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[ATM] Grind More...
Hi guys,
I am merrily grinding my 8" BVC blank... I am too short though (was
aiming for F5, but I am just about F4.6). I am grinding with TOT using
a tile tool. My strokes are about 1/2, center over center, sometimes
2/3 center over center with a slight side to side (Lecleire). I get
about .001" every 10-15 minutes with 220. I got about .010" to go. The
amazing thing is that there was an F5.15 curve ground in when I got it
and about 1.5 hours worth of work, 1/3 w strokes with #120, I got to
F4.5. This stuff grinds fast. But it does not seem to grind as fast
trying to get it longer.
Here is my concern. I can now see the bubbles and other weirdness
better (which is expected in BVC blanks) because the surface is getting
smoother and they look close. I mean, maybe a millimeter close at the
center. I am afraid of punching through to the next layer. I am really
wanting to get the darn edges down more and not dig any deeper at the
center. I am also wondering if it is an illusion and the next layer is
deeper than I think.
Should I hop back to 120? My tool was made similar to Bob May's
instructions with most of the tiles pretty much even with the surface of
the hydrostone (edge protection of the tiles). The edge tiles are even
with the hydrostone, the center tiles are slightly higher than the tool.
Sharpie tests show all tiles except one tile on the edge are making
great contact (all X's go away in a wet). I am willing to stay under
F5, but it is already going to be a short scope at F5.
I know to grind more and worry less, but I don't know how much glass I
got left....
Best Regards,
Jason Hissong
--
"A long journey starts with the first step and an understanding spouse."
http://www.undermidnight.com - astronomy and astrophotography
http://www.n8xe.com - ham radio
http://www.jasonhissong.com - electronic music composition
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