. 
37. Insert the 1/4(#20) screw and tighten it to lock down the table saw insert.
39. VERY IMOPORTANT CHECK: Use the finger hole to test that the insert is truly snug. It should not move at all. If it moves, don't use it; fix it until it doesn't. You may want to add a shim to the top of the scrapwood cam or check the set screws again.
38. Don proper safety gear. Make sure the blade is fully lowered. Stand off to one side and turn on the table saw. Wait for the blade to come up to full speed. Slowly and carefully raise the blade to create the zero clearance slot.


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## Tool Agnostic (Aug 13, 2017)

*INSTALLATION INSTRUCTIONS:*
0. Unplug the saw.
1. Remove the 1/4(#20) screw from the insert plate.
2. Use the bolt to rotate the cam out of the way.
3. Drop the insert plate in the table saw.
4. Check the edges and adjust the set screws if necessary.
5. Use the arrow on the bolt as a guide to align the cam.
6. insert the 1/4(#20) screw in the cam's T-nut and tighten it snug.
7. Pull on the finger hole to verify that the insert plate is locked down tight.

*REMOVAL INSTRUCTIONS:*
0. Unplug the saw.
1. Remove the 1/4(#20) screw from the insert plate.
2. Use the bolt to rotate the cam out of the way.
3. Pull on the finger hole to remove the insert.
4. Use the arrow on the bolt as a guide to align the cam.
5. insert the 1/4(#20) screw in the cam's T-nut to store it for the next time.


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## Tool Agnostic (Aug 13, 2017)

*THE CHALLENGE:*

I took the time to make this procedure for you. Your challenge is to step up and build it, then donate the $30 you would have spent to a worthy charity.

I hope that others will find this procedure from web searches. Good luck!


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## Steve Neul (Sep 2, 2011)

I think pictures would help.


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## woodnthings (Jan 24, 2009)

*A picture is worth 1000 words, a video 10^4 power*



Tool Agnostic said:


> *THE CHALLENGE:*
> 
> I took the time to make this procedure for you. Your challenge is to step up and build it, then donate the $30 you would have spent to a worthy charity.
> 
> I hope that others will find this procedure from web searches. Good luck!



That's a whole lot of effort ^.
How much is the book and when will it be out in paperback? :wink:
You really need to get a You Tube channel!


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## sanchez (Feb 18, 2010)

Way to write it up! This will definitely help somebody do it for the first time.


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## gmercer_48083 (Apr 9, 2016)

Excellent instructions. I have a Dewalt DW746 table saw, and your instructions are spot on!


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## Tool Agnostic (Aug 13, 2017)

woodnthings said:


> That's a whole lot of effort ^.
> How much is the book and when will it be out in paperback? :wink:
> You really need to get a You Tube channel!


Well, I didn't intend to write a book. I started typing, finished the rough draft, looked up and said "Oh [expletive]!!! I'm late!" So I did a quick and dirty edit and posted what I had. Frankly, it is not up to my usual standards. 

My goal was to include excruciating detail, to guide a new woodworker through the process. I felt that the checks were important. I wish I had posted a summary first, which would show how straightforward it is to make one:

* Find a board the same thickness as your insert, or plane one to match.
* Use a router to match the shape of the insert.
* Fix the tabs so that they fit.
* Drill holes and insert the set screws so you can adjust the insert.
* Instead of duplicating the complex cam, make a simple one from a small stick.
* Drill one hole so you can use a bolt to rotate the stick under the front of the table.
* Drill a second hole so you can use a screw and a T-nut to clamp the insert in place.

Easy peasy, but too late to edit the original. 

One lesson that may be missed is "economy of scale". You can make several in only a little more time than it takes one. If it were me, I would stack several boards, and re-order the procedure so that I can rout (is that a word?) and drill the through-holes on several inserts together. The tab trimming and stopped holes must be done one at a time. 

I believe that with a little practice, most people could make 9 $30 inserts in an hour or two in three batches. That's $180 an hour with no shipping delays. ... and you know that they will fit when done. 

How much time did @Show Soogie Bam spend trying to track down Leecraft, and we don't know if Show Soogie Bam got an answer? Furthermore, we don't know if the answer includes packing and return shipping, or extra work at home to modify the bad inserts. How many additional skills and added confidence would Show Soogie Bam have if he/she had made them? In my opinion should encourage Show Soogie Bam to cut bait with Leecraft and step up to the plate (pun intended). I have done my part. Now it is Show Soogie Bam's turn.

Many (most) table saw owners use multiple zero clearance inserts. Zero clearance inserts improve safety, because they support the work fully as it is being cut. 

I recommend inserts for regular and narrow kerf blades, plus more for a dado set. I have 1/4, 1/2, and 3/4 inserts for dados. I also like to keep a few ready inserts on hand, waiting for their slots to be cut.


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## Tool Agnostic (Aug 13, 2017)

Steve Neul said:


> I think pictures would help.


Agreed. Maybe someone else can post photos when they make one. Sorry I didn't have time for more, but I believe that the written text should be sufficient. Use it as a checklist during construction.

Here is the one and only diagram that I drew yesterday. I wanted to include it with the procedure, but I ran out of time.


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## Steve Neul (Sep 2, 2011)

Tool Agnostic said:


> Agreed. Maybe someone else can post photos when they make one. Sorry I didn't have time for more, but I believe that the written text should be sufficient. Use it as a checklist during construction.
> 
> Here is the one and only diagram that I drew yesterday. I wanted to include it with the procedure, but I ran out of time.


Could you post a picture of the saw without the cover plate? It's difficult to understand how the illustration fits.


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## Tool Agnostic (Aug 13, 2017)

Steve Neul said:


> Could you post a picture of the saw without the cover plate? It's difficult to understand how the illustration fits.


Sorry, but I don't own the saw. I wrote the procedure for someone else who owns one. Perhaps someone else can post the photo you want. Basically, the insert is a flat, oval-shaped piece with tabs in the back. A plastic knob rotates a small finger/tab under the front of the table saw to lock the insert down. I called it a "cam" but that may not be correct term. 

The diagram I posted shows the design detail of how my replacement cam works. Rotate it into place under the front lip of the table saw using the bolt as a knob, then cinch it tight using a separate screw into a T-nut. 

The insert is held down in the back by the two tabs. That "cam" locks down the front of the insert. My goals for that cam were:

* Simple to understand and make. No fancy curved cuts, just easy drilling.
* Doesn't require you to cannibalize an existing brand-name insert for the plastic cam. You can make as many inserts as you want.


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## Tony B (Jul 30, 2008)

*Delta Contractors Saw Inserts*

Below is a link to my PROFILE albums for the inserts for a Delta Contractors Saw. This procedure should work for many other saws and other unrelated projects.

https://www.woodworkingtalk.com/members/tony-b-5040/albums/table-saw-inserts/

OH OH!, This is a 10 year old post and somehow the photos got out of order. The good news is you can follow the steps, which are numbered


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## Steve Neul (Sep 2, 2011)

Tool Agnostic said:


> Sorry, but I don't own the saw. I wrote the procedure for someone else who owns one. Perhaps someone else can post the photo you want. Basically, the insert is a flat, oval-shaped piece with tabs in the back. A plastic knob rotates a small finger/tab under the front of the table saw to lock the insert down. I called it a "cam" but that may not be correct term.
> 
> The diagram I posted shows the design detail of how my replacement cam works. Rotate it into place under the front lip of the table saw using the bolt as a knob, then cinch it tight using a separate screw into a T-nut.
> 
> ...


The reason I was asking was to perhaps help someone that was trying to follow your instructions. I myself have never bought an insert for a saw, I've always made a homemade one. Then every different saw is made different and has it's own problems. I used to have a craftsman saw which the cover plate needed to be about 3/16" thick which made it difficult. I ended up using a piece of wood about 1/2" thick and rabbeted the edges so that part of it that sat on the ledge could be that thin without compromising the strength of the plate too much.


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## Show Soogie Bam (Jan 3, 2019)

Tool Agnostic said:


> Sorry, but I don't own the saw. I wrote the procedure for someone else who owns one. Perhaps someone else can post the photo you want.


I own this saw, let me know if there are any pics I can provide that can help anyone else looking to make an insert. I am going to be working on this today. The challenge for me will be figuring out how the insert wants to sit: where to make groves or channels and how deep they need to be. Then the challenge will be using a router for the first time to do it. The factory inserts don't help figuring out where a middle ledge needs to be cut out, just the four little edge ledges.


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## Tool Agnostic (Aug 13, 2017)

Show Soogie Bam said:


> I own this saw, let me know if there are any pics I can provide that can help anyone else looking to make an insert. I am going to be working on this today. The challenge for me will be figuring out how the insert wants to sit: where to make groves or channels and how deep they need to be. Then the challenge will be using a router for the first time to do it. The factory inserts don't help figuring out where a middle ledge needs to be cut out, just the four little edge ledges.


Yes. Please post all the photos you can. The photos will help other people who want to make their own inserts for your saw. They will find this procedure from outside web searches. The photos are something I cannot do myself.

I am troubled by your need for a ledge. Others who made inserts for your saw did not seem to need one. Maybe your purchased insert is thicker than the original, or simply too thick by accident. Does your original have a ledge?

You mentioned a "straight bit" in the other thread. There are multiple router bit types that may help you, and I would not have selected a true straight bit for cutting the ledge (rabbet) around the edge of the insert. Straight bits have no guide bearing. You can guide them with a bushing and a template. The bushing has a small round rim with a hole sized for the straight bit. It is installed in the center hole of your router base. You guide the router with the bushing rim pressed against the template. When you make the template, you must size it smaller than the actual cut, to compensate for the distance between the bushing rim and the actual cutter on the router bit. That compensation distance is called the "offset." 

But ... there is an easier way to make the rabbet around the edge:

If you just need a ledge to follow the shape of the insert, consider buying a rabetting bit for your router. The bearing follows the outline, while the spinning router bit cuts the ledge (rabbet) along the edge. It would be easier than making a template and using a guide bushing for a straight bit.

I don't understand the need for any more "grooves" (dados). You may need a dado to clear the blade before you raise it. In the video, the woodworker simply raised the blade, so I did not think it necessary for your saw. 

Hopefully your photos will help.


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## woodnthings (Jan 24, 2009)

*OK, I'm searching for images .....*

I found this, but I don't know if it's the same as for a 7491rs?
https://www.instructables.com/id/Zero-Clearance-Insert-for-DeWalt-DW745-Table-Saw/
This guy claims 1/2" plywood make a perfect flush fit. Probably explains why ther'es no height adjustment screws.

It looks like they are all the same based on this description:
https://www.amazon.com/Leecraft-Zero-Clearance-Insert-Dewalt-Colors/dp/B0794FMX21


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## Tool Agnostic (Aug 13, 2017)

woodnthings said:


> I found this, but I don't know if it's the same as for a 7491rs?
> https://www.instructables.com/id/Zero-Clearance-Insert-for-DeWalt-DW745-Table-Saw/
> This guy claims 1/2" plywood make a perfect flush fit. Probably explains why ther'es no height adjustment screws.
> [...]


That Instructables link looks very easy. No set screws. Sand to shape. No tabs, because it is held down on both sides by a bar underneath. No special parts needed from an original insert. Router needed only for the blade slot, and a dado blade set could do it on the table saw if you don't own a router.

Easy and fast. Just make sure the bar holds it down securely. Who could complain about that?

Note to those who are following my more complex procedure above: 
You may need to cut a dado (groove) under the insert to allow clearance to raise the blade. I didn't think it was necessary, but I may be incorrect. Use a dado set or a router with a straight bit to make it.


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