well thanks……..hmmm keeping the welding equipment fixed and motionless, while instead moving the part to be welded by a robotic arm would be easier.........but perhaps it may not be the correct method of welding that is being done usually
…… and I’m afraid it may change the main objective of my project.
I've made some amendments in my calculation.
L1 is 30 cm and L2 is 30 cm and L3 is no need.
Here, L1, L2, and L3 are the links
base height + L1 = 40 cm (I forgot about base during my previous calculation)
L3 is not necessary because electrode has it's own height.....so the attachment of only gripper at the end of the link L2 would be fine.
So my assumptions are:
Mass of first link (joint with base) = 400 g
Mass of other link = 400 g
Mass of each servo = 150 g
Mass of gripper = 300 g
Mass of electrode holder = 600 g
And now my calculation stands:
(.4*30/2+.4*(30/2+30)+.15*30+.15*60+.3*60+.6*60) = 91.5 kg*cm or 9.33 N*m required
91.5 kg cm = 1270.71 in-oz
Is my calculation okay now? If okay, then robotzone's '1,715 in-oz. of Power' would be more than enough.
And obviously gearing is essential here as far as high torque is concerned.
Would the required torque be total torque or torque that requires from each servo? If it is total torque, then i think HS-645MG + 5:1 ServoPower Gearbox = $79.90 would be enough……they claim 665 in-oz. of power.
So 665*2=1330 in-oz which is greater than my required torque (1270.71 in-oz) http://www.servocity.com/html/hitec_servos.html
What do you think about this?