Buying a sanding machine? Here are some of the things to consider before you make that purchase.
1 | What are your needs?
Do you want to dimension/calibrate your parts or just sand the surface (independent of thickness variations)? Do you require a specific surface finish, targeted stock removal, or both? What do your parts look like, what are they made from, and how many do you need to run per hour/shift/day/week? All of these questions factor into proper machine selection and should be defined prior to shopping for a machine. An experienced salesman/application engineer will work with you to identify a process to meet your needs. When deciding on a budget, some other items that are often missed are: freight, start-up/training, and limitations of your building/shop. Does your dust collector have enough capacity to handle the machine you are looking at? What about utilities and floor space? Do you need to hire a rigger? Will the machine fit through the door?
2 | Machine selection
Sanding machines come in all sizes, shapes, configurations, and prices. Wading through the seemingly endless number of options is a daunting task – especially if you are in the market for a small to medium-duty machine. Every supplier/salesman/engineer will have their own opinion about the correct machine to meet your needs, and it usually will come down to Duty Cycle (Based on Hours/Day), Head Types (From Application Needs), Machine Width (Based on Part Size or Throughput), and Budget. You, the customer, has the difficult job of trying to compare apples to oranges between all the quotes/specs/info you have compiled to find the “best value” for your needs? Now, best value doesn’t mean the lowest cost machine, but the overall package (features/options/support/lead-time).
3 | Head types
At the most basic level there are only 4 head types in feed-through sanding machines: Knife/Planer, Wide Belt, Orbital, Brush. Knife planers are the most basic using a metal roller with specially designed knife edges to rapidly shave-off large pieces of material. This type of head is great at rapid stock removal but can leave an undesirable finish, so it is usually followed up by an abrasive belt head. Most abrasive belt heads use a rubber covered drum and/or a platen (segmented or fixed) to perform additional calibration/finishing steps to arrive at a final finish. The contact drum leaves a short deep scratch, while a platen leaves a long shallow scratch (and is often located in the last position). The straight scratch from a wide belt head can be hard to see when in-line with the grain, but when perpendicular to the grain can be unsightly. An orbital head can be used to remove this linear cross-grain scratches using a wide platen and special motion (like a handheld “jitterbug”). Lastly, a brush head can be used to break sharp edges and even out the part surface for consistency in stain colors.
4 | Abrasives
The common denominator in any sanding machine is the abrasive. The actual abrasive mineral is contacting the part and doing all the work that you see; the machine is just backing it up. One way to think of abrasives is to compare the application to tires on your car. Many car manufacturers recommend a specific tire to “guarantee” a vehicle’s performance. Replacing the stock tires with expensive racing slicks isn’t going to help in a blizzard but will outperform big mud tires at a race track, but if all you are doing is driving around town and commuting then you are wasting your money with either option. Use the right abrasive for your application/machine, from a quality supplier/manufacturer, to optimize performance and minimize your consumable costs. Many times, premium abrasive products are more expensive but have a lower cost per part, and their performance could increase production speeds or provide a better finish.
5 | New vs. used
For many shops on a tight budget, the cost savings from buying a used sander can be a very tempting option. If you are thinking of buying a used machine, I strongly urge you to do your homework and take a good look at your machine knowledge, mechanical abilities, and possible implications to your business. Is this machine going to be a critical piece of equipment? What will you do if it doesn’t produce a good finish or just doesn’t work? Do you know how to properly align the machine? How is the machine configured (metalworking machines look identical, but have many differences: soft rubber drums, slow head speeds, abrasives run with-the-feed instead of against, etc.)? What is the condition of the machine and components? A new contact drum can cost $4,000 to $15,000 or more! Are you confident in your ability to identify these issues? What is the machine history? A good starting point is to contact the manufacturer and ask them about the history of the specific machine you are looking to buy.
Source: Greg Nykiel is a product development specialist at Timesavers LLC, with more than a decade of proven success in technical communications and support. He specializes in application knowledge, product management and strategies to help customers solve tough problems and achieve an optimal finished part. For information call 800-537-3611, visit TimesaversInc.com, or email [email protected].
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