Thread: Thos. White SO "Rapid Crosscut Saw"

Nice one Van, I came across one of these bad boys when I was looking at a Thomas White Chain & Chisel Mortiser. Is this machine original or has it been restored at some point? Looks very tidy!

Originally Posted by Charlie_6ft

...Is this machine original or has it been restored at some point? Looks very tidy!

I wish I knew. I'm in Wellington, 700km away from where it's stored, and I won't get to fondle it until November .

Cheers, Vann.

Nice looking saw Vann . Id love to have a go on one of these one day to see how they feel, such a different approach to the more usual way of a typical RAS. Ive never seen one yet . I look forward to hearing what you think of it after you get to use it .

Here's a photograph of the relevant pages from a catalogue held at the NZ Timber Museum, SH1 Putaruru.

SO cat.jpg

And a brochure from Scott & Sargent's website.
SO-11.jpg

SO-12.jpg

Cheers, Vann.

Swing saws - the American term for this type of saw - are considered fairly hazardous here in the U.S. I've never quite known why, unless it's how easily it can swing out - if your blade has too extreme a rake, the blade could drive it out pretty fast.

These type of saws just look like they belong in some sort of Horror movie .... Although this looks to be a more compact design than what other manufacturers seemed to have made. There is a Robinson version for sale up in Mackay at the moment and a rather sad version made by Thornley down in Melbourne.

Originally Posted by Bill Houghton

Swing saws - the American term for this type of saw...

I don't know, but I'm not sure this is a real swing saw - or more likely it's a double swing saw, with the bottom arms to counter the swing of the top arm. This would also balance the effect of gravity as the top arms swing the saw down, the bottom arms swing the saw up. I believe it does swing forward more easily than a radial arm saw - and having played with its bigger brother, the SO No.2 (26" blade) at the Timber Museum I can tell you the two sets of arms moving through their respective arcs, gives a really weird motion (and apparently a straight cut).

Originally Posted by Bill Houghton

...if your blade has too extreme a rake, the blade could drive it out pretty fast.

I guess the blade should have a neutral or negative rake like a radial arm saw blade. I'm keen (impatient even) to see what blades I got with it.

Originally Posted by Gaza58

These type of saws just look like they belong in some sort of Horror movie...

Horror movie . Nah, this has to be one of the sexiest saws ever .

Cheers, Vann.

Originally Posted by Gaza58

...There is a Robinson version for sale up in Mackay at the moment and a rather sad version made by Thornley down in Melbourne.

Any chance of photos?

Cheers, Vann.

A little more info gleaned from my nephew (who's storing the saw).

The machine tag:

White SO M23247FI.jpg Ref No. M23247F1.

And the motor tag:

White SO motor.jpg

The HP and RPM ratings confirm this is the smaller No.1 (18") size SO.

There's no indication of who the motor manufacturer is - but the Type "WKT 26/26" is also to be found on my 4hp Wadkin PK motor, which has BTH (British Thomson Houston) rotor and stator. Many other BTH motors I've looked at also have that "WKT" designation.

White NJ.jpg Two identical tags on a White NJ chain & chisel mortiser, that Andrew Hills thinks is 1950s.

SO Put3.jpg Tag on the SO No.2 at the Timber Museum - looks like an older style to me.

Cheers, Vann.

I managed to nag my nephew into sending me a couple more pictures.

SO-15.jpg Saw retracted (back position).

SO-14.jpg Saw fully extended (forward position).

I'm not sure what those lose wires are about. Hopefully just restraining the linkage from swinging during transport - and not dodgy electrical wiring .

SO-16.jpg

Looks like the "Off" button is beyond its 'best before' date. I'll have to see if I can find a less modern button station in my bits and pieces box. That'll give me the incentive to check out the wiring at the same time. Nice brass brake lever at the RH end of the motor.

Cheers, Vann.

Originally Posted by Vann

...and having played with its bigger brother, the SO No.2 (26" blade) at the Timber Museum I can tell you the two sets of arms moving through their respective arcs, gives a really weird motion...

I found it! I knew I'd taken a video of it - I found it on my phone where it's been hiding for a couple of years.

White SO Saw - YouTube

Sorry about the poor quality and focus .

Cheers, Vann.

Originally Posted by Vann

...I'm in Wellington, 700km away from where it's stored, and I won't get to fondle it until November .

In November Auckland was in covid lockdown. I final got to Auckland in mid February. Unfortunately my nephew was away, nevertheless I did go and briefly look at the saw.

Originally Posted by Vann

...I'm keen (impatient even) to see what blades I got with it...

The seller screwed me over on that one. The sale included a stack of blades - four of which were tungsten-carbide tipped.

SO-13.jpg

But when my nephew picked up the saw he was only given 4 blades - none of them tungsten-carbide tipped .

Anyway, while I was there I had a look at the electricals. The saw has a switchgear cabinet just above the base. From there a flexible steel-clad cable goes up inside the curved mainframe then pops out the top and goes down the back of the upper arm to the On/Off pushbuttons (yellow line). When the On button is pushed the contactor in the switchgear locks on and livens a second flexible steel-clad cable which also goes up inside the curved mainframe and goes down the back of the upper arm to the motor (blue line).

SO 1.jpg

I expected to find "Brookhirst" switchgear in the cabinet, but instead found this - which looks very similar to this 1931 "Igranic" advert.

SO 2.jpg Igranic switchgear.png

A closer look.

SO 3.jpg "366" - whatever that means (model number?).

Igranic and Brookhirst merged in 1960.

And this is the terminal box on the motor. Six wires suggests the motor can run on two voltages (though there's no indication of that on the motor tag).

SO 5.jpg

Cheers, Vann.

Originally Posted by Vann

Six wires suggests the motor can run on two voltages (though there's no indication of that on the motor tag).
Cheers, Vann.

Six wires could also suggest that the motor was designed to be used with a star/delta starter.

Originally Posted by Bohdan

Six wires could also suggest that the motor was designed to be used with a star/delta starter.

Yes. I don't know if the motor was made specially for the saw (the motor housing was), of if they used standard stator & rotor combos.

Cheers, Vann.