algale wrote???? Not sure any introduction is needed. Least not on my part. I saw the earlier reference to me in one of JPG's earlier emails debunking my theory (that you must have told him about) that the pivot couldn't be in the same plane with the table legs. 'Twas a beautiful theory debunked by ugly facts (the Mark VII).
Alan
I thought a pm was in the mix, but, I did not know 'who'.:D
In 'retrospect'(because of seeing Dusty's pix), I have come to realize that there is nothing that can be done to eliminate the diagonal tube adjustment need when tilting the table
without moving the lower end of the tube to be directly below the pivot. The tube then will trace the outer surface of a cone of constant height(sorry about the geometry reference:eek:).
BTW I also thought as you did until I gandered upon the M VII table.
So Dusty's 520 is not 'Alan' afterall.
As for the reason for the post/pivot,blade offset, my conjecture is that it allows minimizing blade adjustment when tilting while also providing sufficient clearance for the arbors and structural considerations.
Historically, the 10 had nothing not offset. Pivot to post was one direction, while pivot to the blade was offset the opposite direction.
I think the need to adjust the blade when tilting was recognized as a problem(it is far greater than 510/20 requirement).
When the Mark 5 aka 500 was designed an attempt to reduce the amount of adjusting for tilt was done. The pivot was moved to eliminate the blade/pivot offset. Methinks the post position was determined by carriage design and arbor/guard clearance needs as well as structural considerations for the trunion functions. i.e. an opinionated best compromise.
Then when the Mark VII came along, the need to align the post with the pivot to simplify 90/90 degree stops against the post required the blade to be offset considerably. Back came the greater blade adjustment when tilting.
So with the 505-520 redesign(which returned to a 45/90 tilt range) the blade/pivot offset was again restored to 0. The post offset was slightly reduced by a redesign of the shape of the tiebar across the trunion. The carriage redesign may have also contributed to that reduction.
Bear in mind the designers were not considering how any offset would affect future out feed table attachments.
I think the post offset made other other design considerations 'easier'. As far as the saw function goes, the post location was irrelevant as long as everything came together.
