These are instructions for constructing a rack and an internal gear, along with my original instructions for drawing a gear.
These methods for constructing the vectors for an internal gear or a rack have two features that are not found in almost all other drawing methods.
1. Backlash allowance. This is an amount by which the gear tooth is drawn undersize to provide backlash. Backlash is the “slop” between two gears that are mounted together. Backlash is necessary to prevent binding as the gears turn.
2. Full radius root. The root (space between two teeth) is constructed as a circular arc. This provides a space that can be cut with a round cutter (such as used by a CNC router). The radius of the circular arc is also the radius of the largest end mill that can be used to cut the gear. Most gear drawing programs draw this space as a straight line, with sharp inside corners that cannot be cut by a router.
Here are the instructions:
The original instructions for drawing a gear:
How to draw a rack, internal gear, or gear in VCP or Aspire.
- FixitMike
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How to draw a rack, internal gear, or gear in VCP or Aspire.
Good judgement comes from experience.
Experience comes from bad judgement.
Experience comes from bad judgement.
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Re: How to draw a rack, internal gear, or gear in VCP or Asp
Thanks Mike!
I will code this up, and will post the updated gear program for free downloads.
Cheers!
I will code this up, and will post the updated gear program for free downloads.
Cheers!
Paul Rowntree
WarpDriver, StandingWave, Topo and gadgets available at PaulRowntree.weebly.com
WarpDriver, StandingWave, Topo and gadgets available at PaulRowntree.weebly.com
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Re: How to draw a rack, internal gear, or gear in VCP or Asp
Thanks for the update, Mike.
Bob Armbruster
www.ArmbrusterCo.com
www.ArmbrusterCo.com
- highpockets
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Re: How to draw a rack, internal gear, or gear in VCP or Asp
Amazing work Mike and Paul !!!!
For us dummies who have no clue, Matthias Wandel created Gear Generator that will do Spur, Rack and Ring gears.
For us dummies who have no clue, Matthias Wandel created Gear Generator that will do Spur, Rack and Ring gears.
John
Maker of Chips
Maker of Chips
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Re: How to draw a rack, internal gear, or gear in VCP or Asp
When I grow up I want to be like Matthiashighpockets wrote:Amazing work Mike and Paul !!!!
For us dummies who have no clue, Matthias Wandel created Gear Generator that will do Spur, Rack and Ring gears.
Mike's approach gives vectors that can be cut on a std 3 axis CNC without collisions between gears caused by the finite cutter diameter that leaves excess material on the inside corners.
Cheers!
Paul Rowntree
WarpDriver, StandingWave, Topo and gadgets available at PaulRowntree.weebly.com
WarpDriver, StandingWave, Topo and gadgets available at PaulRowntree.weebly.com
- highpockets
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Re: How to draw a rack, internal gear, or gear in VCP or Asp
Agreed, in Matthias' Gear Template Generator there's a setting for "slop" which allows for cutting on a CNC...PaulRowntree wrote:When I grow up I want to be like Matthiashighpockets wrote:Amazing work Mike and Paul !!!!
For us dummies who have no clue, Matthias Wandel created Gear Generator that will do Spur, Rack and Ring gears.
Mike's approach gives vectors that can be cut on a std 3 axis CNC without collisions between gears caused by the finite cutter diameter that leaves excess material on the inside corners.
Cheers!
John
Maker of Chips
Maker of Chips