Made my engine hoist a little better.

[desbromilow]

I replaced the hydraulic jack with a battery powered linear actuator (3000 lbs. capacity). Raising and lowering the boom became a breeze.

just be aware that you've considerably reduced the capacity of the crane - most of the engine cranes use a 9T hydraulic ram, to alllow 2T at the short extension (no extension), and 500kg (1/2T) at max extension - by using a 3000lb ram, you've scaled your capacities by a similar factor (3,000lb is nearly 1.5T which is 1/6 of 9T, which means your capacity of no extension reduces from 2T to 2t/6, and your max extension capacity of 500kg (1/2T reduces to 1/2t divided by 1/6 = 1/12t which is about 80kg (call it 160 lbs)

[dgbreggin]

I replaced the ram on mine with an air powered version.

[mansworld]

The 1.5 - 2 ton is at the end of the boom. The actuation is way back from that and so through leverage you need several times 1.5 - 2 ton at the actuator to get 1.5 - 2 ton at the hook. Using a 3000 lbf actuator may give you a useful tool but it will not give you 3000 lbf where it matters.

A one good thing about linear actuators/ screw jacks, is that they are oil-leak free. I have 3 oil leaking hydraulic jacks on my repair shelf. There are screw jacks with a capacity of up to 200 ton, and travel length of 3.5 meter/ 138 inch. Screw jacks are often custom-made to meet specific application needs.