Iron Man arm with opening weapons

[Calebxy]

The day before yesterday, I decided to have a go at what this guy is doing (well, apart from the working propulsion system). On the second page of that thread, you can see I posted a screen shot of the clip in which Iron Man shows his weapons. However, as I said in that thread, I'm only going to be doing the blue things.

So anyway, I worked it all out in my head when I went to bed, and then yesterday, I set to work making it. And then I discovered that the mechanics I had worked out didn't work, so I had to come up with how to do it again. I did, and eventually managed to finish it. Well, almost. I finished the mechanics and all that (though I'll add a few things to cover up the workings), but now I have to connect the strings to a motor and batteries. I was planning on using a couple of the motors I took from hard drives, but for some reason, they won't work. I've been using two batteries to see if they work, so maybe the motors require more? Bearing in mind they're supposed to get their electricity from the mains, but I don't want them to be spinning anywhere near that fast.

Anyway, for those of you who want to see it so far, here's a picture:

The flaps open up when the strings are pulled. And yes, I know it's bulkier than it needs to be, but this was very rushed.

 

[JWMines]

hey, i was thinking of doing just the top rockets like in this picture:

 

[laellee]

I remember you mentioning this project, cool that you're following through on this. You might want to look into using solenoids instead of motors or servos.

I get a lot of my stuff from these guys:
Jameco Electronics - Electronic Components Distributor

The drawbacks of solenoids is that they usually want at least 12 volts to work, and as long as they are actuated they will be drawing juice from your battery. They also react INSTANTLY for the most part, so any panel or piece they are moving will move quickly. Not sure if that matters.

Not sure why your hard drive motors aren't spinning, maybe they have integrated circuitry that's preventing the circuit from completing? Most PCs power supplies are putting out under 12 volts (closer to 5 volts I believe), I would think if you can't get it to spin at 3 or 5 volts, something else is going on. Anyways, good luck with this project. Nice to see somebody trying this.

 

[Rancorite]

It looks like a crafty way of getting this done, looking foward to see how it goes. Where would the motors and battery go?

 

[Calebxy]

laellee: Thanks for the suggestions. Though, from the pictures, I don't see the difference between those and motors. Granted, they don't look like hard drive motors, but they look just like most other motors I've seen. What exactly do they do? The metal rod on the end spins, doesn't it? Is the difference just that these are particularly powerful or something?

Either way, I'm going to try some more work on my motors first, since I already have those. I'm a major cheapskate, so I'm not paying any more than £10 on this project, since it was really just to prove to my friend that it was possible to make without needing a ton of skill and money (as my friend insisted), neither of which I have. Now, the mechanics of it work, so I'm happy with that. The batteries and motors could definitely fit too, so I believe I've more or less made my point, but I know he won't be impressed until it actually works, so I do want to finish it.
Rancorite: I was initially planning on attaching the batteries and motors onto the outside of the inner arm (the part my arm actually fits into, as you can see in the picture), but when I made it to its current level of completion, I realised it would be better to put them on the inside of the outer part (since it's bigger). So I was planning on having two motors; each attached to two of the strings, since they don't have to be pulled perfectly straight. These would be fitted near the back, of course, and the batteries could be anywhere.

What I'm planning, for both simplicity sake and coolness, is to have the circuit go all the way to my opposite hand, and have the gap between my finger and thumb (with a bit of old fashioned tinfoil or something on the tips of them both), so to activate the motors, I just touch them together. I think that would be cool.

 

[laellee]

Hey there, no worries. Those solenoids work like a hydraulic piston when current is applied (No spinning motor stuff ). Instead, when you apply the current, that plunger (piston arm) can be used to push a weapon out, or open a door, etc...
Good luck with you project, I especially like the circuit-through-the-fingers idea. :thumbsup

 

[Calebxy]

Hey there, no worries. Those solenoids work like a hydraulic piston when current is applied (No spinning motor stuff ). Instead, when you apply the current, that plunger (piston arm) can be used to push a weapon out, or open a door, etc...
Good luck with you project, I especially like the circuit-through-the-fingers idea. :thumbsup

Ah, I see. That sounds very cool and could potentially be extremely useful for other projects. Thank you for that. Also, just because I'm curious, do you know how that actually works? I don't know very much about electronics, so the only way I know to make something move back and forward is to have a set-up with "arms" and hinges attached to a motor, if you get what I mean.

Thanks again.

 

[laellee]

I follow, I've played with and built with electronics my whole life.
If you mean how the solenoid works, it's essentially creating an electromagnetic situation where the piston and the body are repelling each other, causing the piston to push out (some solenoids are made to pull instead). Electric motors use the same principle, but they are switching the magnetic attraction to keep the motor spinning.
Maybe a better way to explain, as long as electricity is going to a motor, it's spinning, and using power. A solenoid is the same way, but pushing rather than spinning it's keeping that piston extended as long as electricity is applied. A drawback is that they can heat up (and burn out) if left powered too long, so while they work for opening things (releasing latches, etc.) you wouldn't want to use them to hold up a weapon door (or whatever) for more than a few seconds. There are ways around that problem, but not worth going into here.

I'm a super cheap builder on a lot of stuff too, nothing wrong with that. I pull all of the electronics out of stuff to reuse on projects, so I don't feel so bad when I have to spend several hundred dollars on other components (my Patriot cannon was a perfect example of that lol)

 

[Calebxy]

I follow, I've played with and built with electronics my whole life.
If you mean how the solenoid works, it's essentially creating an electromagnetic situation where the piston and the body are repelling each other, causing the piston to push out (some solenoids are made to pull instead). Electric motors use the same principle, but they are switching the magnetic attraction to keep the motor spinning.
Maybe a better way to explain, as long as electricity is going to a motor, it's spinning, and using power. A solenoid is the same way, but pushing rather than spinning it's keeping that piston extended as long as electricity is applied. A drawback is that they can heat up (and burn out) if left powered too long, so while they work for opening things (releasing latches, etc.) you wouldn't want to use them to hold up a weapon door (or whatever) for more than a few seconds. There are ways around that problem, but not worth going into here.

I'm a super cheap builder on a lot of stuff too, nothing wrong with that. I pull all of the electronics out of stuff to reuse on projects, so I don't feel so bad when I have to spend several hundred dollars on other components (my Patriot cannon was a perfect example of that lol)

Oh, cool. That's very interesting, thanks. So, what happens when the current stops? Does the plunger pull back to its original position by itself, or do you have to push it manually? And if so, how much resistance do they tend to have?

Oooh, I wouldn't even dream of spending hundreds of dollars (well, I'm English, so really I should say pounds) on a project. I don't even have £100 in my savings. Though naturally, over 14 years of life, I've managed to build up a collection of many toys. And since I never play with them any more, I always like taking parts from them rather than buying them separately. For instance, I got the two motors I'm using for my web shooters from two remote control cars.

Again, thank you very much for all your help, and taking the time to explain how solenoids work.

 

[laellee]

Of course If anything, it might save you from buying something later to only find out it won't work for what you are building.

Usually the plungers are spring loaded, just strong enough to pull the plunger back to its rest position. So a solenoid could be used to pop open a door, but you can't rely on that spring being strong enough (with the current off) to pull a door back closed. So, you could take a solenoid with like a 1/4 kilo of power, push open a lighter door, but you'd still want a spring to pull that door back closed (if you wanted it to reclose). So your solenoid would have to be strong enough to push the door open with that extra closing spring attached. In the end, servos are just easier, but then you need the controller to operate them.

 

[Calebxy]

Of course If anything, it might save you from buying something later to only find out it won't work for what you are building.

Usually the plungers are spring loaded, just strong enough to pull the plunger back to its rest position. So a solenoid could be used to pop open a door, but you can't rely on that spring being strong enough (with the current off) to pull a door back closed. So, you could take a solenoid with like a 1/4 kilo of power, push open a lighter door, but you'd still want a spring to pull that door back closed (if you wanted it to reclose). So your solenoid would have to be strong enough to push the door open with that extra closing spring attached. In the end, servos are just easier, but then you need the controller to operate them.

Ah, I get it. Thanks.

You are now my go-to guy for electronics.