Drilling Technique

[Brambo]

I'm about to drill the holes in the elevator horns for the control rod attachment. I will do it as per Van's plans first drilling the #30 holes through a wooden block spacer, then enlaging the hole in one horn and the spacer to 3/16. My question is, when drilling the hole in the second horn (through the other horn and spacer) should you just use a 3/16 drill or is it better to try and step drill as you normally would?

I realize it probably does'nt matter either way, I was just wondering which would be considered the best technique for getting the best drilled hole.

Bil Rambo
Rv-7A

[Mike S]

Best bet, if you can find one, is a piloted reamer. First drill under size, (with the guide block), and then use a piloted reamer to final size.

Ask around your local EAA chapter---------hopefully you have one, for the reamer.

Reason to ream instead of just drilling, is hole is ROUND, and a proper fit to the bolt shank.

Good luck.

Mike

[Jekyll]

Start with the #30, recheck to ensure it is correct and then final drill/ream. I made a hardwood block and drilled per the directions but it didn't come out well. I failed to recheck before I final sized the holes and lo and behold, they were off. Solution was to weld it back up and redrill to final size after having a local shop make a full sized drill jig from aluminum block. That sucker was PARALLEL and sized perfectly for the second try.


I now have a great aluminum drill guide, size 12, for connecting the horns to the elevator rod end on a 7 if anybody wants to borrow it.

Jekyll