Hi, 9v thank you, I tried to upload the picture but I guess it limited the size. I possible need to put them on the brick safe first as mentioned by Ankoku earlier.
I just built electric version. I am lucky that the problem I mentioned earlier has been solved, I found out it was due to the fiction between the wheel and the other part, I removed the other part and problem solved. But I do have another new problem :-). The train box can not fit in the unloader smooothly, I do not know if it is because I do not have Slope 45 2 x 1 Triple with Bottom Stud Holder and Slope 45 2 x 1 Double - with Inside Bar.
And I found when train unit was released, the unloader was lifted a little (maybe less than 2 degrees. I do not know is it because of this. Is this lifting normal after releasing the train?