How to make perfect holes in spar?

[Jean-luc]

I made most of the spar drillings for hinges 1/4",flying wires pins .75"and plates 1/4",butt fittings plates 1/4" 3/8" 5/16",ect...They were done on a drilling press before ribs assy and gluing;all were perfect.Then I have glued all plywood plates on one side of each spars,and after drying,I drilled the plates with a small drill,helped by the holes already done in the spars.Then glued the plywood plates on the other side of the spars,and drilled through.But now is the problem;the holes are not straight,not perpendicular to the spars anymore,just some small angles!!!I made some cylindrical parts with spruce that I have glued with T88 in each holes.

So,here is the big question..how to make perfect drills to get holes perpendicular to the spars.

Cheers

 

[Randy]

 

[Jean-luc]

 

[Randy]

 

[Jean-luc]

 

[Jean-luc]

 

[macwolf]

 

[Randy]

 

[Jean-luc]

 

[MarkRadio]

 

[Randy]

 

[MarkRadio]

 

[bigblackmastiff]

 

[scottly]

 

[Randy]

 

[MarkRadio]

 

[bigblackmastiff]