# Best double barrel rock tumblers for running two stages at once Source: https://tumblegrit.com/best/best-double-barrel-rock-tumbler Publisher: Tumble Grit. Picks are chosen from what each Amazon listing states, not from hands-on tests. Method: https://tumblegrit.com/how-we-pick A double barrel tumbler runs two barrels on one motor, so you can keep coarse grit in one barrel while the other moves through medium, pre-polish or polish. Coarse grinding on agate or jasper often takes two to four weeks, so a second barrel roughly halves the wait for a steady supply of finished stones and keeps polish away from coarse grit. What separates the machines: barrel size (two 3 lb, two 3.5 lb or two 4 lb), whether the motor is brushless or a traditional belt-and-motor design, whether there is a timer and speed control, and what the kit includes. Two full barrels are a heavy load, so the motor and belt matter more here than on a single barrel machine. This guide compares eight double barrel tumblers by what each listing states. ## Picks ### 1. KomeStone G2 Dual-Barrel Professional Rock Tumbler Kit, 8LB for Adults KomeStone G2: two 4 lb rubber barrels on a brushless motor and reinforced metal base, with 3 speeds and a 9-day LCD timer with pause and memory. Kit includes 2 lb of rough in 9 named stones. What the listing offers: - Two 4 lb barrels are among the largest in this guide, for bigger batches or larger stones - Brushless motor rated by the maker for 40,000+ hours on a reinforced metal base - Pause and resume with settings memory makes mid-run checks easy Limits to know: - Upper price band for a kit tumbler, tied with the AtoRock - 3 speed settings, one fewer than the KoolStone and VEVOR machines ### 2. KoolStone C1 Pro Ultra Quiet Rock Tumbler Kit - Dual Barrel 7LB Capacity KoolStone C1 Pro Ultra: two 3.5 lb rubber barrels under a noise-reduction housing on a brushless motor, with 4 speeds, a 9-day timer and a cycle record button. Full kit with 2 lb of rough. What the listing offers: - Noise-reduction housing over the barrels suits apartments and overnight runs - 4 speeds, timer, auto shutoff and a cycle record button for tracking stages - Kit includes 8 grit bags, ceramic pellets, sifter, strainer and 2 belts Limits to know: - 3.5 lb barrels are smaller than the 4 lb pairs at a similar price - The housing adds bulk and must be opened to check the barrels ### 3. Thumler's Tumbler A-R2 Rotary Rock Tumbler with Two Barrels The A-R2, the best known Thumler's model: two rubber barrels holding 6 lb of rock in total on one metal frame. Lets you run coarse grit in one barrel and a later stage in the other. What the listing offers: - Two barrels holding 6 lb in total double throughput over the A-R1 for a small extra cost - Separate barrels keep coarse grit away from polish, which reduces contamination between stages - Made in USA with a metal frame and Fasco motor named in the listing Limits to know: - Each barrel is still 3 lb, so it does not suit stones much over 2 to 3 inches - Listing does not include grit or rough, and the copy repeats marketing text rather than motor specs ### 4. AtoRock A1 Pro Brushless Rock Tumbler Kit - Double Barrel for Large 8LB Capacity, Adjustable Speed & Timer, Durable Metal Base for Adults & Rock Collectors - Includes Full Accessories AtoRock A1 Pro: two 4 lb barrels on a brushless motor and metal base with a 9-day timer, speed settings and memory recall. Kit includes 2 lb of rough, 8 grit bags and 2 spare belts. What the listing offers: - Two 4 lb barrels for 8 lb total load, tied for the largest in this guide - Brushless motor and metal base, with spare belts in the box and more offered by the maker - Full kit with grit for two runs, rough, strainer and a printed manual Limits to know: - Listing mentions both 3 speeds and four speed settings, so the exact number is unclear - Same price as the KomeStone G2 with a similar feature set ### 5. KomeStone K4 Quiet Rock Tumbler Kit for Adults, 7LB Large Double-Barrel Capacity: 7 lb (2 x 3.5 lb); Barrel: Rubber; Barrels: Double; Timer and speeds: 4 speeds, pause, memory Two 3.5 lb rubber barrels on one brushless motor, with a cover over them. Lets you run coarse grit in one barrel and a finer step in the other, or keep two rock types apart. What the listing offers: - Two 3.5 lb rubber barrels, 7 lb in total, so two grit steps or two stone types can run at the same time. - Listing gives a noise figure of 50 to 60 dB with the cover fitted, and the cover blocks access to the turning barrels. - Box includes 2 lb of rough rocks, two 4-stage grit sets (60/150/600/1200), ceramic media and 3 spare belts. Limits to know: - Two barrels double the rock, grit and media needed for each run. - The 2 lb of included rough is not enough to fill both barrels to the usual two-thirds level. ### 6. VEVOR Rock Tumbler 8 lbs Double Barrel 4 Speed Settings Rock Polishing Kit VEVOR 8 lb double barrel tumbler with a belt-free direct-drive motor, 4 speeds from 75 to 120 RPM, a 1 to 9 day timer, overload protection and power-off memory. What the listing offers: - Direct drive removes the belt, the part that wears out first on most tumblers - Listing gives the actual RPM range (75 to 120) and a quiet rating of 35 dB or less - Lower price than the brushless kit machines with a similar timer and speed range Limits to know: - Listing notes rough is not included, and does not list the grit or accessories in the box - Text describes a single 8 lb barrel in one bullet, so check the barrel split before buying ### 7. VIYUKI Professional Rock Tumbler Kit -6LB Rock Polisher(Double Barrel) VIYUKI 6 lb kit with two 3 lb barrels, a one-touch day timer with auto shutoff, 2 lb of assorted rough, 8 grit bags for 4 steps and 5 spare belts. A long-selling mid-price double barrel kit. What the listing offers: - Complete kit with rough, grit, jewelry settings and 5 spare belts - Comes assembled and has a 1-year warranty with a 90-day return window stated - Mid-range price for two barrels plus everything for a first run Limits to know: - Listing advises stones under 1.5 inches for this tumbler, which limits larger rough - No speed control mentioned, only the day timer ### 8. Leegol Electric Rock Tumbler Double Drum 6LB Lapidary Polisher Leegol double drum with two 3 lb rubber-lined, leak-proof barrels on a 120V motor, sold with 5 spare V-belts and walnut shell media. The lowest-cost double barrel machine here. What the listing offers: - Lowest price in this guide for two 3 lb barrels - Five spare V-belts in the box cover the most common wear part - Rubber-lined barrels for quieter running and step-by-step instructions included Limits to know: - No timer or speed control, so runs are timed by hand - Walnut shell media is for dry cleaning, and no grit or rough is included As an Amazon Associate I earn from qualifying purchases.