Laguna Slot Mortiser

[Rick Potter]

I have the Chinese Laguna slot mortiser, the later model, about three years old, with the reverse switch.
I have the Laguna birdmouth cutters for it. They are very good quality, but way too long for what I need, they cut about 3-4" deep, and they seem to flex and shudder. I just need 1 1/2" deep mortises max. I have tried upcut spiral router bits, but they grab way too much, and just pull themselves into the cut quickly, and are hard to control. I tried straight router bits, but they don't plunge. I have read that HSS end mills work well, but I wonder if anyone could share their experience on what bits work best??

What I want to cut 90% of the time is 1/4 or 5/16 mortises 1" or 1 1/2" deep, usually in red oak.

I also would like to know what RPM the motor (direct drive) is. I have two crappy manuals which don't say, and I called Laguna service today, and they just guessed it was about 3200, but didn't really know. Nothing on the machine or motor.

If any owner has tips on using this machine, that would be great too. I have not used it much yet because of other duties.

Thanks,
Rick Potter

[david brum]

Rick, I've had good luck with HSS two flute end mills. I bought some really inexpensive ones on ebay and they work great in my mortiser. I also tried a 1/4" birds mouth bit, with the same results as you, I can't imagine how you could get a good mortise with one.

For 1/4" end mills, it's important to get one with a larger diameter shaft, the fatter the better. I think mine have a 1/2" shaft. It makes a big difference in helping to eliminate flex. BTW, if your experience is similar to mine, expect the first 1/4" or so of the mortise to be slightly oversized. The cutter needs a little bit of mortise to stabilize itself. It runs true after that and I get a nice, clean mortise. I just cut the mortise a bit deeper.

I have a Grizzly horizontal borer/mortiser with a 3450 rpm motor.

[Jerome Stanek]

I would try a low helix up cut end mill

[Robert LaPlaca]

I have Onsrud birdsmouth cutters, have to say they cut beautiful mortises. 258211 This is a 1 1/4" L x 1 1/4 D X 3/8 W, mortise in a walnut leg


I have a Minimax/SCM mortising table for my Minimax Jointer/Planer combo machine, the bits came from SCM. The Onsrud cutters have a 1/2" shaft size, no matter the size of the cutter. Interestingly the Onsrud cutters are not long enough to cut a 3" deep mortise even in the 5/8" size, I would say that 1 1/2" is the maximum depth achievable with the Onsrud's i have.. The cutters run at what ever the RPM the jointer/planer cutter head runs at.

[Richard Coers]

I have a multirouter and use standard two flute router bits all the time. You're right, you can not plunge with them, but you can ramp into the work. I cut in a see-saw motion, working back and forth. Just takes seconds to cut the mortise. There are companies that make plunge cutting two flute bits as well. They have an additional piece of carbide added to make the center cut. Most instructions tell you to plunge a row of holes into the stock and then clean it out. I prefer not to do that as the bits I use seem to rattle more in a drilling type of cut like that.

[David Kumm]

I've used birdsmouth, Clico single flute, and others. They all beat you to death if you get aggressive. I typically bore the ends to establish the mortise and then take off no more than 1/16 to 1/8" at a pass. Hard to not get in too deep and you feel it when you do. I've also found that end grain mortises vary a little from long grain. I put a vfd on my Felder 250 to allow for drilling but less speed is not your friend when mortising. Generally about 3450 rpm is standard. Dave

[Jeff Duncan]

Are you looking for speed or cut quality? I go for speed as once my joint is together it's invisible, so I buy inexpensive mills from MSC. A 4 flute, center cutting, roughing mill gets the job done quickly and cleanly for short money. Regardless of rough or smooth cutting, or number of flutes, make sure you get the center cutting or they won't plunge.....DAMHIK! You can probably buy a handful of them for what a single Onsrud bit costs;)

As for speed I'd guess your running in the 3450 rpm range. I'm surprised your motor doesn't have a plate on it? That's pretty unusual:confused:

good luck,
JeffD

[Peter Quinn]

I use the onsrud birds mouth bits on my laguna mortiser (the first incarnation) for small slots, they work beautifully and are dirt cheap. They don't plunge, but sweaping left to right is fairly easy, very accurate IME. I also use Leitz long two flute solid carbide slot mortise bits I got from laguna, they go much deeper and work beautifully too. You can make them chatter if your too aggressive, a light tough and all goes well. I've found the relationship between user input and cut quality to be very connected on these machines, technique is as important as tooling.

I make slots on a Bridgeport at work, we use two or four flute spiral roughing end mills, I think the geometry for milling aluminum is also prefered for wood, though it frankly not critical IME. Those should work on your machine too. The roughing mills leave a fine enough surface for mortise faces and don't heat up quickly because of the stagger tooth design. Keep in mind chip clearance is also important, you need to evacuate as you go with compressed air or vacuum so you don't keep grinding up the same chips over and over, that will lead to chatter and excessive heat that reduces bit life which leads to chatter......viscous circle.

[Frank Drew]

Keep in mind chip clearance is also important, you need to evacuate as you go with compressed air or vacuum so you don't keep grinding up the same chips over and over... Excelllent advice; I hung the air hose from a hook in the ceiling, keeping the blower right at the level of my work so that it was easy to switch one hand for cleanout every few cuts or so. Slight increase in overall time taken to cut a mortise, but as Peter notes you get increased efficiency and cleaner cuts.

I had good results with HSS two flute spiral upcut end mills, mostly from Eskstrom Carlson. And as Peter and other mention, deep cuts with whatever tooling you're using require a light hand to avoid chattering.

[Rick Potter]

Great information guys,

My birdsmouth bits were bought as a set from Laguna when I got the machine. The shortest is the 1/4", which cuts 2 3/4 deep, graduating up to the 3/4" that cuts 4 1/2 deep. They are made by Klein, in Italy. When I got them I asked the salesman if they didn't have shorter ones, since I will never use that depth, but he said that was all they carry. They cost me over $250 for a set of 5. All have a 1/2" shaft.

David and Jerome. I think the low helix is a great idea, not familiar with end mills, and would have never guessed they have a different helix than router bits.

Peter....I will check back with Laguna on those bits, maybe they have changed since I got mine. Controlling the cut is a BIG problem on my machine. I see no way to dampen the travel, and if ( make that when) a bit bites in it tries to yank the work around, causing much of the problem. You can move my table with one finger. Is there something I am missing? Wouldn't be the first time. It literally tries to grab the control arm out of my hand. I cannot controll it from doing this. I wish it had some stops on it that would allow me to take off a quarter inch at a time, without resetting the depth (yes it's that bad).

About that motor speed, there is an info plate on the side of the machine that says nothing, and I took off the motor cover to look, nothing there either, manual has nothing, called Laguna and they said they were just guessing.

OK, now I have some homework to do.....Onsrud birdsmouth cutter in short lengths, center cutting end mills from MSC, low helix end mills, e-bay, route air hose.

Thank you,
Rick Potter

[David Kumm]

I don't know if the motor or the table moves on that model but keep the ways tight enough that it takes a little effort to move them. There is a lot of stress on the machine and any slop will make your life difficult. Dave

[Jeff Duncan]

I think if the table is being "pulled" it's the type of bit your using. My slot mortiser is an older Bini and all cast iron, and movement is not quite as sensitive as the newer machines. I still try to take shallow passes as with smaller diameter bits like the 3/8" I primarily use, it's pretty easy to introduce flexing by being over aggressive.

As for mills designed for aluminum I have tried one particular 3 flute bit for aluminum and it did not work well at all! All bits are not created equal, but when I finally tried the mills I'm using now....I gave up the hunt;)

good luck,
JeffD

[Robert LaPlaca]

Rick,

Doesn't your mortiser have stops that control the X, Y and Z axis? Even though the Onsrud birdsmouth 3/8" bit could cut up to a 1 1/2" deep mortise, I can set a Z axis stop that limits the depth travel to any depth up to 1 1/2".

Not to be a kill joy, but I believe that Onsrud has discontinued production of the HSS birdmouth bits, the only other source I know of is Morris Wood Tool. I haven't attempted to try end mills in my machine.

[Peter Quinn]

I don't know if the motor or the table moves on that model but keep the ways tight enough that it takes a little effort to move them. There is a lot of stress on the machine and any slop will make your life difficult. Dave

Ditto on tight ways. Not sure if your allows you to snug up the fit at all, mine does, I keep it on the snug side on the y axis (in and out) so it won't over feed as I sweep. These cheap laguna's are pretty light machines. Ricks is pretty much a Hammer clone for reference. I'll look up the onsrud numbers for you latter, the Leitz cutters are carbide, long, very expensive and very unnecessary for shallow slots. Laguna had them on their site when I bought mine, they pulled them as they were too expensive ( I was told) but they were glad to get them for me last time I asked a few years back. I got one long Felder carbide tipped birds mouth, the cut was so bad I have never used it, should have sent it back or thrown it out . Those came highly recommended, opinions vary.

[Rick Potter]

Gotcha,

Putting ways tightening on list.

Robert....Yes it has stops, but my problem is that it would like to suck in the wood to full depth (the stop), and it's very difficult to take small steps, and I don't think I should have to reset the depth several times for one mortise.

Rick Potter

[Peter Quinn]

Here is a couple of links to the onsrud birds mouth cutters. They are made for these machines. Its the 24-300 series. Worth a try.

http://www.morriswoodtool.com/Tooling-Misc.htm#Oscillating%20Mortise%20Bit,%20Style%2046 HS

http://www.carbidespecialties.com/Onsrud_HSS_Specialty.htm#24-300_Four_Edge_Straight_Mortising

[Kevin Jenness]

I have used the Onsrud birdsmouth cutters in a Felder slot mortiser. It has roller bearings and one joystick.It is like yours in that there is very little resistance to the inward force of a spiral upcut bit, though it is not due to looseness in the tracking. We can use spiral bits up to 3/8" in that machine, otherwise we use the birdsmouth bits to avoid self-feeding. They are not overly expensive, and easily resharpened as opposed to end mills.

I actually prefer my Steton mortiser, similar to the Bini, as it has more friction in the y-axis and two handles.. I can use spiral end mills up to 5/8" diameter and 2 1/2" cutting length without trouble, bumping the bit in 1/16" and holding that depth as I sweep side to side. I find on deep cuts in edge grain I get better accuracy if I bore overlapping holes and then mill out the remaining waste, something I can't do with the birdsmouth bits. As a note of caution, the one time I ran a long (3 1/2" cutting length I think) 5/8" d spiral end mill in cherry it chattered enough to start working its way out of the chuck. I was able to reseat it and finish the job, but I gained some respect for the forces involved.

Short bits with large shanks, minimal play in the machine tracking and even, moderate feed rates work best for me.

[Jonathan A Smith]

I'm having the (common, come to find) issue that you can't mortise 3/4" material. I have the "newer" MMORT 3000 V-way machine with the moving motor. The cowling over the chuck keeps you from being able to get low enough without having a really long (at least 5") bit. Some have wisely suggested adding additional material to the table, which would work. But I'm wondering if anyone has just left the cowling off, exposing the chuck, allowing you to get at least a couple of inches closer to the table without hitting the V-ways. The chuck is a big hunk of angry looking metal, but a 6-inch bit is no fun either.288124

[Mike Heidrick]

I added a sub table. Took the opportunity to add Kreg track and used some pneumatic clamps and arms from a multirouter.

http://i39.photobucket.com/albums/e169/BloomingtonMike/mortisertable1.jpg

[Peter Quinn]

I have the older original recipe Laguna slot mortiser, fixed motor, moving table, it had a chuck cover that I summarily decommissioned, major pain working around it, never looked back. If you have a pony tail or like to work wood in a sarong this is probably not the way to go....but then again keeping a safe distance from a slot mortiser would be a good idea too in that case. I had no clearance to table issues but IIR the chuck was harder to tighten with cover in place and depth of plunge was limiting, lost maybe 1 1/4" critical inches to the shroud. Contacting the chuck is the least of my worries when a 5" razor sharp slot cutter is spinning at 3500Rpm in my close proximity.

[Rick Potter]

One problem I had was a real shaking vibration when cutting that disappeared when I locked the up/down mechanism on the table. Tightening the ways helped too, but I need to go tighter.

Now it cuts just fine with almost anything, including a $13 set of three mortising bits from HF.

Rick Potter