Comparison Rotary Tumbling vs. Vibe Tumbling
Maybe you are brand new to rock tumbling and are not sure which type of tumbling method is best for you or what you’ll enjoy more, or perhaps you’ve been rotary tumbling all your life but have never taken the plunge into vibration tumbling. On the RTH Forum it’s also common that we get asked about tumbling flat rocks, or cross shapes, or any other specifically shaped rocks that are intended to be made into jewelry. Whatever the case, what we hope to do in this article is to break it down and help you to understand the differences without going too deep into the technical aspects of either method which will be covered in other articles.
Rotary and vibe rock tumbling methods have many similarities. Both require the purchase (or DIY build) of a somewhat noisy machine which costs roughly the same and uses abrasive grit along with various types of media. Both machines mechanically provide movement which causes the rocks to rub against each other until they become smooth to the point of a high shine, depending on the material being tumbled. When you look at a pile of expertly polished tumbled rocks, the chances of anyone being able to positively identify which method was used to achieve such a shine are unlikely.
The purpose of this article is not to determine if either tumbling process, rotary or vibe, is better than the other. Both methods are beloved to many of us and say that one is better than the other would be like saying that fishing from the shore is better than fishing from a boat. Both methods are fun, interesting and exciting and if done right will provide terrific results. Instead, what we have here for you is a quick list of pros and cons of each method to give you a greater understanding of each process without getting bogged down on a lot of complicated methodology. As stated earlier, we will delve into the technical aspects of both rotary and vibe tumbling in other articles.
Rotary Rock Tumbling – Pro’s
The following are several areas where we believe that rotary rock tumbling excels over vibe tumbling.
Machine price and selection – Rotary rock tumblers have been around since the 1950’s and presently there are significantly more brands and sizes to choose from when compared to vibe tumblers. A beginner model rock tumbler can be purchased for less than $100 which makes it much more affordable especially when it is being given as a Christmas or birthday present.
Material removal – Due to its rock on rock tumbling action, rotary is by far the superior method for removing a substantial amount of material, rounding off sharp edges and giving rocks that classic beach pebble shape.
Complete method, start to finish – With the amount of material removal and shaping that rotary tumbling can accomplish, rotary tumbling purists will tell you that it is the only method that can complete a cycle from rough jagged rocks to smooth and perfectly polished specimens. There are exceptions but it’s not far from the truth.
Steady and reliable process – The materials that most rotary machines are made from are engineered for reliability because batch cycles typically run for long periods of time on each grit level, so a total run time of over six weeks is fairly standard. Aside from stops that are needed to recharge the barrel with fresh grit and maybe a bit of water, rotary machines are work horses that get the job done.
Less Tinkering and adjusting – Assuming you have followed a measured and reliable recipe ratio of water to grit when you first started a barrel of new rocks, chances are good that you will achieve a nice slurry coating on the rocks within a day or two. Even if you are off on the recipe a little bit the rotary tumbling motion is still doing a good job starting to smooth sharp corners and rough surfaces and polishing the rocks.
Easier DIY machine building – As is on display in our DIY Equipment Projects page, building your own rotary tumbler can be a fun and achievable project goal. Successful tumble polishing results can be achieved as long as the build includes barrels that are made of materials that can withstand tumbling rocks and abrasive action while spinning at a suitable RPM.
Rotary Rock Tumbling – Con’s
The following are several areas where we believe that vibe tumbling has advantages over rotary tumbling.
Long run times – Start to finish on a batch of rotary tumbled rocks will typically take up to six weeks to accomplish and that’s if you don’t micro-manage the results, or start over several times along the way. Although most store bought rock tumblers are powered by an energy efficient motor, any motor running for six plus weeks will certainly require a measurable amount of electricity.
Less flexibility of rock shape – When it comes to the shape of rocks that can tumble to perfection in a rotary machine, the choice is limited due to the nature of the rock polishing action that occurs in the tumbler barrel. Rocks with voids and concave curves are troublesome for the rotary process because these contain areas of the rock that cannot be reached by the other rocks in the barrel. Media used in a rotary barrel is typically small soft plastic pellets which provide a cushioning effect for the rocks as they tumble into each other and they don’t add anything to the grinding and polishing process. This means a rock that contains these trouble spots needs to either be culled out, or rough tumbled to the point where the difficult feature has been removed, adding extra time to the process.
High consumables usage – Rotary tumbling requires a relatively large amount of abrasive grit. A rotary tumbler uses grit by the tablespoons compared to vibe tumbler which uses teaspoons of grit. The grit is added to the barrel at the start and at each recharge along the way to achieve and maintain a proper slurry. Rotary tumbling requires a substantial amount more grit than vibe tumbling and this fact alone makes it the more expensive process in terms of lapidary supplies.
Required maintenance – Simply put, rotary tumbling machines have a lot of moving parts, from the motor to the belt to the rotating rollers that spin the barrel. Aside from the motor, these moving parts do need regular maintenance whether it be oil for the rollers or replacement belts as needed.
Potential leakage – The fact is that rotary barrels contain a lot of water and at the same time the barrels lie on their side while being rotated for weeks on end. Sometimes it’s just a simple leak where the lid did not get sealed properly but other times they can experience ‘blowout’ when for whatever reason the barrel loses it’s lid seal integrity and the load is dumped.
Vibe Tumbling Pro’s
The following are several areas where we believe that vibe tumbling has advantages over rotary tumbling.
Quick run times – This has to be listed as the top advantage that vibe has over rotary. From start to finish, a vibe tumbler load of rocks can be accomplished in approximately a week or less. Just from a energy usage/time standpoint, not taking motor wattage into account, the vibe tumbler can accomplish the job in approximately a fifth of the time required by a rotary machine. This is also helpful for those who find themselves patience-challenged or those who have a quota of rocks to finish for a project.
Low consumables usage – Abrasive grit for a small to vibe medium bowl is typically measured in teaspoons which is due to the substantially less water used combined with a high percentage of hard media such as small ceramic chips distributing the grit to virtually every surface of the rocks being tumbled. This is somewhat counter balanced by the fact that vibe tumblers typically use aluminum oxide grit and polish which somewhat more expensive than silicon carbide, but the consumables advantage is squarely in the vibe camp.
Rock shape flexibility – Vibe tumbler machines employ an aggressive vibration action during which hard media, typically small ceramic chips, are constantly rubbing on every surface of the rock which include flat sides, concave areas, and some voids depending on size. This gives vibe tumblers a significant flexibility over rotary machines especially when it comes to unusual shaped and flat stones which can be vibe tumbled to perfection. Vibe tumblers are the perfect machine for someone who wants to create polished flat stones called buff tops for jewelry. One hundred percent vibe tumbled buff tops make excellent versatile pendant stones which can be finished by wire wrapping, metalsmithing, or simply gluing on a bail or drilling a hole for a cord to be inserted.
Vibe Tumbling Con’s
The following are several areas where we believe that rotary rock tumbling has advantages over vibe tumbling.
Limited material removal – Rough grinding in a vibe tumbler can be done but it’s not recommended because vibe tumblers do not employ the same waterfall action of rock on rock tumbling the way that rotary tumblers do. Simply put, vibe tumblers cannot remove enough material and smooth out sharp edges and corners to to make rough grinding suitable. Many pits and flaws in a rough rock that would disappear in a rotary machine will virtually never disappear in a vibe tumbler. Also, due to the aggressive vibration that occurs, it is not recommended to use low grit silicon carbide such as 60/90 in a vibe tumbler because of the toll it can take on the plastic or rubber barrel. For these reasons, other methods must be used to prep vibe tumble rocks in advance, or load of rocks must be limited to those that are already smoothed by natural processes such as river or beach tumbling. For a much deeper look at this issue, see this article Can I Rough Grind in a Vibe Tumbler.
More recipe tinkering and fiddling – This point might be debatable because most rock tumbling hobbyists love tinkering and fiddling with equipment and recipes and fussing over their bowls until a perfect slurry is achieved but it’s worth mentioning. Vibe tumblers do need to be checked and spritzed with water much more often than rotary tumblers which isn’t easy on some models that have their lids screwed down tight to avoid loosening. Typically tumbling enthusiasts don’t think about it this way but, with the speed of the vibe tumbling process, when a load ends up being too wet or too dry, or did not have enough or had too much grit, it can represent a full day lost just trying to get the bowl right.
If you found this article helpful, please also watch this indepth video on Michigan Rocks YouTube Channel
Rob Abrams of Michigan Rocks digs deep on the comparisons between rotary and vibe tumbling. While you are there don’t forget to Subscribe and click ‘like’ on all of his videos!
Thanks for visiting www.RockTumbling.com. We have presented this information just as quick educational reference and we hope that it has been helpful for you. What subject boils down to is this – take the time to figure out what you enjoy and want to get out of the rock tumbling hobby and choose the methods that best meet your needs. If you are looking to toss six lbs of very rough rock in a barrel and want to take it out later as beautifully transformed, rounded and polished rock specimens, it’s hard to go wrong with a rotary. If you are purchasing or using a lapidary saw to cut your own flat rock slabs and trimming out jewelry pendant designs and want them polished to perfection, a vibe tumbler is absolutely the right tool for the job. Many of our members use both methods, rotary and vibe in combination or individually.
If you have any questions or comments about this article please feel free to post about it on the RTH Forum. If you are not already a member, register an account today, introduce yourself and let us get to know as part of our ever growing community of rock lovers.