Pye MM

[Retired]

Hi,

A very good point David. Sorting the spindle job out could prove to be only the tip of the iceberg and my fingers are well and truly crossed that Alan doesn't find too many more problems. The metal rectifier was OK on the set I worked on as was the winding.

I once rewound a field winding belonging to a Murphy A30C using my wood turning lathe which at the time was fitted with variable speed control (3 phase). As you rightly say David these windings have a large amount of fine wire in them. At the first attempt the winding was almost completed when suddenly it collapsed. I was not at all happy after spending a few hours and being so near to success; the wire was wasted because it was badly tangled and these coils are huge.

On the second attempt I made a new bobbin with decent flanges and backed these up with pieces of plywood ensuring this time there was no chance of collapse. With the winding completed I wrapped it tightly with insulation tape then with cotton cloth before removing it from the lathe.

I think the spindle will be the hardest part of this restoration for you Alan as the other jobs if need doing will be more easy and straightforward.

Please bring the old spindle to Golborne Alan as I will be interested to see one of these again and I'm sure my chum David will also be interested.

Kind regards, Col.

[AlanBeckett]

I'll answer a couple of questions first, before pressing on with the switch saga.
I didn't try to fire it up 'cause I got just the 'works' from Joe. I don't think he did. I didn't try when I got it because some of the wiring is very fragile. A word of advice to anyone tackling one of these, disconnect the interconnecting wires before removing the 'works' from the cabinet. That way it should survive while you work on the mechanics etc. So, no, as yet I don't know what state any of the elctronics is in, apart from the valve heaters. I don't expect the Rectifier or the Electrolytics to pose a problem, but as Col says, the Speaker Field Coil may be a problem, but that bridge is to be crossed later.
I decided I'd tackle the switch first as, based on Col's experience, it's something of a make or break exercise. Getting it wrong could reduce the set to scrap. I've got the technology to make a new one - Lathe, Milling Machine, Rotary Table etc - but just like Col's setup it's all a bit brutal for this size of job.
So, to battle. I'll divide this story into several Posts to avoid having too many pictures in each one:-
Step one was to remove the 9 tiny (8BA?) countersunk screws which attach the LH Panel to the partitions. That didn't do a great deal because the Panel is still attached by the box which holds the coupling coils. Actually I suppose it's the other way round in that the Panel supports the box.
So, Step two was to remove the 3 Cheese Head screws that hold the box to the Panel. That freed things up a lot more but there were still a couple of wires restricting rotation of the panel.
So, Step 4 was to disconnect the Capacitor on the RHS of the Panel - it was already floating as one end is returned to a Panel screw. There was no mechanical joint to the wire so I cut the wire to allow the wire to be withdrawn.
Step 5 was to unsolder the other wire that passes thrugh the panel. This one goes to the Reaction Cap as far as I can see.
Step 6 was to gently pull the wires through the holes and fold down the Panel, and there was the switch
It was possible to rotate it with a big pair of pliers as Col found. It's so stiff that the detent at the front doesn't do anything. I'm pondering again 'cause I'm not entirely sure how to get the shaft out. I can't remove the Bakelite panel as one of the screws is behind the other side panel. It won't come out of the back 'cause the valve screen is in the way. Anyway, I've applied more Plusgas and knocked off to write this and have some lunch.
More later.
Alan

                   

[AlanBeckett]

I just thought I'd add a better picture of the switch. I've got lots more pictures, just in case
Alan

   

[Retired]

Hi,

Please be careful Alan as you are now ending up with a pile of bits just as I did at first. One suggestion which is obvious if pointed out; remove the switch contacts from the spindle but ensure you take note of how they are attached. This will give you a "flat" to grip on the spindle and possibly avoid causing more damage to the spindle by using pliers on the round sections because if you throw up a burr the spindle will be even more difficult to remove. You already know just how weak these spindles are so avoid breaking or distorting it as you work.

Kind regards, Col.

[AlanBeckett]

Col,
Yes, I'll do that next, as soon as I'm confident that I've got the measure of where all the bits fit. One thing that is exercising me is how is the spindle located, longitudinally? I can't see any bushes etc yet. I'll have to get the torch and magnifying glass out.
Alan

[Retired]

Hi,

Again be very careful Alan; I think the shaft is located by the adjusting screw and lock nut at the far end but the knob end I seem to recall having to cut a circlip groove; please have a good look for a circlip?

Kind regards, Col.

[Joe]

I didn't fire it up before handing it over in case anything decided to go bang in a spectacular way and I wouldn't have learnt much due to the seized controls.

I'm certainly pleased I didn't decide to keep it.

- Joe

[AlanBeckett]

Col,
I remember you mentioning a circlip groove.
I fear I'm going to have to take the other side plate off so that I can take off the Bakelite Panel, then I can get at the end of the shaft, then .......
You're right, it's like a demented Meccano model
Alan

[Retired]

Hi,

I still feel sure that the spindle can be removed Alan without lots of dismantling; the opposite end of the spindle to the knob I think is centred and simply locates onto the point of the adjusting screw; slacken the locknut and unscrew a few turns to see if the spindle becomes loose. If it does you then only need to remove the contacts to allow the spindle to be withdrawn. If I'm right about the circlip this will be positioned to allow removal of the spindle towards the front whilst still attached?

If you end up with all the panels loosened or removed you could find alignment problems later when you try to put it all back together again.

Have you considered moving back to Queensbury then I could pop over?

Kind regards, Col.

[AlanBeckett]

Col,
I don't think so, at least on this one. Have a look at the picture in Post #67.
The adjuster on the Left/bottom is the end of the Tuning Capacotor spindle.
The end that you can see on the right/top is the end of the switch spindle.
I'll check further tomorrow, if I'm spared.

As all old codgers no doubt do I sometimes wonder what would have happened if we'd stayed in Queensbury. I expect we'd have frozen to death by now

Alan