On Sunday, December 27, 2015 at 10:25:37 PM UTC-5, wrote:
Hi,
I've had a Dremel multi max tool for a few years, purchased from HomeDepot for $100. It's the kind with the vibrating head that cuts wood/metal/grout etc depending on the attachment you put on. The vibration speed is controlled by a wheel that you can select from 0 to 10 (slow-to-fast). But lately the wheel doesn't seem to work right and it speeds up and down of its own accord.

Has anyone experienced the same with theirs?
Does anyone know of a reasonable fix, or is it considered a cheap tool and time to buy a new one?

Experienced opinions and advice greatly appreciated.
Regards,
Theodore

Can the case be opened? If so, I'd try blowing out the area around the speed control. Maybe you could even blow it out without opening it.

Could be dust build-up.