View Full Version : linear actuator projects?

04-20-2009, 12:24 AM
I havent posted in a while because my last project got lost in my curiosity for bipeds. Anyways, I am looking into building a biped that uses linear actuators instead of servos. After searching I keep coming back to either SPAL linear actuators or the servo city ones due to cost, speed and force.


Stroke 300 mm (11.81")
Voltage 12 DC
Push/Pull Ratings
Dynamic 107 lbs. max
Static 500 lbs. max
Extension Speed
No Load 0.59 in/sec
Max Load 0.39 in/sec
No Load 0.6
Full Load 3.4
Duty 20%
Enclosure IP54
Pin Holes 5/16"
Retracted Length 450 mm (17.72")
Shaft Dia. 20 mm (0.787")
Size 18-1/4" x 1-1/2" x 3"
Shpg. 5 lbs.

Servo city:

Operating Voltage: 6.0-12 Volts DC
Operating Temperature Range: -20 to +60 Degree C
Operating Speed (12V): 2.00 second at max load
Dynamic Thrust (12V): 25 lbs. Thrust
Static Load: 500 lbs.
Current Drain (12V): 500mah no load operating
Motor Type: 3 Pole Ferrite
Potentiometer: I0K
Gear Type: 4 Metal Gears
Connector Wire Length: 24"
Recommended Fuse: 10amp inline
IP Grade: 2IP 63-total dust protection, water resistant

I cant seem to find any projects at all utilizing either of these and I was wondering why? Is there something im missing? The spal ones seem to be a little slow and the SC seem on the weak side but does anyone know if these can be theoretically accurate enough to be used in a larger biped? ( I think SC has better speed/force options in the making)

I think maybe a large arm project using either would be a safe/easier project to learn from to get the electronics etc figured out? Would really like to hear your opinions on these!

04-20-2009, 05:54 AM
I know why. The price tag.

04-22-2009, 10:07 PM
haha The spal ones arent so bad. They can be had for about the cost of higher end servos. ($80 bucks)