Re: [ATM] Grinding question

[Bill Marriott <bmarriott@pacbell.net>]

Hello;

The quickest way I have found to grind out to the edge is to flip the 
work over and with tool on top, do a short W stroke, this will work the 
edge, but in doing so, it will bring the center up, so then you need to 
flip back over, and work the center deeper. As you get closer to where 
you want to be, use center over center, and once you get past 240 or 
what ever you are using, the radius of curvature should stay put, though 
you can fine tune it if you really need to. Alternating MOT and TOT will 
help insure a good spherical ground surface when you are down to the 
last grit size.

Bill Marriott
VA Optical Labs



dhkblaszyk@zeelandnet.nl wrote:

> Hi guys,
> 
> Well I've started rough grinding on my 12inch mirror. After applying a rough 

curve using a grinder I'm now in the process of smoothing the

surface and bringing the sag to the desired depth. Just the other day I 
reached

  the sag (actually 0,1mm short still), but the edges are not grinded 
yet (15mm

  short on average). So my question is, what kind of strokes should I 
apply to

get the edges done, without going to deep in the center. I have used 
previously

a chordal stroke with MOT, but I suspect I should use a normal stroke 
with small or no overhang TOT. Is this correct?
> 
> Kind regards, Darius Blaszijk
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