DSG lathe kind of unique

[bob]

Not mine. It is for sale on Facebook in Ontario. The guy says the two "extra" shafts are a drive for broaching. New to me
Bob

 

[john.k]

Form reliveing attachment ,more likely..........for making horizontal milling cutters and maybe hobs .

 

[Tyrone Shoelaces]

Form reliveing attachment ,more likely..........for making horizontal milling cutters and maybe hobs .

That’d be my guess also but I’ve never worked on such a machine.

Regards Tyrone

 

[john.k]

I accidentally bought one once ......super low spindle speeds (like 30 rpms) ...and very hard to sell.

 

[Tyrone Shoelaces]

A guy I knew bought 3 super low speed Webster & Bennett 36” vertical borers at an auction. He found those hard to sell also.

Regards Tyrone

 

[bob]

Big lathes are not real easy to sell however this guy is asking $2500 Canadian and would probably take less, that is fing crazy. Around here an old SB will bring $2000
Bob

 

[Clive603]

Agree that form relieving is likely what the lathe is equipped to do but what is the shaft along the front for? Possibly to drive a longitudinal oscillation when doing side relief or spiral flutes?

The Holbrook attachment shown towards the bottom of this page http://www.lathes.co.uk/holbrook/page5.html shows the usual way with a single splined shaft to drive the cam that oscillates the slides back and forth to generate the relief angle. A much more complex process than it might first appear when you start considering helical form cutters like that shown in the picture below. Easier on a Holbrook with the double cross slide arrangement allowing the lower slide to deal with things like taper turning, form receiving et al whist the upper one goes about its normal cross slide business. I imagine that DSG has to do some funny business to hijack teh taper turning set up.

The super low speeds needed tend to be generated via a speed reducer fitted to the front of the spindle which can be removed so the machine can revert to normal duties. I imagine that very few firms would have the throughput to permanently allocate a large lathe to form relieving duties so easy conversion to normal use would have been desirable. Firms that did have the through put for dedicated machines would most likely have chosen specialist machinery.

The brochure pictures for the relieving attachment designed for my Pratt & Whitney B 12 x 30 has numerous components sprawling all along the back side of the bed but, according to the brochure, "dose not interfere with normal use".

Clive