Been eyeing the modest priced, poor performing excavators for years. Using just the shell has been my plan as an economical way to build an excavator without making every single part myself.
Last year the C308 was released. Ordered it blind with only two small pictures and vague dimensions. Upon arrival the machine looks great. Lots of detail, lots of metal and very close to actual 1:14. The bad is the hydraulic system (as expected) gets blazing hot even digging air and pulls over 9A. Run time would be under 20 minutes. Valve block is not too bad. Respectable fine control, modular type for extension. Hydro lines are all 2mm OD but significantly smaller ID than SMC line. Chokes out the bucket and stick cylinders. Machine is very easy to take apart. Blade is electric and Aux hydraulics are fake with solid rod hard lines. Only 3 spool valve.
As factory built.
Short version of the heat is the stock pump spins way too fast. Included motor doesn't have the torque to run slowly. Swapping the motor allows better starting torque, but the internal leakage inside the pump becomes noticeable. System holds at 100psi with very little flow. At pump speed >3k rpm then flow increases significantly, and pressure builds to actually open the relief valve. The combo of pressure and flow increasing together makes everything jerky especially with the tiny bore cylinders. 9A through the stock motor is a lot of power which built a lot of heat.
The fix: leimbach pump with my own outrunner and reservoir similar to my telehandler build. Valves are ScaleArt since I wanted to try them. Boom and stick cylinders were swapped to Magom 10mm to increase power and reduce speed. Lines were all replaced with good stuff in 4mm and 2mm OD flavor.
Pocketing out to make room.
new slew system. I liked the servo drive, but it's too big.
skip a bunch of steps, and the hydraulics are working good with around 3A peak current draw. Stays cool. Stock tank was a really nice billet aluminum piece. Walls were too thin to bore out for the Leimbach. Replaced with a SLA printed tank.