GearHeads Corner

Art,
I am modelling a Functional Gear in Gearotic which has to have the exact ratios as defined in the attached polar file.
It appears to simulate fine and I understand the quality of the simulation is not 100% due to the need to produce real time output. However on the simulation there appears to be some interference between the master and slave gears. As you say this may just be a function of the low res simulation?

My concern is that the shape of the gear teeth produced in DXF/STL format seem to be a bit jagged with steps on the teeth surface (see attached DXF files).

I have used the following simulation parameters:

DP = 2.54
Mod =8.5
Teeth No =24
Target pressure angle = 10 degrees (to reduce the maximum pressure angle to below 60 degrees)
Rollover is un-ticked.
Width 0.53 (to minimise the risk of clashes with so many teeth mating at the same time).

My target centre distance is about 205mm (200-210 acceptable)

I really just picked the DP, Mod and Teeth number targets at random to get the correct centre distance.

I only need the output gear to travel through approx. 41 degrees, perhaps even less.

I am fairly sure I am doing everything correctly, so could you please run the simulation to see if you get the same results. Is there anything I have done wrong? What can I do to improve the quality of the profile?

I am really enjoying using the application.

Many thanks Andrew

HI Andrew:

DO me a favour and post the gprj file here so I can load the project. Be happy
to run it and see.

Thx
Art

Hi art thanks for the quick response. Hopefully this is the file you require? Just getting my head around the program still.

Thanks,

Andrew

Hi Andrew:

  Your close, but those teeth don't look good. First, I suspect their a little thin, Id up the width a bit, but more importantly , for some reason the tops are not being chopped off right, those tall tips don't belong.

  Unfortunately, its hard to recreate. Can you take a snapshot of the screen while you have them on the design screen,
Ill set mine the same to see what it takes to cure that one.

(Interesting gear pair.. :)

Art

It is probably a case of user error/not understanding enough of the program yet.

Art

Thought it may be worth mentioning that my requirement is for very slow moving gears that will be turned by hand to position some optical equipment.

On that basis would a pressure angle of 20 be OK?

Apologies for all the questions,

Regards,

Andrew

Andrew:


  Should be fine.. slow moving gears are not very picky...

Art