DIY straight edge with Epoxy+ aluminum profile. Will it work?

[GTJim]

Any straight edges above 1200mm that I have seen are very expensive. So I hope your suggestion works as I have yet to come up with a better one.
Jim

[mekanik]

Hi Don't see much of a problem here, you say width of rails 1160 so your straight edge will span that distance, to ensure the 1800 rail is straight set the master rail onto the grout leveled frame member and lightly clamp both ends, drill and tap the frame for the hole in the centre of the rail, work your way from the centre of the rail to the ends drilling tapping correcting and fixing the rail as you go, you will have a section of rail that can be verified straight with the straight edge, all you have to do is extend the straight edge 200mm each end to set the remaining portions of rail. the second rail can be set using a fixture with carriages set on the master rail and on the one your trying to bring into spec, most find that using the gantry works OK.
Regarding drilling and tapping you need a couple of jigs that will align in the countersunk holes of your rail, one to align the drill and one to keep the tap vertical.
Regards
Mike

[toomast]

Hi,
I have had exactly the same idea in my head for a week now :)
I will try to make my straight edge out of the "bridge" when leveling my long axis.

[ba99297]

The two 3m aluminum tubes one way or another i should had bought them for general measuring use
Assuming that the extra cost is only the 500ml extra epoxy ( as for the above project will be needed 990ml), i will make a try
I Know that the result will be disputed
Of course i will use my straight edge against the epoxy surface to check the result
Mean while any advice will be welcome.
Thanks for your participation

[JAZZCNC]

Vagelis Personally I wouldn't waste the time or Money. You have decent length straight edge and using Technique Mekanik suggested will work for checking flatness of 1800 rails.

[Naftero]

Did you made the straight edge?