Popular Woodworking 2001-08 № 123, страница 30

a new

Manual

for

Hollow chisel mortisers are decidedly fussier than their cousin, the drill press.

To properly set up one of these useful machines you need a few tricks that aren't in the manual.

Though the hollow chisel mortiser is one of the most useful joinery machines you can buy (besides a biscuit joiner), it's shocking how little information is out there on how to properly set up and use these machines.

That's too bad because a handful of simple tricks are the difference between making perfect square holes and breaking an expensive mortising chisels or scorching the wood. The tricks fall into three categories:

Setup: First you've got to fuss with the tooling, which consists of the square chisel bit and the round auger bit that spins inside it. Believe it or not, it's important to figure out which way to put the chisel bit into the mortiser. Also, to clear chips from the chisel, you've got to create the right amount of space between the end of the auger bit and the chisel. And you've got to square the chisel to the fence and table and then set the depth of your cut correctly (here's a hint: it's not the length of your tenon).

Use: Once you lay out the locations of your mortises on your wood, you've got to set your mortiser's fence correctly. Otherwise, your joints won't be

flush and you'll be sanding and planing for a long time to fix this common mistake. As you make your cuts, you've got to space them correctly or your chisel will bend or break. Also, as the auger bit and chisel heat up, they need to be lubricated.

Maintenance: Sharp auger bits and chisels will make all the difference in the world. You can buy a little $90 device to sharpen your chisel bits, but it's not necessary. You also need to occasionally deburr the shaft of the auger bit.

Set Up Your Machine

If you've ever used a hollow chisel mortiser, you've probably run into some frustrating problems. Perhaps the motor stalled in a cut, or the chips smoked or scorched. Or, assuming you managed to avoid these problems, you ended up with mortises that had to be cleaned up with a chisel, which is the thing you wanted to avoid when you bought the machine in the first place.

CheckYour Chisels: Whenever I set up a mor-tiser, I grab my dial caliper. These useful measuring tools get cheaper every year, and they will ferret out

by Christopher Schwarz

Questions or comments? You can contact Chris at 513-531-2690 ext. 407 or at ChrisS@FWPubs.com.

www.popwood.com 30