I bought a Bristol 800 Indexer from eBay about 6 or more years ago in the hopes of making a full 4th axis from it. Its a lump of an indexer weighing in at 90Kg without a chuck, the centre height is 165mm and I also got the tailstock with it. The problem with it was, being an indexer, there was a bit of backlash in the worm/gear and there was no adjustment. I had several ideas about how I would convert it including using a belt and pulley, or making up some offset mountings for the worm.
Problem with the belt system was no easy way to get things mounted so I could use as a vertical indexer/axis.
Problem with the offset mounts was it would need the hole enlarged and getting the two lined up accurately would mean I really needed to line bore it or make up a long boring head. I had thought of mounting it on the cross slide of the lathe and make a boring bar held in the chuck and tailstock and bore that way but it would be a pain.
Anyway it got shoved in the shed outside my workshop and forgotten about until I bought a servo motor and drive from eBay the last day and decided to look at it again as they would be a perfect fit.
 This time I wondered about mounting the worm over the wheel so with my usual planning (None whatsoever ) I threw ( actually puffed and groaned more than throwing ) it on the mill and cut out the top of the housing. This is as far as I have got but I am hoping I will get some time in the next week or two to get a housing made up for the worm so I can bolt it down nice and snug onto the wheel, good thing is if I screw up and take too much off the housing bottom I can always shim it a bit

Hood

Hi Hood,

That certainly is a lump and a grand project indeed. I am looking forward to seeing the pics of your progress.

( looks like you could use my De-Mag for that spanner  )

Tweakie.

Ha ha I know, not used to crappy iron and steel, mostly Stainless and Alu I do and if that starts sticking to the spanner I will be worried

Hood

Slight bit of progress. Rough machined an extension shaft for the worm, welded it in place then did the finish machining, That way I knew it would be true. I used some angular contacts I had bout years ago, probably 10, for a manual Bridgeport I had at the time.
Hood

Hood
Very nice welding
Graham

Thanks but  it could be better, I need specs, just keep putting off the visit to the optician
Hood