New cylinder rod + head module sandwich
One cylinder rod in the crane was in quite bad shape with dents and scratches all over. So it was replaced with a new one and also all the seals replaced in the process.
Old rod, not very good photo though…
Originally I was planning all kinds boxes to put the head unit board into. But then I thought that as in the head there is a sealed aluminium box into which all the solenoid and sensor cables are wired to it might not be necessary to have another closed box for the circuit board after all. At least for this board version. So I decided to just cut some pieces of aluminium sheet and sandwich the boards between them to provide some physical protection for the assembly.
There is two boards now, the other being a step down switching power supply. The reason for this is that I wasn’t really comfortable with the temperatures of the 5 V linear regulator on the head unit board with the 24 V supply voltage. The original design was planned for 12 V supply voltage. Next version should have the switching regulator on board.
The head module supports updating the software through the CAN bus so that after it has been installed in it’s box and buried under the protective covers it’s not necessary to get physical access to it anymore unless some hardware modifications are needed or signals need to be measured with external equipment. The main module has the support for performing this software update for the head module from a memory card so carrying a laptop with you isn’t necessary if all you need to do is loading new software version. Also the main module can load new software from a memory card to update itself.
And finally the head module mounted in it’s box:
