Using a Flush Trim Router
George VondriskaDescription
Woodworking expert George Vondriska provides tips on how to use a flush trim router bit to cut a chair leg blank, including how to select the correctly sized router bit, set the height of a bit and use patterns to cut perfectly matched pieces. A WoodWorkers Guild of America (WWGOA) original videos.
Router bit provided by CMT Orange Tools. For more information, visit www.cmtutensili.com
I have made a lot of these chairs, it's a real fun project. One of the things that's key to making the chairs look good is that both legs need to be exactly identical, they have to be the same shape, the easiest way to make that happen is to use a pattern like this one. So this pattern is the exact shape of the back leg. In addition to giving the shape of the leg, it also provides all the mortise locations on the leg. So when I make the legs, what I do is start by cutting my leg blank larger than the finished size. So I took my wood, set the template on here and traced it. And then on the bandsaw, I cut about a 16th of an inch outside the line. Now what we need to do is get the material trimmed. So it's a perfect match to the template. And that's gonna call for a bit like this. This is called a flush trim router bit, the bearing and the cutter are exactly the same diameter. So whatever the bearing rides on, it's gonna make the shape below exactly the same. So we need a couple things out of this cutter flush trim bits are available in a lot of different sizes. Looking at this one, it's a big beefy bit, that's very important. Because the leg is so thick, the bit is sticking a long way up out of the router table. So if we had a small bit that couldn't take that it would chatter and that chatter would telegraph into our work, we'd have all sorts of sanding to do later. The cut quality from this bit is gonna be so nice, there'll be very little if any sanding required when we're done. What we need to do next is get our template fastened down to the blank. And I'll do that with double face tape. The double faced tape can get stuck to the pattern and to the material doesn't take a lot of it. In fact, if you use too much of it, you'll just have a hard time separating the two later. With the second paper layer taken off of the tape, now I can put my pattern on, we wanna make sure that the pattern is positioned right the first time it goes on because that tape grabs so well you can't only get one shot at this with a pattern adhered to the blank, now you can see that the leg blank itself is larger than the pattern and that's what the flush trim bit will fix for us. I've got the height of the bit set so that the bearing will ride on the pattern and the top of the cutter is just a little bit above the top of the material. At this point I can turn on the router ease into that bit, get on the ball bearing and trim away all the excess once the flush trim is done, we can take the pattern off. Remove the tape residue, and now you can see just how smooth that is. Even more importantly, every leg we make from this pattern will be perfectly identical whether you're making one leg or a 1000. This flush trim setup is a great way to make your furniture parts.
When should one use a larger diameter flush trim bit (1/2" or 3/4") ?
I tried something very similar to this yesterday using 3/4" white pine for the work piece and a piece of plywood for the template. Less than halfway through the trimming process a large chunk of the pine ripped off. I don't know if I was going too fast, or trying to take too much off with the router, but it was very frustrating.
Good video, looked complete to me.
This video seems to finish before the end. i.e. George says: "at this point I can turn on the router", and we don't get to see the routing.
You could at least finish the video.
Was there more to this video? Weird place to stop.