Hand Coil Wave-Winder

[Yorkie]

I've mentioned before on the forum that I was intrigued by the youtube video of the 'Universal Coil Winding Machine' designed by David Gingery in the late 1980s, based on a 1930s design. I set about making one a couple of years ago as I had all the materials in my scrap bin - a few bits of angle iron, brass bar, steel rod and a peice of ply for the 5" square base. It's a very rudimentary hand-wound machine, but as those who've watched the youtube video will know, is capable of making 'wave-wound' coils similar to those made by Denco, Osmor and the like.

As with many of my projects, I go in fits and starts. Within days I'd almost finished the machine, then other projects took over, and the winder got put on a shelf in the workshop to languish ignored, and was added to my 'round tuit' list and forgotten about.

Lately, having dabbled at winding a replica Repanco DRR2 coil, it inspired me to have another furtle around with the machine with a view to finishing it, but there are to things I'm not impressed by:

Firstly, the friction angle drive, which used an 'O' ring on the rim of a pulley which rubs on a disc at the end of the coil shaft, which it should turn by friction. I coated the disc with wet and dry paper to give it better traction, but thought that I'd try to find a bevel gear to suit. I recently found a supplier and have now fitted the bevel drive. The two shafts onto which the gears had to be fixed were 6.4mm diam (1/4") and the drives had a 5mm internal bore, so I turned the shafts down on my lathe to an interference fit to 5mm and glued them onto the shafts with superglue - a much better arrangement, which works well.

Secondly, I'm not happy with the turns counter, which consists of a 'tally counter' - the things that coach drivers use to count people back onto the coach to make sure no-one is left behind. They're quite cheap - no more than a fiver, and I guess that back in the late 80s when the machine was designed, it was by far the cheapest option, and it does have the merit of simplicity. However, with pocket calculators now available for less than a pound (86p at Tesco for example - don't get ripped off by paying 18% more at Poundland!), not only is a calculator a better option, it's cheaper. So, the next step will be to remove the tally counter and fit a small calculator using either a magnet/reed switch or microswitch to short out the = sign. All that is then necessary in use, it to enter '1' then press the + button twice to make it a constant ('k'), then each time the = switch is shorted out, the display increments by 1. (Try it).

Then to finish the winder, I need to make the wire guide.

I've attached three pics which show the winder, the old 'friction drive' and the new bevel gear. Bascially, to achieve the 'wave-wind' a cam is made by soldering a brass collar to a 1.5" diam steel 'penny washer' with the boss offset to the extent of the desired width of the coil. I made one for 1/4" and need to make another for 1/8". As the handle is turned, the wire-guide shaft goes back and forth as the coil drive shaft rotates, laying on turns in 'waves'.

One day - who knows when - I might even get round to winding a coil on it! I do know that several people have made and used one of these winders successfully.

Hope that's of interest.

[Andy M0FYA]

I recently acquired an example of what I assume is the 1930's machine which was the basis of the Gingery design.
I'll get some pictures taken and post them.
Andy

[Nick]

I recently acquired an example of what I assume is the 1930's machine which was the basis of the Gingery design.
I'll get some pictures taken and post them.

That'll be the "Morris Universal Coil Winder" - got one of those years ago - made a new scale for it - its what I used to rewind my DAC90A output transformer recently...

Simple & effective.

Nice work, David, as always... !

[Retired]

Hi,

Excellent workmanship David as usual. The bevel gears will certainly give a more direct and robust drive. You can't beat owning a lathe ( I might have mentioned previously that I like lathes).

One thing worth bearing in mind David is that if you start saving up now for some silk covered winding wire you should be able to afford a small bobbin of the wire by the time you complete your winder.

Top class David and I'll look forward to watching your progress. Please bring it along if you have the space in the car on Saturday as I'm interested to have a look at it.

Kind regards, Col.

[Radio Fixer]

Nice piece of mech engineering David, beyond my crude workshop. My coil winder is so basic but its surprising what you can do even with that. Yeah! heard about the calculator trick, not tried it. My counters binary but I can read that OK.

I take it the bobbin of new wire goes on the lower shaft and gets packed out to fit? Where did the cones come from that hold the coil former?

thanks Gary

[Andy M0FYA]

Hi Nick, mine claims to a "Morris Improved Coil Winding Machine"! With 'Improved' in both red and italics!
Pictures to follow (maybe tomorrow).
Andy

[pwdrive]

That's a neat job David, proper job, beyond my skills.

Lawrence.

[Retired]

Hi,

You could always fit a PTO to your Land Rover Lawrence to drive one of these lovely coil winders?

Kind regards, Col.

[pwdrive]

Hi,

You could always fit a PTO to your Land Rover Lawrence to drive one of these lovely coil winders?

Kind regards, Col.

Funily enough I had a rear PTO on the last Series 1 Landrover I owned many moons ago along with an Aeroparts front take off winch which was a capstan winch geared 75 to 1 off the front crank, the rear PTO had the flat belt pully drive also, it fitted over the standard PTO spline on the rear take off on the rear crfoss member.
Sadly that winch wouldn't fit my Lightwieghts front bumper without some serious hacking as the front dumb irons on the Lightwieghts are shorter than on the standard Landrover this makes the distance between the front bumper and the front chassis cross member to short to take the winch plate, the Lightwieght does not have the hole in the rear chassis member to take a PTO unlike the normal Series Landrovers do, so no PTO fun on that one I'm afraid.
The other drawback would be no overdrive as the overdrive unit has to be removed to fit the PTO selector gear so far as I can remember.

Lawrence.

[Yorkie]

Nice piece of mech engineering David, beyond my crude workshop. My coil winder is so basic but its surprising what you can do even with that. Yeah! heard about the calculator trick, not tried it. My counters binary but I can read that OK.

I take it the bobbin of new wire goes on the lower shaft and gets packed out to fit? Where did the cones come from that hold the coil former?

thanks Gary

Thanks for your kind comments guys.

To explain a bit further, the feed bobbin of wire goes on the rear shaft, the coil former goes between the cones on the centre shaft, and the front shaft carries the wire guide (presently non-existent on my winder as yet). The wire is fed beneath the guide and goes around it and out over the top of the guide which is fixed in the centre of the front shaft. The front shaft going back and forth to the extent of the 'throw' of the cam adjacent to the turning handle (as I said earlier, the cam being just a 1.5" diam washer with a brass collar soldered to it in an off centre position). As you turn the handle, the bevel gear rotates the coil former shaft, while at the same time, with each rotation, the cam moves the spring-loaded shaft with the wire guide on it. The guide moves the wire back and forth the width of the coil as it feed the wire to the coil former, so that as the coil former rotates, you achieve the wave-wound effect.

I've posted the youtube video before but no harm in doing so again. About two minutes into the video the camera pans back and you can see the whole machine in action.

As to your query about the cones Gary, I turned them, and the 'O' ring friction pulley on the lathe from black Polypenco rod. (On my woodturning lathe actually - not ideal for such a task, but at that time, I didn't have a metalworking lathe). I did actually make a wire guide, but it didn't pass the 'quality controller's' inspection - a little voice in my head that tells me 'good enough is not good enough', so I must get on with that and make a better one.

I've wound coils and transformers in the past, and at one time had a simple set-up using and electric screwdriver fixed on a board, for doing things like rewinding coils for HR headphones when they'd suffered green spot corrosion. Just wound on a full coil of 48SWG enam, and checked the resistance, then removed turns till the coil was the correct resistance then soldered the end.

At one time, Maplin sold transformer kits which were excellent - the primary was ready wound - you wound the secondary to suit your own requirements from the info supplied. I guess some law or another put the mockers on that, or maybe the just didn't sell in sufficient numbers. I've sometimes stripped the secondary off a transformer and wound my own primary.

Anyone who has wound coils by whatever means will know that the feed bobbin must rotate smoothly - not clonk about on its shaft, as any jerky movements in the wire feed is destined to break the wire, so I'll be giving that some thought.

As to Litz wire, ironically, it is in abundance quite cheaply on LW ferrite rod coils, so any coil of that inductance or less could be wound from a sacrificial LW coil, but they're only about 350uH. Rather a shame that small quantities of fine Litz are seemingly not available. Cotton or silk covered is probably just as good, but enamelled wire won't produce wave-wound coils as the turns slip off each other.

Yes Colin, I'll bring the winder to Rufforth on Saturday.

Here’s the video of the winder in action for anyone who may not have seen it before. Neat eh?:

http://www.youtube.com/watch?v=FIOocMoRsYQ