https://www.youtube.com/watch?v=-YlxfzoW8go
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Very nice tool build Paul.
I just got a new test indicator, Mitutoyo, 1micrometer resolution. Now I don't know if the test bar or the surface plate is an issue. It all looked good with the tenths indicator. Zeroing is a real challenge. Looks like this may have less sticktion/hysteresis then the normal surface gauge zeroing mechanism of tilting the spindle.
You wouldn't think 2.5 (2.54) times more resolution per tick would matter. I have a test bar that's precision ground about 1.5" round 8" long, I lay that on it's side, I can test for diameter with the tenths indicator, and over the length very little deviation, but with the micrometer indicator, I can see +/-2-3 tick differences. I was using a different surface gauge, but I'm thinking it's both the bar and the plate.
Thanks! I've found the zeroing mechanism to be very smooth, even with my shaky hands! Can't compare to a normal surface gauge, since I've not used one before.
Afraid your measurement issue is way above my pay grade! I guess you could measure your surface plate independently to rule that out?
That's stuff I don't have, the videos I've seen for measuring surface plates, they use a special flatness indicator called a repeat meter.Quote:
Originally Posted by PaulsGarageProjects
But I see a youtube video about hand scrapping a cast iron plate to grade A which is less then 5 micrometer flatness. Mine, I know is a B grade, but appears mostly beyond my skills as flat. There's many youtube channels of guys with tool making skills of extreme skill, Robin Renzetti, for one. He works in sub micrometer.
I'm getting into surface grinding much more from my hobby perspective, mainly to fix cheap import tools that have serious runout issues, like all ER collets made there, (pretty sure they keep the good ones to sell for high end, and sell the scrap to people like me). I know my 16x40 lathe (PRC) I got in 2004 was made from every incorrect part. Same with the one made in 1976 (Taiwan). So with surface grinding the metrology skills and tools need upgrading.
And then there's integrated circuit manufacture, at a total different level of precision. Measuring stuff where electrons are too large.
Robin Renzetti does have a video where he makes a basic repeat meter. Alternatively, a simple spherometer might tell you how accurate your surface plate is, although not necessarily where problem spots are. I 3D printed a spherometer, which worked surprisingly well with a micron indicator.
I'd love to get into surface grinding myself, but the ones for sale in the UK either seem to be huge and expensive or small and clapped out!
I ran into this guys channel a few days ago. He's a very talented machinist. I enjoy his descriptions of the process.Quote:
Originally Posted by PaulsGarageProjects
https://www.youtube.com/watch?v=RldfmpmzlgY
Now I've never seen the surface grinder he's moved into his shop. That's something that must be common in the UK, but not here in the States. It's got mechanized automatic feeds in all three axis. Amazing amount of mechanisms, and old tech.
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Thanks PaulsGarageProjects! We've added your Surface Gauge to our Measuring and Marking category,
as well as to your builder page: PaulsGarageProjects's Homemade Tools. Your receipt:
<div id="blocks"> <div class="block b1 pngfix"> <div class="bimg"> <div> <a href="https://www.homemadetools.net/homemade-surface-gauge-4"> <img src="/uploads/258859/homemade-surface-gauge-4.jpeg"/> </a> </div> </div> <div class="head pngfix"></div> <div class="left pngfix"></div> <div class="right pngfix"></div> <div class="blockover b1 pngfix"> <div class="title"> <a href="https://www.homemadetools.net/homemade-surface-gauge-4">Surface Gauge</a> <span> by <a href="https://www.homemadetools.net/builder/PaulsGarageProjects">PaulsGarageProjects</a></span> </div> <div class="tags">tags: <a href='https://www.homemadetools.net/tag/gauge'>gauge</a>, <a href='https://www.homemadetools.net/tag/dial-indicator'>dial indicator</a> </div> </div> </div> </div>
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