I recently asked a question about a 3-RRP manipulator but the only answer didn't work for my robot.
I would describe the manipulator as an arm that rotates around the shoulder over the x-y axis, the elbow that rotates around the x-y axis also and the forearm - hand that moves FORWARD and BACKWARDS. (check attached image for a more described explanation).
The solution I calculated cannot be correct as the "hand" moves up and down and not forward and backward.
I tried setting other values to the DH-parameters but I still think this is not the correct answer.
My professor said that we are not allowed to use a structural parameter to rotates the axes and that the use of 3 rows on the DH-parameters is the correct solution.
I've been trying to get this for almost 1 week now and seems impossible to me.
On the image you can see some of my attempts to solve this problem.
A detailed answer with the reason for the values of the DH-parameters would be awesome.