Member postings for John Haine

I've had one for years and it's brilliant. Two things would make it better. First a spring washer under the clamp screw to provide a little friction when setting. Second a Vernier scale on the slide one day I'll get round to fitting the first and engraving the second. Mine has a nice steel thumb nut. A Shame if they've made that from plastic but a good exercise to make one. Highly recommended.

In effect this is exactly how a cnc machine makes large holes (a/k/a pockets). I used to work at a company making microwave cavity filters, some of which had holes bored to precise diameter and spacing in aluminium blocks. All done on a CNC machining centre, nary a boring head in sight. Material later silver plated.

Use car shampoo then

Nothing to be lost by adding a squeeze of washing up liquid

Good luck with that with a modern phone!

If you added an electronic leadscrew that would deal with your threading problem, and you could easily add power cross feed. No need to buy a new lathe at all.

Of course you could also go the whole hog, once you have steppers on both leadscrews then you have the CNC option as well.

Aha! Electrochemical etching to make steel clock hands!

IIRC the thread is M8 x 1 LH. I doubt that the original steel was particularly distinguished by great hardness - a good free cutting mild steel would do especially as it runs in a thread cut in MAZAK. The handwheels IMHO are deplorable - why not make a new one out of nice aluminium alloy to dimensions that will fit the end of the leadscrew? And you might consider taking the thread down to M4 so it's threaded nicely all along.

But you need to have a really sharp tool and well adjusted slides.

Thanks for the info Iain.

As Jason says...

Basically profiling into the end of a bar, then parting off. Under power of course...

Ian, I have to makes some clock hands soon and was thinking of a similar approach. What steel are you using please?

I have successfully milled 10t pinions into the end of a FC steel bar running a carbide 1mm slot drill at 5000rpm, taking it slow, so high speeds are not necessarily needed. Have you considered adding holding tabs and linking the hand shape to a larger surrounding area to reduce the risk of the superglue bond breaking? Obviously you have to file the tabs off at the end but a bit of added security.

I love it!

Right! The thread is needed to make sure the collet is pulled hard against the internal taper. AFAIK Arc don't sell Pozilock though Warco do. Largely superceded by ER I think.

I don't think they can be like ER collets as they have a circumferential groove at the point where the front and back tapers join which engages with the eccentric ring in the nut. I agree that it looks more like an Autolock-type. An angled view of the back of a collet showing any internal screw thread would settle the matter.

For many years I have used what is now Ionos but was 1and1. Have to pay but we get at least 5 email addresses, my own domain and website if I want it, spam filtering, access from regular email clients such as Thunderbird or Outlook, and webmail from any browser. My wife uses it from the Apple email client on her Macbook and the Gmail client on her phone.

**LINK**

Added: they take care of all the domain registration stuff so you only need to deal with Ionos.

Edited By John Haine on 22/06/2023 09:52:41

...and on the rare occasions where I've had a problem I couldn't sort myself their phone hotline answered quickly and was very helpful.

Edited By John Haine on 22/06/2023 09:54:35

Another thing to be aware of is that you can try to part/groove at too low a speed. For the tool to cut there needs to be enough speed that in the small region where the tip touches the work the metal gets hot enough to soften. Manual feeding and going slow is particularly problematic since to start with the tool won't cut,you aren't feeding steadily because nervous about the whole process, so suddenly there's enough pressure for the tool to start cutting but then it pulls the slide forward so the tool digs in. I think it's George Thomas who recommends parting off at higher speeds using power feed - discovering that revolutionised parting off for me.

What rpm?

What rpm?

Could be earthing or interference issue. Do the DROs and VFD both have screened cables? Could you post a wiring diagram showing the main connection points especially where the earths run?

MTs are fine when all the force is axial. With a boring head most of the force is tangential and would easily wobble the taper out.