The Forestry Forum

General Forestry => Sawmills and Milling => Topic started by: postville on June 11, 2025, 09:33:24 PM

Title: rough surface with 747 blade
Post by: postville on June 11, 2025, 09:33:24 PM
I tried some 747 blades and got rough surfaces. LT40, 28 HP motor. I tried to vary the feed and checked the belt tension. Looks like blade was vibrating.
Material cut- poplar and basswood, 14 inch diameter.
I put on a Double Hard 10 degree,  1 1/4", 7/8 pitch, .042 blade and everything settled down.
It was suggested I don't have enough power, that the 747 blade is very aggressive.
Your thoughts?
Bob
Title: Re: rough surface with 747 blade
Post by: barbender on June 11, 2025, 09:46:01 PM
Aggressive blade profiles like the 747 and 739 require a fast feed speed, or they make ripples.
Title: Re: rough surface with 747 blade
Post by: Magicman on June 11, 2025, 10:12:21 PM
Looks like you do not have the HP/speed to empty those deep sawdust filled gullets.