Acoustic Guitar Construction

Im building my first steel string with a slotted headstock.. I ordered Gotoh 35AR510s tuners but now realizing I probably should have gone with slightly different ones..

What I have coming has a 10mm aluminum string post, same size as the plastic ones but this one is aluminum.. there is also a much smaller steel string post option that is 6mm..

Would I be making a mistake using the larger 10mm string post for a steel string guitar??

Well Dave, a 10 mm post is a bit odd for the eye, but it will work fine in the end. Just drill bigger holes in the right position and you will be fine. Remember: First drill the holes (not too deep), and then make the headstock routing. The other way around will show drilling chip-outs at the end of the hole.
Good luck
Herman

I might save those for a classical build. But I think they will work, maybe a little bit sensitive to tuning as the larger posts take away a bit of the effective gear ratio.