Imperial Fasteners

I did try contacting Bracehand a while ago but didn't get a reply. If they are operating I would happily share the drawings I'm making of the Model M Mk1 on Onshape.

It would have been a wholesale job to convert the lathe to metric and it would have been a surprise (but not impossible) if it had remained metric. My thinking for this is that the S&M was based on a German Boley lathe which I expect was metric, but since this was shortly after WW2 I imagine the enthusiasm for things metric would have been limited.

For info, I've now cleaned the threads that were causing concern and ordered replacement screws - the sizes were 2BA and 4BA.

Old Mart and Michael G. Smart and Brown Model M Yahoo group has moved to Groups IO.

Howard, as I am not trying to maintain a museum piece lathe I have put 5/16 UNC hex grub screws into the tail stock adjustment positions to replace the original slotted screws that were worn and annoying to adjust. They may have been Whitworth form to start with but the UNC screws fitted without any issues so that's what I used. Proves your point I believe.

Martin C

No problem with an old machine being upgraded.

It is only if you are trying to keep original that it becomes important.

Some designs benefit from later changes, and in some cases current materials /threads are the only way of keeping a very old machine going.

Retaining a thread made by the local blacksmith in 1725 may be prototype, but no one is likely to be able to reproduce a 17/64 x 7.5 tpi thread with a 42 degree form. Unless you want to file it like the originator.

Working 140 miles from home, I needed a 1/4 BSW nut. Only M6 available, but I had a 1/4 BSW Tap. Not over the moon about being non prototype but the machine could be adjusted and returned to service, there and then.

Once I helped someone who had lost a wheel by recovering the wheel and taking one nut from the other three wheels to retain it, for a slow drive to a garage, for a proper fix.

Where needs must the devil drives.

So you have to adapt to the nearest possible equivalent.. In some instances, the original design, even if using "standard" fittings, may not be as good as a later variation. the original may have been a fine thread in Aluminium, but a coarse threaded bush may be less likely to strip.

Remember Trigger's Broom?

Happy New Year to All

Howard

Just thought i'd share a couple of photos of my newly filed dog pin socket screw - it retains the gear for moving the saddle along the bed. Both the original and the replacement are shown. I heard a similar story to Howard's many years ago - if I remember correctly an expedition to the Duhd Kosi river in Nepal had a problem with a wheel stud - the local mechanic simply filed a replacement which apparently gave good service for the remainder of the exped.

The Model A at the museum is certainly not a museum piece, All the modifications and repairs use metric threads as they are easier to get hold of. The only exception is a 3/8 BSF helicoil in the apron where only about 50% of the original thread was left. I even drilled a couple of 8mm jacking screw holes in the saddle as it was a pain to get the apron separated as the dowels are tight. The repairs to the cracked cross slide use 8 and 3mm threads. If I can find the photos for that repair, I will start a new thread on the subject. 

That pic of the screws reminds me of when I was a kid and broke a banjo bolt in the rocker oil feeds of my R E Constellation. It was miles from home in Kent. I took the broken bits to a local garage and the mechanic made me a new one in five minutes by just filing a flat on a bolt, easy when you have a practical mind.

Edited By old mart on 29/12/2019 13:43:49

Edited By old mart on 29/12/2019 13:49:47

I looked in Groups I O and found nothing.

Try this link **LINK**

Emgee

Shame it seems to be an exclusive Model M group, not much use for the rest of the S& B people.

On the subject of being up the creek, in this case quite literally..

Many years ago, a there was an expedition, using small hovercraft, up, ( the Amazon, Nile, or somewhere very remote) when they burned a hole in the crown of a piston. A sheet of copper was rivetted onto the crown and the engine reassembled. the hovercraft completed the expedition successfully, and was duly returned to the makers. My friend, who had helped build the craft, still has the piston, I believe!.

Once the lathe is operable, it may be possible to turn a stub on another capscrew as a permanent replacement.

Howard

Edited By Howard Lewis on 30/12/2019 14:09:45

With regard to the GroupsIO site. I created it when the Yahoo Group was about to expire. I've copied all the old files and photos to it so at least they're still available. There hasn't been much traffic as there are only 5 members. I'm obviously happy to accept new members or to migrate the data to a more appropriate website. Alternatively, it could be expanded to accommodate all S&B owners, but in order to host all the photos that would come at a cost - which is why I just limited it to Model M. That said I suspect many of the old photos don't need to be migrated. One option is to simply allow it to grow as users find useful.

Happy to consider suggestions?