07-09-2018, 09:53 PM
Digging up an old project here.
The sawmill was pretty much a design on the fly project.
Was sawing some timbers last week and noticed the blade wanting to dive as I went down the log. Checked the guides first then discovered the carriage under the saw head was bent. The headworks are braced to the back so having the carriage bend effectively tilted the blade into the log.
![[Image: WuPFwOuD7SWSbxRigQ-0fLxZ82nDQeJrJZugrt4x...77-h358-no]](https://lh3.googleusercontent.com/WuPFwOuD7SWSbxRigQ-0fLxZ82nDQeJrJZugrt4xGt02nbDMGb6D6YvL7trk1jD4sMvPbUEoFv92oaPdS5eLw-ULKyexTS08LYWvvZJ8DFPjRdGw2rck0xQRz07aCgQnukaDXGbZ2g3R-iJO3eI6UT1fLHJDaGK5ZFrkJt52EwwHA5dVRberh_JlYkD5gOw6GT-NQMpgu_j6zseh2mdual0IJdViBt8-IuYsJmrqxESOZ8Yhmfd31t2kKQoTOTj92I0-YLHQThQ2wIvDqOOxkknR2HnqauxVlf3yDbV0sU6g4Rqy1emgSj_F5h7zRYDELOrpZ5EasESmT7HJd8LYlGsKbwwb5_oPzcnC6Hc7vKQSF-HD1I8X8l1qC-Of_MrlwFr8na8Gzg_jqFTXJY4fQu58agh7m45S9wnuTgX0y7WkJwKVZ1blffRADIg82Nii0FC6rrgwFxWtwVtTCQH1MJCDYqU5PHRaLymzfj6Dg-4dp3hUX4XQAjaJMZjZna7Yv4TbnbutvUu97hV-2fORkQm8wXqo5fd43zQxFlKHaa-Y0zCoIH3b1fyAb3WmyhjZFJ1ySPeP9bJOVihq9apHLJmHdFkCx5DyeivX2xQ=w477-h358-no)
You can see the back bent up about an inch.
The Moment of Inertia for that channel on it flat is only 0.298 in4. Not nearly stiff enough to support the head which Im guessing is about 1000 pounds, judging by the way the tractor struggles to lift it.
I have some 5x5x3/8 angle, the moment of inertia for it is 8.67 in4 or 30 times stiffer.
Started drilling out the corners for the pockets the wheels drop into and bolt holes.
![[Image: 5tj77_CN6s6UR8Z4JV3xzmLHF4HDG7YbwfxoV_0U...7-h1250-no]](https://lh3.googleusercontent.com/5tj77_CN6s6UR8Z4JV3xzmLHF4HDG7YbwfxoV_0UzzFdx80mMWtQXnXLL-B0M-qu3hXUd-M8lDqRHOecfQm_0uDM1lCFyqsrNypaeamJBS_d-r2s1IlKTVcxQfiHLx1a8u7dvVE5k0YftiBKT9o-Y_R1kNCmGh_HGk3MOKfQ15M0cMPIT372z-_Z9fhmHkBlBg9S8t8AlWMXsHd0FQ_3xCG66AadK4mC2w3MWaqsIaqE2PDwkU90HZ0fojBs5msmef32KQU6Vlnm0YrgG3OrAqkZnbSg6rlii740GJI3ALIZG2w9VDAVtefSpcXUkoQmOfB9Pxv8kcauYP_btjhympazljekLlsaZuBVGicmEbpbrXAS0NPDwK4m1xdhlI6NT0GkokgFYvgIq-9SkOKbHVdp-5yARfyekHNzLKyFWszzG5E8lyButm1t6ns_fl63KZ_ycRIfK7h6rx4kzG0zaC2xu4NEqEsK2R6z9CmokvyCOx9VtEc_MJ0NKwGS-VqqjxMYhodaTwKGFHC5SkXuwjth7lMr22Ci2XXpk6uO5NTjjQufYQ1UlaeowNutl5nasXjpYQdm_V7BbhJzu1W96VIjmTA0h4vRaVoN-5k=w1667-h1250-no)
Not sure what this was in its former life, have welded plugs into the slots.
Now to try and cut the existing carriage off and keep everything straight and plumb.
Greg
The sawmill was pretty much a design on the fly project.
Was sawing some timbers last week and noticed the blade wanting to dive as I went down the log. Checked the guides first then discovered the carriage under the saw head was bent. The headworks are braced to the back so having the carriage bend effectively tilted the blade into the log.
You can see the back bent up about an inch.
The Moment of Inertia for that channel on it flat is only 0.298 in4. Not nearly stiff enough to support the head which Im guessing is about 1000 pounds, judging by the way the tractor struggles to lift it.
I have some 5x5x3/8 angle, the moment of inertia for it is 8.67 in4 or 30 times stiffer.
Started drilling out the corners for the pockets the wheels drop into and bolt holes.
Not sure what this was in its former life, have welded plugs into the slots.
Now to try and cut the existing carriage off and keep everything straight and plumb.
Greg
Free advice is worth exactly what you payed for it.
Greg
Greg