Tweaks for Mortising with a DP Attachment

[Tom Miller]

While being satisfied, in general, with my DP mortising attachment, I made a couple mods recently that really complete the setup.

The first is a fence-mounted adjustable hold-down. Don't mortise without one! It attaches to the DP fence, and adjusts for stock thickness between ~1/2" and ~5" (and can easily be made to go beyond).

The second mod is a longer knob for the DP handle -- careful, not too much -- just a couple-three extra inches of leverage is all it takes to really make a difference.

This photo shows both mods:




This is a close-up of the partially de-constructed hold-down:




Regards,
Tom

[bthere]

That's pretty nice looking, Tom. Do you have any problems maintaining 90 degree registration with the chisel as it goes in/comes out?

[dlminehart]

Looks really good, Tom! Wish my fence had T track on top. Guess that's an easy enough project! I like the handle extension; I have one of the HF DPs with propeller shaped handles, and wish I could swap them for the rod-and-ball type.

[LarryG]

Nice, Tom. I may adapt this to my Delta "dedicated mortiser," the factory hold-down of which is a PITA to use.

Say, what's that orange doohickey hanging off the left side of the press? Looks like some kind of bit/key holder, but what's the make and model and etc?

[Tom Miller]

That's pretty nice looking, Tom. Do you have any problems maintaining 90 degree registration with the chisel as it goes in/comes out?

Not sure which 90 degree registration you're talking about...vertical? I haven't seen any problem with that. If you're talking about registering the chisel to the fence, I clamp a straight-edge to the chisel and square it that way.

David -- I also wished my fence had t-track on top; 'til a couple weeks ago... Yes, it's an easy enough project, and well worth it. I was shortening it at the same time, too.

Larry, that "orange doohickey" is just your standard "DP tool holder" or whatever they call it. I probably got it at Rockler. It's nice to have my two drill bit sets at eye level.

Regards,

[bthere]

Not sure which 90 degree registration you're talking about...vertical? I haven't seen any problem with that. If you're talking about registering the chisel to the fence, I clamp a straight-edge to the chisel and square it that way.

Regards,

Yes, it was the vertical I was referring to. I didn't know if the fence would tend to twist any when the the chisel was going in or pulling out of the cut. I had that issue with a Delta attachment on my DP and had be extra careful or add extra clamping to keep from messing up the vertical alignment of a row of mortises.

Overall, it looks like a very worthwhile addition.

[Tom Miller]

Yes, it was the vertical I was referring to. I didn't know if the fence would tend to twist any when the the chisel was going in or pulling out of the cut.

I'm not familiar with the Delta, but with this hold-down there's no force being applied to it when the chisel is cutting into the workpiece. As the chisel is extracted, there's a tendency for it to bind in the workpiece, and lift the workpiece up. This hold-down, as with any mortising hold-down, just keeps everything on the table.

I don't know how the height is set on other mortising attachments/machines; with this one, I just let it drop onto the workpiece, then tighten it. That leaves the perfect amount of clearance for sideways movement, with very little vertical slop.

Thanks for the comments, guys!

Regards,
Tom