Jump to content

Advice on turning down thin pivots

margolisd
 Share

Recommended Posts

margolisd WRT Addict

margolisd

Posted
Posted

Hi guys. Any thoughts on best approach to turning down a thin pivot (.14mm) on the lathe after replacing? Thinnest pivot wire I have is .33. I’ve plugged it fine but keep braking it when trying to turn it down with the graver when it gets close. It is tempered blue steel and I’ve not softened it. Should I stick at it or change approach?

I’ve read that maybe I should abandon the graver entirely and use a sapphire stone? But they’re super expensive so wanted to ask if anyone had any advice. Perhaps on a good brand of sapphire stone that’s not over priced Burgeon.

The pivot is also quite long (long story, it is an adapted ETA part that has to connect with a power indicator module). Are there lathe accessorIes that support long pivots whilst they’re being worked on? Or should I just put the graver rest underneath it and stone it?

JGrainger WRT Addict

JGrainger

Posted
Posted

It should be possible to turn pivot steel but pressing it in may add a bit of hardness to the end. If I was struggling with this then I'd try rotating the graver to an angle so the cutting edge is at 45 degrees, with the tip above the work and the other end below the work. doing this will create a bit of an uneven surface on the work but should allow the material to be reduced in diameter so that the abrasive / burnishing tools have less to do.. starting from the least supported end. Ideally you'll need some sort of optical aid for this and something to be able to hold up to it as a reference diameter while working. A jacot drum is ideal for resting the pivot on for the latter stages of finishing but any stable and located (so it can't be knocked and run into the work) support or the toolrest might work if the height is spot on.

nickelsilver Distinguished Member

nickelsilver

Posted
Posted

Are you using steel or carbide gravers? Either will work, but both need to be sharpened perfectly. It should be no problem to turn to 0.08mm or smaller. I leave about 0.01mm and finish in the Jacot.

Check your gravers and keep practicing. How long is "quite long"?

 Share
Go to topic listing

  • Recently Browsing

    • No registered users viewing this page.

  • Topics

  • Posts

    • JohnR725
      A lathe with indexing that won't break the bank?

      By JohnR725 · Posted

      interesting video nice to see the machine what it can do now I wonder what it costs and I'm sure it's not in my budget. Plus the video brought up questions but the website below answers the questions? What was bothering me was the size of his machine 4 mm because I thought it was bigger than that? But then it occurred to me that maybe they had variations it looks like four, seven and 10. With the seven and 10 being the best because way more tool positions in way more rotating tools. Although I bet you all the rotating tools are probably separate cost https://www.tornos.com/en/content/swissnano   Then as we been talking about Sherline. Just so that everyone's aware of this they have another division their industrial division where you can buy bits and pieces. I have a link below that shows that just in case you don't want to have the entire machine you just need bits and pieces. https://www.sherline.com/product-category/industrial-products-division/   Let's see what we can do with the concept I explained up above and bits and pieces. For one thing you can make a really tiny gear very tiny like perhaps you're going to make a watch. Then another version the center part is not separate it is all machined from one piece. Then fills gear cutting machines have gone through multiple of evolutions. A lot of it based on what he wanted to make like he was going to make a watch unfortunately eyesight issues have prevented that. Another reason why you should start projects like this much sooner when your eyesight is really good or perhaps start on watches first and then move the clocks then local we have from the industrial division? Looks like two separate motors and heads. Then it's hard to see but this entire thing is built on top of a much larger milling machine as a larger milling machine gave a very solid platform to build everything.   Then like everything else that had multiple generations are versions the indexing went through of course variations like above is one version and the one below was the last version. Now the version below I mentioned that previously and somewhere in the beginning to discussion and somebody else had one in their picture. As it is a really nice precision indexing. Then I wasn't sure if I had a the watch photos here is his unfinished watch. No he wasn't going to make a simple watch like none of his clocks were simply either what would be the challenge and that.    
    • Titanium
      Lab Coats

      By Titanium · Posted

      Use a Portwest Howie lab coat. They are the biological type so they have tapped cuffs so you don't end up getting the loose cuffs of normal lab coats catching everything. 
    • Titanium
      Chinese tools debate

      By Titanium · Posted

      Some of the Chinese tools ae great and can be purchased at a fraction of the price of Swiss ones, some are complete garbage and some I'm convinced are coming out the same factory as the branded ones.
    • caseback
      Calendar work certina 25-651

      By caseback · Posted

      I found this string about this problem. I've not gone through it all, but I believe it also mentions making a spring. If not in this string, the info is online.
    • tonydagee
      Calendar work certina 25-651

      By tonydagee · Posted

      No, I now realise it’s broken😥 ive looked for one online, but v. Expensive! im going to service as is, in the hope that  one turns up. Thank  you.
×
×
  • Create New...