Selecting A Tub Grinder
When selecting or buying a tub grinder, be sure to consider five “P” factors.
Production: How much volume or tonnage will you need to process or produce? There are approximately 440 lbs (pounds) per cubic yard of wood material. 8’ tub grinders can typically produce 40-100 yards per hour. The largest grinders can produce 600+ yards per hour.
Product Size: You can adjust your finished product size by changing the screen sizes under your mill. The smaller the screen holes, the smaller the product. A one inch product size will take longer to produce than a two inch product. Larger horsepower grinders will produce smaller product sizes more quickly.
Portability: Will you be towing the grinder to multiple locations, across mountains or working from one facility? Make sure you have a truck large enough to accommodate your grinder choice. Folding tub flares may allow you to tow a tub grinder without any wide load permits and signage. If you are traversing mountains, you may want to consider a track mounted grinder.
Payment: How much grinder can you afford? We know, the cheapest one, right! You may be right. But what if you are not? Most of your expenses work out to be about $2-3 per yard. Each pass through the grinder will run $3 per yard (especially with diesel at $4+ per gallon). Trucking ground material usually works out to approximately $2.50 per yard (depending on distance and truck capacity of course). Payments on new machines can typically be matched with longer term leases or loans. Larger machines obviously cost more.
People: In this business, people can make or literally break your operation. You need a conscientious person to run your tub grinder. Until the recent fuel price increases, the trend was to buy the largest grinder and get the job done as quickly as possible. By getting the job done quickly, you minimize labor and the amount of time you need your support equipment on any one job. You may be able to utilize a slightly smaller grinder and just run a little longer.