collet block

Can any one give me the dia of the stevensons collert block please,,came to me that one of them clocked up in a 4 jaw chuck ,would make a cheap collet chuck for my old south bend ?,just a thought

john

Edited By john brown 17 on 28/09/2019 20:15:37

**LINK**

https://www.arceurotrade.co.uk/catalogue/results.aspx?search=stevenson

MichaelG.

I don't think ARC give teh block sizes.

Also they are not round, for the 4-jaw a square one will be best at 35mm for ER25 and 40mm for ER32.

.

Sorry, I presumed that John must have meant the diameter of the circumscribed circle

MichaelG.

Have you not got the 5C collet adaptor and draw bar for the South Bend ? When I had my South Bend heavy ten 80% of the work was in a collet.

No chris its never came with that ,plus its got a funny taper in the spindle ,think you can get a taper from the states to make it mt3,but they do not always fit,plus dam silly money.

But thats just the ticket jason ,have a spare smaller 4 jaw chuck for the lathe,so the block can be clocked in and stop in the chuck ,just put the chuck on an off as needed,may as well get the most use out of the collets when they come,oh well more money to ARC monday ,but do feel that l am getting there now,with all the help.

john

John,

My old 9" Southbend has a 3MT taper in the spindle and uses an adaptor to accept the 5C collets. Also accepts a 3MT/ER32 collet chuck.

You have said that "its got a funny taper in the spindle".  What type of dead centre do you use ?  Are not most centres Morse taper. ?

Paul.

Edited By Paul Lousick on 28/09/2019 23:32:31

Have you consulted The Oracles (Tony Griffiths' 'Lathes.co' site)?

It might tell you what tapers were used on "old" Southbends, if you can match your lathe to the information given.

There should be a serial number stamped on the RH side of the bed. My old Southbend is a model C with flat belt drive pulleys and with the spindle running in cast iron head stock (no bearings). It was build around 1938 and has a 3MT taper and a 1 1/2" x 8 tpi spindle nose.

The lathes.co.uk site does mention that Southbend also made some spindles with a non Morse type taper. My question again, what type of centre is used in the head stock ? Standard morse or something else ?

Paul.

Are you sure it's not 3C?

The Southbend 9 is 3 MT as you rightly said, and i was under the impression 5C will not fit in a 3 MT lathe spindle. The SB Heavy 10, will, however, take 5C.

The lathe is a 14 1/2" x 16" with a 2 1/4" x 6 thread on the spindle ,whenever l need to turn between centres l put the centre in a chuck ,the taper in the bore is not a 3 nor 4 ,have in the past had a go at making one but could never get it right,so have got used to using it like it is,like l said there is some sleeves to be had in the states so it is then mt3 but the cost is silly.Over time l have got some smaller chucks for it so it makes life better working with smaller stock and with adding the collet block l will be happy with that set up ,plus the ml7 has been rebuilt so happy times ahead l hope.

john

The ER40 one is 1.75 inches square, that's 44.44 mm.

Is the taper quite short? if so could be 5C in which case a 5C to ER32 holder is available

My mistake above . The 9" Southbend has an adaptor from 3MT to 3C collets.

Paul

Yes jason it is a short taper,but in the past have looked at this problem ,and with help from the southbend forum boys some say a 5c fits then others say it will not fit all the lathes,it turns out that southbend had a funny turn and put there own taper in the spindle on some lathes ? mine is 1942 and with my luck its one of them ,never mind l think that l will be happy with the block set up,at the end of the day where do l stop spending.if my collet set will do the mill plus myford and the southbend l can ask no more,if fund allow in the future then l my well add a er32 or 40 set of tooling ,we will se.

john

Using a separate collet holder in a cuck is a truely miserable experience. Field expedient emergency only. Far better to sort out an adapter.

The Southbend bible "How To Run a Lathe has details of the spindle taper sizes. Details for the are 1 3/8 bore spindle large end is 1.626" diameter, small end 1.375 and length 2".

Some useful information here about making an adapter for a 5C collet :- **LINK** . I paid the SouthBend price for a factory adapter when I got my camlock spindle Heavy 10 in the mid 1980's (or thereabouts) as, being a toolroom version it had all the 5C kit except the adapter. £150 with tax, delivery and import duties back then!

Quoting the most relevant part:-

"The 5-C adapter for it is 2.5" overall length. On the large end the flange is 2.3" dia. and .5" thick. The taper is 1.9" long and measures 1.638 at the large, flange end, and 1.545 at the small end, then about .1 length of 1.498" dia. on the small end that is not part of the ground taper surface. The ID at the small end is 1.252" dia. straight for about .5 deep, then is undercut to the large end where there is the taper that matches the 5-C collet."

Measured values come out at 0.5874 inches per foot. I suspect its really 50 thou per inch, 0.6 inches per foot which is Jarno, a section out of a no 14 would work fine. But where you'd find a no 14 Jarno sleeve today i don't know. (If I wanted one my P&W B has a Jarno in the headstock and a taper turning unit so an easy job. Perhaps I should get round to doing the 5C and ER adapters that have been on the "somewhen" list for over a decade and make a few more lengths of Jarno whilst I'm at it.)

Clive

Thanks clive,yes can se it will not be perfect but for what l get up to am sure it will do for now,the money you paid is even more now,at the end of the day when the funds are there maybe its time to to get a er32 or 40 back plate collet chuck and and make a back plate for it,but that will have to wait,so for now the block way is the way that l will have to live with,even if l had a sleeve say in mt3 ,an a mt3 collet chuck ,as jason put me right on am stuck with short work holding,so the chuck version with back plate is the way to go long term,or l get very brave and buy a collet nut and have ago at making a chuck that screws on the spindle,but then thinking about it the southbend will not cut metric ,so full circle its the back plate type,will have to keep looking for a back plate with the 2 1/4" x 6tpi thread,anyone got one?

john

Getting more confused by the hour

Have you tried getting a cheap 5C collet and seeing if it fits your spindle?

Neil