Tramming Jig for 1/4 Collet

I re-purposed a buffer wheel clamp to make a tramming jig for my 1/4 collet, see pic below.

Seems to work.

The four contact points are to verify the jig shank and contact surface are perpendicular. They should all contact the work surface in the same way before and after adjusting the tool clamp.

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That is interesting. How is it working so far?

This is interesting because you can rotate the plate while leaving the spindle fixed, or rotate the spindle while leaving the plate fixed, and movement of the plate can be used to determine whether the shank is square to the plate and whether the spindle rotation is parallel to the shank. And then statically whether the shank is square to the spoil board, if you can precisely get the four feet to be the same length and the spoil board to be flat.

Is that bearing more accurate than the router’s though?

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The fitting in the middle is buffer disk holder (see below). The plate only rotates because the spindle rotates.

I lowered the z axis and rotated the plate until one of the screws touched. I rotated the other screws to the same position and lowered them until they touched. If they all touched in the same place and nowhere else then the z axis has some deflection. If they touch in other places the first screw didn’t then the tool, jig, isn’t perpendicular.

In my case the jig was a little off. Once I corrected that all the screws touched in the same place which meant the z axis was off. I corrected that by tightening the tool holder. All four screws touched continuously as I rotated the plate after that.

I haven’t run the ripple test yet so this might not work at all. I’ll post results when I do.

image

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Ohhh, ok not what I was thinking but still you could loosen the collet to the point that it slips and see if your shank is square to your plate, and if not, shim it until it is. Then you can measure whether the shank is parallel to the spindle axis, and as long as it’s close enough your plate is a good indicator of your spindle. And unlike the arm thingy you don’t have to spin it around to see if your spindle is square to your table.

When are the screws are adjusted to touch where the first one touches then if the plate is perp to the shank they will also touch, or not, everywhere else the first one does.

Ok, I think I understand. You’re right. Ignore me, I’m off in space thinking about lasers bouncing off the glossy surface as it rotates, aiming to get everything true far beyond what matters.

You are not wrong about the slop in this calibration.

I was thinking about putting a dial indicator in one of the positions.