Automatically Move Linear Actuator

Thread Starter

ravens3333

Joined Mar 15, 2016
6
Hey guys! I am sure that there is a very simple solution to my problem but I know very, very little about what I could do to fix this. I am working on a school project and I need to make my linear actuator automatically go in and out, and I am not sure what needs to be connected to it. The end of the actuator has a wire going through it that needs to be moving back and forth, so there is no load whatsoever on it. It just needs to switch directions when it reaches the end full 2" and it will need to run for about 2-3 hours at a time. Below I put the link to the actuator and power supply that were purchased. Thank you for any help that you can provide!

Actuator
http://www.amazon.com/Heavy-Linear-Actuator-Stroke-Lift/dp/B00GYFKDCU/ref=cm_cr_pr_bdcrb_top?ie=UTF8

Power Supply
http://www.amazon.com/AspenTek-Supply-Adapter-Cabinet-Lighting/dp/B0180ASJF4
 

crutschow

Joined Mar 14, 2008
24,130
I could not find the current requirements for that actuator so I'm not sure if the 1A power supply you purchased is adequate to operate it. For example this actuator, which looks very similar, requires 4.6A maximum.
Do you know how much current your actuator takes?
Have you tried it with that power supply?

The simplest way to do what you want is to use two limit switches, such as one of these, and a latching relay, such as this.
The limit switches alternately actuate the relay to its opposite state at each limit and the relay output controls the direction of the current to the motor to reverse its direction.
 

MaxHeadRoom

Joined Jul 18, 2013
19,773
Although the listing does not mention limit switches, according to questions asked there the answers was it has internal limits (apart from the clutch).
If the internal limits are SPDT then you could possibly rewire for automatic reversal, this is done by a diode across each limt.
That P.S. is only 12w may not be enough.
Max.
 

Thread Starter

ravens3333

Joined Mar 15, 2016
6
I could not find the current requirements for that actuator so I'm not sure if the 1A power supply you purchased is adequate to operate it. For example this actuator, which looks very similar, requires 4.6A maximum.
Do you know how much current your actuator takes?
Have you tried it with that power supply?

The simplest way to do what you want is to use two limit switches, such as one of these, and a latching relay, such as this.
The limit switches alternately actuate the relay to its opposite state at each limit and the relay output controls the direction of the current to the motor to reverse its direction.
I am unsure how much current it requires, but I tried it with the power supply and it does work
 

Thread Starter

ravens3333

Joined Mar 15, 2016
6
But for how long?;)
Max.
I have no idea. I attached the wires and had it run until the actuator was fully extended. When I realized it would not retract, I switched the wires around and it pulled the actuator in. All of this was done within 5 minutes so I have no idea how long it can work.
 

John P

Joined Oct 14, 2008
1,785
Is it OK if the unit pauses at each end of the travel? If so, you could measure how long it takes to go from end to end, and add a good margin--say 50%--and then just rig up a timer to reverse the power. The actuator would run to the end of its travel, hit the limit, wait until the power reverses, then run back the other way and hit the limit and pause again.

If you can't tolerate that pause, you could sense current and when it drops to zero, reverse the power.
 
Last edited:

AnalogKid

Joined Aug 1, 2013
8,259
The questions and comments make it pretty clear that the actuator has internal limit switches. Since it has only two power wires, it probably has a diode across each normally-closed contact. The internal switches limit what you can do in terms of controlling the motion. A simple 50% duty cycle timer driving a DPDT relay is sounding better. There's gotta be a long range 555 module on ebay somewhere with either 1 DPDT or two SPDT relays.

ak
 

MaxHeadRoom

Joined Jul 18, 2013
19,773
It looks like the lead screw just has a lift off cover (one screw), if so check to see if it has SPDT limit SW's, then all you need is a on off switch and a relay if the limits are wired for automatic reverse.
Max.
 

Thread Starter

ravens3333

Joined Mar 15, 2016
6
Is it OK if the unit pauses at each end of the travel? If so, you could measure how long it takes to go from end to end, and add a good margin--say 50%--and then just rig up a timer to reverse the power. The actuator would run to the end of its travel, hit the limit, wait until the power reverses, then run back the other way and hit the limit and pause again.

If you can't tolerate that pause, you could sense current and when it drops to zero, reverse the power.
A pause would be perfectly fine. Would I need to buy two timers (one for each end) or just one timer?
 

crutschow

Joined Mar 14, 2008
24,130
Does the actuator stop with the current going to zero at the end of the stroke, or does it just stop with the motor still drawing current?
 

MaxHeadRoom

Joined Jul 18, 2013
19,773
Does the actuator stop with the current going to zero at the end of the stroke, or does it just stop with the motor still drawing current?
From the description, I'm guessing the motor is still powered and if a slipping/torque clutch it is drawing current enough to over power the clutch.;)
Max.
 
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