KomeStone K1 Pro Brushless Rock Tumbler Kit for Adults, Quiet 2.5 Lb

Completed two cycles so far about 20 days each. Did need to change out one belt. Rubber barrel helps with noise and seals well. No leaks. Would buy again

I ordered this on impulse as my daughter had a national geographic tumbling kit. That one is mediocre at best, however I've always wanted to have one. So, I bought the pro K-1 brushless, and I'm impressed with the rubber basin and how airtight sealed it is. Works incredibly well! Functions are simple to use. Great storage capacity also. The instructions are detailed, easy to understand, easy to follow through. They provide two extra pulley belts for the machine. A screwdriver to pop the lid, as the lid recesses into the rubber basin. There's another lid that goes over that with a butterfly style handle/screw. I have mine set up in my shed, as it's much quieter than the previous rock tumbler I experimented with. This one is awesome because it has a built-in timer that sets how many days you would like to tumble the rocks. The instructions have guidelines and suggestions. And then it also has the speed ratio. There's a pause/play button, so if at any time you want to check on the progress of your tumbling, you may do so and press pause and not lose your day counts by powering it off. This kit comes with grits, step 1- thru 4. They're one time use. KomeStone has grit kits available to purchase and reasonably priced for future tumbling sessions. I'm obviously on day 1, but I'm excited to check back in a few days. Not sure if Amazon allows for video updates or anything of that nature, but I'll try if it allows.

Original review is below. However, the customer service was very responsive and understanding. In the end I received a replacement motor and and couple extra for the inconvenience encountered. The new motor has held up much better than the original. I am continuing on with the product and tumbling. I updated to a 4 star because of the excellent customer service. Careful with this item. It goes through belts and the motor gave up before the first batch of rocks was completed. Bought a K1 pro and had delivered on November 7, 2025. It worked great for the first three steps of the process except for going through one belt already. Then the motor stopped working. I have done tumbling before and know not to overload it or otherwise mistreat it. I received prompt email responses from customer service starting January 7, 2026 at which time they said they would replace it at no cost. I have now received emails delaying the delivery twice and is now not expected until mid February at the earliest. I understand some of the winter shipping restrictions but not sure why it may take at least 6 weeks to send a replacement when Amazon can send a new one in a week if ordering new.

I’ve run this tumbler nonstop 24/7 for just over a year. It’s still going, though the lid seal and rollers are worn. Pros: Easy to load, countdown timer, pause button, durable barrel, brushless motor holds up well, fairly quiet, compact, no leaks, and low energy use. Cons: Even on the lowest speed it’s too fast for anything beyond shaping rough rocks and can bruise softer ones (even with ceramic media). You can’t slow it down enough for later stages without changing pulleys. Doesn’t restart automatically after a power outage, and belts wear quicker than I’d like. If you haven’t heard it enough already, the polish that is provided will NOT give you the high polished shine. Overall: Excellent for rough stage one rocks. Once the rough edges are knocked off I move the rocks to a slower tumbler to finish stage one and beyond. It’s a reliable workhorse, though I’ll get the standard motor next time since it’s easier to adjust the speed.

Seeing a LOT of complaints from the past two months about motors failing. Guess what? Mine stopped working today, have only had it since December. It ran strong for those two months, then today after I took off a batch of tumbles, when I went to put a new batch in, it doesn't tumble. Display lights up but the motor is cooked. I Emailed their "24/7" customer support" so I'm hoping I actually get a reply. Sounds like Komestone needs to provide better, durable motors if it wants to stay in business, because this is clearly a chronic issue, and this is supposed to be the "upgraded, Professional" model. UPDATE 02/26/2026 - I initially didn't get a reply from Komestone support when I Emailed them, but I suspect it got filtered and never made it to anyone. I used the "request a free gift" QR code and through that I got a fast reply from customer service, where I was able to explain my situation. The rep was very friendly and helpful and arranged a brand new K1 Pro to be shipped to me at no cost, since it was within the warranty period but outside of Amazon's return window. I got the new unit today and confirmed everything is working, so I've revised my review to five stars since the company is making an honest effort to uphold their warranty. Hopefully this new one will last longer. UPDATE #2 03/09/2026: The replacement unit died on me after one full tumbling cycle and a few days on the next. The motor STRUGGLES with any kind of load on the tumbler, even an empty barrel, and only starts spinning the barrel for a few seconds at best before it locks up. The "cutting-edge" motors they are using in this unit are trash. I moved the loaded barrel over to a different brand tumbler base that is rated for a lighter load and it's tumbling it just fine. This is ridiculous. UPDATE #3: The saga continues. KomeStone support sent me new motors which appear to be from a newer production run, so here's hoping they don't suffer the same fates as the previous ones.