Bicep curling spring device questions

[SilverJW]

Dear Forum,

Please advice. I have a project where I'll be implementing a device that helps with Bicep Curls, adding resistance to it. So I have an idea with 2 pieces of guards, one on the forearm and one on the biceps, it will be conjoined through a latch in the middle which will rest in between the forearm and bicep.
This is easy and all but my issue is, I'd like to know what kinds of springs can I use? Is there any ways where I can implement springs into my device, where I can adjust the stiffness to give different level of resistance to the user?
My initial idea is to have a huge flat spring or torsion spring go through both the pieces, and there will be a slider in the pieces so that at different length where it's pushing on the spring it will provide different resistance, but I don't know whether I'm going in the right direction.

Please advice,
Thank you!

 

[anorlunda]

Have you considered a hydraulic or pneumatic piston? They make it easy to adjust the force. Stone it is muscle powered, the pressure remains low thus reducing the chance of injury if the piston fails.

You can also get ideas from the machines at your local gym.

 

[Orodruin]

Just to try to understand your intentions, what purpose is supposed to be filled by this device that could not be achieved by just switching to a heavier set of dumbbells or putting some extra plates on your bar? Free weights also have a lot of advantages in terms of flexibility in how you perform the exercise (range of motion, positioning against gravity, positioning of your arm, supination, etc) that I am not sure how you are planning to incorporate into your device.

 

[CWatters]

It would need to be strapped to your arm as well.

 

[CWatters]

The advantage of weight or elastic based solutions is that they can also be used to exercise other parts of the body.

 

[anorlunda]

You still need more clarity. Do you mean a machine that stands on the floor, or something that the person wears and uses as he walks around?

 

[SilverJW]

You still need more clarity. Do you mean a machine that stands on the floor, or something that the person wears and uses as he walks around?

Thank you all for the advice, my equipment is supposed to be portable/wearable, not a huge machine, therefore pneumatics are out of the question, I thought of something similar to a mini adjustable shock absorber, to change the resistance, but that is too expensive and/or huge to incorporate into a portable device.

I am aware that weights and without equipment, all these arm exercises can be done easily. But as this is a project, I have to come up with a Upper Limb Exerciser, the criteria/project scope given to me was:

-When a person injures his/her upper limb, the person will need to do rehabilitation therapy to regain the strength and flexibility. Using an upper limb exerciser is one of the ways to speed up the recovery process. The scope of the project is to design and make a prototype of the upper-limb exerciser device.

It doesn't necessarily state that the device has to be portable, but given the circumstances, I'm only given 12 weeks and a 3D Printer to work on my project, with a petty cash budget, so coming up with a machine is also out of the question.

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Please advice

 

[Tom.G]

Well, may be this is cheating, but try: https://www.google.com/search?&q=exoskeleton+arm+workout

Also try it without the "workout"

 

[SilverJW]

Well, may be this is cheating, but try: https://www.google.com/search?&q=exoskeleton+arm+workout

Also try it without the "workout"

I wouldn't say cheating, but the fact that I'm here asking for advice is rather questionable.
However, thanks, this added with 'AS SEEN ON TV' Wonder Arms, I have been inspired quite a lot!