Mortising Machine Questions

[Joe Tylicki]

Just purchased the Powermatic 701 Benchtop Mortiser along with a Delta 1/2" Austrian made chisel/bit set. Had a few issues testing it out and I wanted to see what was normal as well as some recommendations.

1.) How much noise should you hear from the bit inside the chisel when you first power the machine up? I put in the chuck extension and I can still only grab a small portion of the drill bit with the chuck and I'm worried I might have runnout because of it, creating the noise inside the chisel. It's not a loud noise but up to the point the bit hits the wood there is a bit of screeching. When it contacts the wood that stops.

2.) How tight should the chisel fit into the bushing on the machine? I had to use a block of wood and a hammer to get it on. I'll probably need a wood dowel and a hammer to get it off.

3.) How hard can you safely bear down when drilling? To get the first hole into rock maple (my first test in cedar wasn't so bad) required quite a bit of force.

4.) How much should I try to take off with subsequent holes? Is there a rule of thumb, such as half the width of the chisel or two thirds?

5.) What are the most useful sizes of chisels? I started with the 1/2". They had a lot of 5/16" in stock and some 1/4". I realize it depends what type of woodworking you do, but I'd still like to know whats most popular.

6.) What brands of chisel/bits do you recommend? I've read the Austrian bits are worth the extra money, but maybe only if you use them a lot. Also, where do you recommend purchasing them?

TIA Joe

[Leon]

The bit tends to SQUEEEEEEEEELLLLL does it? ;~) Normal. Mine does it, a Delta and so does Norms. However if you spray a bit of TopCote or a similar dry lubricant on the spinning bit it will quiet things down for a short period.

That does not sound right. Did you loosen all the adjustment screws? Mine will push up with my finger pushing up on the pointey end.

I do not know of any chisel that does not need to be sharpened, when new, for optimum performance. LeeValley sells a sharpening cone to take any burs out of the end of the chisel and then you should polish the 4 bottom sides near the point to a mirror finish and your effory should deminish greatly.

I personally try to take as much as possible on the remaining plunges taking care to not leave any small partitions behind. Once the first one is cut the remainder tend to go easily as long as only 3 sides are cutting into the wood.

It is easy to break the 1/4" bits so I try to work with 3/8" exclusively. The smaller the bite, the less stress on you and the machine.

I am still on my original Delta set.

[Joe Tylicki]

Yeah, that's the noise. Thanks, I'll give that a shot.

Well, once the bushing is out of the machine, there are no remaining screws to loosen. I either have too narrow of a bushing or the chisel is too thick.

The Powermatic actually comes with a sharpening cone. After the first try in rock maple was defeated, I dressed it up a little on there and was able to make a hole, albeit with one hell of a lot of force. I was nervous about doing anything to the outside of the chisel lest I change the diameter. Can you tell me more about how you polish the bottom sides?

Perfect, thanks.

Funny, my F-I-L suggested 3/8", and he's never used a mortiser. I had to go for the big bad 1/2". Good thing he wasn't stocking any 3/4" or I might have gone that route.

Do you know if they are Taiwanese or Austrian. I think Delta distributes both. If they are Taiwanese and working well for you I won't bother spending the extra dough.

[charlie b]

Here's The Forty Cent Method for setting the bit to chisel distance

the sides of the chisels - makes them go in AND out a bit easier.

charlie b

[Joe Tylicki]

Another nice thing about the Powermatic is that it comes with spacers that slide in and out to be used this way. Based upon the heat generated, I don't think I'm rubbing at all at the tip, just clanking around in the column.

[charlie b]

Sounds like the bit is out too far.

Another possibility is the drill bit position in the chuck. Try turning the bit a quarter turn in the chuck and see if the clanking gets better or worse. Not all round shafts are in fact round.

charlie b

[Swingman]

That will vary for every type of wood, and often on the oopposite end of the same stock.

Again, that can depend upon the bit size and the particular stock your're mortising at the moment.

I generally start with a cut on either end of the markup, then take as big a cut as I can without leaving anything between. Smaller bits, generally more generous cuts, depending upon the stock.

*It helps, on subsequent cuts, to insure that the chip clearance slot in the chisel is pointing into a previously drilled void.

Depends ... my most used are 1/4 and 3/8's, with an occasional 1/2" ... rarely 3/4.

I have cut a _BUNCH_ of mortises with my machine and I am still using the same Chinese bits that came with it three years ago. But I do use the Lee Valley sharpening cones often.

Sharp chisels and bits, and a reasonable feed rate, are the keys to getting good results from these benchtop machines.

[Stephen M]

I have a delta and does the act same thing... It has gotten better over time, however. Or maybe I'm just going deaf.

I use vice grips. It isn'y pretty.

1/2" is huge. I would not use that size except in softwoods. I think that is at the outer limits of the machine's capability. The material removed increases exponentially. a 1/2" chisel removes 4 times the material of the 1/4"

Definitely 1/4" for stuff like cabinet doors. I like 3/8" for hardwood carcass joinery.

I go to Lee valley, though I have not yet tried their new "premium" line. Do get their sharpening cones and make sure that you lap the outsides of the chisels.

Cheers,

Steve

[robo hippy]

I have the General morticer, and it was a good move up from the Delta bench top that I had. I used the origional chisels that came with the Delta for 10 years, and they still cut fine. I probably cut 1,000 plus mortices. I use the 3/8 chisel only, and use it for m & t for my tables. For some reason, the first plunge always seems to take the most force, but the next one is a lot easier. If it is requiring a lot of force, I will stop, and move to the next cut, then back to the first cut, moving back and forth until I hit bottom. I also make one cut at each end of the mortice, and then take out the middle. I noticed that If I took out only about a 3/16 cut each time, that there was a noticable deflection in the chisel as I cut, so now, it is a full 3/8 cut each time, then backtrack 1/2 cut to remove most of that small piece that is left between the chisel corner and the bit. robo hippy

[W Canaday]

Nothin' to it, mate. Lay it out on a (flat) fine bench stone and give each face a few strokes. You aren't trying for a mirror ... just making it smoother than it was. It's unlikely you'll remove even .005" unless you make a second career out of it.

If you aren't sure if your stone is flat, rub it against another identical stone for a while. Use lubricant.

Bill

[Leon]

Well that is better than nothing but I'll call you on a mirror finish. Nothing cuts quite like a chisel with a mirror finish in addition to a sharp edge. Less friction is what you are looking for.

[Joe]

Thanks everyone for their replies. After seeing a couple people mention the Japanese Lee Valley chisels, I ordered the set of four yesterday at lunchtime (1/4, 5/16, 3/8, 1/2). I also added the package of two sharpening cones in case I find that's easier than using the one permanently attached to the machine. Once I get those I can determine whether the super tight fit was due to the original chisel or the bushing, in which case, one of them is going back to Woodcraft. I may send the original chisel back anyway as the bit was a little on the short side, even with the chuck extension installed in the mortiser. I was a little nervous running the machine with so little of the bit in the jaws.

Anyone know if I have a shot of seeing my chisels by the weekend? I haven't ordered anything from LV is several years (I think it was the plug cutters), but they still had me on file. The confirmation email I received yesterday said everything was in stock.

Thanks Joe

[Stephen M]

That all depends on where you are. They ship out of Ogdensburg, NY (due south of Ottowa just inside the US) which happens to be about 90 miles from me. The regular UPS ground gets order to me the secon business day after the order is placed very consistently. I am pretty sure that I have gotten stuff from them via FexEx Ground and UPS. I never pay for preminum shipping because I'm so close.

So, it depends on where you are. If you are in the Northeast, I would say that it's highly likely you will have your order.

Log onto their site and set up an account. You will be able to see you entire order history and get a carrier tracking number for your current orders.

Cheers,

Steve

[Joe]

Thanks Steve

I just got the shipping notice. Since its after 1:30, that means it will ship tommorow. The service is FedEx Residential (or Home Delivery), which does delivery on Saturrdays, as opposed to FedEx Ground. I'm guessing I'll have it on Saturday based on plugging in Odgensburg, NY on the FedEx site. The tracking number doesn't work yet, probably will tommorow when they arrive to pick up the package.

FWIW, I'm in Wisconsin, which geographically is sort of Northeast, we just call it the Midwest.

Joe

[Joe Tylicki]

*Follow Up*

Received my set of four Lee Valley Japanese made chisels and two sharpening cones yesterday. All problems are solved. Setup runs great. Only bug I have to work out is to tighten up the gibs a little. When the chisel hits the wood it can shift about 1/64 back towards the hole.

The Austrian made Delta chisel will be going back to Woodcraft next week.