Bucyrus Erie 40H Excavator 1:14

[Jared]

Looks sharp! I've never been able to decide when drilling smaller holes in a part like that if it should be done before or after milling. If before, it's a deep hole and more opportunity for the bit to wander. If after, the ears might bend if too much pressure is applied also causing the bit to wander. Anyone got an opinion or am I worrying about nothing?

[Machfab]

Originally Posted by Jared

Looks sharp! I've never been able to decide when drilling smaller holes in a part like that if it should be done before or after milling. If before, it's a deep hole and more opportunity for the bit to wander. If after, the ears might bend if too much pressure is applied also causing the bit to wander. Anyone got an opinion or am I worrying about nothing?

Most of the time, I will drill and ream the holes and then machine away the material.

[ihbuilder]

Originally Posted by Jared

Looks sharp! I've never been able to decide when drilling smaller holes in a part like that if it should be done before or after milling. If before, it's a deep hole and more opportunity for the bit to wander. If after, the ears might bend if too much pressure is applied also causing the bit to wander. Anyone got an opinion or am I worrying about nothing?

I drill ream after . I always spot drill 1st and with proper F&S I've never had an issue unless I didn't spot drill . It also helps to keep your drill bits sharp .