How to 2D Draw A Tooth of Gear?

[JD Mather]

Delete the first yellow circle and trim the second yellow circle as shown below.

 

Repeat this process with the cyan (little_r) arc as shown earlier in post #11.

Attach the file here.

[JD Mather]

Draw line (shown green) from then end of the cyan arc to the center of the gear.

[JD Mather]

Add green Root Fillet as shown.

 

[JD Mather]

Rotate the vertical line -7.5° as shown.

I think you can figure out the rest.

(Join, Mirror, Trim, Array)

there are 12 teeth in this design.

Post back solution or further questions and I will attach the xls (can be set to any number over 12 teeth).

 

[spinecad]

Delete the first yellow circle and trim the second yellow circle as shown below.

[ATTACH=CONFIG]39402[/ATTACH]

 

Repeat this process with the cyan (little_r) arc as shown earlier in post #11.

Attach the file here.

 

The yellow circle shown on above is not similar with the yellow circle you shown on the #13.

 

I can't continue because of this.

[spinecad]

Sorry, I think I skip the #20.

 

Now I can continue.

[spinecad]

Another problem, I don't know how to make the cyan arc in #11.

 

I can not continue.

[JD Mather]

make the cyan arc exactly like the yellow arc was made, but with a radius of .109167 (little_r)

draw the circle with the center at the intersection of the red lines - just like the first yellow circle was drawn.

draw second cyan circle where it intersects the red circle - just like was done with the second yellow circle.

delete the first cyan circle

trim the second cyan cirle

If you still can't figure it out post back and I'll do step-by-step pictures

[spinecad]

make the cyan arc exactly like the yellow arc was made, but with a radius of .109167 (little_r)

draw the circle with the center at the intersection of the red lines - just like the first yellow circle was drawn.

draw second cyan circle where it intersects the red circle - just like was done with the second yellow circle.

delete the first cyan circle

trim the second cyan cirle

If you still can't figure it out post back and I'll do step-by-step pictures

 

Unlike the yellow circle/arc, the problem is I can not find the center of the cyan circle.

 

The center of the yellow circle is known at the quadrant on the top of the white circle (D1.0000).

Edited December 28, 2012 by spinecad

[spinecad]

Meanwhile, come take a look at my current work.

 

I don't know whether it's correct or not.

Geare.dwg

[JD Mather]

Unlike the yellow circle/arc, the problem is I can not find the center of the cyan circle.

 

The center of the yellow circle is known at the quadrant on the top of the white circle (D1.0000).

 

The center of the (original) cyan circle is at the same location.

But as the radius is different - the new center intersection with the red circle is different.

 

Both arcs are created in exactly the same way.

[spinecad]

The center of the (original) cyan circle is at the same location.

But as the radius is different - the new center intersection with the red circle is different.

 

Both arcs are created in exactly the same way.

 

Doesn't really understand.

 

Can you show me the step by a drawing?

[JD Mather]

The key is that the center of the second arcs (of each color) are at the intersection with the Base Circle (red).

 

[spinecad]

The key is that the center of the second arcs (of each color) are at the intersection with the Base Circle (red).

 

[ATTACH=CONFIG]39421[/ATTACH]

 

Now I understand.

[spinecad]

If this is a gear, how to draw its pinion?

[spinecad]

How to draw the tooth of these gears?

gearandpinion.dwg

[JD Mather]

A pinion is the driving (powered) gear in a set while the gear is driven by the pinion.

The driving gear is almost always smaller diameter (fewer teeth) than the driven gear.

 

In the schematic you attached it doesn't make sense - looks like three gears mated with three different ratios - this can't work.

 

Usually information is provided like # of teeth or ratio, pitch, pitch diameter. 2 of 3 variables are needed to calculate the 3rd.

 

I think I asked at the outset whether inch or metric.

It looks like you are interested in metric unit gears.

 

A mating gear is modeled the same way as the first one but with different parameter values from the Excel spreadsheet calculations.

The key is any two mating gears must have the same pitch (distance between teeth).

[spinecad]

A pinion is the driving (powered) gear in a set while the gear is driven by the pinion.

The driving gear is almost always smaller diameter (fewer teeth) than the driven gear.

 

In the schematic you attached it doesn't make sense - looks like three gears mated with three different ratios - this can't work.

 

Usually information is provided like # of teeth or ratio, pitch, pitch diameter. 2 of 3 variables are needed to calculate the 3rd.

 

I think I asked at the outset whether inch or metric.

It looks like you are interested in metric unit gears.

 

A mating gear is modeled the same way as the first one but with different parameter values from the Excel spreadsheet calculations.

The key is any two mating gears must have the same pitch (distance between teeth).

 

I really have no idea whether I can draw a three mating gears (or more) or not such as in my previous attached .dwg file (#36).

 

I was said in inch, but metric is not a problem.

 

How to draw the tooths of mating gear and pinion?

[JD Mather]

Let's assume the the 12 tooth gear is the pinion (since that is as few teeth as the Wellman's Odontograph method will work.

How many teeth (or gear ratio, say 1:2) do you want on the driven gear.

Let me know and I'll attach the *.xls and explain how to do the gear.

(BTW - modern CAD programs like Autodesk Inventor will do all of this for you).

[spinecad]

Let's assume the the 12 tooth gear is the pinion (since that is as few teeth as the Wellman's Odontograph method will work.

How many teeth (or gear ratio, say 1:2) do you want on the driven gear.

Let me know and I'll attach the *.xls and explain how to do the gear.

(BTW - modern CAD programs like Autodesk Inventor will do all of this for you).

 

12 teeths is OK.