I am looking to move a bar about a half inch, the plan is to use a 12v or 24v solenoid, but I can't seem to find one that has about 10lbs of pull, would I be better off getting a geared motor? The project needs to be portable, I have a few ups batteries that I could use.

 

Let's sneak in by the back door with some math. You want to move 10 pounds 1/24th of a foot. That's 0.41666 ft-lbs.
Google a conversion and it says: 0.57 watt seconds.
If you want to move the bar in 1/10th of a second, you will need 5.7 watts for a tenth of a second.
What's the current for 5.7 watts at 12 volts?
5.7/12 =0.475 amps.
That seems like a way to specify a solenoid. Something that uses about an amp at 12 volts should do the job. But I've never actually done this, so wait for some more answers.

 

If using a motor, you could look at precision threaded rod to extend the motor shaft to make a simple pusher.
You should get the required torque.
Not really need a linear actuator for that distance.
A little more info on the application.
Max

 

we have a trap door that needs to open to let birds out and the latch needs to be pulled back with roughly 10lbs of force, will measure the pull later with scale.

 

I am looking to move a bar about a half inch, the plan is to use a 12v or 24v solenoid, but I can't seem to find one that has about 10lbs of pull, would I be better off getting a geared motor? The project needs to be portable, I have a few ups batteries that I could use.

Respectfully, your OP omits two pieces of information vital to our ability to properly advise you:

To wit:
1) How rapidly must the load me moved/accelerated?
2) Must the device merely shift the load or is maintenance of position a further requirement? - if so, for what duration?

Best regards
HP

 

DC solenoids are weakest when extended, compared to the retracted force.
The one thing with a motorized system is a method of turning it off is needed when at either end of the stroke, but it maintains position and generally resists back-feeding once extended.
Max.

 

One other source to check out is a automotive wiper motor/mechanism, that could be modified for the required stroke.
Automotive wreckers are a source.
Max.

 

Another thread tonight about a 2 drawer filing cabinet has a similar problem, and someone has suggested an automotive door lock actuator which is a small geared motor driving a toothed bar. They're readily available on ebay & because they are geared they have alot of pull, or push, & push & pull forces are the same, and stay the same for the whole length of travel. There's usually no limit switch, power is applied for a few seconds which means the motor is stalled for a short time

 

Sounds like the old automatic chicken coop door opener.
Search the AAC forum for chicken coop door.

Example:
https://forum.allaboutcircuits.com/threads/automatic-chicken-coop-door.72917/

 

Solenoids are cheap and simple, but are horribly inefficient and suffer from highly non-linear force vs. stroke characteristics.

I love watching students beat themselves to a humiliated pulp trying to get a solenoid to perform in seemingly "easy" applications - beware.

A motor driven actuator is going to be far more satisfactory here.

https://www.parts-express.com/high-power-door-lock-actuator-2-wire--330-010

 

Thank you everyone, I do appreciate the help, I will look into the linear actuators for some reason they missed my scope of attention,

y

it doesn't have to be precise, and it only has to open it within a second or too, not a critical application in timing or precision of stroke.

 

Solenoids are cheap and simple, but are horribly inefficient and suffer from highly non-linear force vs. stroke characteristics.

I love watching students beat themselves to a humiliated pulp trying to get a solenoid to perform in seemingly "easy" applications - beware.

A motor driven actuator is going to be far more satisfactory here.

https://www.parts-express.com/high-power-door-lock-actuator-2-wire--330-010

That may do , but I do not see wattage requirements and load capacity