ImanCarrot-
I am farmilliar with that type of tool, and the cutter compensation LVDT. I think that it would be quite difficult and messy to lap the tool directly on the machine. I think that your best bet would be to design a tool holder that is removable, but very repeatable. The best way to describe a kinematic mount like this, is just like the mount for the LVDT probe. Six ceramic rods, and three ceramic balls, and a way to clamp it in the center repeatibly with the same force. This same mount could be incorporated into a lap fixture. You would then also need vertical movement to accomodate for the new tool height.
Before I go too far with a new tolholder, which adjustment is causing you the most difficulty? And how accurately do you need it to repeat? If the height and radius are not the concerns, then the XZ position must be the problem. You could make an additional toolsetting fixture that mounts to the spindle on the kinematic mount (for the LVDT) and measures the location of the tool. Perhaps two more LVDT's, one for X and one for Z, so you could simply mount the tool, adjust the height, and bring it over to the two LVDT's, and measure the offset. That new offset should be easily programmable into your tool settings, and that should get the tool within about .00005" if I remember how well that kinematic mount repeats.
The more I think about it, that LVDT tool compensation system has the probe mounted horizontally, so you already have the Z direction done. You could set the Z location of the tool with the LVDT you already have. If you were to get another LVDT, and make another mount like the one you have, except that the probe is mounted perpendicular to the current orientation, you would have an X offset value. Athough due to the geometry of the tool, 90° may not be the optimum angle, as it would miss the radius on the tool. You could mount it at an angle, so that the probe tip still contacts the radius, and do a little trig to figure out the X offset. If the height is also a problem, you could perhaps make one more fixture with another electronic gage head to measure the height of the tool, and dial it in. If I remember correctly, the toolholder you most likely have has a differential thread and knurled knob at the rear, and will adjust the height very accurately.
Neatman  |