Gear C-Hook extra options

[Sunder]

Dear All,

 

Iam trying to create a Gear profile using gear chook.

 

I have to use the following parameters also to create & modufy the gear profile,

 

1. Addendum/ Deddendum modification co-efficient / factor

2. Profile shift calculation

3. Inches & metric option in gear chook dialog

 

can these inputs can be customized to the chook

pls help me & give some suggestions

 

thanks in advance

 

regards

 

Sunder

[John Summers]

What are those numbers, Sunder? GEAR.DLL comes up with 'standard' addendum and dedendums, but doesn't display them. The addendum is the difference between the pitch radius and the outside radius. Profile shift would affect tooth thickness, and vice-versa. We don't have metric yet, but I'm trying to get it to happen. Again, you have to look up some numbers. If you send me the numbers you have, I can help you more.

[Sunder]

Iam not a expert in gear design & have traces of knowledge in gear nomeclatures

 

I have a parameter table(found below) which should be used to create a gear profile...

 

 

[John Summers]

Sunder, the tooth thickness really controls everything. I assume the circular arc thicknes is a transverse value. Then I get the value of 2.11 mm rack displacement. I haven't been able to figure out the span measurement yet, but I'm working on it. How do you intend to cut this gear, mill or gear-cutting machine?

The transverse module is 4.689

The transverse pressure angle is 4.687. You need to use this to draw the gear in M'cam.

The OD is not given. I couldn't figure out how to make use of the Addendum Modification Xm.

[John Summers]

I got some numbers switched.

Transverse pressure angle is 16.287

Transverse module is 4.689

4-tooth span is 47.491 (graphic solution)

A website called enjoyabledesign.com figures out helical gears. Using an addendum modification of .45, they get a 4-tooth span of 47.3946.

Furthermore, Mt/.45 = 2.110, the profile shift I got graphically from a gear with 8.598 circular pitch, so it seems like the figure of .45 may have some merit.

[Acro Engineering]

I have to wire some odd gears (change gears) with profile shift, what is the procedure used to get gear.dll to create the geometry correct?

 

12 DP

20 PA

2.75 CENTER DISTANCE

 

22 TEETH (on a 23 PITCH CIRCLE)

With standard 43 tooth

 

23 TEETH (on a 24 PITCH CIRCLE)

With standard 42 tooth

 

24 TEETH (on a 25 PITCH CIRCLE)

With standard 41 tooth

 

Many more... We have these hobbed normaly and they work great but I have to create some prototypes to work with and need to wire them...

[John Summers]

I am working on the solution, but it is messier than I thought. There is a 'solution' in Dudley, "Handbook of Practical Gear Design", CH 8, Drop Tooth Design, Fixed Center distance. It's good as far as it goes, but you need more parameters to plug into GEAR.DLL. I'm trying to provide them all. If you send me the backlash, I can factor that in to the tooth thickness. There's no data yet, I just want you to know that help is on the way.

[Acro Engineering]

I don't have a backlash or tolerance on what we have but I can do some over pin measurements and put togeather a couple gear ratios and measure the backlash...

[John Summers]

Let me have the measurements over pins, also, so I can check it graphically.

[Acro Engineering]

Very busy day, I will have time in the morning...

[Acro Engineering]

Talked with my gear cutter and he is making me a chart to get you some data...

[Acro Engineering]

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