Hi Mike,

Have you a manual? You need to use configuration 1 on the diagram leading up to the chart which just calls for one of the studs to be on the banjo. On this stud is mounted the 70 tooth gear along with another one just to make up the thickness (any one will do). It's easier if you remove the other two studs from the banjo but you can sometimes move them to the ends of the banjo out of the way.

You need to put the leadscrew spacer outside the driving gear so that it can mesh on the same level with the driver and idler gear. With the banjo slack, position the 70 tooth idler so that it meshes with the leadscrew gear and tighten the nut on the stud and then position the banjo so that the idler meshes with the 20 tooth driver and tighten it down.

[Edit: When meshing the gears don't push them up tight but leave a small gap (say 20thou or 0.5mm) between the teeth to prevent wear. Oil the bushings as you assemble and keep them lubricated if you're running it for the first time or for extended periods. ]

HTH

Jon

Edited By Jon Gibbs on 08/01/2016 09:32:48

Swapping change gears must be one of the jobs where throw away latex gloves could be used then. I know what you mean about messy. People who have Norton gearboxes and have never changed the headstock gears don't know how lucky they are. Feed rate changes were more likely than screw thread changes for me. If made me tend to leave the feed rate at a low value and suffer the time delay this resulted in. It is part of the reason I put CNC on my machine. Not to be wonderfully clever with what I could do but to be able to thread and feed without changing gears. I also was missing some gears from the set required to do all common threads (no 127 tooth amongst others so approximate metric was the order of the day). I did make some aluminium gears when I really needed them. Not running change gears even when perfectly set up is also quieter but that is just a pleasant by-product.

Martin