Recent content by Skyman

ooops - forgot second attachment.

Gentlemen, my sincere apologies. I had to go "offline" there for a couple months due to a family illness related item and haven't responded for a while. Fortunately, I can now get back on track with this. I think I now have a good grasp of the forces involved in moving this shuttle/arm...

AlephZero - perfect and understood. Didn't think of "flattening" the shape before calculating loads but it makes perfect sense now - thank you Fred - angular contact bearing - I do see how this would eliminate the thrust bearing as long as I could get a bearing diameter small enough to fit in...

Anyway, going back to the question of friction forces noted by AlephZero, can someone please help me understand the magnitudes of these forces in relation to the torque selection for the motor? I have multiple motor/gearboxes I can select from as well as output torque capabilities however...

Hmm, tapered roller bearings - didn't think of these. The purpose of the thrust bearing on the pin is two fold 1). To provide a true thrust bearing function to control rotation in the XY plane and 2). as a rotating surface for the outer casing of the roller bearing to bear on as it...

AlephZero - thanks for the additional help - I am reading intently! Your thoughts are somewhat simialr to what I thought regarding position 6 being the problem area. I have spent quite some time trying to figure out a method of reducing the friction forces between the pins and the slots they...

Apologies for over doing this but one more picture that shows the trajectory curve of point A noted at the top of the picture as the shuttle moves from the left most position to the right most position. This is the motion of this point over the whole shuttle movement from arm vertical to arm...

FYI, I have added a couple 3D renderings of a very early version of the concept here for those that may need a visualization. The two pictures cover the "up" position and the "down" position and shows the rails either side of the shuttle/arm assembly. Note that the sprocket positions have since...

AlephZero - ooops! I just reread your e-mail. "Hold it steady" is the key I think and I believe you mean put the shuttle/arm on the rails and attached a spring scale to see what force is needed to hold the unit in certain positions along the curve. This, to me, implies a prototype of the...

Fred, Danger is correct. The arm is fixed to the shuttle as is the driver motor and the two sprockets that drive the shuttle over the curved profile. The shuttle is about 70mm wide and there is a sprocket on either side of it in the location shown in the drawing. At the two locations showing...

Danger - yes the arm does tip backwards (to the right in the picture) for a short period of the traverse and then back to vertical and the tips the other direction (to the left in the picture) all the way down to the more hoizontal position. In my mind however, the peak torque to move the...

Folks, hopefully someone can assist me. I am a EE by education and am in the process of designing a mechanism that I need some assistance on. The basic issue I face is determining the torque needed for a miniature drive motor/gearbox for this mechanism. The problem, I think, might be fairly...