Wireless Set No. 52 Canadian - Project

[David Dunlop]

Back in Posts #765 and #766, when I first decided to tackle some of the work on the Supply Unit, I had discovered a small patch that had fallen off the upper rear corner of the left side of the case for the Vibratory Supply. It had been lacquered in place to serve as insulation to shield some wiring on the main supply unit from accidentally contacting the side of the case.

At the time, this small piece looked either made of a thin’ plastic, or thick manila sheet. On closer inspection now, I am pretty certain it is a thin plastic. Over time, it had developed a few ripples in it and was proving difficult to get to lay flat again on the side of the case.

I decided to use some old clear nail polish my lovely Wife had donated to the cause, due to the polish having turned a light amber, to reattach the patch. As soon as that was done, I set one of my hydraulic jacks on top of the patch to weight it down and fired up my heat gun on low heat (350 degrees F) and directed the airflow into the back corner of the case, under the jack. I did that for almost two minutes. At that point, the rear sheet metal of the case was uncomfortable to the touch and the base of the jack was warmer than room temperature. The heat gun was then turned off and the entire assembly allowed to cool down for 6 hours. Quite pleased with the result.

Now there are a couple of items to address on the Supply Unit itself, related to the Vibratory Supply.


David

[David Dunlop]

The last small project directly related to the Vibratory Supply was finished this morning, which involved reinstalling the hardware set that had fallen out of the right side of Panels, Phenolic No. C1 (ZA/CAN 4229). This discovery was also covered back in Posts #756 and #766.

This Panels assembly is fitted to the back end of the tray in the Supply Unit the Vibratory Supply and its Case slide in and out on. The Panels supports the three Sockets, Metal, ¼-in OD 40 tpi thread, No. C1 (ZA/CAN 4583), which are basically a form of Banana Socket the Vibratory Supply plugs into when in place.

The front collars of these Sockets have ridges in them parallel to the longitudinal axis of the sockets and the sockets are fully threaded on the outside. On the backside of the Panels, Phenolic there is a 1/16-in free space between the Panels and a pair of hex nuts run up against each other and lacquered in place. This gap allows the Sockets to ‘float’ on the Panels, which allows the plugs on the back of the Vibratory Supply a better chance to capture the sockets. Probably a gauge was used on the assembly line t make it easy and consistent to attain this gap. The Sockets and Panels assemblies were likely assembled to the tray for the Vibratory Supply, before the tray was riveted in place at the bottom of the Supply Unit chassis. This latter point makes it trick to replace the right side screw assembly that had fallen out of the Panels.

When the wiring was disconnected from the Sockets, the lowermost lock washer was covered in rust that needed to be tidied up. Removing the wiring, with its large tags provided more access to where the hardware went, in behind the chassis side frame. The other thing that was necessary was to slide a wooden wedge between the chassis side frame and the back of the Panels to hold the Panels firmly up against the back end of the tray assembly. This allowed the screw to be reinstalled to fully pass through the Panels far enough to easily engage its lock washer and hex nut when the time came to fit them.


David

[David Dunlop]

Given the tight space behind the Supply Unit chassis and the back of the Panels assembly at the rear of the Vibratory Supply tray, I needed to be sure the hex nut and lock washer stayed put long enough for the screw to capture them.

To do this, I glued the hex nut to my 5/16” Box End Wrench with clear nail polish, and then glued the lock washer to the hex nut, being sure to keep the polish out of the hex nut threads and the washer centred over the hole in the hex nut. Once dried, it was easy to hold the two parts in place and manoeuvre the screw to engage the thread in its hex nut. As the hex nut tightened down, it popped free in the wrench and shed all the nail polish. I could then switch to the open end of the wrench on the backside and a screwdriver on the screw to carefully tighten the hardware. A final wipe of polish across the back of the hex nut and it was all done, and the wiring could be reinstalled on the Sockets.

Now that is out of the way, I need to look at how best to access the hex nut binding the Case for the Vibratory Supply and fix that problem. All that work is in the Supply Unit itself but has a major influence on the Vibratory Supply.


David

[David Dunlop]

Well this part of the project is going to be full of challenges.

I need to get the Blower Motor assembly for the Supply Unit out of the way to gain access to the hardware set causing the case for the Vibratory Supply to jamb in its tray. I studied the blower for the better part of half an hour looking for an easy way to remove it. There are none. The blower assembly and its related Covers were definitely installed on the front panel of the Supply Unit before the panel was installed on the Supply Unit chassis. Then its power feed wire was soldered in place. In situ, there is not enough room to easily get even the smallest tool onto any of the Covers hardware to remove it. You can loosen it all but end up resorting to fingers to ease the hex nuts out. A small shop magnet on a telescopic stick helps, as does a small pair of needle nose pliers. But even with all that, I still dropped one hex nut and one lock washer into the innards of the Supply Unit. Fortunately, they both dropped to the bench when the supply was carefully turned upside down and I knew what two sets of hardware the bits came from. Still interesting for what is intended to be a temporary disassembly.

Once off, the Covers was actually in better shape than the one on the Sender. The screen was popped inward (as was the one on the Sender), but no screen wires were broken and the screen pressed back flat with a little gentle thumb work. The rust accumulation on the inside of the Covers and the Blower Fan Blade is about the same as on the Sender Blower. I think dust settles inside the Covers, and static clings to the fan blades. Over time, this dirt accumulation attracts moisture and then rust settles in on the surfaces. Also, the inside surface of the Covers is primed only. There is no Gloss Navy Grey topcoat inside there at all.

The large pieces of front panel paint missing inside where the Covers sat had actually peeled off and curled up into tubes inside the Covers and the red oxide primer on them confirmed the paint was from the 1966 rebuild.

That was enough excitement for this evening. I shall study and plan for the next step tomorrow.


David

[David Dunlop]

Unlike the grub screw on the Sender Blower fan, the one on the Supply Unit fan was well and truly seized in place.

Two days of soaking in sewing machine oil, lots of hand tapping on the fan hub with a suitable sized punch and I was able to pop the grub screw free and into about a one-quarter turn mode, back and forth. Another day of soaking and I was able to slowly work the grub screw back and forth more and more this morning until it came out of the hub completely.

A soak with Deoxit this time and I was able to drift the fan back and forth on the Blower Motor shaft to within an eighth of an inch of coming off completely. I then took an old, dull half-inch wood chisel, and with the blade resting on the shaft and the flat of the blade against the fan hub, I was able to tap the chisel head with a small hammer and pop the fan off its shaft.

This should make removal of the Blower Motor assembly from the Supply Unit a lot easier.


David

[David Dunlop]

Two good evenings in a row working on the Supply Unit

Yesterday I disconnected the power lead from the Supply Unit Blower Motor (Photo 1) and undid the three mounting bracket screw assemblies that hold the motor to the front panel of the Supply Unit. Exactly the same process as for the Blower Motor on the Sender, but with more limited access to the hardware in this case.

If you are planning on doing this work at any time, I would suggest you place a small sheet of paper towel underneath the Blower Motor to catch falling hardware: hex nuts, lock washers or flat washers. When they drop, they are a lot easier to retrieve on a white paper towel than when they dive deep into the bowels of the chassis and hide among all the other shiny, metallic bits and pieces.

As hoped, once the Blower Motor was out of the way, I had a good view straight down the right side of the Net Switch, at its back corner near the large metal coil box to the round head slotted screw I needed to get a screwdriver on. Once the screw was captive, I carefully tightened the hex nut and did a test fit of the case for the Vibratory Supply. It cleared the hex nut nicely, but hit the screw head on. This was a replacement screw for some reason and it was 1/16 “ to 3/32 “ too long. About ten minutes careful work with a large flat file, with a large piece of paper towel on the tray to catch all the filings, and the screw was flush with its hex nut.

Another test file of the Case this evening and it slid easily all the way back to its spring clip. A nice way to end the week.


David

[David Dunlop]

I realized after my last post that I had neglected to give much detail on how I actually removed the Blower Motor assembly from the Supply Unit, so best sort that out now.

The three mounting studs are located top left, top right and bottom dead centre and the hex nuts require an 11/32-inch spanner or small socket. Since there is not a lot of room inside the chassis to swing a spanner effectively, my tool of choice is a ¼-drive socket drive, which I use just to crack the hex nut loose. Once loose, I resort to just the socket with my bare fingers to back the hex nut to the end of the screw. I then use my fingers alone to remove the hex nut, keeping the lock washer well out of the way. With the hex nut out of the way, I then use a small slot head screwdriver to nudge the lock washer far enough down the screw shank to be able to grab the edge of it with a small pair of needle nose pliers and remove the lock washer. There is no lock washer on the mounting screw assembly in the upper right corner of the Blower Motor assembly. Electrical grounding braids terminate here on a large Shakeproof Tag, which serves as the lock washer. With the lock washers and Tag out of the way, the next item to be removed is a flat washer. It may stick a bit to the rubber grommet style shock mount behind it. If so, a small blade screwdriver will pop it loose and the same removal process as used for the lock washer works well.

I generally leave the three long mounting machine screws in place up to this point. As the hardware is loosened, the weight of the Blower Motor holds the screws in place quite nicely. I start with the lower mounting hardware, go to the upper right set and finally the upper left. While holding the Blower Motor with one hand, I remove the three screws in the same order. To remove the assembly, I moved it straight back into the chassis and swing it to the left as the fan shaft at the front of the motor clears the front panel. This will bring the Blower parallel to the inside of the front panel, with the fan shaft facing the large opening on the right side of the Supply Unit chassis. You can then angle the Blower down slightly as you bring it out the right side to ensure the Phenolic Panel assembly on the back of the blower clears the chassis upon removal.

Sorry I missed all this originally.

David