Question what is the minimum torque required for 4 dof

Hiii
I have 2 motor elektrik wheel chair with 300rpm and for now i will reduce to 60until 80rpm i check the torque become 28 until 30NM.

And also i have 2 dcservo with wormgear reducer 1:50 170watt 32V 52rpm. I check the torque is 30 until 31NM.

I have rig with me wheight around 100kg until 110kg.
I ask for that motor inaf for make 4dof?? Because i see 4 dof without Ujoint like a 2dof. Before i spen many time and money for this.
Thank you friend.
My rig like this.

You can use the tool to make the necessary calculations, https://www.xsimulator.net/community/marketplace/simcalc.184/

I know from test that having 4 motors one in each end will require more powerful motors than using a u joint. And 2 motors.

When using a u joint the rig is fairly ballenced around the ujoint meaning the weight is been supported by it. Most of the motor power goings in to inertia, ie moving the rig, when using 4 motors you have the entire weight of the rig plus the person in it. The rear 2 motors will be taking about 60 to 70% of the weight.

As has been mentioned previously you can use the above tool to work this stuff out

So that mean 30NM not inaf for 4dof sir???

Only for 2dof sir, i dont see for 4dof

Depends on your arm length , with a short arm probably. 30nm is strong, someone else may have done something similar to what you are.

You must do the calculations to know how much weight a motor can move, for example, with a 10cm lever, the result will be in kilograms meter, from there make the distribution