Help on wadkin table saws. Who is BTH anyway?

[IronMonger]

Hello...
This thread is in reference to my growning wadkin table saw problem. Does anyone out there know anything about a company by the name of BTH? I think they made stator and rotor sets for direct drive table saws.

I need to find out more about the direct drive stator and rotor used in the english made wadkin PK table saws. Who is BTH and what does the motor types ZF and ZEF represent.

Also, I have seen every wadin carry both a serial number and a test number. What the heck is the test number? What meaning does it have?

Thanks.

 

[Scrit]

Hi Dev

BTH = British Thompson Houston part of the old GEC-AEI empire. The test number is a serial number denoting the mechanical/electrical testing of the machine to meet whatever market requirements the machine needed. Not all Wadkin machines were built in the same factory as Wadkin owned, at various times, factories in Leicester (head office), Trawden near Colne (Bursgreen routers), near Scarborough (Bursgreen, fabricated bandsaws), Houghton-le-Spring (main Bursgreen site) and Sowerby Bridge near Halifax (Ryburn/Ryburn-Fell makers of Pickles stair trenchers and Fell auto lathes) as well as having machines made by third party companies such as the Royal Ordnance Factory in Nottingham (mainly cast-iron bandsdaws), Dominion in Halifax (single end tenoners, and I recall seeing ECAs being built there in the 1980s) and I believe that some machines were also made by Sagar in Halifax for a few years in the late 1950s and Cooksley in Kingston-on-Thames as well. The company also imported and handled a number of machines from abroad, notably the ill-fated Wadkin Agencies machines of the 1970s and 1980s, more succesful agencies such as Weinig and "badge engineered" machinery such as the current range of imported Robinson moulders. The test department therefore issued their own test certificates with unique serial numbers fior everything Wadkin sold which bear no relation to the date of manufacture, although it is possible to calculate the date of manufacture if you have a copy of the test certificates block list (which no-one outside Wadkin is supposed to have, BTW) :?

Scrit

 

[IronMonger]

Thanks Scrit...
Your a walking history book. Sounds like the old Wadkin empire were busy little beavers. I had no idea that they were scattered about like that. The old US Oliver plant was in the same old building since it was finished about 1900 something and never moved. The Eagle Machinery group who now owns the parts franchise are still in a section of the old building. Building #1, Oliver Machinery Company, Grand Raphids, Michigan.

The reason I ask is that I got some information off a US imported Wadkin PK saw. The stator and rotor set are evidently made by BTH. I am not sure yet as to the current dispensation of BTH. They may be like our Louis Allis. The company is defunct but those in the know covet these motors. Worth every penny to rebuild and rewind. Here is the info I got which is representative of a Wadkin PK motor made for the US. By the way, I do not have access to this motor as its not for sale to me.

Wadkin Ltd. Leicester, England
BTH Stator & Rotor Set
Type: WKTY 26/30
NO: 98701F4
Volts: 220/440
Phase: 3 Cycle: 60
HP: 5
RPM: 3420
Amps: 13/6.5
SW 36880

This information came out of PK 1841. I am wondering how this differs from PK 1935 or other English made PK saws.

What I find interesting is the horse power output. Most english made PKs were 4 HP and the US made PKs were 5 HP. That is a strange bump up and hard to understand why they did this. There is a good possibility that the way in which the US measures HP and the way inwhich the English measure HP are indeed different and that is the difference were looking at.
Because these were dedicated direct drive machines, the motor's outer housing was most likely the same. It was just just a different rotor and stator set. Possibly only variations in the stator only. Often to increase horse power, the rotor is lenghend. But that would conflict with the bearing journals and bearing locations within the common outer housing.

So clearly I need to continue to do some detective work to identfy the differences between these two configurations.

 

[Scrit]

Dev

The BTH motors were latterly made at Brook Motors or Brook-Crompton in Huddersfield and now called Brook-Hansen, they're Danish I believe. As to the HP rating difference, this may be down to the frequency difference between the UK and the USA (50Hz vs. 60Hz), although some of the earlier PKs were 3HP over here.

Scrit