Jump to content


Johnmasters

Member Since 15 Aug 2005
Offline Last Active Today, 05:27 PM

Topics I've Started

Has anyone seen this Youtube film?

21 July 2016 - 05:42 PM

Each work-station has a person who learns to see things very well,  and there is no wasted motion.  And notice the piles of work in progress !

 

https://www.youtube....h?v=0SvfNhMlnBE


Height of arch ??

10 July 2016 - 03:35 PM

Could someone please tell me what is the standard terminology to specify arch height ?

 

Are people speaking of the rise from the top surface of the trough,  or from the flat (gluing) side of the wood?


My Wien Bridge Comparitor

10 March 2016 - 04:39 PM

.


CONFORMAL mappings

09 October 2015 - 11:57 AM

These are interesting.  I think that "Raguz" or Mr. Robert Zuger actually is intending to do something like this.  If he used the word "conformal map"  he could write the whole thing in 100 words or less.

 

I think he makes a transverse line at the post and either side is intended to be what we would call a conformal map of the opposite side.  (flipped over as in a mirror)   Doing this would map points of one end of the violin into the other end.  At corresponding points,  the thicknesses and arch height would be the same.  But did he really arrive at a true conformal map ??   I don't know,  I am asking HIM.

 

I arrived at this in a period of waking up from my sleep.  I often get insights this way.  I recalled that on his website, Mr. Zuger drew a rectangle and drew in it a violin with top and bottom the same size and shape.   Then he moved (continuously) the rectangle sides outward to make a trapezoid.  The drawing went along for the ride.  I thought it was a complete fudge and I threw out the idea completely.  Jim Woodhouse had asked me to take a look at Zuger and I wondered why Jim was not alarmed at this strange pseudo-science.  I now see something of interest.  If only Mr. Zuger had the word "conformal map" in his model,  he could have boiled down his website to a single page.

 

If y'all find this interesting,  I can post more about the special properties of conformal maps.  In the meantime,  here is a page with many illustrations of conformal maps.   Notice that they preserve angles and shapes at CORRESPONDING POINTS but not "all over the map'  as one could say.  That is to say,  they preserve shapes and angles LOCALLY.  A transformation exists,  but it varies as one moves through one of the areas.  (If you choose the other area,  you use the inverse of the transformation.)

 

http://images.search...fullyhosted_003


For the math geeks

24 September 2015 - 12:23 PM

I corresponded with ABAQUS student addition manager about a problem with installation and he took an interest in my usage. Here is a site if anyone wants to see how FEA is being used by someone involved with guitars.

He is just revising his site, so perhaps it will eventually be interesting.

https://sites.google...alguitardesign/