Burke No. 0

[Gary Ayres]

Many thanks, Don and Woodtickgreg.

 

[Gary Ayres]

Good progress again today.

First, the table casting was stripped of the old light green paint:



It was then given three coats of matt black stove paint and reinstalled on the machine. OK - this picture proves that I'd rather faff about with vintage machine tools than weed my back yard:



I then started working on making a rear spindle locking nut. On another forum I was given to understand that using a tap to match the external thread on the back of the spindle would be a fool's errand. However, rather than embark upon learning screwcutting (and clamber over my drill press to crane into the corner of my tiny workshop to access the lathe changewheels), use a tap I'm afraid I did. And here is that tap, proudly displayed on the newly-cleaned table of the Number Zero. It's a bit of a belter:



It worked! Here is a trial 'nut' made from aluminium demonstrating that the tap matches the thread on the spindle:



There won't be any further development on the No.0 now for about a month because I'm making three different trips away and will hardly be at home. In the meantime, can you advise me what I should make the spindle locking nuts from? Will bronze or brass do the job? Is aluminium solely for wimps...?

 

[woodtickgreg]

I like the black paint, looks nice. And what weeds? lol.

 

[Gary Ayres]

Thanks Don.

Cheers WTG

Oh yes - weeds. Weeds? You're right.... I see no weeds...

 

[mattthemuppet2]

what a cool looking mill. Sounds like you're stocking up a really neat workshop!

For the rear spindle nut, I would personally make a keyed steel lock washer (you may even be able to buy one), polish it on the bronze bearing side and mill a matching key through the threads on the spindle. Slide it on and then use the nut (personally I'd make it out of steel) to take up the slack in the bearing. A suitably sized belleville washer (I think that's what they're called) between the lock washer and a double nut is another option as this will allow some movement when the machine heats up from use, but maintain the correct bearing preload. Either way, oil from the oiler should keep any friction to a minimum, although you could always grind a couple of oil ways in the washer to make sure.

The first option is sort of how my ancient mini lathe works. Very occasionally I have to slacken it off a touch if the garage is hot and I do a lot of work with it, but most of the time it stays as it is. I tighten it to the point where the chuck stops after 1/2 a rotation or so. I would avoid any kind of compressible washer as the spindle will move when it cuts, leading to chatter and other kinds of mess.

As for the stuck flat head screws, use an impact screwdriver. One of the ones that you hold in your hand and smack the end with a mallet. The impact drives the driver into the screw, so it doesn't slip out, and also provides the shock needed to break the threads loose. I had to use mine to take apart the cross slide on my lathe and it worked a treat, came loose with one tap after several different nerve wracking attempts using a normal screwdriver.

 

[Gary Ayres]

Hi MTM - stocking up a neat workshop, or feeding a burgeoning addiction. Or both...

Interesting advice regarding the nut and washer. What I think I'll do is start off with the simplest solutiuon (i.e. two locking nuts behind the bearing and a similar arrangement in front of it) and see how it goes. I think the machine was probably originally designed that way. Also, I'm not too keen to cut a keyway in the spindle if I can avoid it. If problems become apparent with heat or anything else (and as I get braver!) I could look towards implementing a system along the lines of your suggestion. I do still wonder whether simple fibre washers might do the job quite well, though.

As for the screws, they are actually hex head, not slotted. Is there such a thing as an impact screwdriver for hex head? It would have to be a very small one though. That said, the problem isn't a huge one because there's no real need for me to dismantle the table. I only managed to get two of the screws out. On each of the table surface plates, the central screw hole is actually an oiling point (you can see the word 'OIL' marked on the front one in the picture). The oil goes down into the slideways for the x-axis travel. One of the two screws I managed to get out was one of the oiling point screws - the only other one it would really be useful to remove is the other oiling point screw. A very small hex head impact driver (if such a thing exists) might be just the job for that.

Thank you!

gary

 

[mattthemuppet2]

as addictions go, it's probably one of the more socially acceptable/ useful ones

I vaguely remember reading somewhere else on here another machine tool that held the spindle in the same way - double nut in front of and behind the rear bearing, so I'm sure that would work, I just liked the sound of my approach! I'd be wary of anything, like a squishy washer, in the preload set up that can't resist a bunch of pressure before deforming as even a hair off snug on my lathe spindle allows a ton of run out. Still, that might be because it's an ancient abused tool that's used way beyond its reasonable work envelope

My impact screwdriver uses hex shank bits, so I'm sure you'd be able to find hex shank hex head bits for one. The big plus is that using one would reduce the risk of rounding that small hex bolts are prone to, something I've fought with a lot in the past.

 

[Gary Ayres]

Ah, yes - I take your point about the squishy washer. The No 0 I'm working on is in surprisingly good condition. As far as I'm aware for at least the last third of its life the only abuse it has suffered was to sit under someone's workbench for 30 years, and it shows very few signs of having been abused prior to that. However, I can see that a soft washer could lead to accuracy problems. You have certainly given me some food for thought, particularly if my initial attempts at solution don't work out.

On the table screws: good to know. Although it may not be essential to get them out, it would be nice to know that I can, especially that second oiler screw. Will look into what you suggest.

Agreed - not the most destructive of addictions. Quite an expensive one, though. At least until I figure out how to get some of the money I have have spent back again. That could take me a while...

Cheers,

gary

 

[mattthemuppet2]

well, I don't drink, take drugs or have mistresses (!!) and if I'm not in the house, at work or on the bike my wife knows that she can always find me in the garage. Plus she thinks it's endearing that I'm such a toolaholic, at least until she found out how much they cost to move across country!

 

[Gary Ayres]

Ha, yes. My girlfriend and I keep separate accounts. Something she has never regretted... :allgood: