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Old 27-10-20, 17:18
David Dunlop David Dunlop is offline
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Join Date: Feb 2006
Location: Winnipeg, MB
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Default PINS, Studs Cowl-Fastener, Shakeproof No. 98-2-CP ZA/CAN 4839

Sometimes the side projects are just as interesting as the main event. A good example of that is the research done to track these items down.

As with all of the parts for the Wireless Set No. 52, the above noted description for these parts is the military one, taken directly from the Illustrated Parts List for the 52-Set. If one searches the web using this description, or even parts thereof, one does not find much. Searching with the name ‘Airloc’ found on the larger Cowl Fastener Studs did turn up some illustrations of the studs and their corresponding receptacles and a general description of how they worked, and not much more.

Several styles of studs were shown and confirmation was given their prime use was in the aviation industry, where the most common studs were either slotted truss head, or slotted countersunk. The wing head styles used in the 52-Set are largely ignored.

When one actually has a complete 52-Set on hand to study and cross reference to the Illustrated Parts List, the light bulb eventually goes on that the Shakeproof Company also made similar, though smaller, wing head cowl stud fasteners, and these were used on the Supply Unit and Sender. An even closer look at the four of these on my set, after they had been cleaned, revealed a third company, Dot Fasteners, was also making these smaller wing head cowl fasteners as one time.

It took some digging, but I now know the fixed receptacles for the larger Airloc stud fasteners can be found on-line at vintage aircraft parts suppliers. The wing head studs of any size or company are still proving elusive. That just left the PINS to deal with.

The PINS are what make these fasteners work. When the stud is inserted into the spring receptacle and given the required one-quarter turn, it is the two ends of the PIN, sticking out either side of the stud that engage the slots in the receptacle and follow them down to the cups where they lock in place. These PINS are one time use only. If the stud needs to be removed for any reason, the PIN is pressed out and removed, and a brand new one put in its place when reassembled. Logic said the PINS had to be available somewhere as the studs in one form or another are still being used today. It was not until another recent search of the web that I spotted a photograph of one of these PINS, with a description of it being a ‘cross pin’ that the mystery was solved. Sticking the name ‘Airloc’ in front of the words ‘cross pin’, on the very first try, took me to a company called AIRCRAFT SPRUCE CANADA located in Brantford, Ontario and their very helpful Sales Rep, Carolyn Harris.

Carolyn pointed me to Stock Number 04-01071 in their inventory, which turned out to be:

AIRLOC Cross Pin, Steel 99785-2

See the attached photo. These are the cross pins needed for the smaller Shakeproof and Dot Cowl Stud Fasteners on the 52-Set Supply Unit and Sender.

Carolyn also took the time to mention that these two different sized Cowl fasteners have an industry standard identification across all manufacturers. It shows up in the last digit of the Airloc Part Number above, ‘-2’.

The larger cowl fasteners, as used on the 52-Set Receiver and Coil, Aerial Tuning are referred to as ‘#5’, or ‘-5’ sized fasteners. The smaller ones like the Shakeproof and Dot are referred to as ‘#2’, or ‘-2’ sized fasteners.

Overall, more needed parts for the project found and an interesting addition to the learning curve.

David
Attached Thumbnails
PINS, Cowl Fastener No. 2 ZA:CAN 4839.JPG  
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