J & S 540 – valve block

[gerry maddenParticipant @gerrymadden53711]

After a long period of distraction I’m back working on my grinder. Over the last couple of days I removed the cross-saddle and extracted the valve block from it. Like the rest of the machine, what an elegant piece of machinery this is.  (I sometimes wonder why the Chief Designer of such successful machines such as this are not placed on the same pedestal as people like Teddy Petter and De Havilland, but I digress.)

Although the machine appeared to worked perfectly well before I started to dismantle it, I have nevertheless found one broken spring. This will be easily replaced. Other than that, and the all-pervading gunge, the unit was in excellent condition. I like to think that my disassembly and reassembly processes are meticulous and nothing gets missed, but a slight doubt has crept in with regard to one on the valve controls as I began to reassemble.

The left-hand  control, known as the Cross-Feed Throttle, appears to have no downward support for its spindle. This will make the eventual fitting the control lever difficult as this requires a downwards push onto the shaft, at which point the spindle will just make an escape down into the block with just its tip showing.

The other two valve controls have springs and a ball under them to keep them up. These components are clearly shown in the parts-list diagrams as you see here:-

However, the Cross Feed Throttle is described differently:-

The actual parts taken out of my machine looked like this:-

The bore hole in the valve block in my machine is considerably deeper than appears to be shown in the manual which is why my spindle drops down too far.

I can only conclude that either I have lost a spacer, or the block has been drilled too deep accidentally and they fudged the final fitting of the lever with a bit of jiggery pokery.  Has anyone else come across this or can tell me what I’m missing ?

Gerry

[Swarf MakerParticipant @swarfmaker85383]

Looks to me that you can assemble all the parts off the machine before dropping it into place and fixing with the two allen screws.  No need for bottom support?

[gerry maddenParticipant @gerrymadden53711]

Hi Swarf, if I understand you correctly, I don’t think I can do as you suggest. There is a cover plate that goes over the valve block.  The valve lever can only be fitted to the spindle once this cover is in place. So the valve spindle has to protrude through the cover and stay there by some positive means. One cannot access the valves or Allen screws once the cover is in position. Its a catch 22 !

 

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