Hi, all. I have tried to simulate load of a shaft. I use 2d simplification and set two forces 51250 N per item. I have three fixtures. The shaft is d=300mm. You can see that i have R1=17400 N, R2=67700 N and R3=17400. When i set d=10mm, the reaction forces are changing like R1= 16000 N, R2=70500 N and R3=16000 N. I have calculate by hand the reaction forces of beam like that shaft i received reaction forces near to R1= 16000 N, R2=70500 N and R3=16000 N.

Why i have different reaction forces when i change to d=300mm?