UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post

TonyDuell · 26th Apr 2019, 3:38 pm

My late mother had a Singer sewing machine with that 3 pin connector (I have it now). I repaired it a few times, and I think it pretty much meets the requirements for double insulation (and thus the lack of earth is not a major problem) :

The motor is encased in a (bakelite-like) plastic housing, which also holds the ball races. Thus the motor and spindle are insulated from the machine body. The motor spindle has a metal worm gear on the end which meshes with a fibre (insulating) gear on the back of the handwheel. Note that the spindle/worm can only be reached by removing covers with a screwdriver.

The lamp/switch is a solid bakelite-like moulding.

All internal wiring is sheathed, so I think that's double-insulated too.

26th Apr 2019, 3:38 pm	#10
TonyDuell Dekatron Join Date: Jun 2015 Location: Biggin Hill, London, UK. Posts: 5,208	Re: Vintage sewing machine suppressor help! My late mother had a Singer sewing machine with that 3 pin connector (I have it now). I repaired it a few times, and I think it pretty much meets the requirements for double insulation (and thus the lack of earth is not a major problem) : The motor is encased in a (bakelite-like) plastic housing, which also holds the ball races. Thus the motor and spindle are insulated from the machine body. The motor spindle has a metal worm gear on the end which meshes with a fibre (insulating) gear on the back of the handwheel. Note that the spindle/worm can only be reached by removing covers with a screwdriver. The lamp/switch is a solid bakelite-like moulding. All internal wiring is sheathed, so I think that's double-insulated too.