Drilling a long hole

[mashcaster]

I have some timber which is 1 inch thick and need to drill a few holes length wise which are 150mm long by 13mm wide (diameter). How can I ensure the hole is straight and does not come out from the side of the timber?

 

[big-all]

clamp into a workmate/vice /clamp vertical or horizontal to the surface with a square sitting on the bench for guidance[if vertical]
use a flat bit drill in halfway then turn rounds and approch from the other end

what exactly are the holes for!!!!!

 

[mashcaster]

I can't drill from the other side because I am drilling into 1" by 2m timber, and I only need to drill into it by 125mm, So I can get some furniture bolts in there.

 

[regsmyth]

what exactly are the holes for!!!!!

He's making a bed, remember?

 

[big-all]

what exactly are the holes for!!!!!

He's making a bed, remember?

use my design where the sides extend beyond the ends by 44mm giving you an "L" shaped space to affix the legs/ ends to without bolts
obviously iff you choose 69mm legs you extend the sides by 69mm each end