L6 with Lexan base

Hi everybody

Could I lenghthen the length of the robotic arm for examp;e to 60 cm ?

Uh, well, maybe but you need to realize that is about 2x the reach it is now so you would need servos with roughly 2x the torque.
Using the SES

you could make an arm quite large if you have servos with enough torqe to support it. Might need to make your own tubing lengths though as it looks like the stock ones only go up to about 15cm so the above arm would be in the 40-45cm reach.