Re: [CAD_CAM_EDM_DRO] Re: Newbie: Two halves of simple die not aligning properly - Long

Tom Hubin wrote:

>kaptainkarst wrote:
>
>
>>My X and Y tables are not traveling perpendicular to one another. I
>>can dial in one Axis and get it within .001 over 8" of travel but
>>then the other Axis is out by .02 over about half that distance!!
>>
>>
>Hello Jim,
>
>This error would have shown up with four pin holes if two were separated
>in X and two were separated in Y. For accurate alignment, separate as
>much as possible. Perhaps the four corners of your pieces.
>
>

Yeah, that's what puzzles me about this, too. The holes should not line
up, either, if the axes really are skewed.

>I sometimes use as many as eight 1/8 inch dowel pin holes on a 4x8 inch
>aluminum plate. I ream to 0.126 inch. Sometimes the mating pieces are
>too tight with all eight pins so I leave out the 1 or 2 that seem to be
>binding. The end result is usually good mating with no play that I can
>feel while not bound too tight.
>
>Actually, I am wondering how you got three pins to mate if your axes are
>not perpendicular. Are the three in a straight line or do you permit a
>very loose fit?
>
>

He's complaining of .020" over 4". Unless his pins were real close together
in at least one axis, they should be as far off as the slots.

I'm wondering if there is a lot of slack in the gibs or the leadscrews,
and the
cutting forces are pushing the table in one axis across the backlash as the
cut is traversed.

Or, I'm wondering if the workpiece slipped on the table. That has
happened to me
more than once! I think the OP drilled the holes FIRST, then milled the
slots.

Jon