I need a rubbing plate


Temporal Novice
Can anyone tell me where I can purchase rubbing plates in the UK??.I need it for a new design im working on.Thanxs.
Rubbing Plates are usually home-made. The most basic is one of those soft plastic lids, like they have on the top of Pringle Potatoe chips cans. Other ones have a coil of wire glued under them.
Thanxs J.s.Im having trouble finding schematics that actually make sense.Do you know of any new schematics on the web that in theory should work??.