I have connected a LA12 Linear actuator to SS32 channel 0. Using the Lynx Terminal I am able to move the motor from #0p1000 to #0p2000.
Sometimes it works quite predictably. Quite frequently Ifind that the position goes beyond the programmed position. For example, it is at P1300. When I send P1400 command It goes to 1900 and above . In the next command it comes back to p1400 position. I can see that it has gone past the 1400 position, but I have no control to stop it or kill the previous command. I also tried putting a time value such as T500 and Speed value S50 to move it slowly. But it goes past the programmed position. any other commnads i should try?. thanks. ayyangar. july 9
Images of the wiring would be a good start.
More info…
Show ALL wiring. 
What is a 7.5vdc battery? NiCAD / NiMH is 7.2vdc Lipo is 7.4vdc…
Show the battery.
Why are you using such tiny little wires to power the servo?
Why are you trying to power everything from a single supply?
Dear Jim
I am testing only one motor. The LA12 draws nearly 150mA at 6V .
I have a make shift arrangement with a 6V pack and a 1.5v dry cell.
The wires that are used by the motor are even thinner.
Are my problems related to power or connections?
thanks
ayyangar
No!
I think it might be safe to say that the battery(s) is the problem.
Dear Devon
Could you tell me what is wrong with my current arrangement?
I made sure there is good connection and the ssc32 power light is ON and blinks only when the signal is recd.
What would you suggest for a better power connection?
i am sending p1xxx signals in 100+ increments.
Why would the motor move past the position go up all the way to 1900 and then come back?
When i interrupt power it actually tries to starts back at 1000 position.
thanks
ayyangar
The battery arrangement is cause for suspicion because of the friction connections from springs, and the taping of wires to the battery for connection. The servo may only draw 150mA but I’m willing to bet the startup current is more. Wires need to be solidly connected to work reliably.
It is not clear to me why the servo has 5 wires. Can you show what is actually on the servo as far as electronics go? Maybe a link to more information on that specific servo.
I can not think of any reason the servo would move past its commanded position.
I searched for LA12 and it appears it’s made by Linak, not Firgelli… Or you have a different part number than you stated. If it is made by Linak I do not believe there is a version that can accept servo pulses as control signals. It appears that the LA12 that has 5 wires is a simple motor and potentiometer feedback, but no control electronics.
Please enlighten me on what you actually have.
Dear Jim:
Thanks for the detailed reply.
No I dont have the LINAK. I have the Firgelli L12. Could not attach pdf document
Here is the link
firgelli.com/products.php?id=41
firgelli.com/Uploads/L12_datasheet.pdf
There are 6 wires. I am only using 3 wires black red white.
When i originally connected the ssc-32 with 6v battery, it did not work.
Then I added the 1.5v cell. I secured the connections with crocodile clips.
What i dont understand why 2 out of 10 positions fail, by the motor going beyond intended position
and then return back. if there is not adequate current, it should actually lag behind.
see the graph below.
I intend to power the servo separately with a 6V power supply.
Should i power the ssc-32 with a 7.5v separate power supply?
Please advise me.
regards,
ayyangar
L12_datasheet.pdf (461 KB)
You are still making me guess. ok, so I assume you have the L12 with the RC controller interface. This is a 12vdc servo. You are only giving it somewhere around 6-7.5vdc. Power the L12 with 12vdc. Power the SSC-32 with a 9vdc battery. See if it improves. I read in their manual…
If the motion of the actuator, or of other servos in your system, seems erratic, place a 1–4Ω resistor in series with the actuator’s red V+ leadwire.
This is the dumbest thing… They have had trouble in the past. This warning is dumb because it would have been much better for them to state what this 1-4 ohm resistor is supposed to be doing here.
Beyond all of this. If you have a normal hobby servo, try connecting it to see if the problems go away. If they do then it’s the L12, not the SSC-32.
Dear Jim
Sorry for the confusion. We have the Firgelli L12-100-210-6V-I model
See attached picture.
We purchased a RB-Fir-90 from robotshop
robotshop.com/firgelli-techn … oller.html
So i should power it with 6V and 9V to the ssc32
Does 9v cell battery power adequate for the ssc-32, if the motor red wire is connected directly to the 6v battery?
thanks
ayyangar
Sigh… Do you have a normal servo you could install to ensure the SSC-32 is functioning properly?
Why do you suspect the SSC-32 if you have to apply 7.5vdc to a 6vdc servo for it to sort of work?
I still strongly suspect the battery setup. Do you have access to a reliable battery…
lynxmotion.com/p-331-60-volt … -pack.aspx
Dear Jim
Problem resolved. I believe the servo cannot take more than 6v. When i connected 6V to servo and 9v to ssc-32, it worked well.
here are the results.
thanks a lot for your help.
regards,
ayyangar
Glad you got it going.