Hi Russman,
to IIS.
Nice starter project, be careful, you will fall into the black $$$ hole of astrophotography real fast !!
Nope, should not make a blind bit of difference. How are you intending to drive the arm ? I notice screwed rod (?) at the other end but a lack of further detail. I presume you got some measurement specifications from off the web to determine the correct distance from hinge to the screw mount point.
Cheers
Brent