My modification is similar to that of the “Tools and Mods” webpages (
http://www.toolsandmods.com/lathe/mini-lathe-saddle) but with a few changes:
The two new gibs are made from stock ¼ x ¾ inch stock mild steel.
I drilled and tapped only two holes for the smaller grub-screws (making sure that the ends of the screws were flat). These holes are as far to the edge of the gib away from the lathe as I could make them without fear of breaking out of the side.
I didn’t use studs, I used M6x30 socket head grub screws. They are a few pence each and don’t require the faffing about with two nuts and spanners.
I didn’t use Loctite on the three M6 grub-screws; plumber’s-tape has the advantages over Loctite of being cheaper, always within its shelf life, no problems over the grade or of it not working because the hole isn’t degreased properly or because it has been poorly stored. Loctitie is really good stuff for some applications, but sometimes there are alternatives. If I do want to change things later I can always get it apart again.
These two smaller grub screws are also locked with plumber’s-tape. Provided one leaves a thread or two showing the screw will engage easily enough, and it won’t become loose under vibration. This, to my mind, is a better arrangement than locking with a nut as there is no danger that doing up the nut will disturb the position of the screw – the screw locked by plumber’s-tape just stays where it’s put.
The setting up process is simple. Use a clamp to hold the new gibs flat against the underside of the bed. Fit the two small grub-screws and wind each in until it just touches the gib. Next, wind on the two lock-nuts. Tighten the first until it touches the gib, then remove the clamp and adjust the nut until the feel of the saddle becomes just too tight when the handle is wound, then back off a smidgeon (is that a sort of small pigeon?). Repeat this exercise with the second locking-nut. Then repeat for the first nut, tightening the nut until the saddle starts to stiffen up a little and then back-off the nut a smidge (a small midge?) until it feels right. The second adjustment of the first nut compensates for any settling of the system during the process due to the weight of the gib acting as a lever before the second nut is adjusted. (In the photo you will see that there are three locking-nuts. The middle one does nothing – it isn’t tightened down, it’s just there in case I ever want to change the arrangement).
I no longer have any trouble with slack under-slung saddle-nuts, especially the ones hidden behind the apron – ooooh Matron!