Spindle square - video

[mklotz]

Hi Marv, I agree with you. My original idea was only to showcase the fabrication process of my solutions to some problems, or particular implementations of some common-ish tools without focusing on explaining them, and I do enjoy seeing the chips fly around and "reveal" the part underneath. But I understand my wants may not match the audience needs, and in retrospective, I do feel that I missed several opportunities to communicate more things with the video. I'm still trying to find a good balance, and these kind of feedback is much appreciated, so many thanks!


Regarding the actual device, I've used the DTI on a bar approach up until now, but it always felt clunky to me, bumping the tip over the edges of table slots and blocks or something. The tramming square gets rid of it, and allows me to continually observe the change in the spindle axis orientation as I rotate the head, without having to pause to give the indicator a spin (as you said, I should've put this stuff in the video). Price is not a particular issue with these tools, I spent like $5 in metal and fasteners. I had the indicators already, so they're not really an extra expense, and I can remove them from the square and use them somewhere else when needed. They also do not have to be matched, unless you want them to be zeroed at the same position in the dial.

Re: "bumping the tip over the edges of table slots and blocks or something" ...Get a brake rotor and lay it on the (clean) table; swing DI on that.

Your costs, DI availability, and the fact that you have a CNC mill available aren't necessarily the case with your viewers. If you do cost/time comparisons, assume the worst case for your viewers.

The orthogonality of the frame to the rod that supports it in the mill is important, as is the equal spacing of the DIs relative to that rod. I didn't have the patience to watch the whole video. Did you make that clear? If not, you should for the benefit of folks who are inspired to build one.

[atomicmill]

Re: "bumping the tip over the edges of table slots and blocks or something" ...Get a brake rotor and lay it on the (clean) table; swing DI on that.

Yup, or a bearing race. Or better yet, make a spindle square, because sometimes the other stuff doesn't fit on top of whatever one is trying to indicate .


The spindle square shaft doesn't need to be precisely aligned with the frame, nor do the indicators precisely spaced from the center. It can be off like 0.1 inch on a 5 inch spindle square and it wont matter (the error created by this decreases the more you get in tram). Home shop tolerances are more than good enough to make a functional tool. Think about it as hooking two indicator tramming bars to the mill at the same time. The position of the bars and the indicators is irrelevant, i. e. one can be above the other or they can be facing different directions. The only things that matter are that their tips are 180 degrees apart, that you can reach roughly the same spot on the table to zero both of them. We can even have some indicator cosine errors, as long as they're roughly the same, as we only compare the produced measurement without really caring for the actual linear displacement.

And no, I didn't mention any of that in the video , but I do realize that explaining some things in more detail is necessary.