When using a router and a circle jig what do you do when you get to the end of the cut to keep it smooth?
As the last section of wood gets cut from the circle the router can move anywhere it wants and so the last 1/8" or so of my circle usually ends up with a bit too much or too little cut.
When I have easy access to the bottom of the board and don't care about damage to that side I have screwed a piece of wood across the circle to hold it in place. But that isn't always an option.
Anyone have any tricks or is it just a steady hand?
As the last section of wood gets cut from the circle the router can move anywhere it wants and so the last 1/8" or so of my circle usually ends up with a bit too much or too little cut.
When I have easy access to the bottom of the board and don't care about damage to that side I have screwed a piece of wood across the circle to hold it in place. But that isn't always an option.
Anyone have any tricks or is it just a steady hand?
Don't cut all the way through. I leave about a paper-thin amount of wood (MDF) and cut through that with a knife afterwards. I suppose solid wood or plywood would require a thicker remaining bit.
I use double face tape and a foam board on the underside of the piece being cut. That way the center piece doesn't move. You can use wood or MDF as a substrate, too.
Works like a charm. I had to ask a friend to figure this one out, too. 🙂
Works like a charm. I had to ask a friend to figure this one out, too. 🙂
The final cut I leave 2 tabs uncut.
The tabs can be cut with chisel or jigsaw.
Remove remnants of tabs with profile cutter (straight bit with bearing).
The tabs can be cut with chisel or jigsaw.
Remove remnants of tabs with profile cutter (straight bit with bearing).
I'd adjust the bit to leave a very thin layer, then you can push your fingers through it, turn the piece over and trim from the other side with the router.
It’s easier to control, and less heat for that expensive bit if you make the cut in several passes.
Most of the time I use a pattern bit with my circle jig, with a bearing at the top. See sketch.
Make several passes, maybe 1/8" or so at a time, until you have about 1/8" left.
Adjust the depth to cut through the last 1/8" without moving the router on the pivot. (Or use a drill bit with the same diameter as the router bit to go through it)
Then adjust the depth so that the bearing rolls on the previously cut surface.
Until you get to the last inch or so, the circle jig pivot will keep the router in the path. When it breaks away, remember to keep the bearing against the wall of the cutout.
When I'm able to, I clamp the workpiece to saw horses or over the edge of a table top so that the circle cutout can just fall away.
Check to make sure that the router bit doesn't pass through and into something you don't want cut. (speaking from experience!) 😱
Make several passes, maybe 1/8" or so at a time, until you have about 1/8" left.
Adjust the depth to cut through the last 1/8" without moving the router on the pivot. (Or use a drill bit with the same diameter as the router bit to go through it)
Then adjust the depth so that the bearing rolls on the previously cut surface.
Until you get to the last inch or so, the circle jig pivot will keep the router in the path. When it breaks away, remember to keep the bearing against the wall of the cutout.
When I'm able to, I clamp the workpiece to saw horses or over the edge of a table top so that the circle cutout can just fall away.
Check to make sure that the router bit doesn't pass through and into something you don't want cut. (speaking from experience!) 😱
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I've cut hundreds with very few problems. I've used double sided carpet tape and it doesn't allow the remaining center "disc" nor surrounding rectangle to move. A bit tough to remove, but it works.
I like the double sided carpet tape too, if you really want a firm grip, can apply it with a roller to each side. It isn’t fun to remove the pieces after, but it is great for milling and some router work too.
Is what I used when I did an inlay working with 3/4” oak flooring.
Is what I used when I did an inlay working with 3/4” oak flooring.
I actually have some double sided tape that is narrower than carpet tape and possibly not as sticky. It can be an effort to remove, but not terrible. I use it on the router table too, for patterns and templates.
Never had an issue when I use a circle router guide for speaker holes. Leave the last cut about 2-3mm thickness and when coming to the end of the cut push the router towards the centre. You get left with a small bit of material that can be trimmed with a knife and sanded but usually not required as the back of the driver hole is bevelled.
The trick for me is to start the final cut in a location so the flat surface of the guide is at right angles to the side of the enclosure. That way I don't even have to look at the bit but only the guide.
The trick for me is to start the final cut in a location so the flat surface of the guide is at right angles to the side of the enclosure. That way I don't even have to look at the bit but only the guide.
I did some template routing the other day using double-sided carpet tape to hold the parts. Searching for a way to separate them, I used an autobody squeegee (the plastic, flattish, flexible tool used for Bondo) and slid it between the pieces. To my amazement, with a bit of force, it rolled the carpet tape and lifted it from one side. Pushing further to the second piece of tape gave the same type of result, by which time I could pull the pieces apart. I could have used a lever of some kind, but I didn't want to mar the wood.