Avo-Douglas coil winder restoration

[Mike Phelan]

This is a restoration, but, although completely electronics-free, might be of interest to many members as a tool to use in radio restoration.
I obtained one of these in a reasonable state end with an excellent price, with not many missing parts, from a fellow member. Thanks, Peter.

A first look:
It all seemed to work OK – I intend to restore it, rather than just get it to work. Need a motor and flat belt as I want to retain the ‘fast-and-loose’ pulley arrangement acting as a sort of clutch.

Missing parts:
Cone for left hand reel holder.
A few 4BA and 2BA grub screws.
6 BA screws for counter cover.
0BA screws and nuts for holding end frame on base.

List of things to do:
Dismantle everything. This might mean drilling out a couple of grub screws with damaged heads.
Make/restore label and scale plate – black on aluminium.
Counter sticking and was covered in grotty black paint; clear window missing and one cover screw snapped off, others missing. Complete overhaul needed.
Wash all ball races – a few were slightly rusty.
There are two journal races for the ‘loose’ half of the F&L pulley (neat!) and another for the r/h end of the leadscrew with the disc on it.
The others are all the same size, and are angular contact races; a couple were slightly pitted and rusty, but I’ll put them in parts that don’t rotate at speed.
Most other screws were painted, so the slots needed a hacksaw running through them.
Clean all the painted parts, prime and respray grey with a ‘rattle can’.

Here we go:
I have dismantled everything and put all the ball races including the ‘loose’ pulley, and drilled out one of the grub screws that had no slot in the head. They were nickel-plated brass, but I opted for steel ones with allen heads – not original, but better for tightening.
The scale for setting the wire diameter was a bit grotty, but I managed to clean it up.
The label had through holes for the rivets, so I punched them out, but the scale plate had steel rivets sriven into blind holes and I had to drill the heads off, remove the plate, and drill the rivet shanks down so they could be fished out. I tapped the holes and used screws.
The label was beyond repair, so I made a new one from alloy sheet and drew the legend on waterslide transfer film using MS Paint.
All the ball races had a soak in some engine oil and white spirit mix – left them there until needed.

The counter:
This needed nearly as much work as everything else put together! It took some thought on how to dismantle everything; it’s one of those things that has to be done in the right order. I soaked the cover, frame and resetting lever in acetone as they were covered in some ancient black paint. The broken screw for the cover was drilled and tapped, and the two rivets for the window were also filed off and scrapped, while a CD cover furnished me with a new window.
The number drums needed a clean, but I declined to use any solvent in case the white filling for the digits was damaged. Some detergent and hot water brought them up like new.

The rest:
The entire chassis was cleaned up, primed and painted; all the ball races went into a mixture of white spirit and oil, and I soaked them for a few weeks.
I made some missing ¼” BSF screws by turning off the hex heads of the bolts I had, and cutting slots to match the existing ones. The two end frames were than assembled and another coat of paint given, I remade the label using a sheet of alloy and some clear waterslide transfer; I had to recreate the writing as the original was too far gone.

The missing cone was made using the other one as a pattern; a steel spindle with an indentation in the end for a single steel ball. The scrapbox yielded a piece of silver steel rod of the correct diameter, but I did not have anything in steel for the cone, so I used a bit of alloy rod and drilled it. I ran a 6BA hole and a steel stud so it could be locked to the spindle part so I could turn the cone on the alloy. The stud can just be seen in one of the pictures as a small dot near the edge of the cone.
Next thing I found was the trip stud did not look like a 45 degree angle – that was because it had broken off and presumably Araldited and left a stump in the trip lever, which was flush! I had to make a hole so I could get the stump out and measure it.
A new stud had to be made from carbon steel and hardened and tempered. I then gave the “gable roof” a fine polish which it must have to work properly.

The two brake linings on the reel spindle were quite hard so I removed them and found a piece of skiver to reline them.

The assembly that carries the wire guide arm was soaking in acetone together with a few other bits. When I removed them, one of the ends of the guide assembly that carries the trip lever fell off! <Gulp>
I was going to braze it on, as it is a steel casting, but decided that the broken part was really redundant; the pin the trip lever pivots on is knurled and pressed into the hole. It is robust enough to work without the other hole. All that is needed, and was done, was to thread the end opposite the knurl, press the pin in, replace the trip lever and add two nuts so the endshake on the lever could be finely adjusted and the nuts locked together.

The restoration as such is now complete – I just need to motorise it - watch this space!

This might be useful as well.

[Mike Phelan]

And finally, the finished job:

[dave walsh]

Brilliant Mike. Looks very like one I saw sold at the B+Buy in the last but one QRP Rally at Rochdale, before the Rev Dobbs retirement. That's not too far from you! Dave W

[Nickthedentist]

Incredible work, Mike.

Do you know its previous history? When do you estimate it was last used?

Nick.

[Hermit6345]

What a great job you did on that Mike! Is it difficult to set up to do different types of coil format?

Ian.

[Brian R Pateman]

Nice one Mike,

And an excellent concise write up.

I've always wanted one of these so I'm really, really jealous!

Regards,

[FRANK.C]

Brilliant job mike.
What a great piece of gear to have.
It should be able for many trouble free years of work now.

Frank

[Mike Phelan]

Thank you, everyone.

Originally Posted by Nickthedentist

Do you know its previous history? When do you estimate it was last used?
Nick.

Only a little bit, Nick. It came from a company (what sort of firm, unknown) in Liverpool who had at least two of these things.
They were sold to the person who was either a relation or someone who happened to be there when the company (possibly) closed down. He then sold it to Peter (PWH) who sold it to me.
At a guess, it possibly might have been used 5 or 10 years ago, but no way of telling.

Originally Posted by Hermit6345

What a great job you did on that Mike! Is it difficult to set up to do different types of coil format?

Ian.

Ian
Jim Beacon's site will reveal all, here. There is a different model from the same stable that does wave winding, using change wheels like a screwcutting lathe. Jim has one of those as well.

Originally Posted by Brian R Pateman

Nice one Mike,

And an excellent concise write up.

I've always wanted one of these so I'm really, really jealous!

Regards,

Brian
Thanks!
I had given up and started to make one (15% complete and parts will be recycled ) when I found this; there were plenty on eBay at a price, but one that was working and complete, like most things, did not really float my boat - no fun at all.