Reply To: hardinge 5c collets

[Pete RimmerParticipant @peterimmer30576]

Posted by Barry Stone 1 on 11/07/2020 20:44:30:

Hi to everyone, especially Paul Rayner.

I am Barry, I started my apprenticeship at Hardinge Machine Tools, Exeter in 1966, ending in 1971. There was a factory in Hanworth Road, Feltham, Middx, but that closed a couple of years after I started. The head company base was Hardinge Brothers in Elmira, New York, USA. I continued to work as a Hardinge fitter building HLV-H centre lathes, a few HC turret lathes, but mainly the DV/DSM 59 range of centre and capstan lathes, as well as all accessories. Finally, I worked in the Drawing/Design Office and left in early 1979 to become a SkillCentre Bench Engineering Instructor. Before I left, I worked on redesigning the American KL pedestal unit to fit the English HLV-H to become "our" KL and updated HC models.

Your pictures show very different designs of 5C collet (known in English factories as a PH92 collet), going by the face engraving/stamping. The top one (5/32" looks correct but the lower one, 9/32" was not made in UK, in my opinion. It may be an American one, the circular collet design with Hardinge stamped through it is not an English factory 'thing'. It has added stampings "O" and "B" – I'm not familiar with this, it could have been made as elsewhere as a copy (Hardinge lathes were copied by a few foreign companies, including a Taiwan company called Feeler but their parts would not fit the genuine factory built machine). The spindle back bearing diameter is nominally 1.2500" with an exceptionally tight tolerance of +0.0001" if I remember correctly. Collet back bearing (you describe as just before the thread), I believe, has a diameter of 1.2498" tolerance of only -0.0003". The body length measures from the 10 degree head angle. Bore diameter max runout is 0.001" at a point 1" from the front face. The spindle collet key entering the back bearing is locked in place with a short, #10-32 UNF, grub screw, and is set for depth of engagement against a special gauge.

Pete Rimmer sounds to be very familiar with Hardinge, I'm sure his opinions are reliable too.

Hi Barry,

Thanks for you r detailed information, it's great that you have been able to provide some insight into the production of those collets. Tight tolerances indeed.

My interest comes from doing a full restoration of my own Feltham HLV. I had the bed ground and rebuilt the carriage, scraped the various ways and rebuilt the headstock too.

I have a question to ask of you – can you tell us what it is exactly that defines the KL-1 model as opposed to a HLV-H? Is it just a UK designation for a HLV-H? A metric machine? I can't seem to find a definitive answer, I'm hoping that you know.

Pete.