How much weight do you think one motor can carry? I’m just trying to figure out the motor power in relation to the weight of stars/ blocks… 
~Update // what is the torque?
Attached below is a screenshot from VEX Robotics regarding motor torque. Hope this helps.
Here are some links that may help you with your question.
[https://vexforum.com/t/motor-torque-speed-curves-rev2/21868/1)
[https://vexforum.com/t/stall-torque-question/29072/1)
[https://vexforum.com/t/motor-torque-speed-curves/21602/1)
Rule of thumb we use is that beyond 7 in-lb or torque, the current is in the danger zone for tripping the PTC. So try and stay under that.