Best Mortiser Bits ?

[John TenEyck]

I saw an old thread about using 4 flute end mill roughing bits in a J/P mortiser. Is that what most of you are using? If not, what are you using? Is anyone using Laguna's birds mouth bits? And whatever you use, where do you buy them? I'm mostly interested in 1/2" bits about 5" long for making mortises in the stiles/rails of interior and exterior man doors. Thanks.

John

[Joe Cowan]

I got mine from Lee Valley, along with the sharpening cones. BE SURE TO SHARPEN THE BITS PRIOR TO USING. I was shocked how difficult it was to drill before I realized these sharp bits when brand new, was not sharp enough.

[peter gagliardi]

I think you will be hard pressed to find a 1/2" bit that will go deeper than 3- 3 1/2" anywhere. If you are looking to do thru mortises, you will have to work both edges of your stock.

[Alan Lightstone]

I just got a set of the Fisch bits off Amazon, as the Lee Valley set was backordered for a month. Not sure if that's still true. Arrived in 2 days.

Should I sharpen them also before using, or do they come really sharp (sorta like what people ask when they purchase a Lee Valley or Lie-Nielsen plane)?

[Bill Adamsen]

I think John is asking about spiral end-mills (horizontal mortiser). I know nothing about them. Peter's comments are relevant to the OP's question.

To continue the off-topic ... for square, hollow-chisel mortising bits, I have found the chisels from Lee Valley are outstanding ... and work well out of the box no honing or sharpening required. They sell two flavors ... a $40/chisel and one much much less expensive. The more expensive (shown) is marked LVT Made in Japan. They cut very square holes, precise to the stated measure, cut quickly even deep, extract well, evacuate chips well, will cut most hardwoods well and last well. The one shown has just cut about 100 1-1/2" long mortises in White ash and shows no indication of wear.

[Robert Engel]

I just got a set of the Fisch bits off Amazon, as the Lee Valley set was backordered for a month. Not sure if that's still true. Arrived in 2 days.

Should I sharpen them also before using, or do they come really sharp (sorta like what people ask when they purchase a Lee Valley or Lie-Nielsen plane)?They will work, but -- Yes!
You can use a diamond cone shaped hone for the inside.
Hone the outside of the housing to a mirror polish on your regular stones.
Makes life a lot easier.

[Alan Lightstone]

Thanks for the info, and sorry for the hijack and wrong info.

[Kevin Jenness]

Best value for slot mortising is machinist's end mills from MSC, McMaster Carr, etc. I have mainly used 2 flute to good effect. The shorter they are, the less bit deflection and the more consistently sized your mortises will be. Birdsmouth bits work well and are easily resharpened, but are more costly and you can't plunge with them. I have made many doors with 2 1/2" deep mortises and inserted tenons that are holding up well.

[John TenEyck]

Yes, I was asking about slot mortising bits. I didn't realize the birdsmouth bits were not center cutting. Thanks for that info, Kevin.

John

[Warren Lake]

I guess all my slot cutters are the birdsmouth you mentioned just never heard them called that. I wouldnt say you cant plunge cause you plunge in a certain amount then go side to side. Dont see any reason to plunge deeper as you would be hogging off alot of material and more chance of deflection on small diameters. Are you saying with a metal working end mill you plunge in 1" or some amount then go side to side? Im curious how much you mean.

Ive had end mills that can cut a very long length in the past up to 3" of cutting flutes if i remember correctly but will check that. Ive also never checked the shank size of the bits for my machine so will do that Ive always had good results with the birdsmouth bits that came with the machine but agree with you they wont go that deep but I do the mortises for the most part on the mortising machine. Struggle with finding good mortise chisels for that.

[Peter Quinn]

I'm using long slot mortiser bits bye Leitz bought from laguna. They are two flute, with a tooth geometry like a roughing end mill, solid carbide, not cheap but they last a very long time. IIR they were in the $65 range for 1/2" and do reach around 5" depth of cut. Obviously you have to take care with your technique when plunging that deep. I have them in 1/2" and 5/8". They used to be on the site, last time I ordered I called and described them and they told me they were not on the site but are still available. I understand you can also get them from a Leitz dealer. For regular mortising I use HSS onsrud birds mouth cutters. I can't see why end mills wouldn't work fine but my mortiser is left twist and those are less readily available. For speed and quality I have never had a problem with the birds mouths.

http://lexicon.leitz.org/product.php?pgid=34892&itemid=14586&hasleafs=Y&chash=3cd0ed

http://www.toolsxp.com/Onsrud-Cutter-Router-Bits-24-300.asp

[mreza Salav]

Did you find a chuck for your machine (through SCM)?
Whatever bit you get don't go plunge more than a little. These are meant to cut in side-to-side action and it is very easy to break a 1/2" bit (DAMHIK).

[Warren Lake]

thanks Peter on those bits Have bought other bits from Onsrud the past one particular bit was stellar.

John OP you want to make a deep mortise in rail end grain how big and how deep? and how thick is your material? Im curious on the material dimensions and sizing of the mortise you want to make, I prefer to make tennons so dont need to do this but am curious and would think its harder to mortise end grain? There must be some safe working length on those bits as well depending on what your machine is. Would you not get some whip in very long cutters?

[John TenEyck]

Did you find a chuck for your machine (through SCM)?
Whatever bit you get don't go plunge more than a little. These are meant to cut in side-to-side action and it is very easy to break a 1/2" bit (DAMHIK).

You have a good memory Mreza. I thought I'd escape the embarrassment. It turns out that the chuck was already on the end of the shaft. I had no clue what a Wescott chuck looked like and it was completely closed when I looked at it, and the lousy owner's manual was of no help in enlightening me from my ignorance. It was only after I inspected the thing a coupld of days later that I figured out what it was and how it worked.

I built a horizontal router mortiser several years ago and will probably continue to use it for most mortising work. It's only for large, deep mortises that the Mini Max mortiser would have a clear advantage. Using the router mortiser I learned very quickly that you get the longest bit life and smoothest mortises by taking shallow bites. I use a sort of saw tooth action to route the mortise, probably no more than 1/32 to 1/16" depth change along each leg. So my question about center cutting ability was more for information than a desire to use the bits like a drill.

Fortunately, my Mini Max J/P was built back when the mortiser is installed on the back of the machine so the bit rotation is the same as a router. I chucked a 1/2" spiral upcut Onsrud bit into it and made a test cut. I have to say the router mortiser cuts more easily with the same bit, probably because it's going 20K rpm compared to only 5 or 6K in the Mini Max. And that makes me wonder how a 2 flute end mill will cut. It would seem that a 4 flute one would cut more smoothly. But the birdsmouth bits are only 2 flutes and people say they cut smoothly, so maybe there's more to it than just the number of flutes.

As I said, I likely will do most of my slot mortising work with my router mortiser. Where the Mini Max mortiser has it's greatest appeal is for cutting large, deep mortises for doors, table legs, etc. So I'm mostly interested in bits with 4 or 5 inch overall length so I can cut at least 3" deep. I found the birdsmouth bits on Laguna's website: http://www.lagunatools.com/accessories/accessories-mortiser/motiser-long12 and they are not exorbitantly priced for their size. Two flute HSS end mills are cheaper
(for example: http://www.mcmaster.com/#end-mills/=zoz2bc) but I'd rather spend more if it cuts better.

So that's the background and the comparison I'm looking for. Thanks all.

John

[John TenEyck]

thanks Peter on those bits Have bought other bits from Onsrud the past one particular bit was stellar.

John OP you want to make a deep mortise in rail end grain how big and how deep? and how thick is your material? Im curious on the material dimensions and sizing of the mortise you want to make, I prefer to make tennons so dont need to do this but am curious and would think its harder to mortise end grain? There must be some safe working length on those bits as well depending on what your machine is. Would you not get some whip in very long cutters?


My experience so far is with my horizontal router mortiser. I use Onsrud spiral upcut bits, and I've cut some 1/2" x about 2" deep mortises in the end of door rails with no problems. You only take 1/32" cuts back and forth as you go so I haven't noticed any problems with bit deflection even though the grain orientation makes it more difficult to cut. The mortises come out nice and smooth.

With the Mini Max mortiser I'm interested in primarily in 1/2" up to possibly 1" mortises for doors and table legs.

John

[John TenEyck]

Thanks very much for those links, Peter.

John

[Peter Quinn]

The onsrud bits I have are 4 fluet, the geometry is meant for slotting, my mortiser is direct drive with a wescot chuck on the end of motor shaft, so it's turning at 3500 rpm, they work great for standard depth mortises, that's my go to bit. The leitz bits are 2 flute, they also work well, feed is a bit slower. Amana makes slot mortising bits in right twist only that are very long, made for door lock box machines which are router driven, but should work on your spot mortiser too.

http://www.amanatool.com/45540-carbide-tipped-up-shear-bit-slot-mortiser-1-2-dia-x-1-inch-x-1-2-shank.html

[Peter Quinn]

As a side note, IME the slot mortiser bits don't have the up shear like router bits to push chips out of the hole, so you have to proactively clear deep mortises. I've used compressed air and vacuum with equal success. I bought a semi rigid vac line such as for a drill press to rig up, I had a yoke on a regular shop vac 1 1/4" hose that worked well. Just plan to do something about chip extraction.

[John TenEyck]

Thanks for the added info. Peter. The Amana bits look to be a great choice. The link showed they are for use only in a slot mortiser which is exactly what I need. Perhaps you were thinking of another bit when you said they were for a router driven machine. The test mortises I made convinced me that I need to add some vacuum extraction near the bit. I did the same on my router mortiser. That bit pulls the chips out OK, but it blows them all over with no vacuum. With the slot mortiser the chips don't come out as well, as you said, and they go down into the mortiser mechanism. I spent a good half hour cleaning out all the old accumulated chips and grease from the prior owner before I bolted it onto the machine. That guy liked grease. On the bright side, nothing was rusted - just coated with a thick layer of wood/grease gunk.

John

[Erik Loza]

Rangate sells birdsmouths...

http://rangate.com/products/birds-mouth-mortise-bits

Erik

[peter gagliardi]

Another thought on this, from another angle;
If you have the Domino 700, or can borrow one, it will make very quick and accurate work of this. I just finished a job with about 7 Teak exterior doors 1 3/4" thick that I through mortised the stiles with my big Domino, and tenoned on my Newman tenoner with the carbide chicklet style heads. Sized my tenons to fit the 12 mm bit. It was a little slower than my auto mortiser, but not by much. I did it because I didn't have any carbide tooling for the mortiser.
I would do it again without question.

[Peter Quinn]

Thanks for the added info. Peter. The Amana bits look to be a great choice. The link showed they are for use only in a slot mortiser which is exactly what I need. Perhaps you were thinking of another bit when you said they were for a router driven machine. The test mortises I made convinced me that I need to add some vacuum extraction near the bit. I did the same on my router mortiser. That bit pulls the chips out OK, but it blows them all over with no vacuum. With the slot mortiser the chips don't come out as well, as you said, and they go down into the mortiser mechanism. I spent a good half hour cleaning out all the old accumulated chips and grease from the prior owner before I bolted it onto the machine. That guy liked grease. On the bright side, nothing was rusted - just coated with a thick layer of wood/grease gunk.

John

Thats the bit i was thinking of, I think they can be used in a porter cable or similar lock mortiser that clamps to a door frame for mortising lock boxes. Though the description certainly sounds like its appropriate for slot mortisers. I have a couple of braised carbide tipped birds mouths from Felder, honestly not my favorite thing, the braised carbide is not nearly as sharp as either solid carbide or HSS, and you feel that in the cut. Never tried the ones from Rangate, look very similar to the ones I have.