Yesterday I promised DennisGrosen that I would have pictures of what I was doing, a picture book, as it were.
So this is the story of today in the shop, nothing momentous, but it was the first time I had used a plunge router. It is only a couple of weeks old, a Bosch 1617 EVSPK fixed and plunge kit. It works very well, and allows above table bit change and height adjustment, using the fixed base in the router table.
So I took the motor out of the table, and put it in the plunge base. I experimented with it, and figured out how to precisely set the depth. As I said previously, I decided I would really hem this thing in because I didn’t want it going astray on the only decent piece of plywood I had. So I made a setup using some metal guides I use for the circular saw, and some very carefully measured, cut, and marked pieces of wood, effectively a jig, to set up the position of the cut.
Here is the router set in position, hemmed in by the metal guides, and the wood blocks front and back:
I digress: This is a very large sled, because it is meant to be used for items my radial arm saw can’t handle. The RAS is so quick, accurate, and easy, there is no way for the TS to compete with it for ordinary crosscut, but the RAS has a 15” limit.
So back to the story, let me explain what I did to get to this point:
First I scribed the exact position of the T-track slots on the sled base board. Meaning, the center of the initial and end position of the router bit. I used a 3/4” straight bit, 1/4” shank, carbide teeth from a set built by Hickory I bought some time ago, months before I bought this router. They were purchased for my ancient Skil, that subsequently decided to retire on disability. I outlined the edges of the slots also, as a reality check.
I digress again: Now you oldtimers and pros are saying, ‘I would just put a couple of marks there, clamp down a straight edge, and go for it’. It is kinda like I do surgery, which is part of my day job. I don’t even bother to mark the skin, I just whip out the scalpel and I can make the exact cut I need without even thinking about it. Never crooked, never too short or too long, curved just right….............but I wouldn’t take that kinda chance with my wood!
Now I have the start and end points, here is how I made sure the router started where I wanted it to, made the perfect groove, and ended where I wanted it to…........OCD in action.
There are two items of interest in the above picture. First, the board under the clamp. It is the exact width of the router in its normal position, left to right, with the flat part in the back. This is important, because it makes the router symmetrical, left to right when held in this way. This board also has an exact center mark on the front of it, you can’t see it in the photo. I made two of these boards. So they separate the metal guides the exact width of the router. The first thing I do is set those boards on the beginning and ending center marks (the odd board with the hole in it has a mark on its side right next to one of those center marks) and then clamp the metal guides against them. Now I have a channel that will guide the router exactly in the right to left dimension.
I then made the third board, the one with a hole in it, by clamping the router to it, and plunging the bit (any bit with a known diameter will do)to make the hole. The router was clamped so that its flat back side was at the top of the board, as centered as I could make it, and then I drew a line around the rounded part of the plate in front. And then I cut the board down to that circular line. And then I bisected the hole with crosshair lines, easy to do because we know that is exactly a 3/4 inch hole. And I drew them down onto the sides of the board. So now I have a board that when the mark on its side is at the center of the beginning or ending point of the slot, determines where the router should start and stop. The top end is used for the start position of the cut, and bottom end is used for the end position. And so I moved the two exact width boards to those positions. Hard to explain, but once you have these boards, you can set the track and the beginning and end boards in a few seconds.
So here is the first slot I made, with the T-track sitting in it:
For the next slot I removed the middle clamp that held the width boards on each end. Just loosened the clamps on the metal guides, and slid the whole mess over to the next slot position and set them up in a few seconds.
Here are all the slots, with the little boards that I have carefully marked and stored with router, the heros of the story….....(-:
And here is a mockup of the sled, still missing some pieces, but coming along fine….......
........and that Dennis, is the end of the picture book, time to go to sleep…...........(-:
-- Jim, Anchorage Alaska