Member postings for ega

I shall continue to pray for an effective spell checker - not that it would have saved this typo.

Thanks for your 5C/ER comparison.

There is an obvious temptation to grip work shorter than the collet in an ER chuck and I wonder how far this can safely be taken? Certainly not 1mm, but have you a helpful rule of thumb?

There is, of course, no reason why a backstop cannot be contrived for use with an ER chuck.

I was intrigued to see from your patent link that the Germanic-sounding Herbert Kohn Staub was a British subject. Picador were major players in the early days of my interest in machines and it is a shame that they seem no longer to function.

Thanks for the noga link.

I see that the reversible tool is not only recommended for diametral holes in pipe but will deburr the other side of the hole, too!

Interesting point; my Quick Step Mill with ER20 spindle came with a rather loose collet nut. The designer/manufacturer may have had the same idea in mind.

Tony Griffiths gives them a good write-up as you are no doubt aware.

The OP doesn't say what tool holding facility he has but I can't help feeling that for most purposes almost anything would be better than the standard sprung clogheel arrangement.

sean logie:

For 'tis a jolly good lathe!

Here is my shop-made version showing also a GHT-inspired dividing attachment for use with milling and drilling spindle:

Not obvious in the photo but I have made the chuck body long enough to be able to work up close despite the gap.

Thanks, Oldiron, for these tips from the horse's mouth; it is indeed interesting to compare them with opinions on the thread (always remembering that the author is concerned with industrial applications).

Can anyone confirm my faint impression that this development had started pre-WW2?

I seem to remember that my 1931 Austin Seven had fastenings with the reduced size hexagons and that this caused me some confusion when buying my first spanners.

Thank you for this cogent explanation. I am going to check the height of my parting tool which is of the tangentially-clamped variety. The makers, ISCAR, claim that the design "Provides a solution to the problem of inserts being pulled out during retraction"; this is not the "diving" effect you have described but the tangential tool does seem to be better able to resist it.

If I read you correctly, you would recommend that the rear mounted carbide tool be set below centre?

Can you elaborate on "cope badly"?

Good point about the GHT groove.

I use an inserted carbide tip parting off tool on my 1960s Willson slant bed whose top speed is 954 rpm, typically parting off at up to half that speed.

I think that speed is only one factor; the topic has been well canvassed here, of course.

Unfortunately, in my experience the pricier tipped tools work better than the budget ones.

And you could get a fair price for the unwanted MT3 tooling by advertising here.

Feel free!

Mine uses a metric drill that rises by twos but a more versatile tool would be in steps of one millimetre. Again, if you didn't want to tie up the step drill permanently it could be held in a chuck handle.

Where does one obtain a parting off tool with a 5" projection? And what lathe runs it?

Not everybody has power cross feed. CNC apart, how does conventional parting off account for the progressive reduction in surface speed of the cut?

ajl langley:

I assume you have tried Castorama?

Reading your post made me think of the sorely-missed K R Whiston; his "cat" listed very much the kind of thing you are after.

blowlamp:

Well, he certainly looks as though he is about to do a "quick change"

jimmy b:

Thanks for Aloris link

There was a contributor with a French name, Yves Rayssiguier: see MEWs 27 and 50. He seems not to be a member although there are three other Yves.

I assumed "Adonis" was a typo for Aloris.