AC Motor upgrade - pulley sizes

[birchy]

After MUCH deliberation, I've decided to go for a direct drive as suggested above. Main reasons are:

1. Maximum shaft centres is 46mm between motor and gearbox input. With shaft diameters of 19mm and 15mm, that doesn't leave much room for pulley adjustment.

2. Having removed the head, I've discovered that the gearbox is mostly plastic gears. I don't like plastic gears unless they're for damage limitation AND easy to replace.

But, of course, a direct drive raises new engineering problems...

My main issue is the length of the bearing journals/shaft as there's nowhere near enough meat to fit a pulley of any description. I want to keep the hand feed for drilling. I'd make a new piece, however I have no way to cut the internal splines. How do you guys suggest I extend this? Weld a lump on and machine it back? The gears will be redundant, but appear to be machined onto the same lump as the spline and bearing journals.