Specialty Actuator?

Have you considered an electric motor with reduction gearbox and brakes, like a lifter, and a parallel position feedback system with controller? Maybe you'll have to build one...

Thanks for your suggestion. I may consider using a DC motor (torque & directional) with a gear drive. The feedback device and controller may become a challenge for me. Could you suggest a vendor that deals with this type of application?

Welcome.

Someone will be along to help you. I'm going to bed.

not sure your budget, but a gearmotor with brake sounds like a good idea. you'll need to do some calcs. to figure out what would work, and it seems to me if you want to retain the pulley system, you could double up the cable to reduce torque requirements. an electric linear actuator could be used as well... or hydraulics!

the device could be controlled by a closed-loop system that would watch your temperatures and adjust via preset parameters. viola! more time to go snowmobiling!

WWW.Granger has some automation and temp monitor stuff, along with linear actuators.

I am a big fan of SEWeurodrive gearmotors, Automationdirect is a good source of most all things automation, A company in new jersey; GCF Inc is the best automation distributor in your area (i buy stuff from them way over here in Cali!) they should know someone who could help you. google any of those for more info.

find a local automation company to consult with, we love this stuff!

or, you could move to California, and leave all the cold behind... (used to live over in the catskills...) miss the hills, and Roscoe diner, but not the cold!

it is late, I think I will retire and see what answers "the other side of the world" - Asia, Australia, Africa and Europe suggest.

good luck, post some pictures!

JB

Thanks for your input on the specialty vendors. I will google GCF for a contact person.

The Roscoe diner is just down the road from here. I think it is a national landmark! Call me crazy, but something attracts me to the lousy NY weather...

Do you want to build or buy?

If build, look on the internet for details on how to convert a car alternator to a heavy duty (stepper or normal) motor:-

http://www.youtube.com/watch?v=rrNYIqhkTQc

http://www.youtube.com/watch?v=Cqf4ICwFBIU&feature=related

http://www.youtube.com/watch?v=wgqD7avNtyE&feature=related

http://www.alternatorconversions.com/

Google "convert alternator to motor" for even more...

Think about hydraulics... it might be a nice solution(controllabilitywise)... but quite expensive. A closed loop hydraulic/hydrostatic application is just fine(if your need is just a capacity and not much on torque +- precision)... and if you want a little bit energy efficient and higher technology(torque is variable by varrying the displacement of a hydraulic motor... stepped) try the "control of the secondary unit" (it is servo controlled). Try the forum "hydraulicspneumatics.com", there is an interesting discussion of hydraulic control of the secondary unit.

Thanks for your suggestion. I am somewhat familiar with hydraulic motors and servo valve control. I probably will not go in this direction, however, because it would require leaving a hydraulic pump running... and there will be a process reset rate of about seven minutes between position changes, so it probably would be overkill for my process.

I also thought about hydraulics, but I remembered that if your process does not change that much you really dont need a hydraulic system working and pressurized all the time. I really think that the best solution would be electric. No working fluid, power only when needed.

Maybe a VFD motor if it is cheaper and can sustain the environmental condition and the torque capability is enough... if it can be coupled to a gearbox equipped with a brake system(for the winch to stay in stop mode). But most of the gearbox braking system is hydraulically operated, but if braking is not a problem, then its your choice. If you can find a rotary position transducer, then your system can become a close loop and automated.

Another option is using linear actuator(if possible) in a possibly rack and pinion process wherein a cylinder can be activated to respond in a more precise manner. It depends on the budget where either you can have a conventional bang-bang system but with a cheaper position transducer or the more precise like the proportional control system. Both can be close-loop controlled.

But if the process really needs a rugged and precise response,a more expensive variable displacement(control of secondary units) hydraulic motor(varrying the displcement varries the torque/speed) coupled to a reduction gearbox.

One of the of the problem of electric operated system is it cant stop/brake immediately with high mommentum. Since the application is vertical, there might be a possibility of overruning load where-in hydraulic applications are more suitable.

I stand corrected if my opinion is not good...

Rack & pinion may be viable with a dc motor drive. I believe I will have to research applications vendors for the control loop and feedback device(s) since the position proportion control is going to be a bigger chalenge than the mechanical drive. Thanks for your suggestions