Potentially a cross-topic query/discussion!
For some time, as I get older and weaker, I have been looking at options for a small workshop crane for lifting chucks and machining accessories onto my lathe and mill without finding anything commercial that fits the bill. To explain a little of why I am doing this, the weight of the heaviest chuck on my lathe is around 40 kg. I can almost lift it but placing it on the lathe and fitting it is way beyond me. Other lathe accessories and accessories for the mill likewise. The idea is to be able to lift the object, extend it over the lathe bed/mill table and lower it gently onto the surface without causing damage to either. It will be fitted to a mobile trolley to service 3 or 4 machines. It will be stable in its most likely used format but extendable supports may be fitted if required.
I have now moved on to designing/planning for a self-build and have come up with three construction alternatives for a small scale crane with a safe lifting capacity of 100 kg.
In each case the requirement is for a lifting and extending jib plus a winch.
Option 1 is for an all-hydraulic system however the cost of hydraulic winches is very high and those I did find were all high speed so not satisfactory. A small electric winch will therefore be used in all cases. The hydraulic actuators for the jib functions were reasonable but also require a hydraulic pump and reservoir, valve system and lots of high pressure hoses and hydraulic fluid. Altogether not exactly encouraging/desirable.
Option 2 would be an electric winch and two self-contained electric-hydraulic actuators. These are self-contained units with each having a small electrically driven pump powering a hydraulically driven piston (actuator). No need for a separate pump and reservoir, valve manifold or hoses.
Option 3 is the electric winch coupled with two electric linear actuators, i.e. no hydraulics involved.
The cost for the components for each system would be roughly comparable. I think the precision of control would be greatest with the electric linear actuators but have no experience with these so would welcome any thoughts or comments.
I know this topic has come up a number of times but don’t remember anyone planning to go to quite these extremes before so all thoughts and comments on the project would be welcomed.
I have previously considered an overhead system but as the lathe and mill are at right angles have abandoned this option.
Thanks for reading.
Pero