Answer 3.... (answer two deleted due to new information.)
Assuming your blower matches this: Louis Poultry blower

Tilt of chute is controlled by chain drive sprocket on outer hub of blower shaft bearing housing. Chain loops over sprocket on top, and down around an idler on either side and thence to a slide shoe moved by hydraulic cylinder.....

Simply stated: OUCH....

Not something easily modified. You are also asking for position / range adjustment. That's even harder, but doable. Much easier to accomplish with a bit of electrics, be it moveable limit switches or some kind of encoder on chain that counts links or rotation of a spocket.

Actually moving the chain with anything near same amount of torque suggests only one type of mechanism. That is substituting a powered screw mounted in substitution of hydraulic cylinder. Screw would need to be mounted on each end with a thrust bearing with a travrling nut assembly moving slide shoe hydraulic cylinder now moves. Then drive end of screw with an electric motor connected to positioning controller. I'd guess screw diameter at least 1/2 inch, 5/8 would be better (just to find cheap thrust bearings and have thread beefy enough to do job.)
Standard all-thread would probably be adequate, but tougher (and faster ratio) ACME thread shaft could be used as well. (See SURPLUS CENTER for bearings or ACME rod / nuts).

How to drive threaded rod...

DC motor. Simple relay (or solid state relay) drive with polarity reversal at end of stroke controlled by limit switch. Suggest using electric scooter motor, sprockets and chain. (Try: TNC Scooters for reasonably priced parts.)

Or...

Stepper Motor... controlled by stepper motor driver controlled by Arduino or other micro controller. Best prices probably ebay or Chinese supliers such as banggood.com or aliexpress. Kind of requires a local CNC guru or teenager Arduino hobbyist. CNC mechanisms probably adaptable, but not off the shelf.

So... that's my best thoughts for answer 3.

Doc

Last edited by Doc; 02/09/2019 06:15 AM. Reason: Complete redesign

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