05-09-2013, 08:17 AM
Hi,
I've been fortunate enough to see this neat coil winder close up when David kindly brought it along when we last met up. A lot of care has already gone into constructing this winder and full credit to David for progressing thus far. I was impressed by the pulleys as they looked so professional especially the round pulley groove to accept the drive belt.
David also kindly demonstrated to me how the digital calculator could be set to add increments of "1" allowing it to be used as a turns counter which I thought a very smart and simple idea compared to some counters which look very complicated for a novice to clone.
Using a secondhand sewing machine motor for the drive is very effective; these motors are cheap and readily available even if it means buying a full sewing machine from a car boot sale just for the motor and foot control. Because of the low load and very low gear ratio placed upon the motor in this application just about any sewing machine motor would be acceptable.
You are right to be worried about winding such fine gauge wire David as the wire breaks so easily. One problem easily overlooked is the starting force placed upon the fine wire just to start the feed bobbin to revolve; any jerk here is sure to break the wire because the weight of the supply bobbin acts like a brake also when winding stops the bobbin needs arresting otherwise it will over-run as already mentioned. A large feed bobbin full of wire compounds the problem.
If you are adding fixed cheeks/flanges to the former being wound David then please ignore the following. Many years ago when I first started winding transformers/coils as a total novice I made all the usual mistakes. One of the largest coils I ever wound was the field winding from a Console Murphy A30C; this was a big heavy coil requiring a great deal of wire. At that time all I had was a variable speed wood-turning lathe which was way too powerful for this delicate winding job but I set everything up and commenced pile winding guiding the wire best I could free hand which actually worked extremely well.
After a lot of worry I thought this isn't so bad after all as I neared the end; suddenly the whole coil collapsed wasting virtually a brand new field winding; no way could I salvage the wire as it was so tangled. What a terrible thing to happen and what an expensive learning curve this proved to be.
From that day on I learned the lesson well and never attempted to wind another coil without firstly securely gluing a pair of cheeks/flanges to the former; these cheeks could be cut from a corn flake packet or from tufnol sheeting I have in stock but lots of materials can be pressed into service costing nothing for the cheeks; I never had another coil collapse on me.
The very best of luck David for when you start winding and it will be most interesting to follow your progress; of course now you've start so publicly you have stuck your neck out so success is the only option but I've got a great deal of faith in you and look forward to your success in due course.
Kind regards, Col.
I've been fortunate enough to see this neat coil winder close up when David kindly brought it along when we last met up. A lot of care has already gone into constructing this winder and full credit to David for progressing thus far. I was impressed by the pulleys as they looked so professional especially the round pulley groove to accept the drive belt.
David also kindly demonstrated to me how the digital calculator could be set to add increments of "1" allowing it to be used as a turns counter which I thought a very smart and simple idea compared to some counters which look very complicated for a novice to clone.
Using a secondhand sewing machine motor for the drive is very effective; these motors are cheap and readily available even if it means buying a full sewing machine from a car boot sale just for the motor and foot control. Because of the low load and very low gear ratio placed upon the motor in this application just about any sewing machine motor would be acceptable.
You are right to be worried about winding such fine gauge wire David as the wire breaks so easily. One problem easily overlooked is the starting force placed upon the fine wire just to start the feed bobbin to revolve; any jerk here is sure to break the wire because the weight of the supply bobbin acts like a brake also when winding stops the bobbin needs arresting otherwise it will over-run as already mentioned. A large feed bobbin full of wire compounds the problem.
If you are adding fixed cheeks/flanges to the former being wound David then please ignore the following. Many years ago when I first started winding transformers/coils as a total novice I made all the usual mistakes. One of the largest coils I ever wound was the field winding from a Console Murphy A30C; this was a big heavy coil requiring a great deal of wire. At that time all I had was a variable speed wood-turning lathe which was way too powerful for this delicate winding job but I set everything up and commenced pile winding guiding the wire best I could free hand which actually worked extremely well.
After a lot of worry I thought this isn't so bad after all as I neared the end; suddenly the whole coil collapsed wasting virtually a brand new field winding; no way could I salvage the wire as it was so tangled. What a terrible thing to happen and what an expensive learning curve this proved to be.
From that day on I learned the lesson well and never attempted to wind another coil without firstly securely gluing a pair of cheeks/flanges to the former; these cheeks could be cut from a corn flake packet or from tufnol sheeting I have in stock but lots of materials can be pressed into service costing nothing for the cheeks; I never had another coil collapse on me.
The very best of luck David for when you start winding and it will be most interesting to follow your progress; of course now you've start so publicly you have stuck your neck out so success is the only option but I've got a great deal of faith in you and look forward to your success in due course.
Kind regards, Col.
Happiness is a wreck of a cabinet to restore.
