Brown and Sharpe Indexing Head (not BS0-3)

[GreatOldOne]

Hey all - can any of you help with some documentation / parts diagram for this? I just picked up on eBay. Googling brings up loads of stuff for the usual B&S heads and their numerous copies - but I’ve yet to find anything on this bar an entry in a 1916 catalogue.

 

[OTmachine]

IMHO, dividing heads are pretty much generic and self deduced.. 40 to 1 gear ratio, (in most cases). If you do not have all of the plates, there are a lot of plates that can be made to fit for cheap.

 

[GreatOldOne]

Thanks. Plates aren’t an issue as I have an electronic solution for that. It’s more a nice to have documentation really. Plus an exploded diagram of all the parts so when I eventually tear it down for a clean and refurb, I know what’s what and if anything is missing.

 

[GreatOldOne]

Ok, so I got it broken down and cleaned, ready for paint stripping, repaint and reassembly. The tilting of the head has been restored, as it was stuck solid. I tapped the head from the upright casting with a copper faced mallet and once out you could see why it wasn’t moving.

The bore that held the head in the upright was marred. It looked as if a previous owner had used a dremel or a file to take some burrs or dings out and had just made it worse. I used a cylinder hone to take them out and get an even surface. Now it‘s fine, rotates up and down and locks with the three nuts on the locking plate. There appears to be no slop / rocking in the bore, so I don’t think I’ve over cut it.

I believe that I’m missing two caps for the oiling points on the head casting - I have two that’s on the cover for the worm gear so hopefully I can copy them. And the lever for the direct indexing pin isn’t original. I think this should be of a similar size and shape as the main rotation locking lever (tapered with a large and small ball on it). Oh, and a ball detent that should make the pin click in place. I should be able to source an appropriate ball bearing and spring, but I will need to work out what thread size and type the grub screw is that holds that in place. That’s been butchered to put a new screwdriver slot in it. I guess it was stuck at some point as when they did that, they managed to catch the casting as well. (See the second picture)

 

[GreatOldOne]

So its all cleaned, the castings have had the paint stripped, the small cut where the previous owners had dremmeled into the grub / set screw I mentioned previously has been repaired and then a new fresh coat of paint applied. Now it needs re-assembly.

It needs a little bit of additional tidying up on the machined surfaces where the paint managed to get to even though it was masked off and then I’ll be putting it back together. This is where i might needs some help - I’m not very knowledgeable when it comes to imperial threads. I’ve measured the buggered up set screw, and it measures as 28 tpi and it’s what I think is 7/32” (the old screw diameter is ~5.5mm. It’s difficult to measure as it’s truly trashed and very short). This seems to be as common as unicorn poo. I can’t find anything that size. Can anyone suggest what it might actually be?

I’m also stumped at the locking pin for direct indexing. It seems to have another pin on the opposite end - which I think might be to hold a compression spring? And the set screw I’m trying to replace I think would be there to hold a ball detent. But I can’t find any parts diagrams for this dividing head. Does anyone else have this type that can advice what is missing here?

Thanks in advance.

Jason.

 

[GreatOldOne]

So it’s back together.

I couldn’t find the right size screw for that buggered up one. So I retapped the hole M6, and added an appropriate slotted screw as a replacement.

I put a compression spring on the end of the indexing pin


So it now snaps into place on the indexing plate (and won’t drop back or vibrate loose when in use). There is not enough room / depth for a ball bearing, spring and screw - so I’ve just opted for the screw. When you’re not use the indexing pin, the lever pulls it back and I can lock it in place by tightening the screw.

I’ve replaced the index pin lever with a ball handle one as the one it came with was obviously a shop made replacement. And as I had them, I put oil cups on each of the oil points - as it was missing two of the friction fit caps. I might try and make a pair of matching caps to complete the set and use them later, but for now it’s usable.

 

[OTmachine]

Looks Really Good! Thanks for sharing. I have an old K&T, 40 to 1, that I need to go through. Probably about the same vintage as yours. I would like to make a 2 1/4 - 8 spud for it so I can move from the head to the lathe.