I’ve finally gotten to set up my tondo making jig in my new woodshop. Here’s a run down of how it looks and an example of what it can do.
Here you can see the basic layout. I’ve created the body of the jig on a nice piece of half inch by 6 inch by 3 foot oak. Being a hard, strong wood, the oak will hold the mounted router well. The router itself (a nice mid-range Porter Cable model) is attached by removing its base plate and mounting it to the oak board as shown. The screws are recessed to assure good connection to the router.
Then I mounted a small “lazy susan” type ball bearing swivel deck to the other end of the board. I’ve measured and pre-drilled stations for the swivel deck in my standard tondo sizes – 12 inches (to give me a 24 inch tondo), 20 inches (40 inch tondo) and 24 inchs (48 inch tondo). I set it up to move the swivel deck to reduce wear and tear on the router mount area. I don’t want to take the router off at all. You can see how I’ve put some base plates along each edge of the board on the router end so the swivel deck and router approach are level when placed on the board to be cut.
To cut a tondo, I select my size (in this case, I want a 24 inch tondo) and put the swivel deck there (above). Then I screw down the other side of the swivel deck to the board to be cut so things are nice and secure (below).
Then – with the bit still recessed up into the body – I will start the router and slowly plunge the bit about halfway into my wood. I learned in my previous experience with cutting tondos to take it slow and cut in a few passes to ensure a good, smooth cut but also to protect the router. The harder the wood, the more wear on the router – obviously with this piece of MDF the router could have done the entire cut in one pass, but I feel more comfortable taking a few extra minutes to keep the tool nice.
After the first pass – and each subsequent one – I use my compressor to blow out the dust. This increases the ease of the next pass and keeps the risk of charring or actual combustion down. I also make sure to blow out the vents of the router since the sparking within the motor can ignite dust that collects there.
In the above picture you can see the bit being adjusted down for the final pass.
After the final cut I remove the excess wood and blow off the dust (above), then remove the swivel deck and start to sand any burrs (below)
Here’s a look at the edge of the tondo – pretty smooth cut!
And the final products!