I started with the T5 pulley and belt profile because I need a large tooth to suit CNC machining. But recently I found that the GT2 profile can be drilled with a 1.3 mm diameter bit. Sure the outside perimeter still need to be cut. So I will reconsider the pulley and belt profile later.
Here is the 12 tooth pulley and belt profile that I coded:
The belt is wrapped around the pulley (the red circle is the pitch circle).
Note how loose the fit is! This appears to be part of the design feature:
Other belt profiles (GT2) have lower backlash and should be considered later.
Here is T5 belt profile:
and the pulley profile:
And here is the design:
Here are the calculations:
|Cog and Belt Design||T5||
|Z1 Pitch Diameter||19.249||mm|
|Z2 Pitch Diameter||95.643||mm|
|Pitch Centre (meshed)||57.446||mm|
|Z1 Outside Diameter||18.249||
|Z2 Outside Diameter||94.643||
I will upload the spreadsheet to the file area.