[photo-3d] Re: Improved mounting with RBT jig

["John Goodman" <jgood@xxxxxxxx>]

Dr Dave wrote:

> The standard white pins are 0.05mm offset from center. That
> means that if you place one up and one down in the same
> channel you will get 0.1mm offset. 

Now I get it, right. Then, your next sentence...

> If you place one in the upper channel and one in the lower
> channel you will get 0.05mm offset. 

Are you sure? Both an instruction sheet in English, and a fall 
1998 page from 3-D Concepts say that the standard pinbars 
provide 0, .1, .2, .3, or .4mm adjustments (height difference 
between the chips), but not .05mm or combinations thereof. 
According to this info for standard pinbars, one in the upper 
track facing down, combined with one in the lower track facing 
up, yields a .2mm difference in chip height. Then, upper one 
down with lower one down gives .3mm, and upper one up 
with lower one down provides the maximum .4mm difference.

I found an RBT "Reference tables" info sheet in German that I 
had not paid enough attention to, and though I can't read the 
language I can understand the tables. These explain all the 
possible adjustment combinations, including the two non-
standard pinbars, as has been mentioned. The variables are: left 
and right pinbar type (standard, .1, or .2); left and right pinbar 
orientation (up or down, noted as "blank" or "minus"); and 
pinbar location (upper or lower track). According to the master 
table (with 142 entries!), .05mm differences (and .15, .25, 
etc.) can only be had by using one standard pinbar in 
combination with either a .1 pinbar or a .2 in various 
orientations and tracks. The maximum adjustment is listed as 
.7mm (with a .2 facing up in an upper track and a .2 facing 
down in a lower track).        

The next time I'm fussing with a pair that the standard pinbars 
don't quite accommodate, I'll remember to consult this table. (It 
would be outstanding if the several paragraphs in German on 
one side of this important sheet could be accurately translated 
into other languages for RBT's international customers.)   

I'm afraid that for Spicer mounting with RBT jigs, I don't usually 
worry about extremely fine "special" pinbar vertical 
adjustments, since I float the window-set pair on the Spicer and 
then do final delicate vertical adjusting (and cropping) of the 
pair together. Tiny vertical discrepancies between the chips in 
the jig could be translated into micro-rotational errors, I 
suppose, but these are below my current bother threshold.      

John Goodman