tamiya dumper trailer

I always wanted a dumper-trailer, but I never wanted to spend the big money on it as they are way overprized. So when I was considdering on designing one I started looking at parts that could be re-used.
Therefore a big thank you to the creators of the flatbed tamiya trailer, the dumper mechanics and the dumper itself. I've used and reworked some of your parts to make them fit together.
So I took something from the community and therefore it was time to give things back to the community...

I'm using a geared engine and a spindle both from aliexpress to let the parts move. Some old bearing from a roller blade wheel and that's about it...
well... apart from the 200+h of printing of course :-). The dumper itself will take over 90h, the chassis with a density rather high on ABS also at least another 90h, all small parts easily 20h, wheels another 20h,... and so on...
assembling is pretty easy. Just make sure to have bolts and nuts from M2, M2.5 and M3.
The tipping at the back was