Delta mortising attachment

[Gregory King]

Well, this past week-end I had my first chance to mount the Delta mortising attachment 17-924 to drill press 18-900L. After cleaning up the oil coating that was shipped, I also had to lightly sand the paint on the inside of the chisel holder in order to fit over the ring on the drill press. It fits nice and snug. As I attempted to secure the steel fence with the bolts supplied, it became obvious that this was not going to work on this model. The square nuts supplied have a double shoulder that is too large to fit the table slot. As well the two bolts are approx. a quarter inch too long. In order to finish my project, I used 2 x 5/16" hex- head bolts. Bear in mind that this is a universal mortiser to fit most of Delta's drill presses so this is a small over sight. The only other point of note is that the chisels out of the box are dull. Really dull. To nobody's surprise. Anyway, a machinist at work can quickly modify the two nuts for me, I'm sure.

[Matt Day]

I think the general concensus on these motising attachments is they do a poor job at best - poor results and bad for your DP. If you have just a few to do, I'd recommend using a hand chisel or if you have a lot to do, I'd recommend a dedicated mortiser.

[Bill White]

Yep. They are not the best option. Wanna buy mine?
Bill

[Ole Anderson]

I have one mounted on my Craftsman DP, took a lot of mods to make it fit including hogging out one of the bushings to fit my quill. To complicate matters, I had 58 fairly large 5/8" square mortises to drill, in QSWO for a mission style head/foot board. It was a tough go, but it worked. Also used it recently with the 5/8" bit to cut sixteen 3/4" x 2-1/4" hickory and soft maple mortices. Would I rather have a dedicated mortiser, sure, but what I had worked. And my DP (or my wallet) is none the worse for it. And if you really want to do it right, get the Multi-Router like David Marks uses, those can really cut some clean motises. Lots of ways to cut mortises, at lots of different price points.

[Gregory King]

Tend to agree with you Ole. Thats why I wanted this heavy drill press. I did not purchase it to strickly do mortising, but it saves on one extra item in my workshop. I think the key point is that when the bits are as sharp as they should be, then this greatly reduces the wear and tear on the quill bearings. We have a delta mortiser at work. Works great, the only disadvantage is the overall capacity. Even with its riser block, its no match for any drill press.

[keith ouellette]

I have a grizzly universal mortiser which is probably very close to the delta. I put it on a large jet drill press.

I found a decent jet bench top mortiser and never used the drill press again.

My bits and chisels were also a little on the dull side when new. The drlll press system did work though. Just not nearly as well.

[Tom Hintz]

I did a "review" of these drill press attachments because so many people were offering up the ones they had just to get them out of their shop. I tried three different brands and came away with the impression that all of them were designed by evil engineers. The original attachment that I bought has been rusting to death in the woods behind my house where I threw it. I couldn't bring myself to sell or give it to anyone. Since that review the number of people who have emailed me with identical feelings is large enough that I am thinking of getting matching jackets and giving each other nick names. I know that some people have actually used these things successfully but I think that is a bit like the guys who landed on the moon. I know it happened but nobody I know will ever do it successfully.

http://www.newwoodworker.com/reviews/dpmortattachrvu.html

[george wilson]

I have seen a LARGE,heavy duty old Delta drill press used for mortising. All of he teeth on the cast iron quill were broken off from having too much force put on them. I'm afraid to try that on a regular size drill press.

[Ole Anderson]

Tom,

You are killing me here man. I even posted the pictures. Not photoshopped like the ones from the moon landing (just kidding).

[Rod Upfold]

I used one for a couple of years before I purchased a mortise machine - it worked okay. My biggest problem was that once I got it mounted and setup - I need the drill press for some drilling. Then I would have to take it off and the down the road - more mortising to do.

[Lee Schierer]

In addition to being sharp, I found that polishing the outside surface made the square bits go in and pull out easier. I lapped mine on a sheet of 3/8" glass with various grades of fine andpaper.

[Paul Murphy]

You can add me to the list of guys who use the drill press mortising attachment. Setup is a PITA, and if I'm not careful when tightening the collar-quill bolt, the attachment will eventually slide upward from the mortising force. I had to make a wood aux-fence to enable the "universal" fence fit my DP table slots, but that was definately worth the effort. In the end analysis, if I ever make mortises on more of a "production" basis I will likely buy a dedicated mortiser.

[Ruhi Arslan]

I know it happened but nobody I know will ever do it successfully.

Nobody I know landed on Moon, therefore it didn't happen successfully.

I've got one for $10 and tried it on a HF drill press. It just happen to be the correct size so fitting was not a problem at all. I had only used chisels so it took a bit more force then I anticipated but after a careful setup, it does what any other mortiser would do; drill a guide hole ahead of a square chisel to clean up the corners to obtain a square hole. I cannot comment on whether the structure of the drill press an handle repeated use with extra vertical push. I've tried it, it worked and I determined that I am capable of making mortises so I went ahead and bought a dedicated mortiser but not because drill press did not work.

[Scott Vigder]

Well, I have met Buzz Aldrin, and if you tell him otherwise in person he will quickly set you straight. With a left hook.

I bought the Delta attachment and took it back for a full refund after several frustrating attempts. My dedicated bench-top General mortiser does a fabulous job each and every job with minimal setup time. The chisels that came with it are pretty good, too.

As Ralph Cramden would often say to Alice: To The Moon!

[Peter Quinn]

I have the delta Dp mortising attachment on an el cheepo delta floor model DP, it works fine for what I do with it. I don't usually go above 3/8" on a regular basis, I have done 1/2" mortises successfully, the chisels are not sharp out of the box, but neither were mine dead out of the box. I have never understood all the complaints, so I wonder if I got lucky? I have never been to the moon, but i have used a number of floor model mortisers, so I have a basis for comparison. I use a woodpeckers after market fence with hold downs, and have never used those steel hold downs that came with the thing. Its not a floor model, but I have a slot mortiser that does the heavy lifting, so I don't need another dedicated machine for mortising. Occasionally I do need square holes, and this does it for me. My fence is a chunk of 10/4 poplar jointed square. The bit spins just ahead of the chisel, the bit goes in, the hole comes out square. The first time I set it up was a PIA, but now it goes on and comes off in under three minutes, so its a minor annoyance. I don't like chisel mortisers as a rule, but they have their place even in my shop. So put me in the "It gets the job done adequately" category.