I bought the tumbler for my 7 year old but have had more fun than him. Running it near constant for a month has been no issue at all with the exception of the noise. The noise comes from the rocks tumbling, not the machine. I highly recommend building a box for it and filling lining the inside with foam to heap deaden the noise, then put it in a garage. That's what I did and I only hear it when I go in there. You get used to the noise but it is noticeably quiet when it gets switched off after a month. The safety features such as cut off it fingers are caught in the rollers are great, not that it is any concern as it is only the weight of the rocks. I highly recommend it but be prepared to find your own rocks and grit after.