J & S 1310

I have a J&S 1310 EIU cylindrical grinder the work-head of which has an internal spindle taper of 1.4375" 3.5"/foot. I have never been able to source an additional J&S chuck back-plate with an integral male taper of this size. The only alternative is to manufacture one in the lathe, finishing it on the grinder itself as I have J&S accessories with this taper integral to them to use as a setting gauge. However, if this taper is a recognised standard I may be able to obtain one from a dealer.

So, does anyone recognise this taper as a standard or is it particular to J&S machines?

3.5" per foot is the same taper angle as BT tapers I think. Which end is the 1.4375"?

like this Chris Ebay listing

Is that your listing Chris? 

Edited By Pete. on 06/10/2021 22:23:00

I should have read the listing, did you buy this one in error?

Pete, Yes, it is my listing and, yes, I did buy this one blind but in error. I have tried to get the correct one from several J&S legacy dealers but nobody has been able to help me. It was one of the dealers who supplied the information about the taper but he was unable to supply the correct taper.

John, the 1.4375" dimension is of the large end although I have not measured it myself to confirm. The taper data was supplied by a J&S legacy dealer who also supplied a few other details about my machine which actually surprised me as I had no idea such details would be on record. This was the email he sent me: -

Hi Chris

Apologies for the delay

The serial number was correct but the sales order number is BO55567. Ex Coventry Education, 1964 1310EIU.
Supplied with
UJ8022 Hardinge 3C340 Collet system.
34628-105 Collet Draw Tube
34771-104 Collet Adaptor Plate
The taper in the workhead is 1.4375" 3.1/2"/foot.

Incidentally here are some other part numbers on the machine
UJ8021 Workhead
34567-001 Blank Backplate

Unfortunately we do not have stock of any of the above, and cost for a 1-off new collet adaptor plate I would expect to be in the region of £1200.

Best Regards
Alan Fisher

INT20 is the one sometimes used for T&C grinder workheads. Never seen one on ebay when I was looking a few years ago as they would normally be carefully kept with the grinder or binned when some dumbos liquidated the business.

All the INT sizes have the same taper but the base threaded boss for the drawbar won't allow a larger size to fit the smaller socket. However a BTversion (ie BT30) which has the same taper as the INT but no boss can clumsily fit and ISO20 or INT20 socket I think.

There's another on ebay, the seller has put that it's a 50 int, is yours a small 30 taper as John says 3.5"/foot is an iso taper? if it is maybe searching for this would find you something.

Ebay 50int

Pete, I have INT30 tapers on some milling machine tooling and it does not fit the grinder work-head. Someone is suggesting INT20 may be the one to try but I have never actually seen this taper before, so it may be quite rare.

Chris have you tried Andmar machinery services. https://www.andmar.co.uk/

David

Plus 1 for trying Andmar. Andmar rebuilt a 1310 for me when I was managing a toolroom but it was maybe 20 or more years ago.

You know that BT taper, Iso taper and INTernational tapers are all the same angle, all 7/24.

A google of ISO20 came up with this instantly.

The small 20 size is much more common in USA ebay than the UK.

Thanks to you all for your kindly advice. I have e-mailed Andmar with an enquiry and I am just awaiting on their response.

Have just consulted my Apprentice training notes.

Inetrnational Taper is 3.5" per foot.

Dimensions:

No.30 INT Length, flange to end 2.625" , Major diameter 1.25" Parallel diameter 0.5625"

No.40 INT Length, flange to end 3.5625" Major Diameter 1.75" Parallel diameter 0.6406"

No.50 INT Length, flange to end 5.125", Major diameter 2.750" Parallel diameter 1.250"

Howard

Howard, thank you. I think we can now discount any idea that the taper is INT/ISO as I have just measured the taper major and minor diameters (as far as is practicable) with a digital vernier. The major diameter is almost certainly 1.4375", which corresponds to the dimension given in the e-mail, and the minor diameter appears to be 0.850. over a distance of 2.250". There is approx 0.500" of parallel beyond the end of the taper of 0.750" diameter. This contains a fine thread which I suspect will be 0.625" UNF L/H. Not sure what the included angle will come to without drawing it out and applying some elementary trig.

I did e-mail Andmar as advised by David and attached a photo of the taper I require alongside the one I bought in error but so far I have not received a reply.

Edited By Chris Crew on 08/10/2021 15:50:29

Have a look at "Tools-n-Gizmos"

They list many tapers and their dimensions, so yours may be among them, somewhere.

Could it be a B & S taper, possibly? Nearest might be No.11

Howard

I take it you are measuring the outer end of the throat . An int taper male does does not go in full depth of the socket - the dimensions given are just gauge points and the actual length provided by the manufacturer is variable. So if your outer end is 1.4 then it is probably intended for Int40 arbors. It is important that the arbor sits proud as in life some male tapers might have been damaged and reground and must not then vanish down the hole,

The manufacturers of toolroom grinders were not entirely stupid They knew the primary purpose of the machine would be to sharpen the cutters for the works milling machines which would mostly have Int40 or Int50 spindles unless the company had been suckered into getting one with a proprietary taper to get locked into single source spares. Matching that on the workhead enabled greater precision and speed of turnaround,

Well, Andmar did get back to me in a very civil and professional manner and they could help me but, although I am sure the price is very competitive for a new back-plate, it is a little out of my budget. So the search goes on for a suitable used part or I will just have to get down to making one.