10-06-2014, 05:13 PM
In 2011 in Model Engineering Workshop Magazine there was a design for a coil winder to wind 'solenoid' type coils - coils with turns laid side by side in layers. It was made in part from Lego, and covered interesting aspects of design, not least of which is the use of 'heart shaped cams' which enable thread or wire to be traversed back and forth evenly in a constant velocity motion. An example which is - or used to be - very commonplace is that of sewing machine bobbin winders. The article covered the geometrical design of heart-shaped cams and explains how the cam-follower enable the thread (wire) to move back and forth. I'm not sure if the cam on the original 'Morris' winder was heart-shaped for winding solenoid coils - I guess it must have done. Maybe those on the forum who have an original machine (three members I believe), could comment on this if they're reading this post?
Wouldn't be appropriate from a copyright perspective to copy the whole article from M.E.W on the 'Lego' coil winder, but maybe a few pics to give the gist of it would be OK? A glance at the solenoid coil wound on the winder will show that the turns aren't laid as neatly side by side as we might expect. The rate at which the winder traverses from left to right is a function of the wire gauge and the worm drive, and is critical or the turns will either be spaced slightly apart or slightly too close. Either way, the turns will soon ride over each other in an uneven fashion.( The article expands on that).
It doesn't seem to be worth the effort to try to create heart-shaped cams and worm gears to do the traversing when it's possible with a hand wire guide on a motor-driven winder to attain acceptable results easily as good as the one in the pic. That said, the particular winder made from Lego was for a one-off run of solenoid coils. The writer stated that stepper motors are the way to go, and was considering developing a winder along those lines, but that has yet to materialise!
The 'Gingery/Morris winder is along similar lines to the original - the time honoured 'KISS' technique, of which there is much to be said!
In the 'Occam's Razor' principle adopted as the G-QRP Club: 'tis vain to do with more that can be done with less'.
Hope that's of interest.
Wouldn't be appropriate from a copyright perspective to copy the whole article from M.E.W on the 'Lego' coil winder, but maybe a few pics to give the gist of it would be OK? A glance at the solenoid coil wound on the winder will show that the turns aren't laid as neatly side by side as we might expect. The rate at which the winder traverses from left to right is a function of the wire gauge and the worm drive, and is critical or the turns will either be spaced slightly apart or slightly too close. Either way, the turns will soon ride over each other in an uneven fashion.( The article expands on that).
It doesn't seem to be worth the effort to try to create heart-shaped cams and worm gears to do the traversing when it's possible with a hand wire guide on a motor-driven winder to attain acceptable results easily as good as the one in the pic. That said, the particular winder made from Lego was for a one-off run of solenoid coils. The writer stated that stepper motors are the way to go, and was considering developing a winder along those lines, but that has yet to materialise!
The 'Gingery/Morris winder is along similar lines to the original - the time honoured 'KISS' technique, of which there is much to be said!
In the 'Occam's Razor' principle adopted as the G-QRP Club: 'tis vain to do with more that can be done with less'.
Hope that's of interest.
Regards, David.
BVWS Member.
G-QRP Club Member 1339.
'I'm in my own little world, but I'm happy, and they know me here'
BVWS Member.
G-QRP Club Member 1339.
'I'm in my own little world, but I'm happy, and they know me here'
