Author Topic: Beginner- advice needed for 4 prong claw arm design  (Read 8610 times)

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Offline FireBirdTopic starter

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Beginner- advice needed for 4 prong claw arm design
« on: July 18, 2006, 11:33:58 AM »
Hi,

While Im not quite ready to go to the robotics level
(Im still at the studying part for that!)

I am working on a different project- specifically I am
working on makeing a functional Stargate staff weapon.

(okay functional in the sense it opens and closes- and an internal light comes on...)

 And the key piece I need is to have 4 gripper claws
set at 90 degree angles from each other and be
opperated in sync from a common arm.

My goal is for there to be 3 positions:Closed- light off
Partially open- light starting to come on
Open- light pulses

The robotic arm design seemed to have the main design
that I wanted except I cant seem to find any 4 claw
versions.

Ive included my rough diagrams as well as a picture of the real version
and a close up of a nonworking prop.

Do you know where I might find any schematics on such?

Any help is appreciated

Sincerely

M Lumsden


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Re: Beginner- advice needed for 4 prong claw arm design
« Reply #1 on: July 18, 2006, 11:59:04 AM »
a few questions:

would you want it push button, or pull a lever to activate it?

how much time/effort are you willing to spend?

how much building experience do you have in something like this?

there are products on the market that do something similar to what you want.
the first is these gutter cleaning claw things that actuate like you want at the ends:
http://www.guttersense.com/

there are also these kids extendable robot arm toys (pic included)
http://www.playfairtoys.com/index.asp?PageAction=VIEWPROD&ProdID=1187

you might want to buy one and see how they work (or modify it).
« Last Edit: July 18, 2006, 12:08:03 PM by Admin »

Offline FireBirdTopic starter

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Re: Beginner- advice needed for 4 prong claw arm design
« Reply #2 on: July 19, 2006, 04:25:35 PM »
Thanks for your advice
To answer your questions

The robotic toy shown in the second link was actually my inspriation for this method.
The mechanisms used however isnt easy to convert to a 4 claw. 

Im willing to spend several weeks working on it-  (Trying to get it done by Sept 1st)
Ive been reading some books on this - and have worked on diagrams for the last 2 years off and on.


The opperating mechanism is based on the bolt action gun lever system
I would be using two button/triggers that would be located on one side of the staff half way up the shaft.

Directly on the opposite side I will have a small lever that would move it into postion.

THe relaxed postion would be the weapon in closed position.

Im including a diagram of this part.


1-  would be when its partially opem
2- wide open
Also I had talked to a techinican at Radio Shack and aquired the batter pack, switch and light bulb, wire for the electrical part.  The battery pack will be concealed in the blunt part of the staff.

- I had planned to use PVC piping as the outer part of the staff.
and currently am trying to find a good material for the internal lever/piston


Hope this gives u a clearer picture....


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Re: Beginner- advice needed for 4 prong claw arm design
« Reply #3 on: July 23, 2006, 09:51:30 AM »
Ok so here is my idea . . .
What you do is use a special motor called a solenoid
http://www.societyofrobots.com/actuators_solenoids.shtml

To power it, all you need is an on/off swith and a battery. Bush the button, it opens up. Release, it closes. You could also put your light in the same circuit.

Attached is the device. The claw things are on hinges fixed to your pipe (staff) and the solenoid is inside the pipe. Took a good 30min to make this so no complaints  :P

And to get 4 claws, just add two more perpendicularly . . . I would have them in the animation but it made it hard to see everything.
« Last Edit: July 29, 2006, 10:24:55 AM by Admin »

Offline FireBirdTopic starter

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Re: Beginner- advice needed for 4 prong claw arm design
« Reply #4 on: July 25, 2006, 09:06:28 AM »
 8) Great!   This is exactly what I needed!

Thanks for your help!

I ll post u a pic of the final product

--Firebird


Offline FireBirdTopic starter

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Re: Beginner- advice needed for 4 prong claw arm design
« Reply #5 on: July 25, 2006, 04:06:55 PM »
 :-[  Okay....sorry but I actually have one more question

*sheepishly*But what type of hinge did u use? 

I was looking at Home Depot for a hinge small enough to work
and nothing there appeared to fit...

I really Really appreciate this!

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Re: Beginner- advice needed for 4 prong claw arm design
« Reply #6 on: July 25, 2006, 09:10:35 PM »
hmmm ask the home depot staff for a hinge the size you want. probably a hinge for furniture or cabinet doors maybe.

you could also easily make one.

Offline wolfy_9005

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Re: Beginner- advice needed for 4 prong claw arm design
« Reply #7 on: March 09, 2007, 06:51:27 AM »
Been a while since anyone posted here, so this might not reach whoever needs it. Try making your own by simply(reasonably) making a + shaped thing with gaps like = at each "leg" of the cross. Attach 4 legs/claw parts, then simply use small hydraulic cylinders or a solenoid to push/pull the legs/claws. This is a really rough guide but should(hopefully) help.

 


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