Customer Reviews

DELTA 17-924 Mortising Attachment with 1/4 Inch, 5/16 Inch, 3/8 Inch, and 1/2 Inch Chisel and Bit Sets

5 star:		(10)
4 star:		(16)
3 star:		(11)
2 star:		(4)
1 star:		(3)

 

 

As an aspiring woodworker, I found the Delta mortising tool a useful addition to my collection. Its best feature is definitely the price and the fact it utilizes your existing drill press. However it does have some limitations.

First is the depth of cut. I have a Delta 12" drill press with 2.5 inches of travel. The attachment method of the mortising tool eats up about 1.5 inches of the total travel. I was able to optimize the mounting somewhat to achieve about 1.25" of travel for the 1/2" mortise. The smaller bits are shorter, so this might further limit travel but I haven't tried them yet. If you have a press with 3-4" of travel, this probably wouldn't be an issue.

Bear in mind there are two levels of mortising bits from Delta. The set of four bits included are the cheaper ones made in Taiwain, whereas the better ones made in Austria are about $40 each. To the novice they look similar, but the experts insist you get what you pay for. Personally I opted for the 4 included Taiwanese bits and then bought a single higher quality 1/2" bit which I had an immediate use for. I figure I will use the cheap bits for now and if they break, I'll upgrade them later.

As for set up, it can be very time consuming, especially the first time. I ended up scribing perpendicular cheater lines on my drill press table and support column to assist in determining when the fence and bit were square. Because I was making deep mortises, I had to raise my table several times in order to achieve the desired depth of cut. To facilitate maintaining the proper table alignment, I used a C-clamp to lock the toothed rack in place on the support column. I also referenced the scribed lined on the column described above.

Once set up was complete, I was able to make some nice cuts in a reasonable amount of time. I feel the mortising kit is well worth the price, so long as you are aware of its limitations.

I purchased this attachment a couple months ago, and it has proven to be a real surprise. Since it is an inexpensive tool, with the more inexpensive chisels and bits included, I didn't expect it to be a precision tool, but it really does well. I have now used it to make mortises in red oak, white pine, and southern yellow pine, and am glad that I didn't spend more money than I did. The other reviewers are absolutely correct that set-up is time consuming, but for a hobbyist woodworker like me, it does the job efficiently, cheaply, and well. I would definitely purchase this item again.

I have mixed feelings about this tool. Here's my pros and cons:

Pro:
Cheap - compared to a dedicated mortiser.

Fits the drill press nicely - once it's set up, it works well

Cons:
Compared to a dedicated mortiser, this is junk. But it's also a fraction of the price. So for that reason, it's a good tool to start with

Some people complain about poor chisel quality and broken chisels. I havn't had that experience. I'm getting ready to cut a bunch of moritses in white oak though so maybe my opinion will change.

When it's set up, you can't use your drill press as a drill press. This is made worse because...

Setup is horrible. In order to cut a mortise (really a straight line of square holes) everything has to be square. This is tough because the chisel and fence need to be perpendicular and parallel. Tough because the table on the drill press moves side-to-side. Then the fence turns on the table. And the chisel rotates in the fixture. I'm planning on making a jig to help line everything up.

The bottom line is that it's good to start with. I like mine. I wish they had included a jig to help with the alignment.

I've owned Delta's mortising attachment for about a year. When I first purchased it, I really disliked it. But, over the past year, I've replaced the bits and chisals with high quality versions and have built a more appropriate work table with stops and lockdowns. Now I'd put the attachment up against all but the very best dedicated mortising machines given the amount of use it gets (1 hour per month).

With this attachment you get what you pay for. However, with the right accessories added plus a little work, you get much more.

Once it is set up, it makes great mortises with ease; once it is set up. While the setup is not difficult, it is time consuming. For me the plastic storage box is completely useless. The box is cheap and in order to be used the mortising attachment must be completely dissasembled. Also, the plastic box that came with mine seems to be made for a different version. The part number I received is 17-924 but it doesn't resemble the picture on this page and it doesn't fit the moldings in the box. It took me about 20 minutes to set up the first time and will probably take about 10 now that I've done it. Once set up it was as easy to use as any other drilling operation. To Delta's credit the manual was fairly thorough and accurate.

After reading all the previous reviews of this tool, I was a little hesitant but decided to purchase it anyway since I was not ready to buy a dedicated mortiser. I needed to make tenon and mortise joints (my first ever) in hard maple for a children's play table. As in the previous reviews, the case is clearly not meant for this tool (but I use it anyway to keep the tool "somewhere"). Set up was very easy on a Delta 11-990 drill press however with the adjustment of the table, fence, etc. I found it easiest to set up the chisel, then hold a straight edge on the tool to make the fence parallel (cutting and fine tuning the tenons later to match the mortises). The workpiece hold down worked well however the two arms to hold the workpiece to the fence would not clear the 2.25 square table legs requiring clamps (or strong fingers) to hold the piece to the fence. I've made about 150 1.25 inch deep plunges with the 1/4 inch chisel into the hard maple without any difficulty. Some tips (some of which I read elsewhere but probably have contributed to the ability to make so may cuts without a tool break): Drill speed was set slow (1100 RPM for 1/4 inch chisel); plunges were made "every other position" so the tool was always cutting 4 or 2 sides which is supposed to reduce the bending of the tool (and therefore the breaking of the tool); "pecking" was used to clear the chips (a small air nozzle would really be helpful); adjusting the hold down clamp as close to the workpiece as possible to keep from bending the tool during the retract. Based on the other reviews, I was expecting to have to purchase spare drills and the local store where I purchased the attachment carried them but 2 drills were nearly 50% the cost of the entire attachment! I didn't buy the spares and luckily, didn't need them. A great tool for the price!

I've been using this attachment for a couple of years now. I recommend it only if you cannot afford a bench top mortiser.

First, attaching the fence to my 16 1/2" Delta drill press is not easy at all. In fact, it's a real pain in the keester. You would think this would be easy because it is a Delta drill press but it isn't.

Second, the workpiece holddowns are cheap and difficult to work with. No matter what you do, the workpiece moves when you don't want it to move, or it stays put when you want it to move. It's not a good design.

Third, the chisels do not drill perfectly square holes. The auger bits are just a hair bigger than the chisels. So, you end up with a circle with square corners. This effect is more pronounced the bigger the chisel/bit.

I finally ditched the table accessories and built my own table jig (which works surprisingly well and looks cool too). This solved the first two issues. If it is really important to have perfectly square mortises, I cut them by hand. This solves the final issue. (Note: the mortises are OK for most joinery because you have a shoulder on the tenon to hide the slightly out of square mortise.)

UPDATE I was hanging out at Woodcraft last Saturday and this guy walks in...to return an auger bit. The pointy tip on the bit was not on the same axis as the drill bit. He rotated the bit and I looked at the pointy thing, and it was tracking a circle 3/32" in diameter. That explains why the drll won't drill a square hole.

This is a tool that will let you make square holes in wood better known as Mortises which are the female part of a Mortise and tenon joint. I bought this because I needed to make some for a project I am building and did not want to fork the money for a dedicated machine. As other reviewers have noted the bit set that comes with is CHEAP. However the tool itself is well made. Set up was easy. It comes with different collars for adapting to most drill presses(check to see that yours is compatible before purchase) If you have a small bench press like I do there is not a lot of room left after attaching. I had to remove the table from mine to make it work! However if you have a 13" or larger drill press there should not be a problem. If you can afford it or if you do a lot of mortises BUY A DEDICATED MACHINE. But if you only use it occasionaly than this is a good way to go. The quality is there ease of set up is good I only rate 4* because of the bit set. A better way to go might be to buy the attachment w/o the bits and then buy a good set of bits to go with it.

I haven't used this a lot, but I do have some comments. I have the Delta DP400 drill press. I bought the mortising attachment from another company not knowing it was also a Delta brand. When I got it, I read the instructions and started to install it. At first I found out that all three bushings that were supplied didn't fit. A couple of pages later I found out that for my type of Delta press, they weren't needed and it fit perfectly without needing one. The manual didn't make any mention of the DP400 model specifically.

One odd problems was that the T-nut that is used to mount the fence to the table wasn't tapped. I had to anneal it and then run a tap through it. Of course this was happening about 1am, so it wasn't like I could get to a hardware store.

One last item is about aligning the mortising chisel and fence. While I haven't made an alignment jig yet, I plan on making one by very carefully aligning the fence then making a single hole into a straight piece of wood. After that I can just plug the chisel into the hole and use the attached board to align the fence. I will go ahead and drill a hole using all four chisels.

Overall, it seems well made and fits my Delta drill press perfectly. It seems pretty stout and while the carrying case doesn't fit well, it does hold everything. You just have to disassemble almost everything first.

"For the money" is the key phrase here. Compared to buying a dedicated mortiser or doing it by hand this tool is chpear than the former and quicker than the latter. The good things are that it does work. Once you have it installed, aligned, and tweaked it seems to work fine. I use it in oak without a problem. People who are burning or breaking bits may need to adjust the position of the dril vs the position of the square chisel. Or maybe they have a defect of some sort. It seems to help if you back out often and allow the bit to clear itself of debris.

Now for the bad. The molded plastic case seems like it doesn't really fit. There are not slots for all the piece and no matter how you put the parts in it doesn't seem quite right. This seems like a pretty obvious mistake so I assume Delta is just too lazy to address this. The setup requires a bit of patience and time. If the bit is not exactly square to the fence you get some wacky looking holes. Lots of fussy screws, knobs, etc.

Overall this is better than not having a mortiser and the price is right. I would buy it again since I don't want or need to invest the money or storage space required for a dedicated mortiser.