GearHeads Corner

Hi All:

  Version 4.85 is now online and includes many code changes, but the only thing youll hopefully see
as a change is the new Geneva Gears. While a great deal of code has changed in order to clean up some
internals and speed up displays, the geneva's are the only new functionallity.

  Due to this, you might get some errors or bad behaviour, if so, please let me know. This is a
entire new build and I can redact the changes and revert back to previosu version if my changes are
too drastic and some video cards have trouble.

  The geneva's are inverted geneva's with a rythmic capability. This means that unlike the maltese cross
geneva's, they use the standard lantern gears to function. They can be cut without pocketing or double
layering of the shapes involved. They will very much look like a standard lantern gear set with some important
differences. Youll find them on the lantern gear tab. Checking the box for a "rythmic geneva" will activate them.
 
  Youll notice you get one tooth that performs as a geneva, but the button beside the checkbox allows you to add
teeth by simply clicking on the spur gears tooth location.

A geneva usually pulses the driven gear by a set amount per rotation,
    the GM version allows you to have several sets of pulses of various widths.
   
    Take note that the amount of rotation is a bit non-intuitive. Take for example,
    two gears that are both 10 teeth. 10 pins on the cage, and 10 pins on the spur.
    This is easy to figure the ratio from, its obviously a 1:1 rotation. But what
    if the cage has 10 pins and the spur has 1 tooth. Whats the ratio? If you said
    1:10, youd be wrong. One tooth of a geneva will move its mate by 2 teeth.
    This means a 10 tooth to a 1 tooth will have a 5:1 ratio.
   
      Each impulse tooth overlaps the next tooth so it can be difficult to figure
    by looking what the ratio is till you play with it enough to understand that
    relationship. Youll understand that as you play with them so I wont dwell on it. :)
   
    Some of the display text may still be wrong on the ratios and such, this is a
      preliminary release to ensure I havent screwed up compatability with anyone.
     
     
      Have Fun
      Art
     
     
     

Hi Art
What can I say - Fun just plain Fun.  ;D

Some old issues showed for me - Trouble with spokes - Standard is OK but some others only produced half the spokes in the project view.
The little circles in Mach 3 are there again sometimes.

Never mind its still great - many thanks.

John

John:

  Already!!! wow, I didnt even get close to cutting one yet. lol.

Ill check again on the spokes and circle issue now that Im done with
the geneva for the most part. Its possible my earlier fix for that didnt make it to
this build. Ill check it otu and reissue in a day or two.

Have fun,
Art

Hi Art
The spokes that do generate only appear on the Geneva component - and not the lantern - was that intentional?

John

Hi John:

  Yes, the disks on the pinwheels have never had spokes, they are generated on the fly to simply match the size of the pins, which are the only real objects being made. The lantern gears are really one of the weirder gears internally as they arent so much an actual object as a construction assembly made up of primitives. I may look at spoking them eventually but
its normal at the moment that they have no  spokes.

Thx
Art

Hi Art,
I'm doing something from time to time in my playing around that delivers the message (different modules) on the project screen (when I'm playing with the Geneva gears).  Since I only set one module I'm confused as to how it is seeing two modules.

Any help?

John

John:

  Hmm, it may be mixing its errors. There are a couple rules. Ill check the outputs..
A driver ( pinion) may only be placed as master or on a shaft. A driven( wheel) may only be placed on a driver.
You may change the tooth count of a wheel and place it on the same driver as another wheel , but you may NOT
change the toothcount of a driver and place it on another drivers wheel. ( Clear as mud? )

  In other words a driver may share many wheels, but a wheel can only use one driver.. those are the only errors
hat shoudl occur with geneva's..

Thx
Art

Hi Art,
I can reproduce the problem by trying to put in a high reduction - like 12:1 for a minute/hour hand arrangement.  If the driver gets too small then things get funny.  If I keep the gear sizes reasonable then it will work.