4th Axis Set Up

[Cartierusm]

So I'm building a 4th Axis from a new Harbor Freight 9x20 Lathe Head with a 2.865 Pitch Gear Pulley and using a 570 oz/in. Stepper with a 1.194" Pitch Gear Pulley.

As far as alignment I take it just put it on the mill and with a nice straight rod in the 4th axis chuck use a dial indicator in the mill chuck to go along the centerline on the side until its good?

I was also thinking of mounting the 4th axis to an aluminum plate (faced of course) and using dowels and liner so setup after the first time would be a breeze. Would this be accurate enough? Thanks.

[John Welden]

Sure you can dowel it on.

It's better to indicate a surface that is perpendicular to the bore. That may be the nose/face or another ground surface. The problem with indicating a rod is that you don't know if it's in there perfect.

[Cartierusm]

So if the 4th axis is being used vertically I could just traverse the face of the chuck? That sounds easier.

Then whats the best way to find the centerline after lining up the 4th axis.