@Gero is correct. Improved accuracy compared to the quadrilateral kinematics using the original brackets to mount the chains to the sled.
This isn’t a small amount of accuracy, this is a change from being off by inches
to being off by 1/8 or less.
There has been a comparison between the 45˚ kit and the top mount.
MeticulousMaynard did an excellent job documenting his comparison. You can
read it here:
Triangular Linkage Evaluation Criteria and Measurements - #61 by MeticulousMaynardSpoiler: “So my conclusions on the comparison between systems is that I think
the 45 degree is a better system all around.”Since then I think there have been some improvements made to the top mount
design but I don’t think anyone has tested them again since then.
Since that test there have been two major changes to address the problem
this found.
- the holes are now .25" instead of .26" (less play)
- the kit includes a metal center section so that the holes are at exactly
the correct distance (and there is no chance of the mounting bolts flexing)
The result is that you are NOT going to be able to get the top mount kit to
‘click over’ like the earlier version did.
Now, I also changed the horizontal bars to be much thinner, and they are
now 7" hole to hole instead of 5" (so they will clear the handles of a 12"
wide router). But it doesn’t seem like this adds any noticable flex, even
under extreme pulls.
you can see the new version at
David Lang