# Help needed for a linear actuator



## Haunted Spider (Sep 6, 2010)

Ok guys, this isn't Halloween related but I need some help with a linear actuator.

I took on a project for a friend of mine. His grandson has Cerebral Palsy. He wanted him to have a Power Wheels Jeep to ride around in so he could play with his Brother.

The whole car is RC controlled using a Mamba Max ESC for the motors on one 12 v battery, and RC receiver for controlling the things, and a Firgelli Linear Actuator for the steering plus accessory lighting on another 12 volt battery.

Below are two videos. The first is of my 11 month old son helping me test it out. The systems here worked perfect.

The second is where the issue comes in. The Linear actuator locks up when I hold down the turning wheel on the remote control for a few seconds. So if I want to turn in a circle and come back, it will lock out and I have no control for about 10 seconds. The forward and reverse still work so the Mamba max ESC and the Receiver both still function at this point. The Actuator is what is having issues, or actually the LAC board it is connected to is likely the culprit, but maybe not.

Any ideas as to why it would stop and not respond?

I have the video submitted to Firgelli as well but I doubt I will get a great response from them. I am hoping one of you has messed with linear actuators enough to know what my problem is. I would hate to get this Jeep to the boy only to have the steering cut out on him all the time.

Anyway, here are the two videos.

Son helping test out





Linear actuator problems





Thanks in advance


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## HomeyDaClown (Oct 3, 2009)

Firgelli offers linear actuators with direct R/C servo control which would be one option here. I've used them in several projects but never got into an actuator with their conversion control board. Seems the problem would be in that board or it's configuration.

another option would be to use a standard 12 volt linear actuator (from surpluscenter.com or servocity) with a standard esc. All you really need is forward and reverse switching of 12 volts for a standard DC actuator. 


You could also use a monster servo (heavy duty R/C servo).


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## Haunted Spider (Sep 6, 2010)

I actually have the RC actuator from Firgelli. It comes with the LAC board as the RC Actuator can be configured like 7 different ways through the LAC board but only 2 ways with RC, Either powered directly with RC or powered through a battery at higher voltage, and then the RC power cut but still run with RC which is what I did.


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## HomeyDaClown (Oct 3, 2009)

I am referring to the L12-R Linear Servo for RC types. They have the servo amp / h-bridge built-in and require no separate board. You can plug them directly into an R/C servo receiver. They make a similar model for NXT Lego as well. 

The one you have requires the external board.


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## Haunted Spider (Sep 6, 2010)

Ah, the problem with those is the power. They have no where near the 35 pounds force applied by the actuator I currently have. They are designed for much smaller applications it looks like.


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## CrazedHaunter (Nov 18, 2012)

What a great project. Wish I had seen this when my nephew was younger, he would have loved it.Hope you get it figured out


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## HomeyDaClown (Oct 3, 2009)

The control board has a stall detection function that could act this way.
You might want to take a look at the USB board config program and play with the Stall_Time setting and or the Movement_Threshold. You can also adjust the response to an RC signal that may improve stability. There are also extend and retract limit settings that should be adjusted to the actual throw distances you need since just like a servo, the actuator will try to go beyond it's physical limits to reach a position and stall.

0x05 SET_STALL_TIME 

This is the amount of time in milliseconds that the actuator will wait before turning off the motor when a stall is detected. This timer is triggered when the actuator determines the speed of movement is below an acceptable level. The actuator will exit this state when the input signal tells the actuator to move in the opposite direction.

0x04 SET_MOVEMENT_THRESHOLD 

This value determines the minimum actuator speed that is considered a stall. When the actuator speed drops below this value, the stall timer begins counting. 

0x0E SET_AVERAGE_RC 

This value determines the number of samples used in filtering the RC input signal before the actuator moves to a new position. Increasing this value can increase stability but does effect response time. The default value is four. The delay time can be calculated by multiplying this value by 20ms. This value does not affect the feedback filter delay. The actuators control response to a valid input signal will not be affected.


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## Haunted Spider (Sep 6, 2010)

Thanks for the response. The board does have a USB port that I can tap into. I just need to sort out how to power it or not power it before plugging in. I will call tech support at Firgelli tomorrow and ask about the stall detection and see if I can adjust it up. 

The last tech guy I talked to though didn't think there was such a thing. haha, grand when the Hauntforum guys know more than the tech guys for a company.


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## HomeyDaClown (Oct 3, 2009)

The power during setup comes from the USB port, no external power needed for that part.

http://www.firgelli.com/pdf/LAC_Advanced_Configuration.pdf


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## Haunted Spider (Sep 6, 2010)

I figured as much. I would need to disconnect the 12 volt in and run the set up. I don't have a set up program. I need to download it form the Firgelli site I think. I have an email into them as of 11 last night asking for the proper program and why I should set. I am waiting for a reply today. If not, tomorrow I am calling and asking for a tech guy. I will sort this thing out if it is the last thing I do


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