Jump to content

Making A Cutting Tool With Hss


clockboy

Recommended Posts

The one thing that has hooked me onto Horology is that it is never ending learning curve whether a collector or repairer. I purchased Star lathe a couple of years ago and after many trials and tribulations have become quite competent at turning & polishing. It also came with a cross slide but I could never get it to cut as it should and also the post does not have an easy adjustable height so catching centre is a matter of packing the cutting tool. As consequence I always use the tip over rest and a graver. But when cutting down stock the slide rest is the way to go so after watching the vid below I decided to make a cutting tool.

 

When I did the first couple of cuts with the new tool I was really pleased but then I started to get a really poor cut. On inspection with a loupe found that the tip of the tool had broken. I then reground and the same happened again. Then after some research many engineers recommend that never quench HSS steel when grinding as it can create macro fractures. So on the third attempt I re-ground without the quenching and low & behold the tool has stayed sharp and cuts with a really nice finish. Attached some pics hopefully shows this and one of my set up.

post-234-0-35997900-1416396346_thumb.jpgpost-234-0-30990000-1416396356_thumb.jpgpost-234-0-43568800-1416396361_thumb.jpg

 
Link to comment
Share on other sites

Yes I have been looking at these.

I have been toying with the idea of purchasing a carbide graver such as supplied by eternal tools .com

They are supposed to stay sharp for a long time BUT to sharpen them is pain unless you have diamond wheel

 

I love their carbide spade drills - honestly, they are amazing.

 

BUT the carbide gravers! Whilst they cut through steel like a hot knife through butter, you will spend half your life sharpening them. They are very brittle and you quickly end up with imperfections which make the finish quite undesirable. And then if you slip, the tip can easily snap off. Anyway - this is my experience with them, but just be aware, they do not solve all your problems, they have problems of their own. Another thing with the carbide is that you can turn at lower speeds.

But I went back to using my HSS gravers for the bulk of my work.

Link to comment
Share on other sites

Thanks Mark, My brother-in-law uses them but warned me about the re-sharpening issue. The spade drills though sound good I did purchase a 1mm for a specific job from flee bay & was impressed.

The other drills I use are the Tungsten carbide ones from Cousins

   
Link to comment
Share on other sites

Hi guys,

 

This is a great thread and since I'm a complete novice in this lathe business, I must ask:

 

How much space does a watchmaker lathe takes?

 

and most important,

 

is it possible to use it in a room in the house (I'm thinking about the mess)?

 

Thank you in advance.

 

Bob

Link to comment
Share on other sites

It's about a two foot by one foot.

 

I have used mine on the kitchen table in the past, no problems.

 

If you mount it on a sturdy piece of wood with a nice big hook you can even hang it on the wall until needed.

Link to comment
Share on other sites

Thanks for the tip clockboy, maybe I can devise some sort of shield or enclosure. I'll figure it out when I get it and also consider it will probably be like Mark's initial lathe: in the kitchen. I'm starting an ebay search for something decent.

Link to comment
Share on other sites

I got a chinese one from Sincere Clocks (ebay) and have been very happy with it. I regularly strip it, clean it and lubricate it - its a great tool for the price. The only issue I had was when I first got it the collets were very very tight. I had to grind out the bore some (not touching the tapered edge) and it runs true and perfect.

 

I have another Lorch wide bed but I can't remember the last time I used it :)

Link to comment
Share on other sites

It all depends on what is going to be cut. If the lathe is only going t be used for small watch parts i.e. balance staffs then the narrow bed lathes are very good. 

However I have found with my lathe (Star) that has a narrow bed when cutting thick stock or using as I was using yesterday a cross slide without doubt it struggles. Because of this only thin cuts can be made because the bed tries to flex. The ideal is to have two lathes one for the watch bits and a mini engineers lathe for the clock & larger bits. I do not have enough room for this but wish I had.

Link to comment
Share on other sites

Providing you purchase one that looks like it has been looked after and also comes with some collets to get you going. Then if you like it and enjoy you can always sell it on & upgrade to a better machine. Also I recommend  a book Model Engineer's Lathe by Donald De Carle.

Lots of useful info on the subject

Edited by WatchRepairGuy
  • Like 1
Link to comment
Share on other sites

Thank you clockboy, I'm waiting for that book. Geo recommended it too. I've been researching and asking questions everywhere since it might be a substantial investment....or not depending of what I buy. In any case, I want to be sure it is not a repeat story of when I bought my first screwdriver set if you know what I mean.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.



  • Recently Browsing

    • No registered users viewing this page.
  • Topics

  • Posts

    • OK, welcome in the world of alarm clocks... I guess the 4th wheel is dished because it is from another movement. If it was not dishet, then it would not mesh with the pinion of the escape wheel, am I right? The marks of wear on the 4th wheel pinion doesn't corespond to the 3th wheel table position, at list this is what i see on the picts. Calculating the rate is easy - there is a formula - BR = T2 x T3 x T4 x T5 x 2 /(P3 x P4 x P5) where T2 - T5 are the counts of the teeth of the wheels tables, and P3 - P5 are the counts of the pinion leaves. Vibrating the balance is easy - grasp for the hairspring where it should stay in the regulator with tweasers, let the balance hang on the hairspring while the downside staff tip rests on glass surface. Then make the balance oscillate and use timer to measure the time for let say 50 oscillations, or count the oscillations for let say 30 seconds. You must do the free oscillations test to check the balance staff tips and the cone cup bearings for wear. This kind of staffs wear and need resharpening to restore the normal function of the balance.
    • Glue a nut to the barrel lid, insert a bolt, pull, disolve the glue.  Maybe someone will have a better answer. 
    • The stress is the force (on the spring) x distance. The maximum stress is at the bottom, and decreases up the arm. That's why they always break at the bottom. I used a round file, then something like 2000 grit to finish. I gave the rest of the arm a quick polish - no need for a perfect finish. Just make sure there are no 'notches' left from cutting/filing. The notches act like the perforations in your toilet paper 🤣
    • It's probably a cardinal rule for watch repair to never get distracted while at the bench. Yesterday, after finishing a tricky mainspring winding/barrel insertion (I didn't have a winder and arbor that fit very well) I mentally shifted down a gear once that hurdle was passed. There were other things going on in the room as I put the barrel and cover into the barrel closer and pressed to get that satisfying snap. But when I took it out I realized I never placed the arbor.  When opening a barrel, we are relying on the arbor to transfer a concentrically-distributed force right where it is needed at the internal center of the lid. However, when that isn't present it's difficult to apply pressure or get leverage considering the recessed position of the lid, the small holes in the barrel and the presence of the mainspring coils. It was a beat-up practice movement so I didn't take a lot of time to think it over and I pushed it out using a short right-angle dental probe placed in from the bottom, but that did leave a bit of a scratch and crease in the thin lid. I had also thought about pulling it using a course-threaded screw with a minor thread diameter smaller than the lid hole and a major diameter larger, but that may have done some damage as well.  Thinking about how this might have been handled had it been a more valuable movement, is there a method using watchmaking or other tools that should extract the lid with the least damage? 
    • 🤔 what happens if lubrication is placed directly on top of epilame ? Making a small groove so the lubrication doesn't spread across the component but what if when lubing a little overspills and sits on the epilame .
×
×
  • Create New...