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💎 Turn Rough Rocks into Polished Perfection — Join the Elite Rock Tumbling Movement!
The KoolStone C1 Rock Tumbler is a professional-grade, beginner-friendly kit featuring a large 2.5LB rubber barrel that operates 75% quieter than typical models. It offers precise tumbling control with 3 adjustable speeds and a 9-day timer with memory and auto shutoff. This all-in-one kit includes assorted rough stones, polishing grits, ceramic media, spare belts, and jewelry fastenings, supported by a 1-year warranty and 90-day money-back guarantee—ideal for STEM enthusiasts and hobbyists eager to transform ordinary rocks into stunning polished gems.










| ASIN | B09YM33DGD |
| Age Range Description | Suitable for children aged 13 and above |
| Best Sellers Rank | #16,935 in Toys & Games ( See Top 100 in Toys & Games ) #6 in Kids' Rock Tumblers |
| Brand Name | KoolStone |
| Color | Brush Edition: C1 |
| Customer Reviews | 4.5 out of 5 stars 2,832 Reviews |
| Educational Objective | STEM |
| Included Components | 1-Year Warranty Card, Illustrated Learning Booklet, 1A Power Adapter, Jewelry Fastenings, Mesh Strainer, Screwdriver, 1LB Assorted Rough Rocks, 3 Belts for Spare Use, 4 Bags of Polishing Grits, 1 Bottle Ceramic Tumbling Media, Rock Tumbler Base, 2.5LB Capacity Rubber Barrel |
| Indoor Outdoor Usage | Indoor |
| Is Assembly Required | No |
| Item Dimensions | 11.22 x 9.02 x 5.71 inches |
| Item Type Name | Rock Tumbler |
| Item Weight | 2.84 Kilograms |
| Manufacturer | KoolStone |
| Manufacturer Maximum Age (MONTHS) | 1188.0 |
| Manufacturer Minimum Age (MONTHS) | 156.0 |
| Manufacturer Part Number | KS20220422 |
| Material Type | 1.)Tyre grade rubber barrel and top-quality stainless steel. 2.) If you received the package and missing parts or damaged, no worries, please feel free to reach out at: [email protected] to take the replacement. 3.) Any problems before purchasing, please reach out at: [email protected] to get the answer. |
| Model Number | KS20220422 |
| Number of Batteries | 1 AA batteries required. |
| Number of Players | 1 |
| Operation Mode | Manual |
| Power Source | AC Adapter |
| Set Name | C1 Rock Tumbler Kit |
| Size | Large |
| Supported Battery Types | No batteries required |
| Theme | Perfect gift for rock lovers and hobbyists to create stunning polished stones. |
| Unit Count | 1 Count |
A**S
Great small rock tumbler….
Great product. Works well, tumbles relatively quietly in the rubber drum. Easy to load/unload rocks for the various stages. Easy to set up the duration in days and speed required. Excellent instruction manual. Would recommend to buy for anyone interested in seeing the beauty hidden away in some fairly common rocks..
M**R
Great value for people who constantly tumble rocks.
Product works well. Arrived with extra belts, some stones, grit, and ceramic. Customer service A+. MOTOR died two weeks into tumbling; I contacted customer support and messaged with Daisy. She sent out a replacement motor which I received within a week. Also sent out a screw driver and extra screws, and emailed a link to a video to show how to take out the old motor and replace it. Replacement was easy. Machine is up and tumbling again! Barrel size is larger than my other tumbling barrels. Noise level isn't quiet, but it isn't outrageous either. It is compact, light weight, and for the money, it is an excellent product. The bonus is the customer service.
G**H
Great for a First Time Tumbler
For a first time rock tumbler this is great! Super easy to use- the instructions are clear & simple to follow. The machine is easy to use & pretty quiet for what it is, but I also have nothing to compare it with. It's small enough I'd take it camping with me as long as I've got an electric site. I've just started the second phase & the first phase worked well!
J**N
Best in class IMHO
Great beginner tumbler. Kit includes everything needed to get started right out of the box (tumbler, stones, grit kit, jewelry findings, instructions) and a generous 1 year warranty. Digital controls regulate on/off, rpm, and number of days per tumble and work smoothly and accurately. Grits include coarse, medium, fine, polish, and ceramic tumbling beads to cushion stones during the tumble. Stones are dime to quarter size quartz, jasper, etc and do tumble nicely. The jewelry findings are definitely kid oriented but are a nice inclusion. Only negative is that some reviewers find that the drum spins too fast for a really good polish. T his is discussed on many Youtube videos. I feel the tumbler is fine for kids or amateur adults and certainly a step up from the others I have used in the under $100 dollar range, especially given the generous 1 year no questions asked guarantee. Recommended.
C**S
Great machine.
I've had no problems, runs 24/7 with no issues. They sent free belts as a gift after purchase. Customer service is excellent, Daisy always replies to emails right away and is willing to help with any questions or requests I may have.
T**D
Great Tumbler! But do some research about proper tumbling technique before using.
Edit 11/29/23. Still love this tumbler. Had a problem with it. Contacted customer service and they took care of it right away. Awesome company, and the best service! Makes a terrific gift for the holidays. We got one for our grandkids this year. Got this tumbler for Christmas. Favorite gift this year. I Love going out and Beaching and finding Afates, Jasper and Quartz treasures. This unit is great! It's quiet, works well and the company has responsive customer service. It comes with a beautiful color instruction manual. The manual isn't bad. But I've learned from groups that tumble on Facebook and forums that there are several things tumbler manufactures get wrong in the instructions. The biggest one is speed. This tumbler spins too fast in all speeds and will bruise stones easily if you run it in speed 3 or 2. So always run it on speed 1. The manual lists RPMs at the axle I timed the RPMs of the barrel and that is rotating at 70-90. It is still faster than recommended but if you fill the barrel as close to 3/4 as possible along with ceramic filler you can minimize bruising. I included picks from my 2nd Tumble and they turned out good with speed 1 and mostly full tumbler. After first cycle you will need to have filler for other 3 cycles. Ceramic works but if you don't have enough ceramic to fill close to 3/4 I found decorative glass beads at the dollar store that work great as filler. I also use 2 tbs of Borax between each cycle and run for 2 hrs will clean the grit from rocks and tumbler pretty well which is essential por good polish. After polish cycle I run for 2 hrs with 2 tbs Ivory soap flakes to help increase shine. Also be careful in cycle one with small stone as this tumbler turns very fast and small stones can dissappear if you run it for a full week. So I check after 4 days to see if I should pull them out and sub in glass beads as filler. Some stones make take more than a week in first cycle. Agates take awhile and you don't wants pits or irregularities to carry grit into polish cycle. So I try to get very smooth in first stage. Anyways this tumbler is alot of fun and I am looking to purchase other tumblers now. I am particularly interested in a vibratory tumbler, they are much faster and use less grit. Potentially you can have polished rocks in a week instead of a month.
M**S
Broken after 2 weeks
My original review was that the tumbler Stopped working after 2 weeks. Amazon said I was unable to return. The company gets 5 stars for customer service. The company reached out to me and informed me they were aware of some faulty units and they offered to replace the unit or refund me.
L**S
Motor dies out fast, can’t handle much load
Update: the company reached out to me on their own initiative, advised they had had a batch of bad motors that have all since been pulled out of the stock, and sent me a full replacement of one of my two units that had died. I have been running it 3 weeks so far with no issues. They made the process very easy and positive. Everything about this product seems truly great, especially for the low cost, until you try to actually run it for more than a month or two. I bought two of these, I liked them so much, and I have never filled the tanks over the weight capacity, but both motors died out within the first two months of use. It seems as though the motor simply isn’t designed to handled a tumbler load where the water level is much more than 1/2 full once rocks and media are added. And the drum is pretty small so you really aren’t able to tumble much with this guy, which is frustrating considering it takes a full month to get through all 4 cycles. It was exciting at first but then truly disappointing when it died out within the first few months. Both did. Only buy this if you intend to use it very lightly. I’m really bummed they couldn’t make the motor handle the overall design.
N**3
Poor quality
Worked for a month then the motor gave up, I followed all the instructions on weight. The belts are also poor quality, went through 2 In just a month.
D**Y
Solid construction
This is well built and not at all a toy. We're only partway through our first set of rocks but we eagerly anticipate each new tumble. There was an issue with the drum but the company very quickly addressed it and sent a replacement. Very impressed.
A**E
Works great, fantastic customer service
Edit Nov 12: I have to say my experience with Koolstone has been fantastic! Top notch customer service. Very quick response, very polite and understanding. They quickly resolved my problem by replacing my “lemon” and I am back and tumbling. After a week or so they even reached out again to make sure everything was still running smoothly and that I was happy. Thank you 😊 EDIT Oct 25: more disappointment! The tumbler just randomly stopped mid cycle. I had it on speed 2 for 6 days, I had 2 days left and it just stopped. At first I didn’t think much of it and checked my rocks. They looked ok so I rinsed and was doing a 2hr cycle on the slowest speed to wash them between cycles. After 30 min I went to check to make sure everything was going good and it wasn’t tumbling anymore. The lights are on, shows days (1) and speed (1). But nothing happens when I hit start. I’ve unplugged it and everything, and yes the belt is still good. At this point this tumbler has caused more grief then enjoyment and want my money back! I was super excited to get this. Read the directions a couple times to make sure I did it all correctly. Went through stage 1 twice. Stage 2, 3 and 4 once. The final outcome was nothing but disappointment. Zero shine at all. So went back and watched a few dozen videos. Threw them all in the tumbler with a bit of powder laundry soap(videos used borax but I didn’t have any) for about 2hrs to make sure they are very clean. Rinsed really well and back in stage 3. Once that was done I did another laundry soap rinse for 2 hrs, rinsed well and on to stage 4. They are not shiny at all!!!!! The rocks that came with the kids have shrunk so much too! Very frustrating and disappointing. Wish I could get the original rocks again cause this definitely wasn’t the outcome that was promised 👎🏻 Giving a 1star for the outcome As for the tumbler itself, it’s been running almost none stop for 2 months and haven’t had any issues. Did change the belt cause it snapped. But other then that it seems to be working as it should.
N**S
Study good quality
Grandson loves his tumbler
N**K
Kids love it
Product works great. Easy to read manual & easy to use. Excellent customer care.
Trustpilot
1 month ago
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