[DrRobert]

I'm building the Woodsmith model and getting the hardware together.

Here is a demo of the machine:

The XY tables slide on rods with bronze bushings house in wood blocks (Sorry I can't provide a pic at this time). I considered another build which uses linear bearing and mounts instead of bushings.

My question to the engineer/designer types is would linear bearings be better than bushings? My thinking is if everything is aligned properly there might not be an appreciable difference. Maybe a little bit of resistance might be a good thing?

I'm talking about these:

 

[Tree Hugger]

I think those linear bearings (which use ball bearings) would clog up quick with just a little dust.
As far as bronze bearings I would use Oillite bearings (oil impregnated).

 

[DrRobert]

I think those linear bearings (which use ball bearings) would clog up quick with just a little dust.
As far as bronze bearings I would use Oillite bearings (oil impregnated).

That's what they are calling for in the parts list.

 

[JohnGi]

I've been putting together something similar out of old odds & ends.

The sliding carriage came from a Dodds patio door router: built in 1968, ran production until 1991. I reworked in 1992 to rout doors for European mortise locks. Ran until 1999 when the machine was scrapped out. I brought this carriage home. The linear bearings are Thompson recirculating ball type. Well over 500k cycles on them, and they run like new. The seals don't look like much, but this spent a long time in a dusty production environment, and the bearings were clean inside when I started to work on it. The carriage weighs a ton and slides effortlessly.
No idea what the spindle came off of. Built like a milling spindle, but I haven't run it yet. Motor came out of the same dumpster. I needed to make the cowl for the cooling fan and the belt guard.

 

[builtinbkyn2]

Those linear bearings should be fine. There are all kinds of router sled builds and diy mortising machines on YT that use them. That mortiser looks a little "fidgety" for my liking. I think there are better builds.

 

[woodnthings]

I've been putting together something similar out of old odds & ends.

The sliding carriage came from a Dodds patio door router: built in 1968, ran production until 1991. I reworked in 1992 to rout doors for European mortise locks. Ran until 1999 when the machine was scrapped out. I brought this carriage home. The linear bearings are Thompson recirculating ball type. Well over 500k cycles on them, and they run like new. The seals don't look like much, but this spent a long time in a dusty production environment, and the bearings were clean inside when I started to work on it. The carriage weighs a ton and slides effortlessly.
No idea what the spindle came off of. Built like a milling spindle, but I haven't run it yet. Motor came out of the same dumpster. I needed to make the cowl for the cooling fan and the belt guard.

It's a different approach than most DIY'ers have used in that the spindle provides the second axis of movement rather than a sliding assembly.
I wonder if an old drill press spindle would work in spite of the concern about radial forces on the quill and bearings?
For a router bit in 3/4" diameter and not being forced to badly, it may not get overloaded to the point of failure.
I like the ease of depth adjustment using the quill assembly as you did. Good job of back yard engineering!

 

[woodnthings]

This got me to thinking after I built this radial arm router from an old radial arm saw and carriage.
Because you can tilt the carriage to any angle from 90 degrees vertical to 90 degrees horizontal and move the carriage front to back, maybe it would make a good horizontal mortiser?
I planned to use it in the vertical mode for making "T" slot and I did make a vertical mortise as a test when I first set it up.
I think I used the elevation crank for the depth of cut, but I don't recall exactly.
In the horizontal position the depth of cut would need to be in towards the fence using the sliding carriage and lock on the arm.
I would prefer it be a finite adjustable mechanism rather than a "move a bit and lock" approach.
So, maybe vertical is the best mode for mortising:

 

[DrRobert]

This got me to thinking after I built this radial arm router from an old radial arm saw and carriage.
Becasue you can tilt the carriage to any angle from 90 degrees vertical to 90 degrees horizontal and move the carriage front to back it would make a horizontal mortiser?
I planned to use it in the vertical mode for making "T" slot and I did make a vertical mortise as a test when I first set it up.
I think I used the elevation crank for the depth of cut, but I don't recall exactly.
In the horizontal position the depth of cut would need to be in towards the fence using the sliding carriage and lock on the arm.
I would prefer it be a finite adjustable mechanism rather than a "move a bit and lock" approach.
So, maybe vertical is the best mode for mortising:
View attachment 447299

Great so now I need to buy another radial arm? Why would I be surprised coming from you, WNT 😂😂. There are two ways to do it, move the wood or move the router, IOW an XY table vs. router mounted to an XY. That was the difference between the two designs I was looking at. You would have to figure a way to make stops, depth control?

I have seen then setup as a pin router. There is a guy named David Beoff who builds reproduction furniture (who also has some serious skills) and he has a set up just like yours. Can’t remember what he used it for.

Off topic, but the more I use that Rockwell radial arm, the more I like it. Gotta get a new blade. What’s your feeling about using a thin kerf blades on an RAS? I’m not intending to do off the saw final cuts. That said, I’m going to keep an eye on alignment but so far so good.

 

[woodnthings]

Off topic, but the more I use that Rockwell radial arm, the more I like it. Gotta get a new blade. What’s your feeling about using a thin kerf blades on an RAS? I’m not intending to do off the saw final cuts. That said, I’m going to keep an eye on alignment but so far so good.

On my old Craftsman 12" RAS, set up "permanently" at 90 degrees to the fence, I use a 60 tooth Diablo for most cuts. It's a positive rake blade, BUT I have an Oshlun negative rake blade "standing by" which I will try sometime soon. Amazon had one in 5/8" arbor which my saw requires. Your saw should have a 1" arbor?
The Diablo gives great cut, I just just need to let the blade cut at it's own rate, not overfeeding it. For years I used a typical 40 tooth blade, table saw type with no issues to "self feed" with a positive rake, I just used a stiff arm on the carriage. Then, thanks to You Tube and this forum I learned about tooth rake angles and what they should be used for. I'm still in the "dark ages" using a positive rake blade, mostly because they are more available, inexpensive and they work just fine.

Here is one of the most "contrary to popular opinion" radial arm saw videos I've ever seen.
This guy doesn't even hold onto the wobbly workpiece and feeds the carriage faster than I ever would. Amazing!
Now you safety police don't rag on me, I'm just the messenger, and I'm not advocating this method.
It's being posted for educational and entertainment value only. Be safe, use common sense when operating any machine.

 

[woodnthings]

Speaking of radial arm saws being modified, I've never posted these photos of my 2 axis panel saw I originally made to be used horizontally on legs so the work laid flat. Then because it takes up way too much floor space, I cut the legs down and tilted it back an a angle so the wood panels would rest on a fence across the bottom:

Shop made blade guard with dust port for a shop vac;

Then, a better shot of the Radial arm router tilted at an angle:

Finally, I had great plans of having 3 Craftsman 12" radial arms all in a row on a 10 ft long table for various operations in my long since abandoned "wood milling room"