Sorry for the late reply, I was on vacation. I do not exactly know what the maximum payload is. It depends on the angle and the accelerationspeed.
Mechanically you can say the platform can take easily 200kg (with this I mean the weight of the driver). But since the motors have to bring everything in motion I think a person may weigh 120kg.
I'm still not in the proces of finetuning. The motorarms we made in school have to be replaced by the ones you can see in the attachments. Unfortunately in summer a lot of companies are closed for vacation or are to busy before the vacation. Luckily I found someone who can make these for me next week. It is a bit frustrating to have the simulator finally in my basement but can't do anything
As soon as I can start tuning I will make some more posts.