Tuesday, November 7, 2017

Router Plane Revisited

I went back to the oak router plane I made a while ago and added some handles. It worked OK without them, but they give me a bit more control and it's easier on the hands this way. They're just a pair of tawa drawer-pulls.

Because its depth adjustment is by tap-and-hope rather than by means of a screw thread, it's a bit tricky to use with the precision of my Stanley or Record routers, but nevertheless it's pretty smooth and easy to use once you get used to its little quirks.

I'm using Veritas cutters in it, and though they're excellent cutters, they've introduced a complication.

As you can see, the back of the cutter curves forward towards the sole — I'm not sure why, but probably just as a side-effect of the tool's production when they're bent into shape. Anyway, the effect of this is that if the cutter is set to too shallow a depth, when the eye-bolt is tightened, it engages over the curved section and cants the cutter forward, and the edge of the blade is suddenly much deeper than one might have expected.

I have a couple of ideas for ameliorating this issue.

The first is to add a sleeve, anchored to the top of the router, through which the shaft of the blade runs. That should help some, and it's the most straightforward solution, but it won't entirely eliminate the problem because it will have to be fractionally loose on the shaft to allow the cutter's depth to be adjusted at all, and any slack will still allow the cutter to cant forward ever so slightly when it comes under pressure from the eye-bolt.

The second is to cut out the existing eye-bolt housing entirely, and glue in a new block in which a new housing is cut that will engage higher on the shaft of the cutter. I'd say, for safety's sake, the eye-bolt really needs to be engaging at least 10 mm higher up the shaft of the blade. That's a pretty major bit of surgery, and it would probably be quicker and easier just to make a whole new tool, taking into account what I've learned from this one.

Next Day:

I added a collar to restrain the forward movement of the cutter when the eye-bolt is tightened, and it works well. It's made out of a 100mm (4") nail.

It looks a bit unsightly, I admit, but it does the job, and as an added bonus it ensures the cutter sets square to the cut. It can't be seen from this angle, but there's a vertical groove in the body of the router that ensures that the shaft is square vertically.

As I suspected, it doesn't eliminate the issue completely, as it has to be loose enough to allow the cutter shaft to move up and down, but the unwanted movement when the cutter is set shallow is now minimal, and much easier to compensate for.

Part Two
Part One