I’m not sure what happens here but after fitting the geabox, I seemed to lose drive to the apron. So I removed the prevoiously fitted pulley and removed the unit. By taking off the round cover plate (the larger one in the foreground) it is possible to push back the rack that the speed selector acts upon. It is in the centre of the gear when you remove the plate. Voila, the gearbox then works again. I think this all came about when I removed the selector dial.

My only issue now is that when I removed the pulley, it shot off the shaft, hit the casing and landed on the motor and you guessed it, it chipped a lump out of the edge. I will braze this all back up and turn up on the lathe. Looking at the chip, it has rust in the broken area and it looks like I dealt the final blow to it breaking off. Photos to follow when I get a moment.

This is the view from the top inside the belt ‘well’ – pulley removed.

Below, you see one of the twin dials on each of the axes. It seems unecessarily complicated but I suppose there is some good reason the Swiss made it this way! The picture show all the parts except the nylon gear that is hiding behind the screw extension on the left.

Below, you see the extension fitted to the screw. This is fitted in place with a roll pin – the hole shown ready for the pin to be driven in.

The photo below shows the twin dials fitted.

….you find a bit left over in the box! To be more precise, you find a part you are not sure about.

The part in question is item ’20’ in the above diagram and is fitted to keyway in the screw for the apron slide. I’m not sure of its purpose (I will investigate this later) but The bad news was that it was in the box and no in the assembled machine!! So, looking at the diagram, I decided I needed to drop the rapid traverse unit (removing the 4 bolts) remove the two end caps of the apron and then I should be able to remove the screw to insert this ‘slider’.

Of course, the nut needed to be removed again (above) and then the screw would move out to the right. If you look at the photo below, you will see the screw withdrawn enough to allow the brass ‘spacer’ to be slid down along the bore to line up with the key fixed to the gear. The tang on the brass ‘spacer’ drops in by the gear so it will not slide out.

It was then a matter of aligning the screw and pushing it all back together. Evertything was bolted back up and it was operational again! Hopefully I will not be taking the apron apart again in the near future.

This section should have been described before the fitting of the apron slide!

I have trial fitted the traverse screw and nut together with the gear and bearings. The gear as below.

For some reason I forgot to photograph the completed gear and bearings. To fit you must fit the bearings into the gap before you try and fit the gear. This is because the casting has two shallow recesses and the whole assembly of bearing and gear is too tight to fit in one go. Once pushed together in the recess, they will stay in place whilst the screw is fitted to the apron. I’m still a little concerned about the play between the slot in the screw and the key which fits in the gear above. (you can just see the round fitting pin for the gear at the right hand end of the gear)

All that was now needed was to bolt up the rapid traverse unit – nothing tricky here, it just gets a little heavy when trying to line up all of the holes for the bolts. I quickly fitted the handles to make sure everything was working OK – and it was!

I have decided to carry on with the rebuild and I will worry about any wear to the traverse screw and nut later. (and there is a fair amount of wear since cleaning every thing thoroughly) It is not difficult to remove these items to replace them – on the assumption you can even get them!!

It is now starting to look like a complete F3!!

Having fitted the arpon/carriage, I was trying to remember how you locked the carriage vertically. It them dawned on me that it was via this threaded hole on the lower right! And the clamp ring? It was sitting on the bench!!

So I dismantled it all again and then fitted the clamp and bolt.

Still, it was a lot easier and quicker this time!