Leatherfrog

Hello, I purchased the leather splitter FENDA made by RAFFLENBEUL a few days ago. I have no experience with this tool and I wonder how to adjust the rollers correctly. The gap between lower roller and upper roller is approx. 12 mm, means too much to work with. I have to bring the rollers more together and near to the blade. Can anybody help with a manual / instruction how to adjust the rollers, please? Best regards, Andreas from Dortmund, Germany