|Project by Krisztian||posted 08-03-2008 04:17 PM||5480 views||30 times favorited||13 comments|
If you need to do precision woodworking one of the necessary tools is a zero clearance tablesaw insert. The reason these are so important is because they help prevent tear-out on the bottom of the board that’s being cut. They are simple to make and you should have one for each of you saw blades and different width dado cuts.
Here’s what you’ll need:
A piece of wood as thick as you tablesaws metal insert.
Dial or digital calipers.
6’’ Digital Caliper
Digital caliper has 50% larger display, giving you easy-to-read numbers and .0005” accuracy. Can be used for inside, outside and depth measuring. Inch or metric display can be easily converted at ..
Band saw or scroll saw
Router with a flush trim pattern bit
Pattern Flush Trim Router Bit
Double back tape
Cut a piece of wood about three inches longer than the metal insert and about 1/4” wider. The extra length will allow for any snipe you have from your planner.
Using a dial caliper measure the distance from the top of the tablesaw to the top of the pads that the insert sits on.
Measure to get the thickness for the wood insert
Plane down the piece of wood to that thickness.
Place the metal insert upside down on the wood and trace around it leaving about 1/16” to 1/8” clearance all the way around.
Trace about 1/16” to 1/8” wider than the insert
Cut out the insert staying just outside the line.
Cut close to the line but on the outside
Double back tape the metal insert to the cut out piece of wood.
Three pieces are plenty
Using a flush trim pattern bit in your router copy the metal insert to the wooden one. You can do this with either a top bearing or bottom bearing bit.
Pattern match the metal insert
Remove the metal insert and see how it fits in the tablesaw. If it’s too tight just some light sanding should make it fit.
If you find that the support tabs for the insert on the tablesaw are not even you can use countersunk screws in the bottom of the wood insert to level it.
Put the insert into the tablesaw with the blade turned all the way down. I put my fence over part of the insert to help hold it in place.
Raise the blade through the insert
Slowly raise the blade through the insert until you get to the desired height. Go a little beyond and then back it down to where you want it.
For ripping blades it’s a good idea to put a spreader into the insert. Cut a slot the width of the saw blade into the out end of the insert. Cut a piece of hardwood the thickness of this slot.
Glue in a spreader to prevernt wood buning
Radius the end that is toward the saw blade and glue it into place. This will help reduce any burning if the wood tries to close up after it’s been cut.
Make a zero clearance insert for every dado with combination you plan to use and mark each insert with the with or blade combination.
That’s about it. I hope you liked this project.
-- Krisztian VA My website: www.vacarpentry.com