hello everyone tonight

Well lets talk about the guide block --this is a quite an important part of the whole scheme of things it guides the upper end of the pitman in its proper orientation to the blade as it delivers vertical motion from the turbine's rotating motion, it has to be constructed to withstand the jerking motions as the turbine speeds up to cutting speed both at the upper and lower ends of the stroke

at the upper end especially it has to reverse the upwards travel of the weight of the heavy blade which is about 50 lbs. in a few slit seconds, but, if you think about it, as the pitman approaches top dead centre and before it begins its return down it has some sideways motion across the arc which has no upwards motion so it helps to lessen the effect of the up travel, and the stress and strain on all the linkages

now back to the guide block--

it is quite heavily constructed, and is fashioned in such a way that it can continue to work and work day after day week after week and yes year after year without failing

the whole (main) part of the unit if my memory is correct is about 30" wide and 24" high give or take a little made from 2.5" hardwood usually white burl oak, the wrought iron linkages at the top for the blade and at the bottom for the pitman are connected vertically through the unit, with (2) -- 3\4" bolts which take the jarring strain and also hold everything together

I might say right here that the mill's guide block has never needed to be changed since it went into operation in June of 1961 when it cut its first plank--quite a record--cutting approx. 20000 bd. ft. yearly--you can do the math--

more to this story

enjoy NH

Last edited by northern hewer; 12/04/15 03:26 PM.