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Topic: Small electric actuator suggestions? Need something fast and programmable! (Read 169 times) previous topic - next topic

JoeNova

Halloween is coming up!

I want to try and take a shot at making an arduino powered prop.
I need a small electric actuator of some sort. 12v is fine.
I'm having trouble finding something suitable because I have some particular requirements:
-Small. 8" or so is ideal.
-Powered by 12v
-Very fast moving. The quicker the better.
-Programmable positions. Will need 6-10 positions with pneumatic like speeds.
-I only need a maximum of maybe 3-4" of travel.
-Will only be moving a couple of pounds.
-Pneumatic is NOT an option.

I know they exist because I've seen them used before, but they were insanely expensive and I can't get them to tell me which actuator they are using. I've found a few high speed linear actuators but they are $150+ and have a 20+ lb force. I need something much smaller.

kenwood120s

The only cheap one I ever saw was from Mindsets north east of London UK, but I can't find it on their site. I have a feeling it got discontinued. It was about 10GBP (~15USD) if I recall.

But it was a threaded rod on a motor, so it's unlikely to have been fast.

Cheap hobby style linear actuators do not seem to exist.

[gumby]I've got my head stuck in the cupboard[/gumby]

Robin2

I want to try and take a shot at making an arduino powered prop.
I need a small electric actuator of some sort. 12v is fine.
You need to provide a diagram of the mechanism you want to create.

Why not just use a regular servo?
They are easy to use mechanically, electrically and programmatically.

...R
Two or three hours spent thinking and reading documentation solves most programming problems.

MarkT

Halloween is coming up!

I want to try and take a shot at making an arduino powered prop.
I need a small electric actuator of some sort. 12v is fine.
I'm having trouble finding something suitable because I have some particular requirements:
-Small. 8" or so is ideal.
-Powered by 12v
-Very fast moving. The quicker the better.
That is not a specification.  Say what the minimum acceptable speed is.
Quote
-Programmable positions. Will need 6-10 positions with pneumatic like speeds.
Whatever that speed is...  Say what you mean in numbers please.
Quote
-I only need a maximum of maybe 3-4" of travel.
-Will only be moving a couple of pounds.
force or inertia? or both?  Moving a kg mass with rapid acceleration takes a very large force
and high power.  Definitely need the numbers for this to see how feasible.
[ I will NOT respond to personal messages, I WILL delete them, use the forum please ]

JoeNova

Right now I'm using a cable actuator for a prop. A small lever controls the cable, which activates any one of 7-8 functions. The problem is, the lever has to be moved by hand so I am constantly having to go and change it myself. I want to be able to control it on a number of different principles, such as a timer, a photocell, sound activated, etc.

The problem with the speed is that if the cable is in between 2 positions for any amount of time, it pops a breaker. I don't have nearly enough money to redo the entire setup. The cable actuator and things that it control are rather complex (its an OLD large robot prop that I bought from a company that was doing haunted houses and went under).

The lever itself is less than a foot long, but only moves the actual cable 1/4-1/2" when clicked into a different position. I need to be able to set it to change functions every 10 mins, or when it gets darker outside, or in a pattern that I decide. Arduino is perfect for this.

2-4" per second would be ideal, and would only need a maximum stroke of probably 3" (I need to go measure). I know of a company that was making small linear actuators capable of doing this. They've been doing similar functions (cable actuation) in other hobbys at the stroke/speed I want, but they are $1200 for the setup and they won't provide a part number for the actuator they are using when I asked.

I found these linear actuators, which are MORE than enough. The main problem is length. for the 4" stroke version, I'm looking at 17.5" extended (the other company is using something probably 6-8" extended). 9" per second speed. $150 isn't really out of the price range. Is something like this able to extend to a very specific position through something like PWM?

https://www.firgelliauto.com/products/high-speed-actuator


JoeNova

I've been looking at various cruise control actuators. They already do cable actuation, and are cheap.
I can grab them for 10 bucks at a junkyard, and can easily use them to set to multiple positions with 12v. The only problem with them is speed. They are fairly slow.

Robin2

Referring to Reply #4, I don't see anything in that which excludes the use of servos. They are commonly used to operate push-pull cables to control flying model airplanes.

...R
Two or three hours spent thinking and reading documentation solves most programming problems.

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