The mill has nailed down their saw specs, chosen their primary and hopefully secondary saw supplier, and have decided to sharpen in-house. But selecting filing room equipment can be a daunting task if one doesn’t analyze what is wanted out of, let’s say, the new grinder.
In my opinion, accurate grinding of the saw’s teeth is one of, if not the most important part of preparing the saw to cut lumber. Most all of today’s sharpeners can do this and more. How much more is needed for a particular operation can be a big question. Of course, we all have our preferred name brand equipment – but to keep advertising and politics out of this article, we will just discuss available options and technology.
The important question is what your filing room needs to keep the saws in your mill running at their maximum potential. Another question is, will you be only repairing saws or purchasing plates and building new saws? When purchasing grinding equipment, a great deal of thought needs to be put into not only current needs but what the mill’s future plans may be – some mills have a three-year or a five-year plan.
Although management and the proverbial bean counters may want to cut some corners with a machine’s bells and whistles, to be able to make transitions later, it’s better to fully research all the machine’s options and whether or not they can be added later. I am simply saying, purchasing more than you need will help you grow to fulfill the mill’s future needs. Today, a certain amount of automation is practically standard on new equipment. For this article, I will focus the discussion on automatic top and face grinders.
In years past, sawfilers were more plentiful and a mill’s filing room might have anywhere from two to four experienced, professional sawfilers employed. With the shortage of sawfilers in our industry today, many mills are struggling to be fully staffed. However, because of automation and technology in the up-to-date filing centers, some are getting by with one or two experienced, professional sawfilers. But let’s be honest, automation doesn’t replace experienced filers – it only helps them safely manage their work load.
When purchasing saw grinders, one will find a long list of options. Let’s consider what is needed for your particular filing room:
First, consider your saw specs and determine if the machine that has caught your attention will accept your maximum diameter and automatically feed the tooth pitch without manual intervention.
Next, a major consideration is deciding on the machine coolant, oil or water. Most of today’s sawfilers will suggest always going with oil coolant. By using it instead of water, it will give you a sharper tooth while keeping the correct temper. Oil also adds years of service life to your purchase and makes maintenance and day to day operations easier for the filer.
Another consideration is whether one should purchase a saw grinder to do both facing and topping of the same saw, at the same time, on the same cycle. I personally would answer yes on this question. Saws will be finished in almost half the time, and it frees your sawfiler to work on other projects such as benching and inspecting.
Although most machines offer both without an option fee, make sure your machines can be operated in metric or both U.S. customary and metric. The metric system may have taken a long time to make its way into the U.S. filing rooms, but now professional sawfilers find the system to be more accurate when it comes to grinding off exactly what is needed each pass. The metric system allows for tighter tolerances and in our industry, it is now considered the standard in many mills and filing rooms.
A few other options to consider:
CNC controlled machining is certainly a must, and with today’s high-tech machines, may be an absolute. By purchasing controlled axes, you will be able to grind most all tooth geometries in one cycle.
Oscillation grinding, in my opinion, should be a must. During my time in filing rooms repairing and sharpening teeth, a light finish grind will always make a sharper tooth.
Automatic lubrication system is without a doubt the way to go. Take the time to read my article Saw Filing 101, in CFI’s Jan/Feb 2022 issue: A properly greased filing room.
Grinding wheel wear programs, honestly with me, is debatable. While I see it as a must with automatics, lights off, grinding, I question it with machines sharpening one saw at a time when manually operated. With lights off sharpening, you will have to find the correct sweet spot that will keep the correct advancement sequence while sharpening the tooth, keeping the wheel in the correct match with the tooth. It’s my belief when a filer is controlling the sharpening of the teeth, that filer will adjust as needed during the setup of each individual saw.
Tracking software:Â I do believe in the ability to keep up with how many teeth the grinding wheel grinds. This will help with determining which grinding wheel performs the best and will help to prove purchasing a cheap wheel may not be the best choice in the bottom-line vs. performance quandary.
It’s also a good option to be able to know how long the machine has been on and how long the machine has been working actually sharpening saws and how many teeth were ground. When asking to add a sharpener to your filing room, it’s wonderful to be able to show management why another machine is needed.
Wheel rotation programming will be needed when grinding alternate top bevel teeth such as seen in trim saws.
Variable grinding speeds are also important. This will be a big factor if you’re rough grinding or finish grinding.
Sensors to automatically adjust for tooth pitch will be needed if teeth are not the same distance apart, such as a welded tooth not getting centered properly; variable pitch tooth spacing; and will make for a quicker grind without having to drop your feed pawl so low under the next tooth.
There are many other options to consider when purchasing grinding equipment, but we can cover more in future articles.
Paul Smith is a saw filing consultant and founder of Smith Sawmill Service, now part of BID Group. You can reach him at paul.smith@bidgroup.ca.
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