Brian Howie wrote:


Hall effect switches will be better.

Good idea, if the problem is dirt etc. on the contacts.

If it is caused by poor machining, them it won't help.

Poor machining can cause contact, or parts initiating contact, to 'wobble'
rather than make / break cleanly and stay firmly made. You get a similar
effect in laser based sensors which use mirrors to form a closed path, eg a
ring laser gyro. There you are not closing a contact, you measure something
else, but if the mirrors can move......