Advice on a small morticing project

[kwalmsley]

I've got a "small" morticing project that involves making a dozen or so 1/2" wide X 2.5" deep mortises in a 2X4. Without doing my homework I went ahead and bought the mortise attachments/bits that shopsmith sells. I have an unmodified 1950 SS (3/4HP). After reading some of the hysterical reviews I've concluded that most of the difficulties people experienced by the sharpness of the bits. But there were a couple of more, more reasoned reviews that seemed to indicate that even with the chisels sharp a 1/2" mortise is on the outside edge of the SS capability. I notice the level arms on dedicated routers is about 18" long where as the SS level arm is about 8".

Anyway, after reading all, and given I'm in no particular hurry, I'm going to give it a try. If its in the grey area where its too much stress on the SS. My plan B is to limit the number of mortise plunges I subject the SS to; Step 1; Plunge only the ends of the mortise with the SS. Step 2 turn the part over on a non SS router table and with 1/2" straight bit route between the holes. Does anyone see any problem with that plan. That limits the number of plunges (and fatigue on the SS) and I still wind up with a square hole.

Anyone see any difficulty with Plan B?. I was going to experiment with the SS attachments and bits tonight to get a feel for it.

[kwalmsley]

sorry meant dedicated morticer instead of dedicated router in the 1st paragraph

[JPG]

Do sharpen the bit and chisel.

A 2x4 can effectively back up the table. All the stress is at the center under the bit/chisel.

The SS router bit will also work for the middle cleanout.

P.S. you can edit a post after it has been posted!

[jsburger]

There should not be too much stress on the SS. The only issue is the possibility of downward table creep and that is preventable. I made two sets of shutters for a friend using both the 1/2" and 1/4" mortising chisels with no problem. The picture only shows one set. There was another set exactly the same. Also in the picture of the stiles only half of each 1/4" mortise is cut. They were made out of pine and had hundreds of mortises.

First is make sure you have sharp chisels. A lot of tools (including the SS mortising chisels) are not sharp out of the box. With a dedicated mortiser you have a beefy machine with a long handle and lots of mechanical advantage. You can brute force dull cutting tools and maybe not notice. Not so with the SS. I supported the front of the SS table with the telescoping legs and the table carriage with two pieces of aluminum angle iron set around the way tubes.

I certainly would not hesitate to use the SS for your project.

[masonsailor2]

I hate to seem old school but sometimes it is faster and simpler. Why not router out the mortises and then just square them up with a sharp chisel. Since it is Doug Fir that should go fairly quick.
Paul

[kwalmsley]

I tried it, your right the biggest problem I had was keeping the table stable. The 2X4 worked OK, but I think next time Im going to do something a bit more stable than wedging it. If I wasn't careful it would pick the whole SS up so it was difficult to keep in place.

The other thing I found was the hold down clamp for the my SS Mark V won't work on the edge of a 2X6 I wound manipulating clamps.

[charlese]

The ONLY way to cut mortises in my shop is by router. One method is to use the horizontal mode of the shopsmith. believe it or not, 750 RPM is enough to rout a slot in hardwood. Taking shallow passes.

I like to make matching double mortises and milling the tenons separately. No need to square the mortise/tenon ends. Rounded ends work perfectly well.

History: At one time, Shopsmith stopped making the mortise attachment. Their reasoning was the advent of routed mortises took over. Later (around 1995 +/-) - SS again offered the mortise attachment following popular demand.