Mark VII Trunion Tweak
Posted: Sun Oct 21, 2012 11:59 pm
The table was very hard to move. I worked with it after removing the table and before using it to maintain way/lower tube spacing. The reason for the 'stiffness' was a buildup of crud on the pivot. Probably the result of using grease on the pivot.
First step was to remove the segment clamp post by backing the nut all the way out and applying considerable torque to back out the post threads in the trunion itself. The post was staked, and I will use blue locktite when reassembling. The Mark VII has two separate trunion clamps(a second one at the rear segment).
[ATTACH]18838[/ATTACH]
Not too clear, but the crud buildup caused the stiffness
(both pivot posts).
[ATTACH]18837[/ATTACH]
A second problem(also observed by me on other models) was a scraping noise when tilting the table. Closer looks revealed the segment was rubbing on the trunion pad that the segment clamps to. The pad showed rough wear and apparently was also initially painted. I filed the burrs off to create a flatter surface. The scraping diminished, but was still occurring at one end position.
[ATTACH]18839[/ATTACH]
The segment was not perfectly perpendicular to the post so it was closer to the trunion pad at one end of the tilt range. A minimal filing of the segment surface that clamped to the trunion pad eliminated the scraping. The rear segment was also scraping at the same location and was similarly filed.
[ATTACH]18840[/ATTACH]
You can see in the pix above where I filed the area of the segment that the stop(45 degree) screw is located. I then realized that a burr on the trunion pad was causing that. The burr was around the outer periphery of the trunion pad.
Not clearly shown, but the Mark VII differs from other models in that it tilts 90 degrees both ways.
This thread is part of a Mark VII refurb thread that is linked to from https://forum.shopsmith.com/viewtopic.php?t=11373
First step was to remove the segment clamp post by backing the nut all the way out and applying considerable torque to back out the post threads in the trunion itself. The post was staked, and I will use blue locktite when reassembling. The Mark VII has two separate trunion clamps(a second one at the rear segment).
[ATTACH]18838[/ATTACH]
Not too clear, but the crud buildup caused the stiffness
(both pivot posts).
[ATTACH]18837[/ATTACH]
A second problem(also observed by me on other models) was a scraping noise when tilting the table. Closer looks revealed the segment was rubbing on the trunion pad that the segment clamps to. The pad showed rough wear and apparently was also initially painted. I filed the burrs off to create a flatter surface. The scraping diminished, but was still occurring at one end position.
[ATTACH]18839[/ATTACH]
The segment was not perfectly perpendicular to the post so it was closer to the trunion pad at one end of the tilt range. A minimal filing of the segment surface that clamped to the trunion pad eliminated the scraping. The rear segment was also scraping at the same location and was similarly filed.
[ATTACH]18840[/ATTACH]
You can see in the pix above where I filed the area of the segment that the stop(45 degree) screw is located. I then realized that a burr on the trunion pad was causing that. The burr was around the outer periphery of the trunion pad.
Not clearly shown, but the Mark VII differs from other models in that it tilts 90 degrees both ways.
This thread is part of a Mark VII refurb thread that is linked to from https://forum.shopsmith.com/viewtopic.php?t=11373