Sorry Greg, that comment is completely wrong! Correct engineering is making it work efficiently and safely because any mug can put a 5" thick piece of Titanium under the telescope and it will work is it effecient? NO, is it cost effective NO. Hence this is poor engineering! If i did it that way ide find myself out of a job because nobody would ask me to design their commercial high rise buildings.
Quote:
Originally Posted by gregbradley
My CDK 17 has a dovetail plate twice the size of a regular Losmandy plate and it needs it. Its correct engineering. You want things way overstrong.
Greg.
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The thickness of these plates isn't really the issue, as what you fellas are forgetting is that you have a tube that sits above that dove tail it provides strength to the over all Y axis of the bar. The real difference is in the X axis or the major axis or in another term again the strong axis of the bar which is its depth the losmandy bar is for simplicity 100mm where as the vixen is 35 i think possibly 40mm in depth so the calculation for that is;
((b*d^3)/12)*A*h^2)
b= bredth
d=depth
A= Area
h= centroid of each section from the Nutral axis of the overall shape (or section as its commonly refered to)
If you want to figure out the deflection of your dovetail in the Y axis or weak axis then you have to go into beam formule for a cantileaver beam of the distance away from where the dovetail saddle finishes for simplicity as the saddle is far stronger due to its geometry. Remembering that in most cases you have to resolve your forces into X and Y to do the proper analysis as the telescope isn't bearing vertically.
I havn't gone into half the things that should be considered during a analysis like this but it isn't just a simple 2 second Jig needless to say
So in essence Peter what it is changing is the moment capacity of the bar bending in its strong axis allowing less "Twist" to happen when the tube is at its worst orientation! Its completely a flexural issue which affects pointing in a reasonable way! as you can get Vixen dovetails on large foot print plates see William optics version.