I love my mortiser except for ...

[Vince Heuring]

I just got my Delta 14-651 set up and working. I scary-sharp-polished the outsides of the chisels, and did what I could to file off and sharpen the ragged edges of the augers. The augers look like the worst of cheap, imported tools such as would be expected from HF.

I have been able to cut 1/2", through mortises in 2" red oak with no trouble - no burning, no binding, no racking. Except...

I'm having problems with the augers. No matter the size of the mortise the augers over-cut the holes, so I'm left with little half-moons cut into one or more sides, seemingly at random. Here are a couple shots that show it:

and . Am I just expecting too much of a) the cheap, import bits, or b) mortisers in general?

If not, how do I fix? Complain to Delta? Grind off some of the widest part of the auger? Buy better morising bits?

[Swingman]

That's unacceptable results for sure. The bits are encased by the chisels, so it sounds as if you may have them sticking out too far at the bottom of the chisel. Although there are explicit instructions for doing so in the manual, I generally just leave the point of the bit even with, or slightly above, the four points of the chisel, allowing the sharpened points of the chisel to make contact with the wood first..

If you indeed have the bits set the properly with the bottom of the chisels, I'd say you got a problem with the bits not being straight, or perhaps with the chuck..

While the best chisels will give you the best results over the long haul, I use the el cheap Chinese chisels and bits all the time and don't see anything like that.

[Doug Miller]

This may be caused by the bit following the grain of the wood. I've observed the same problem, and in my experience it's much more pronounced with 1/2" bits in oak (red or white) than with 3/8" bits in oak, or 1/2" bits in maple. Try honing the auger as sharp as you can make it, and feeding the bit into the wood at a slower rate.

Also try cutting a few 1/2" mortises in cherry or maple, and see what happens. If you have the same problem there, it's likely that the auger isn't straight, in which case a complaint to Delta is in order.

Check the diameter of the auger with a dial caliper or micrometer. It should be a bit under 1/2"; if it's oversize, put the auger and chisel assembly into the mortiser and hone the auger to the correct size by holding a stone against the side of the chisel, and powering the machine on. Then remove the auger, and resharpen it.

If you get no satisfaction from any of these routes, then it's time for better bits.

-- Regards, Doug Miller (alphageek-at-milmac-dot-com)

[George]

Jet says to bottom both the auger and chisel with a dime between the top of the chisel and the upper housing. Tighten the bit, remove the dime, raise and tighten the chisel. Seems to work pretty well.

[Lawrence L'Hote]

You will have this same problem even with the high-end mortisers. I get a little of this with my Multico and their auger/chisels. I have learned to live with this and usually these defects are hidden by the shoulders of the tenon. I believe if I make some adjustments I can probably fix it but will have to endure the banshee screaming more than it does now. Try to fix your problem and report back to us.

Larry

[Doug Miller]

Careful with the attributions, please. I didn't write that. I responded to it.

-- Regards, Doug Miller (alphageek-at-milmac-dot-com)

[charlie b]

snip

Couple of things

1. while scary-sharp-polishing the outside faces of the chisels you may have removed more metal than you intended - especially if you started with a medium or fine grit paper.

1. when you removed the bur from the spur on the auger you maight have thinned the tip enough that it curls outward juts a little

2. you may have the auger set too low. Try the "40 Cent Method" for setting the auger/chisel gap. The Fisch rep showed me this one and it works. Here's the url that illustrates this method

ww.wood-workers.com/users/charlieb/MChiselBitSettingTrick.html

And to minimize the annoying, irritating squeal I remove the auger and wipe the inside of the chisel with some teflon mold release on a Q-tip. It dries quickly, doesn't catch dust or chips and lubricates nicely - for a while.

Hope this helps some

charlie b

[Unisaw A100]

It could be the way your auger is seated in the chuck. Try loosening the auger and turning it an 1/8 of a revolution. Re-tighten and re-try. If the problem persists re-do the above. Keep it up until you've been all around.

If the problem goes away you're gold. If it persists then its something else (see other responses).

UA100, whose Mama always told him, "try the cheap, easy fixes first and work up from there"...

[Rumpty]

Your half moons are "normal", learn to live with it. Try slowing down your plunge a bit, i.e. let the center point grab the wood first then finish your plunge.

[John Grossbohlin]

The chisels should be sharpened on the inside and the outside deburred at the cutting edge only... taking measurable material off the outside results in undersizing the chisels in which case dressing the augers' diameter a bit with a stone may help. In regards to the now undersize mortises make sure you compensate on your set-up for the tennons so that you don't have to hammer the joint together. Also, making sure the augers do not protrude so far out of the chisels that they are unsupported may help.

John