DP Mortising Attachments

[Tom Hintz]

I don't own one either, but I did read Tom's article and noticed the drill press he mounted it to looked pretty old, beat up, and low end. Not that the Ryobi is what would typically be considered "top shelf" but it certainly is several cuts above the benchtop Craftsman, Black & Decker, and Delta's that I've seen in a similar price range. Perhaps a good quality drill press is required to make these things work?

FYI. During that story we tried two of the DP mortising attachments on high-end drill presses made by the same manufacturers as the attachments. Still sucked, still got tossed in the woods. The owners did keep the drill presses though as they worked fine.

[smorris]

I bought the mortiser after looking at the DP attachment and conferring with LOML who pointed out the Jet mortiser wasn't that much more and it was task oriented. It's good when the wife is also an engineer.

Disclaimer: I've never used a DP attachment but I don't believe the DP was designed for the forces which could be involved, especially with larger chisels.

[BobSch]

Last time I used a DP mortiser was back in school some 40-mumble years ago and as I remember it worked, but if I was going to do any quantity of mortises, I'd be looking at a benchtop dedicated unit.

[scmhogg]

Many years ago, I bought this POS from Sears.



This set required a three step process. First drill the holes. Second remove the drill, unplug the DP, and mount the chisel in the chuck. Third, muscle the chisel into the wood around the drilled holes.

I went from that to the HF dedicated mortiser. I paid $85. $99 - 15% off coupon.

I imagine that the DP unit would require the same sharpening that the HF chisels required before the first use. I've found very few sharp tools that are good to go, right out of the box. I flatten the outsides of the chisel on glass plate and use the conical diamond tool from Rockler to complete the sharpening. It makes a BIG difference.

When you talk about force necessary, I bent the tubular handle of the HF unit on Purple Heart. I replaced the tube with two feet of steel bar stock.

Steve

[chopnhack]

I had read that the wear on your drill press was unacceptable for more than the occasional mortising. I had never looked into getting anything like that and the few mortises I have cut have been by hand or with a router.

[SARGE..g-47]

"When you talk about force necessary, I bent the tubular handle of the HF unit on Purple Heart. I replaced the tube with two feet of steel bar stock"..

Smart move, Steve. Just to add a note to those that might have a benchtop with a handle that is short as the older style Jet had. I believe they replaced it with a longer handle as on my Shopfox benchtop before I got a floor model. The short handles just don't deliver enough leverage as in the purpleheart Steve mentioned which I worked with yesterday on a small box.

Simply the short handle fix.... slide a longer iron pipe over the existing handle. Not pretty but pretty is not required to complete a task with the maximum efficiency you can squeeze out of a tool.

[cork58]

I own one and use it once in awhile. I made my own jig for hold down though. It is also used on a floor model drill press.

[Black wallnut]

A few tips I have since using mine a bit, and keep in mind I've only really used it for soft woods are as follows.

1. Make sure the bit is sharp and set right.
2. Slow down the DP speed, i.e. for 3/8" I've been running 740 rpm.
3. Go slow, light even pressure.
4. Watch your shavings, if they are large and chunky use less pressure.
5. Before each plunge make sure the chips have cleared the bit and chisel.

I even tried spraying a dry film lube on the bit to help clear chips. This worked for about 10 mortises.

I have found that with things set right it really did not take much pressure to make each mortise. It was however a very slow process. I'm sure a dedicated mortiser is much faster as is a plunge router. Depending on ones abilities with a chisel using a just a DP and cleaning up the waste with a chisel may be just as fast. My hands just are not that steady and I do not have a broad range of good useful chisels to do it by hand.

[John Hunter]

I have one and use it. The first thing I did was to replace the hold down with an XY Vice.

Here is a project that is filled with 42 mortise cuts. I had no problem at all and the accuracy was great.



Larger mortise & tenons I haven't tried yet with it. For me it is also a matter of space, I just am running out of room for a dedicated piece of equipment that I use seldom.

[pizzarco]

drill press mortisers...

Yeah the one above is the ticket. Jealousy insues. That said, I've got the delta attachment I think. It works. Sometimes. Mostly. It's fine if you're careful. You can get good results, but it's much slower and laborious than the real deal. If you rigged up a good hold down it would speed things up - foot lever? If you have only a select few joints the fostner and chisel work faster than setting up the attachment. Designated mortisers work better. Go figure.

mg

[leehljp]

As a kid and teenager in the late 50's and early 60's I helped my dad use a Delta? type of DP mortiser. From what I remember, it worked OK. That said, my first saw that I owned personally was a radial arm and I made lots of things with it. After I got my TS, I wondered how I ever made as much as I did on the RAS.

The point is, if you don't have a dedicated mortiser, AND if you are a good experienced woodworker with patience and skill, those two can overcome the weakness of an inadequate machine. In this case, the mind is well aware of the machine's weakness and strengths and is constantly preparing work-arounds for the weakness.

On occasion, I see extraordinary work done with what I would consider totally inadequate tools. ON THE OTHER HAND, a tool that breaks, bends or doesn't hold within specific tolerances isn't worth the effort to use.

[catta12]

DPMs

I have the Delta setup (DP and mortiser) and they are sufficient at making square holes. I think it goes without saying that a dedicated machine is better, but a DP attachment is kinder to me on $$$ and space for now.

[Tom Miller]

When I bought my Jet DP, it came with a mortising attachment. I've made a fair number of mortises with it, and haven't been frustrated by it. But, it's a bit fiddly, and if you don't understand how to do the fiddling, it could be very frustrating.

So, I'd probably advise against spending the money on an attachment, because there's at least a 50-50 chance it won't be a satisfying solution. Better to put that money towards a dedicated mortiser, if you have the room (which I don't).

Otherwise, don't try an attachment on anything but a beefy floor standing DP. Also, a slight handle extension is good for leverage, but don't overdo it lest you find the weak point in your DP.

That's why I voted "it works, but...."

Regards,
Tom

[MikeMcCoy]

I tried a drill press attachment years ago but my drill press at the time didn't have enough back bone so I switched to the Delta mortiser. I treated myself to a Domino last month but haven't been home enough to figure out how to use it yet.