What are these for?

[trigger_andy]

1 hour ago, Dan Maynard said:

8 hours ago, CDMR said:

They leave marks on the beam you use as a guide so you can tell if you start to go off vertical as the track from one of the pips disappears.
 
Personally, never use mine for anything but the roughest jobs.

Really? You may well be right but if that's the real answer I'm disappointed, you would be reusing the guide beam so the second time you can't tell if the lines are new or not.

And the beam is usually snug, not gripping, but snug to the beam. At least mine where. This helps helps everything on track. There was very little chance the saw could go off vertical. 

 

I certainly would not be relying on three grub screw tracks that cause undue friction/drag to tell me Im milling off of vertical. By then its too late anyway. 

Edited May 12, 2020 by trigger_andy

[CDMR]

1 hour ago, trigger_andy said:

And the beam is usually snug, not gripping, but snug to the beam. At least mine where. This helps helps everything on track. There was very little chance the saw could go off vertical. 

 

I certainly would not be relying on three grub screw tracks that cause undue friction/drag to tell me Im milling off of vertical. By then its too late anyway. 

The steel section is smooth and has rounded corners so fairly easy for it to roll without something that engages with the guide beam. You can always flip the beam so at least you get two uses. I'm not saying its a good design (in fact I said it wasn't) just what I think they are intended for.