Looking for radio control components - wireless stepper motors

[DaveC426913]

I'm ready to begin proof of concept experiments on the Mk IV Tesseract, following on the limited success of https://www.physicsforums.com/showthread.php?t=205845"

What I need is a motor that
- is reasonably compact (we're talking <2 centimeters) though weight is not a factor
- can be operated remotely from my computer (probably a communications component attached to each motor)
- can extend a piston several inches, whether directly or through some sort of conversion such as rotary-to-translative gearing
- is affordable considering I'll need 32 of them

Can anyone give me pointers?

 

[Danger]

That post that you linked to gave me a headache the first time that I saw it, and this was no better. :tongue:
If you're willing to use a gearbox, as your post indicated, then is it necessary for these to be stepper motors? Wouldn't any reversible DC unit be adequate?
Personally, my first thought for something like this would be low-pressure/volume hydraulics, possibly in combination with solenoid stop-blocks for the pistons.
On the other hand, you're the Science Advisor and I'm drunk.

 

[montoyas7940]

Dave, I found these. There is no price unfortunately.

http://www.globalspec.com/FeaturedProducts/Detail/Linear_stepper_motors/77689/0

 

[Topher925]

Thats a tall order. The communications part shouldn't be to big of an issue, this is assuming your a BAMF with a hot air gun. http://www.sparkfun.com/commerce/categories.php?c=16

But not only do you need just your motor and communication, but you also need your motor controller and power supply. There is no way that all this will fit in a 2 cm2 cube unless you have some very special manufacturing equipment. If I were you I would just throw the motor idea out the window. I would start looking at other avenues such as muscle wire or possibly even "linear motors". You haven't really specified what kind of force or displacement you will need.

http://www.sparkfun.com/commerce/product_info.php?products_id=8751

 

[berkeman]

I'm ready to begin proof of concept experiments on the Mk IV Tesseract, following on the limited success of https://www.physicsforums.com/showthread.php?t=205845"

What I need is a motor that
- is reasonably compact (we're talking <2 centimeters) though weight is not a factor
- can be operated remotely from my computer (probably a communications component attached to each motor)
- can extend a piston several inches, whether directly or through some sort of conversion such as rotary-to-translative gearing
- is affordable considering I'll need 32 of them

Can anyone give me pointers?

Fun video, and interesting project. A couple thoughts:

-- Don't over-constrain yourself by setting the size of the TS and working into the motor/power source size. Start with the motor and power source sizes, and work out to the TS size. Sure, it will be bigger than you'd originally envisioned, but so what, it will work.

-- The tubes all have to be able to change length, right? So you have two pieces that slide into each other to contract in size?

-- Since it has no fixed points, the power supply has to be batteries contained in one or more of the arms, right? You can't hook a power cord onto that morphing beast!

-- Will it be hand-held as it morphs? Same as the power cord -- no way to suspend that morphing beast from a cable. I guess you could let it crawl across the tabletop as it morphs...

Fun project, Dave.

 

[DaveC426913]

Thats a tall order. The communications part shouldn't be to big of an issue, this is assuming your a BAMF with a hot air gun. http://www.sparkfun.com/commerce/categories.php?c=16

Awesome link! Though I have no idea what a BAMF ...

Oh. Right. I got it...

But why a hot air gun? Don't you mean soldering iron?

But not only do you need just your motor and communication, but you also need your motor controller and power supply. There is no way that all this will fit in a 2 cm2 cube

Motors come in that small easily. They can be powered by watch batteries. (It doesn't have to have much endurance).

The motors will power the struts which need to triple in length from min to max. Smaller is better, but I will scale up as needed. So far, my prototypes are ~5", so the total strut change is from 1.5" - 4.5".

 

[DaveC426913]

-- Don't over-constrain yourself by setting the size of the TS and working into the motor/power source size. Start with the motor and power source sizes, and work out to the TS size. Sure, it will be bigger than you'd originally envisioned, but so what, it will work.

Yep. You're thinkin' what I'm thinkin'. I provided the dimensions as a "most optimistic" first start. Don't want people to be offering motors the size of my fist...

-- The tubes all have to be able to change length, right? So you have two pieces that slide into each other to contract in size?

Yep. The MkII uses that way. The MkIII uses elastic ribbon. There are other rigid ways, such as a rack & pinion system.

-- Since it has no fixed points, the power supply has to be batteries contained in one or more of the arms, right? You can't hook a power cord onto that morphing beast!

Yep yep. It's impossible, even in theory, to wire up a power supply. The thing turns inside out; it would wind up the cord.

-- Will it be hand-held as it morphs? Same as the power cord -- no way to suspend that morphing beast from a cable. I guess you could let it crawl across the tabletop as it morphs...

Fun project, Dave.

Yep yep yep.

You have an excellent grasp of my project.