Wadkin PK Sliding Tables.

[Vann]

Hi PK owners out there. I have a query.

But first some background. I bought my PK (PKA 800 of 1945) in 2015. It came with two mitres - and it soon became apparent it had some accessories from a second PK (the second being a 1955 machine). Originally PKA 800 was not supplied with an extension for the sliding table - but when it came to me it had an extension table (just the table - no stand, no long fence). I made up a box for the extension and put it aside (no room in my garage workshop for the extension). However, recently I managed to pick up a PK sliding table extension complete (extension, stand with angle, long fence, and pivot for same).

When I tried the long fence I found the pivot wouldn't screw into my sliding table. the pivot has a 5/8" BSW 11tpi thread, while my table only has a 9/16" BSW 12tpi tapped hole .

Similarly, the main mitre pivot pin on mine wouldn't stay in the pivot hole. Initially I thought the thread had stripped. But when I tried the pivot pin of another PK (the one I got the extension pieces from), it screwed in perfectly. So I measured my mitre pivot pin as being 9/16" BSW 12 tpi, while the hole in my table has a 5/8" BSW 11tpi tapped hole.

No, I didn't put the wrong pin in the wrong hole .

However, IIRC Jack has said the mitre pivot hole is 1/2" BSW (12tpi) on his. So there seem to be a whole bunch of wrong size holes in my sliding table. Here's what I've got:

Blue circles indicate 1/2" BSW (12 tpi) threaded holes;
Yellow circles indicate 9/16" BSW (12 tpi) threaded holes; and
Red circles indicate 5/8" BSW (11 tpi) threaded holes.

I believe the red holes should be 1/2" BSW (blue), and the yellow holes should be 5/8" BSW (red). I've spoken with a friend in Australia and that's what he's got on both his old PK (PKA 390 of 1937) and his newer PK (PK 1892 of 1956).

Can I ask if anyone else has anything different?

Cheers, Vann.

 

[Vann]

I've just watched Jack Forsberg's great Youtube video on the Wadkin PK features.

Using the picture of mine, I've marked up the holes in his:

Blue circles indicate 1/2" BSW (12 tpi) threaded holes;
Red circles indicate 5/8" BSW (11 tpi) threaded holes; and
Green circles indicate preset holes for when main mitre is in the second (lower) position.

His has the same hole sizes as my Aussie friend's two machines. But in addition, he has an extra 1/2" BSW tapped hole at the very bottom (heavy blue circle to the left of the filler strip). Like mine he also has an extra preset hole (green circle and arrow - LH side), and unlike mine his has a further preset hole (green circle and arrow - top left), which I believe neither of the two Aussie machines has.

Cheers, Vann.

 

[Cabinetman]

Sorry Vann, but what does/is a PK? Love to follow your machine talks but I’m a bit stumped on this one. Ian

 

[Robert]

Sorry Vann, but what does/is a PK? Love to follow your machine talks but I’m a bit stumped on this one. Ian

Here's one Wallace did earlier

viewtopic.php?f=23&t=4253

 

[Vann]

Sorry Vann, but what does/is a PK? Love to follow your machine talks but I’m a bit stumped on this one. Ian

Well, if you don't know what a PK is then chances are you won't be able to answer my query .

Wadkin made their PK dimension saw from ~1928 through to 1960, producing around 2100 PK saws over that period.

About 2014 Jack Forsburg (in Canada) made the PK every Wadkin fans quest machine, when he did one up to a standard probably higher than Wallace.

And here he is explaining many of it's features: https://www.youtube.com/watch?v=W9rW_02QztE

Mine's a very moth eaten example in comparison.

Cheers, Vann.

 

[Vann]

...His has the same hole sizes as my Aussie friend's two machines. But in addition, he has an extra 1/2" BSW tapped hole at the very bottom (heavy blue circle to the left of the filler strip)...

On closer examination of mine, I find the small hole in that location is actually a 1/2" BSW tapped hole that was (until yesterday) full of gunk. So I too can screw in a handle like Jack does.



Cheers, Vann.

 

[Vann]

This is the sliding table off PK 1857.

Blue circles indicate 1/2" BSW (12 tpi) threaded holes;
Red circles indicate 5/8" BSW (11 tpi) threaded holes; and
Black arrows indicate preset holes for the main mitre. The circle marked 'A1' is the pivot point for the double mitre. The circle marked 'A2' is the pivot point for the double mitre when located in the secondary (lower) position. Note that one is 5/8" BSW while the other is 1/2" BSW (the latter being the original size for both I believe).

I guess the owner only ever used the upper pivot hole as the mitre pivot pin is 5/8" BSW.

Cheers, Vann.

 

[Vann]

Anyway, I want to be able to (eventually) fit the sliding table extension WITH fence, to my saw.

I could tap the offending 9/16" BSW holes out to 5/8" BSW - but with one being 12tpi and the other 11tpi it going to have to cut a new thread. And with the difference in diameter being 1/16" (1.6mm) = 1/32" either side - part of the old thread will most likely remain, weakening the new thread. And as the number of bastardised holes in my table (and PK 1857's table) show, threads in cast iron are vulnerable at the best of times.

So I decided a new pin would be a better solution - made to fit the existing 9/16" BSW thread in the table. A friend offered to make one up for me - out of an old bolt he had.

The new pivot pin ready for a trial fitting on Saturday.

It's amazing what can be found hiding inside an old bolt . The pin head is 1 1/2" dia. so the old bolt must have been ~ 1 3/4" diameter.

And the finished product parted off and trial fitted yesterday.

And that's only half the fence (it's about 3' long). Then on top goes a ruler bar that's 7' long!!

Cheers, Vann.

 

[DaveL]

That's a very good solution.