DP Mortising Attachments

[Black wallnut]

Okay folks I think this would be a great time to revisit this issue. There seems to be two schools of thought on DP mortising attachments. with a very small third school in the middle. Tom Hintz leaves no doubt in his opinion of them in such a way as I had to chuckle. See this. If you do a search of this site with search terms of "Delta Mortising Attachment" you will read where many of our members have had positive experiences with them in the past.

What brings this to my attention is that I just purchased both a Ryobi DP121L and the Delta mortising attachment. I'm in the late stages of building a toddler bed out of pine (Idaho white, very soft) and have been pleased so far with this combination. Many of you will recall the many and various projects I've posted over the years. I have been quite content with my BT3K when many others have traded up. A look in my shop shows an almost brand loyality to Blue. Yet I am able to produce beautiful projects with a rather low investment in tooling.

I would like to have a dedicated mortiser but at this point I needed a drill press more than a mortiser and since I was chopping the mortises with the aid of a DP and Robert Sorby Registered chisel (see I do actually own some really top shelf stuff!) I figured a mortising attachment might just work for me. In use, so far I've found Tom's opinions unfounded. Set-up was a breeze. My mortises were just as good on the surface as those I had already done with the dp and hand chisel; better in fact because of the old DP had excessive runout of the quill. I'm not saying that I could not have done as good with just the new DP and a chisel but it would have increased the amount of time needed about 10 fold.

So time for a poll on this. Please just pick one.

[Uncle Cracker]

I'm in the fourth school... I did my mortises with drill and chisel (when I couldn't avoid it) until I got a dedicated mortiser. Never had a DP fixture. I didn't see a place for that in the poll, so I didn't vote.

[dbhost]

I've never owned one, but I understand the principle just fine, and have seen them in use, specifically the Grizzly mortising attachment. It woks fine. I am simply drilling it out and cleaning up with a chisel, that seems to work for me and my wallet for now.

[docrowan]

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?

[BadeMillsap]

Well I didn't vote because ...

I've never owned a DP mortise attachment ... I am however; smack in the middle of a project that requires over 80 mortises before all is said and done and I wouldn't have tackled it the old fashioned way (chisel and mallet) ... I am using a dedicated Delta mortise machine and even with that it's a tough row to hoe (at least for me as this is my first experience with this type of joinery) ... so I would have to say that ANY machine assist would in my mind be an improvement over the "hand tools only" way ... but I am not a purest as are many fine craftsmen ... I just don't have the patience.

I'm working with rift sawn white oak which is a bit harder than the pine you mention but would still opt for a machine assist of some type ... I say if it's working for you then ... "power to you"!

[cgallery]

I own one, but have never used it. When I purchased my Ryobi "wood drilling system" press (maybe almost ten years ago), I went for the mortising kit and chisels.

Once of these days I'm going to give it a shot.

[SARGE..g-47]

I didn't vote simply as I have no intention of getting into a "phishing" contest as the question has potential to lead to chosing sides and possible hard feeling which I feel is not necessary. Just my opionion of course..

I don't have a DP drill press attachment but have used several. I did have a bench-top for several years and now have a 650 lb. industrial floor mortiser with a stroke of luck. I also hand cut mortises for years before the bench-top as I use M & T's weekly and it is probably my most used joint. I even do face frames with them.

But.. even though I didn't vote.... I will state why I would not purchase one personally based on the one's I have used:

1... Mortising soft-wood and hard-wood are like comparing a domestic tiger to one in the wild. More force is required to plunge the chisel in hardwood and that's a fact even though the chisel should be removing the main waste before the chisel takes the sides.

2... More pressure requires better leverage. Compare a mortise machine column and gears to a DP. Again... apples and oranges. The MM has a very sturdy column... strong gears that are made to take pressure and a long handle to increase leverage.

A DP is a "finesse" machine which is engineered to deliver a small drill bit tip to start a hole and then an engineered twist to complete the task. Very little pressure is required really.

3... When you take # 2 into account... forcing a chisel 1/2"-3" deep into hard maple.. oak.. etc.. etc.. is putting a strain on the light gears on a DP as it was engineered to do a rather light task and that is drilling holes. Bad medicine for the DP gears that will lead to wear and excessive run-out IMO.

4... Hold-downs are critical in hard-wood. If you have ever got a chisel stuck in hard-wood or any wood it is a PITA. Even bench-tops come up short here as most have an over-head clamp that allows you to with-draw (which a DP doesn't) but they have no means of exerting any real pressure to keep the stock from creeping on the fence. You generally have to modify and come up with something on a bench-top... I suppose you could on a DP also?

5... I do mortises often.. I use the DP often especially with forstner bits. I don't have the time to switch as often as I use both from a time or PITA stand-point.

So... those are the reasons I wouldn't purchase one. If you mainly use soft-wood and don't do many MT's it would be worth consideration. But... I feel the fact that a DP is a "finesse" machine is enough reason I won't subject my DP to do task it really wasn't designed to do.

With that said... I have a friend named Ray Pine who is a professional restorer and furniture builder ( a poster boy for FWW mag in the early days) up in Virginia who has one and has had for years. He swears by his even though he does admit to using very light plunge-withdraw-plunge-withdraw method as he is aware of what over exerting on DP gears can do.

Go figure...

[Black wallnut]

Thanks for the input Sarge! Not to start a different debate but have you ever compared a 3/8" hand held corded drill and a 3/8" <1/3 hp DP while using a 7/8" forstner bit in white oak? Another apples and oranges type deal. Drilling with just large diameter forstner bits also requires plenty of down force to cut with a marginally sharp bit. The mechanical advantage of a drill press makes all the difference. I've not seen anyone lately with a spec chart of what drill press capacities are for drilling in mild steel but I suspect that drilling holes in 1/2" steel with a 1/2" bit takes a bunch of force. Check that I know it takes a bunch of force as I've done it, several times. I for one am confident that a DP can handle the task without undue wear. With the added leverage of a bench top mortiser I think I'd bolt it down if I had one. The smaller leverage a DP provides might be a mixed blessing. That said you make some really great points that prospective buyers should think about. For lots of folks a dedicated mortiser makes more sense. In the long run I'm also in this group but when the dollar meets the cash drawer it just is not in the cards right now.

[LCHIEN]

I agree with Sarge's evaluation. A DP mortiser attacment will work OK in soft wood, but the main work of a mortiser is still pushing the chisel into the wood - brute force done manually through the handle (with the center removed by the auger bit).
The throw and the leverage of a good mortiser exceeds that of a DP. On my old delta DP I could feel the arms beginning to give when I was pushing a mortise into hard wood.

I think one problem with your survey is that not very many people have used both, to compare. I have had a Delta mortiser attachment for DPs and used it on a 12" delta benchtop, sold it, and currently use a Jet JBM-5.

[SARGE..g-47]

Actually Mark.. I slow the DP down to around 250 rpm on forsteners over 3/4" and take small.. crisp plunge and releases or the cutter will catch and either stall the DP or twist the forstner in the chuck which is a no-no as it cause a burr on the insertion shaft and must be filed off before re-using.

So.. will agree to dis-agree on that as it's simply my opinion that little force is required to drill large holes.. just slow speed and patience to plunge and release to avoid grab and keep the forstner cool. If it over-heats if dis-tempers and loses the sharp edge. And once it over-heats not only does it lose sharp but... difficult to re-gain it for any period afterward.

And will also dis-agree on using a 1/2' dirll bit in steel.. even though constant pressure is required I don't find it anywhere in the range I use in hardwood with a mortise machine. And trust me.. my mortise machine can exert some down-ward pressure.

BTW... I recently swithced to DW pilot point bits for metal as I do quite a bit of machine modifications. The pilot point is very agreesive and not a good choice for wook IMO.. as it is too aggressive and will splinter if not cautious. But in metal where I used to struggle with Snap On bits.. it has some gitty up and go. I got them a HD in a set and they are actually cheap though again not the best choice for wood.

But.. for what you are doing the attachement should be fine especially if you don't do a lot of M&T's. I think the key is how Ray Pine does and what I adapted to Forstner bits.. plunge and withdraw which exerts less force and allows the bit to catch a breath of fresh air as in "air cool" on the fly.

I really don't think an attachment should be condemned and pushed aside nor do I think it should be adapted and thrown in the arena with no thought as to what has to face once there. A light-weigh has no busines in the ring with a heavy-weigh. As long as you understand the limitations and match them with your species.. depth required.. how often you can make up your mind if you want one or would be better served elsewhere.

I know in my case but.. my case see frequent use and the rare use of soft-wood anymore so it's a cut and dry for me. And.. at this point I think I have every bit of machine I need for now and the future. But... that only covers my shop and doesn't necessarily apply to my neighbor.

Regards...

[Black wallnut]

Sarge we mostly agree with the important part, at least I think we do. It's workable but far from ideal. Feel free to move into my neighborhood so that I can come and visit whenever I have mortises to chop! That looks to be one fine piece of machinery!

[SARGE..g-47]

"It's workable but far from ideal" ... Mark

That sums it up about as well as it can be summed up, Mark. I know I am right from an engineering stand-point but... that dad-gummed Ray Pine has put a "loop-hole" in my theory he stands by his attachment as all he needs.

He is one of the finest period furniture restorers in the country and a respected period reproduction builder on top of that. So... his does not sit idle. One of those 6 of this.. half dozen of the other situations or what NASCAR would call... "one of dem racin' deals" which is just the way the cookie crumbles sometimes.

Again.. I don't think the attachment can be fully condoned or condemned. The answer lies somewhere in the middle IMO. I can't move I'm afraid.. The reasons are:

1... Fault lines scare me and not much scares me...

2... The house is paid for and I am what one might call retired as nobody is going to hire a 61 year old after I was laid off a year ago. So... with that said I can't afford to go much farther than the top of the drive-way.

3... Almost all my wife's family trickled down from Pennsylvania and she won't allow me to venture farther than the local hardwood store as she is aware the Border Patrol and Merchant Marines are hiring.

4... See reason #3 as she said... No.. you're under house arrest and you will use all those tools down in the shop to fill our home and my families home or else.

What can I say... she said No... ha.. ha... ha..ha..ha..

But drop by any time.. the welcome mat is always out 24/7....

Regards...

[Russianwolf]

I have a Ryobi DP and the Mortise attachment and have actually used it in Maple. The only problem I had was in extracting the chisel once the cutting was done. I was cutting mortises that were the exact size of the chisel so all four sizes were causing friction. Later, I had a project and was cutting with only the first cut having full friction, the process was much easier for me.

Is the attachment on a DP ideal? Is sanding a surface flat with a belt sander ideal? of course not. There are specialty tools out there that will do a job better and faster than any attachment on some other tool. Same for jigs on tablesaws. They aren't ideal, they are compromises.

All that being said. If you already have a DP and only occasionally need to do mortises, the attachment works and will save you some time. If you have the finances or have projects that can make it pay for itself in time, then buy the dedicated mortiser.

[Uncle Cracker]

If you look at the HF mortiser, you might be able to have the best of both worlds. Mine works fine (although you will want to fab something to replace the cheesy hold-down clamp) and I only paid like $60 for it, because it was on sale and I also had a coupon. I don't recommend HF motorized tools very often, but this has been a pleasant surprise.

[drumpriest]

I have never owned one, I briefly considered it, but a friend gave me a review much in agreement with Tom's. For years I cut my mortises with a router, as I'm sure you've all seen here...

http://www.bt3central.com/showthread.php?t=27419

Then I was lucky enough to score a Domino. Mostly I now just use it, unless the dimensions of the mortise are such that the Domino is insufficient. (large mortises for entry doors, as an example, as the Domino maxes out around a 1 1/4" wide mortise)

I have cut mortises with the drill and chisel approach, and can't believe that people do that with any regularity if they have a plunge router. It was a painful experience. I also tried out the beadlock stuff, and found it lacking.

If I had room for a dedicated mortiser, I'd probably go with a nice bench model, a grizz or jet or something. They look handy, especially for things like arts and crafts stuff, where you really often want a small square mortise. Alas there is hardly room in my shop to walk around, so it's a tool that will wait until the next shop.