Backlash

[Dan1931]

Hi art; Thank you for your response. It works fine.
I just cut two gears for my clock ( the two In the previous example). I set the centers per the center distance on the tools menu. The gears worked and meshed fine. I cut these with a Laser that cuts on the line with a 0.005 kerf. I noticed a little looseness between the gears resulting in possible backlash. Although Backlash should not be a problem on a clock I would like to get a better fit between the gears. , Is there an adjustment for backlash in your program?
On my CNC machine I use Aspire to write the Gcode which gives me the luxury of offsetting from the line to adjust the fit. The problem is I must use a 0.0625 down cut bit for the final pass. This slows down the cutting process.

thanks again
Dan

[ArtF]

Hi Dan:

  There is a setting for Tooth Width on the screen, you can increase or decrease that by small amounts to get the type
of backlash correction your looking for. However, if you building a clock make sure you HAVE backlash. Clocks use the
epicycloidal typically on gears after the escapement, and involutes before ( from spring to escapement). Youll notice
the epi's are very loose ( almost 50% air gap, and that is by horilogical society specification. Epi's being loose means dust, dirt etc wont slow
the works, and friction will not take away energy from your chain of gears...

Good luck,
Art

[John T]

Hi Dan,
With respect to backlash, you definitely want it and in fact I built a successful clock where the the gear tooth was shaped on one side only and there was radial cut from the tip of the tooth down to the gullet.  If you use Aspire's offset you might adversely change the shape of the driving face.  Anyway it was a funny looking gear and the teeth were not as strong as they could of been but they ran well, kept time accurately and gave me something to talk about.

As one writer said clocks don't run backwards - ever!

you'll have more headaches from too little backlash than from too much especially if you use Gearotic's technique.