# Linear actuator



## mopar44o (Sep 8, 2015)

Hey guys,

My last prop I used pneumatics for my monster in a box.

This year I'm thinking of building a jack in the box but not sure if I want to use pneumatics again... Anyone know of some high speed electric linear actuators?


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## halstaff (Nov 18, 2009)

FrightProps carries them - http://www.frightprops.com/electric-motors/linear-actuators/linear-actuators-assemblies/high-speed-linear-actuators.html


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## BillyVanpire (Apr 22, 2015)

hi mopar44o,

i built a jack in the box using pneumatics. i needed 2 cylinders to make it work.
controlled by mikkojay's 4banger , one lifted & closed the lid the other lifted the prop out.
having 2 cylinders i was able to make the prop jump up & down while the lid stayed open.

depending how many actions you want, using 1 actuator might be tricky.

i didn't want the prop slamming into the lid to open it but maybe you can figure a way.
i've seen a saloon door style lid, with 2 halves, but it doesn't have the same look/effect.

you might try gearing like SLAM did for his awesome jack.

best of luck on yours, 
holler if have any questions.


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## wickedbeernut (Dec 14, 2016)

Hi mopar,

I'd start by estimating how much force you'll need to open the lid and lift the clown. To Billy's point, you'll want to decide whether to use one actuator or two.

If your jack in the box will be similar in construction to your monster in a box, you should be able to use the monster in a box pneumatics to measure the needed force. You just want to make sure a high-speed linear actuator will be able to deliver the needed force (and speed).

I used a single 1-1/2" bore, 10" stroke, double-acting air cylinder to open the lid and lift my Crate Beast,

http://wickedstone.com/Halloween/Html/crate_beast.htm​
The air cylinder drove a four-bar linkage. I added a "fifth bar" between the follower and the underside of the lid.

The nice thing about using a single air cylinder is you don't need to worry about accidentally smashing a $150 foam-filled mask through the lid.

At one point, I started collecting parts for my "Pop Goes the Evil",

http://wickedstone.com/Halloween/Html/pop_goes_evil.htm​
including this spectacular Death Studio's Slim Klown mask,

http://wickedstone.com/Halloween/Jpeg/slim_1_100_100.jpg​
however, it's yet to come to fruition.

wbn


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## mopar44o (Sep 8, 2015)

I plan to build this one out of lighter materials than my monster in a box. I used old skids for my monster in a box. I want a good spring effect for the lid and jack. I figured I can use some sort of hinge system so that they can open and close together without it smashing into each other. 

I only have a small compressor so I don't want to use it for both props. Most of the "Fast" acutators are 12 in a sec or so? Anything faster on the market?


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## wickedbeernut (Dec 14, 2016)

I only have a small compressor so I don't want to use it for both props.

[js] How small? You could put a portable / reserve compressed air tank between your compressor and your pneumatic props.

Most of the "Fast" acutators are 12 in a sec or so?

[js] The FrightProps 12" high-speed linear actuator is 4.5" per second under load or 2-2/3 seconds to 12".

[js] I'm anxious to learn how folks are using linear actuators. I'm intrigued by the fact they can be stopped mid-stroke. In order to achieve digital control with a pneumatic cylinder, you need a five-port, three position solenoid valve.

wbn


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## diamonddave_k (Nov 9, 2016)

Hi Mopar, I also just built a similar prop last year but using 2 pneumatic cylinders like Billyvanpire did. I used a 2 bar linkage for the "jack" and it achieves a pretty quick jump with a cylinder that has only about a 6" throw but throws the head about 1.5-2ft. 



 In this video the action is a little slower due to the pressure being dialed down because the head flew off right before this video lol. I don't see why you shouldn't be able to do the same thing with actuators and linkage. I have more pics and video of the inside if you're interested. Good Luck!


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## DarkOne (Oct 16, 2012)

What about using the actuator to move the short side of a lever and let a short action control a longer action? The speed of the action will be faster then. You may only need the actuator to move a couple of inches and then stop.


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## wickedbeernut (Dec 14, 2016)

You can mount the actuator (whether electric or pneumatic) on the "crank" closer to the "ground" in order to increase the speed and travel of the "coupler",

http://wickedstone.com/Halloween/Html/four_bar_linkage.htm

However, this will also increase the required force.

Again, I'd measure the force required to open the lid and lift the clown before investing in an electric actuator.

wbn


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## IMU (Apr 8, 2009)

I bought mine at AliExpress.

Here is what I did with mine during a proof of concept.


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## wickedbeernut (Dec 14, 2016)

Very nice. Yes, that's a four-bar linkage. If mopar can maintain that speed with the added weight of the clown (and the box lid ... assuming a single actuator), you may have a winner.

wbn


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## greenjeep79 (Jul 18, 2018)

I have seen actuators used for jack in the box type props, but instead of pushing them up they used springs to pop the figure out and then the actuator pulled the prop back into the box slowly, after the catch held the mechanism in place it would return to the extended position to allow the springs to pop the figure back out when triggered.


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## robbieleecanada (3 mo ago)

mopar44o said:


> Hey guys,
> 
> My last prop I used pneumatics for my monster in a box.
> 
> This year I'm thinking of building a jack in the box but not sure if I want to use pneumatics again... Anyone know of some high speed electric linear actuators?


You might want to try micro actuators that a small and lightweight. FIRGELLI have a huge range of linear actuators for this and they sell alot for haloween props etc. 

https://www.firgelliauto.com/collections/linear-actuators

These actuators range from Pen size to large industrial sizes to lift your truck. the larger they are the more force they can push/pull. the smaller units will push less force of course.


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