On Tue, 28 Sep 2010 14:30:16 -0700 (PDT), GarageWoodworks
wrote:

I'm still struggling with my X,Y tables for my H-mortiser. I've tried
full extension drawer guides and they had way too much vertical
slop. I also looked at under-mount slides today at Woodcraft and
they too had too much slop.

How were they mounted? Were the X guides in the closed position when
the table was up against the Z gantry? Were the Y guides just a
couple inches open when the table was centered? Most joints won't be
but 2 inches in either direction, so you should have the ball bearing
glide stiffness working -for- you. Weight of the table and part
should keep them pretty much together, too. (Support that stray end
of a long table leg, bed sideboard, or whatever, though.)


I am thinking about using 4 steel rods (2 per axis) and using guide
bushings. Four bushings total inserted into two separate equal
lengths of wood. The wood would support the table (two per axis).
If I lube the crap out of the steel rod do you think this would work?
Hope this makes sense.

If you use old-technology, go with sintered bronze bushings and grease
or oil them, not the rods.

If you use linear motion bearings, you won't have slop and they'll
have seals around them. They're not cheap, though.

CNC routers usually use 5/8", but for the shorter tables, you could
probably get by with 7/16 or 1/2".


--
You can't wait for inspiration. You have to go after it with a club.
--Jack London