Seeking Advice For Restoring Front To Back Tilt

[Aiph5u (Aiph5u (not affiliated with Onefinity))]

Hey Andy, hey John @jnordyke, hey BJ, hey SkyKam, hey all,

@AndyP

Front to back tramming: if I understand you correctly I achieved this by shimming with varying folds of tin foil behind the zslider.

I think John rather means the Guide Tramming - Front To Back in the FAQ category, is this right John?

@jnordyke

If I completely loosen all eight bolts and then by eye/revolution count run each opposing set of two the same amount inward until all are gently snug, does that get me to a good place from which to try again?

I haven’t used these tramming bolts yet, but that sounds logical. It think (hope) it can be assumed that the machined holes holding the hollow shafts in the X feet are of good precision and that the screws are of identical length.

How do you measure? Do you have a tool to check perpendicularity between router axle and table surface like this, this, this, this or this (no guarantee for ascending price order) ?

Or do you check your accuracy by looking at the patterns your surfacing bit makes, like here?

@SkyKam

I needed a .03" shim before fine tuning with the tramming bolts. The tramming bolts will not correct the tilt if the error is too large to begin with.

That sounds logical. The weight of the router/milling motor and of the Z Assembly, in conjunction with tolerance in the linear bushings and bending of the linear shafts both in X and then in Y axes might add to an error even if tramming bolts hold the X shafts in a centered position in their holes.

@jnordyke

At the moment, I still have useable but poor front-to-back tilt and most distressing for me, a different amount tilt when at Y=0 inches than when at Y=32 inches, and some of the adjustment bolts are already as deeply seated as they will go.

Did you check this: Support: Removing Twist From The Onefinity Rails?

Also did you do something to ensure flatness and coplanarity of your machine’s base (=table or QCW frame) before both the tramming step and the surfacing step?

Did you surface already?