Rim Thickness Control

[John T]

Hi Art,
I'm not sure if I asked about this before - maybe. 
I can control the rim thickness on a normal spur gear and the external "rim" on an internal spur gear, however when I design a "cage" or "pin wheel" I can't find any way to control the thickness of the gear (blank) that lies outside the pins.  Is there a way to get the rim control to do this?

John

[ArtF]

John:

No, I never added anythign for selection of that, the distance chosen was an algorithmic one corresponding to the so called "perfect" sizing..which is why the pinions teeth end in a point..while in thery they could be stubbed down somewhat..
  I will add that to my list to take a look at..

Art

[Mooselake]

I'd like this, too.  A long time back I made a lantern and pinion gear toy with 1/8" dowels - IIRC 8 pins.  I had to remake the cage several times because the very thin area between the pins kept breaking.  Since the dowels were flush with the outside of the cage, the rim was interrupted (is that the right way to say it?  a bunch of gaps?).  A larger diameter cage would have gotten rid of the gaps and made it stronger.

Perhaps if I had better hand-eye coordination...

Kirk

[ArtF]

Kirk:

  Just so I understand properly, you mean the disk outside needed to be larger to have bigger gaps in the teeth?
The distance pin to pin is currently set to the normal distance for a spur gear of that DP. So if I allow rim control to make the disk larger it migth be better? Ill have to look to see what I can do there withoutt invalidating the
creation of the matching spur.. the diamter of one relates itself to the other..

Thx
Art

[John T]

Hi Art,
I'm not sure that Kirk and I are talking about the same thing or not.  I'm referring to the distance from the edge of the pin to the edge of the disc.  It really has nothing to do with the gear design only the outside "rim". 

I include a photo - Obviously its not a problem in this photo but I have had problems in other sizes.

Hope this helps.

John

[ArtF]

Ahh, I see.. OK..
Ill see what I can do.


Art

[Mooselake]

I meant the same thing as John - my lantern was pretty small, and the pins touched the outer edge leaving small gaps instead of a continuous rim.  This made the cage weak enough the resulting small triangles broke at the narrow point between the pin holes when I tried to insert the pins with a pair of tweezers.  A thicker rim would have held it together.  The pinion was fine.

I found the old project file, 6 pin lantern, 56t pinion, 1/8" pins.  It's attached if that helps.

Kirk

[Mooselake]

Just so I understand properly, you mean the disk outside needed to be larger to have bigger gaps in the teeth?

The lantern disk outside the pins needed a wider rim, i.e larger diameter disk without moving the pins..  John got tearout, in my case the pins were flush with the outside of the rim and actually left a small gap over each pin.

I've got a picture of it somewhere, I'll see if I can find it.

Kirk

[ArtF]

Kirk:

  No need, Version 8.1 now uses Rim% on the spoke panel to control the disk size..

Art

[John T]

Hi Art,
Works as advertised - thanks very much.

John

[Mooselake]

Thanks!

@John:  Cool!

Kirk