The Home Machinist!

Harold_V wrote: ↑Wed Jul 13, 2022 2:01 am I would. It's obvious...

H

You're making me feel inadequate. Tell me more, please.

There are so many subtle things to be aware of. I have been concerned with safety, and more so ever since I tossed my square. I was doing the "five block test" which seems to be a thing. I just thought of it on my own after not getting my square "perfect" the first time. Some wil...

Magnets placed closer togheter. Fine pitch vs coarse. Yeah, I get that, but what isn't clear is how that relates to the 3/4"/2mm mentioned. H The chuck specification (lip service) is fine pole with pole pitch of 2mm. The top plate has alternating steel/brass (copper?) plates that are ~2mm thic...

For some reason I made five ~1/4" diameter x 1/10" thick steel discs to place at each corner and center of my mag chuck. I proceeded to grind each one to the same height and noticed some were skating on the chuck. I discovered strong magnetic fields are ~3/4" apart. What I mean by tha...

That is exactly how I made the measurements. I do have a set of "JO" blocks that I can check the caliper's readings. This is what I would do and check over the range of the instrument. IME, when high accuracy was important, calibrated standards are used as a measurement reference, and the...

Now that you mention it, that seems obvious.

Back to my square, I had not measured the side squareness, and it was out over half a thou. I set in my screw-less grinding vise with the outside edge against the fixed jaw, and I use a square to set the side-side lean. I haven't been able to get it square. The difference between sides is 5 tenths, ...

The point of the article seems to be that, for a particular out of round shape, there IS a v-block angle that accurately represents the amount of error, and other angles could be used to determine the same through additional calculation. My point extends that to, for a particular out of round shape,...

I will refer the concept of a Reuleaux triangle and the result of measuring that directly on a surface plate - you would not see the error. So, it seems complicated. I tell you the v-block angle answer is, it depends. The meat here is in tables 2, 3, & 4. https://www.matec-conferences.org/articl...

So you're saying Don is incorrect? I suspect there is a particular shape that would not reveal any out of roundness in either V-block using that method.

Well, of course I meant 90 or 60 degrees. I was thinking of the 45 you get when you set a square block into V.

But just in case: https://www.youtube.com/watch?v=YUeFNGslzZo

Well, I guess after watching a Suburban Tool video, which is more accurate to use when measuring out of roundness, [strike]45[/strike] 90 or 60 degree Vs? I can say neither