I do not think you will be happy with round ways. I built a large
woodturning lathe, and the bed was made from a 4"x8"x1/2" thick rectangular
tubing. To this was plug welded 19 lb/ft 6" channel iron. The bed is about
6' long. The rectangular tubing was orientated with the 8" dimension
horizontal, and the 6" channel was then welded to the 4" sides, with the top
flange about 1 1'2" above the surface of the tube. It turned out the
flanges on the channel was not square so I ended up grinding/draw filing the
flanges to get them flat/square/smooth. Took about a day to do this.

The tailstock was fabricated from 1/2" plate and a turned/machined
tailstock. It has gibs that ride against the top vertical corners of the
channel.

The lathe weighs 1500 lbs, has a 24" swing, and will mount 48" between
centers.

Also, it has a compound Reeves drive, a spindle lock, a spindle brake, a
tool drawer under the bed which pivots on the right front corner, all shop
made.

I spent approx 1500 hrs. over a 1 year period building this lathe, but have
never regretted it.

Now, having established that I know a little something about lathes
(especially wood lathes), none of the wood lathes I have ever seen that had
round ways were worth a fiddlers damn. Unless you can stiffen them up in
some manner, they will never prove satisfactory.

To see photos of the lathe, go to www.hillcountryturners.org then click on
'James R. Johnson' then click on 'Click here to see lathe'.

Regards,
J R Johnson