04-08-2013, 05:15 PM
Hello David, re the sewing machine motor and foot controller, well we have 4, yes four Bernina machines and a lot of spares as well.these are not the latest machine but all have a resistor in series with the motor.The motor is a series wound type with two carbon brushes, not easily reversed but possible if one needs to use the motor for other uses. Some have wire wound resistors others have a block of some material (maybe hard carbon)with wipers either side,but still in series with the motor, both type are foot switches. When needed I wind motor contactor coil on my lathe and maybe you could do the same, its not easy to regulate the tension on fine wire. I made a block of wood with a reed relay mounted on it and a plastic disc attached to the lathe chuck, the disc has very small magnet attached to it. Now as the chuck rotates the reed switch opens or closes. I bought a large calculator and modified the pcb so that the equals key is connected to the reed, incrementing as the chuck rotates. I think I have got the details correct, I seem to remember some thing peculiar about it, I made the set up several years ago, but it works well. It won't work at high speed (reed contact bounce) but it allows me to layer the turns in a neat orderly manner. I also made a foot switch for the lathe, such that I can turn it off quickly if necessary.I haven't used it a lot but its handy when needed and is easily stored. If you need any more details let me know.Ted
