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Unread 27-12-2011, 10:01
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AKA: Stephen des Jardins
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Re: pic: I was bored... so I designed this.

It's good to see some exploration of bearing options but the application of the thrust/needle rollers on the wheel drive shaft is problematic.

1) The keyway would not be compatible with the needle bearings.
2) The counter thrust for the thrust bearing at the wheel would be by the needle bearing housing or the frame member, which is not good. A preloaded pair of angular contact bearings would be better. There is no particular side thrust to keep the thrust bearing loaded.
3) The gear separating force from the tooth meshing + the torque from the robot weight will be bending the vertical plate. It may be better to continue the removable vertical plate down the the lower shaft, so that the wheel shaft is not cantilevered.
4) Why is the wheel contact patch offset from the pivot axis? My understanding is that you want to avoid the turning force from a wheel drag moment seen at the pivot. This moment could cause twisting, scuffing, excessive drive resistance and problems with rigging to drive straight.
5) Note that I am not itemizing the many things I like about the module design.
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