# accordion arm



## debbie5 (Mar 2, 2007)

I am not an engineer AT ALL.
I want to make a 1 foot long, thin foamcore arrow encasing chasing lights around the edges that says CANDY. Problem is, I want it on one of those Rube Goldberg, cartoon-style accordion arms and I want the accordion arm to flex open & back, "pointing " the way. I therefore need some type of gearing movement at the end that can accommodate two points of adhesion and rotation/movement. Then the whole weight of the arms comes in to play: they need to be stiff enough to hold the weight of the arrow without flexing, yet not so heavy as to kill the motor.
Has anyone already "invented the wheel" so to speak on this one? I don't want to abandon this project, as yet another one that is out-teching the limits of what I know....


----------



## debbie5 (Mar 2, 2007)

Arghh..a cartoon pic is on my Timeline on FB..can't think of a way to post pic on here....it's a directional sign from World Of Warcraft that would be easily made out of recycled 2 liter soda bottles and a spinning light on top..all of which I have already. I just can't figure out the arm part.


----------



## niblique71 (Dec 2, 2009)

I'm sure that Roxy, Vlad or Haunti will help you get a pic or video posted of your idea. After that I'm confidant I can figure something out for you. If not me, I'm sure someone else can. Between all of the great minds here, We'll get your Rube Goldburg scissor mechinism going. 

BTW, It sounds like a really fun project


----------



## Allen H (Feb 13, 2010)

This is an expanding coat rack, I bet it would be the right size and everything.
I would use a wiper motor on this kind of set up.
http://www.robives.com/mechanisms/piston
Simply turning the spin of the motor to back and forth.


----------



## debbie5 (Mar 2, 2007)

Thank you Allen! Okay- but how do I connect BOTH end points of the arm to one motor turn point?


----------



## Vlad (Aug 2, 2005)

Hi Deb, As always when people are talking about movement, I like them to look here first >>>>>>> http://www.robives.com/mechs The Flying pig mechanisms page is legendary. You could easily use the Quick Return one to open and close your scissor mechanism.


----------



## Allen H (Feb 13, 2010)

Not both, just the first center point. Does this help? can you see how i combined my two links?


----------



## debbie5 (Mar 2, 2007)

OH DERP! See, I never thought of that (using only one connection)! Aww..And you took time to draw a pic for me! That's very kind. Thank you very much! 
I have the robives page bookmarked..it's the little things like TWO connection points that make my brain fry. Thanks.

(doing happy dance, as I already have a scavenged reindeer motor!)


----------



## debbie5 (Mar 2, 2007)

Hmmm..but that center point needs to remain able to rotate so the arms flex making the "X" of the accordion bigger or smaller...how to connect an throwing arm to it...??..I'm thinking a loop of wire might work, but the friction & wobble will soon break the wire...??

this is why my brain gets hot.


----------



## Vlad (Aug 2, 2005)

Deb, I can't stop to draw a pic now, but do you also understand that at least one of the "feet" of the scissor mechanism will have to be mounted on a slider, such as a drawer slider? I can show you at the make and take if you want me to have something ready. I know Rich wants to work on a scissor mechanism also. Or hopefully Allen has time to draw another pic lol


----------



## debbie5 (Mar 2, 2007)

That's what I was thinking..the feet as you call them need to move if BOTH are being mounted...but Allen's idea should work too, if the center post is allowed to pivot. Ok..so I have a pic of what I want to make, and now am looking desperately for the attach button on bottom right...can't find it. I swear- I feel like a 90 year old Amish woman, trying to learn.LOL. (still looking)

EDIT_ I found button...put in photobucket address and...nothing. How do I get it INTO the post?


----------



## debbie5 (Mar 2, 2007)




----------



## Vlad (Aug 2, 2005)

Deb, if you're going to mount ANY kind of a weight out at the end of that scissor mechanism, both of the feet (the ends of the purple lines in Allens pic closest to the center point he attaches the shaft from the motor) will need to be mounted or most likely the whole thing will be unstable and fail. But at least one of them needs to be able to slide up and down to enable the scissor mechanism to function.


----------



## debbie5 (Mar 2, 2007)

Can U see the linked pic?


----------



## debbie5 (Mar 2, 2007)

I see a M & T in my future....


----------



## RoxyBlue (Oct 6, 2008)

The linked picture is seeable, Deb


----------



## debbie5 (Mar 2, 2007)

(cheering)


----------



## Vlad (Aug 2, 2005)

Yes I'm sure it's viewable, just not for me here at work, lol and grrr.


----------



## debbie5 (Mar 2, 2007)

It's just the cartoon image of a direction sign from World of Warcraft that shows what I'm trying to make..but I'm gonna have to modify it to make the motor fit inside.


----------



## Vlad (Aug 2, 2005)

You want the motor inside the arrow sign on the end of the scissor mechanism?


----------



## Allen H (Feb 13, 2010)

Deb, a bolt right through the joint will allow it to move (as long as the nuts are not to tight) and will hold the arm on on.

A slide could be used for the two arrow ends, or elastic holding them to the pistons outer tube. I will be able to do another pic tonight.


----------



## debbie5 (Mar 2, 2007)

No, Vlad..Im sure the weight & motion of the motor would warp the arm. I'm planning on putting it in the stack/post.


----------



## imthegoddess (Feb 3, 2012)

Check out post # 5 at this sight. http://www.halloweenforum.com/halloween-props/114762-anyone-use-cam-lever-animating-their-props.html I'm thinking one of the ends of the sissor mechanism could be a fixed point, and the other could be attached to the lever. the motor would turn and make the sissor mechanism retrace, and the cam would force the lever up, thereby causing the sissor mech to open.


----------



## imthegoddess (Feb 3, 2012)

Should say retract not retrace. Also, sorry if I was not suppose to list another site.



imthegoddess said:


> Check out post # 5 at this sight. http://www.halloweenforum.com/halloween-props/114762-anyone-use-cam-lever-animating-their-props.html I'm thinking one of the ends of the sissor mechanism could be a fixed point, and the other could be attached to the lever. the motor would turn and make the sissor mechanism retrace, and the cam would force the lever up, thereby causing the sissor mech to open.


----------



## RoxyBlue (Oct 6, 2008)

imthegoddess said:


> Should say retract not retrace. Also, sorry if I was not suppose to list another site.


Perfectly okay to list another site


----------



## debbie5 (Mar 2, 2007)

I want to thank you peeps for helping me. I know that part of the fun of making things is discovering solutions to problems, but I am so dim-witted when it comes to making anything move...I really appreciate the help. Thanks again.


----------

