The Forestry Forum

I'll start this thread with my most recent adventure. My 70Super is a 2019 Wide model. 55 hp tier 4 Yanmar. Please keep in mind that 70 Super has engine driven hydraulics, Power feed and up down are  via hydraulic cylinders.

So I just finished installing a new 2 inch cylinder that raises and lowers the chain turner, shiny black in the center of this photo. Notice that the cylinder is attached at the top through an eye welded to the top of the cylinder.

(https://forestryforum.com/gallery/albums/userpics/21495/IMG_7806.jpeg) (https://forestryforum.com/gallery/displayimage.php?pid=360136)


Here is the reason I installed the new cylinder.

(https://forestryforum.com/gallery/albums/userpics/21495/IMG_7800.jpeg) (https://forestryforum.com/gallery/displayimage.php?pid=360135)

When I was sawing, I was turning the log, and a side board partly on the loading arms got trapped underneath the turner. After a bit of turner joystick action-on this sawmill I get accustomed to solving problems with the joysticks –  I realized nothing was happening and walked around to find that the eye had been peeled wide open.  Fortunately, I just had several small logs left in the job and managed to finish them with my Logrite peavy. I wish I had taken a photo of it, but unlike Magicman, I do not get enthused about taking photos during periods of distress.

I am guessing from rust showing on the ends of the break in the eye, That perhaps it had been broken for some time and this event was what it took open it up.

I also realized after the new install, that Every time I've lowered The chain turner, it hit an adjustable stop underneath it before the cylinder is completely closed. Almost closed, but not completely, still extended by less than 1/8 of an inch. It seems then that this eye was stressed every time the cylinder closed, it cracked, but I didn't notice it, and that stress was relieved by the sequence valve opening to allow the uprights to lower.

So I adjusted the stop bolt underneath the turner, probably an eighth of an inch lower, to let the cylinder fully close. Hopefully in the future this eye will not be stressed every time the turner  is lowered.

Your hydraulic shop can weld a new eye on that cylinder and you can keep it as a spare so that it will never happen again.   :thumbsup:   ffcheesy

A hammer, pipe wrench and a welder will fix it good as new.