Optimal Circle Saw Size
60-inch circular sawmill blades can be problematic to use, so many sawmillers prefer a smaller diameter blade. October 3, 2009
Question
I have a friend who runs a 60" saw with, I believe, 57 teeth. He's had nothing but problems since he started. Doesn't de-bark and uses carbide. I told him the carbide is probably the better bet, but he should be running a 56" saw. I have found that the extra 2" means the whole world. I have found the 56" will cut truer, pull less, heat up less than the larger saw. What is your experience?
Forum Responses
(Sawing and Drying Forum)
From Professor Gene Wengert, forum technical advisor:
I used to manage a mill that had both 60" and 54" saws. The tension for the two 60" saws was difficult to obtain... That is, the person that hammered our saws (a traveling saw doctor) never did a great job on one of these large saws. We did have one time when it was hammered correctly and worked well for a while. (Of course, any heat will quickly change its operating parameters, so avoiding heat, even a small amount of heat from the mandrel bearings, is critical.) We finally had it cut back to 54" and then we had it tensioned correctly and it worked like magic. So, the bottom line is that 60" saws work well if properly tensioned and if there is no heating, but the skills to tension these large saws seem to be in short supply.
Incidentally, 60" saws allow easy cutting of a 34" diameter log. That is why they were used in the first place. Of course, today, we do not need such a large saw. A 52" saw can only cut a 26" log! What many mills have done is cut the large saw down to a smaller saw, which is much more stable indeed. Then if large logs are sawn from time to time, a top saw (a second saw on top of the main saw and a few inches behind) is used.
The tooth width (and therefore the kerf) is wider with the larger saws. With 56" and smaller, we can use an inserted "F" style tooth which is 9/32" wide. I believe that we always will have an even number of teeth. A 56" saw will have 54 "F" teeth; a 54", 52.
Regarding carbide, the carbide is quite brittle, so with logs that still have the bark (and sand and debris in the bark), I think steel would be better. When you hit a small stone with carbide, that tooth is no longer very effective.
From contributor M:
I switched to carbides a year ago. I don't debark and I will never go back to steel teeth. Carbides last twice as long between sharpening and you should see any rocks or mud patches big enough to damage them. Carbide teeth were strong enough to saw halfway through my log dogs before I got my saw into reverse.
From contributor N:
"Optimal" size saw depends on the power available and the size of the logs. Run the smallest saw you can get by with. I run 48" with 34 teeth. I can cut a 25" log without much trouble. I would rather split the big ones than fight a big saw all day.
From the original questioner:
Currently running a 60" saw with, I believe, 58 teeth. 300 hp. Max cut is 24". Not interested in using a 48" saw. Our logs in our region are too large. Ideal situation would be a 52" saw with a top saw, but that ain't happening due to current finances. Thanks for the response.
Would you like to add information to this article?
Interested in writing or submitting an article?
Have a question about this article?
Have you reviewed the related Knowledge Base areas below?
KnowledgeBase: Knowledge Base
KnowledgeBase: Primary Processing
KnowledgeBase: Primary Processing: Sawmilling
Would you like to add information to this article? ...
Click Here
If you have a question regarding a Knowledge Base article, your best chance at uncovering an answer is to search the entire Knowledge Base for related articles or to post your question at the appropriate WOODWEB Forum. Before posting your message, be sure to review our Forum Guidelines.
Questions entered in the Knowledge Base Article comment form will not generate responses! A list of WOODWEB Forums can be found at WOODWEB's Site Map.
When you post your question at the Forum, be sure to include references to the Knowledge Base article that inspired your question. The more information you provide with your question, the better your chances are of receiving responses.
Return to beginning of article.
|
