Pneumatic Vs Spring


I am a freelance IDer and doing an interest project; I have to creating a movement similar to the anglepoise lamp, but am investigating using pneumatic hinges instead of springs. However I am having a hard time finding information or suppliers to talk to. Does anyone have any knowledge on pneumatic hinges/joints or springs for that matter?


i would think more about the movement you are are trying to achieve and then what tool might be the solution. A pneumatic hinge may end up being more complicated ( usually a lot more resistance and slower to move) than a spring or friction fit pivot…

go look at some things with pneumatics or gas springs and see how they work and if they are performing as you’d like…

Cheers FloatingHead

I have been looking at the other products, however it is as much the range of movement that it can deliver as well. I am needing it to hold about 3kgs where the lamp head would be and was unsure if springs could hold that weight which is why I was thinking towards the pneumatic/gas springs.
For it to be able to be moved with ease then frozen in the desired place.

mechanical springs are stronger than gas springs.

Friction and the like maybe a cheaper and easier bet. Rotatory mechanical springy springs may work.

Would think that linear metal springs are cheaper and more reliable than pneumatics but have a much less good “feel”. Mechanical springs can be cheaply and easily made to spec by most suppliers. Need to spec material and dimensions which is an easy calculation but have lots of options.
e…g MITcalc - Geometrical design and strength check of 15 springs types

Pneumatics will use a penumatic piston with non-return valves. I think you will get what you pay for in terms of gas leakage (i.e. how long before readjustment). Similar inputs i.e. how springy, what feeling you want to create

Alot of it depends on the “feel” you want and results that you expect. A well designed gas, metal, friction fixation will work better than less well design one (which is duh when you write it). By that i mean that a cheap friction clamp well done, is better than a pricy but thrown together gas spring.

Cheers bobo for the links they are of much help, it looks like I will need to get my maths skill on when deciding on what springs but that wont be for a while.

I am defiantly after the softer feel of spring or pneumatics and dont think that a friction joint will deliver that smooth movement across several joins.

You may find this page of use in looking up references for what your free body diagrams look like

If your doing something that looks like an angle poise I think you are going to need lots of trail and error so good luck.

Dont forget the mass of the lamp beams in your calculation and extremes of position may want to use excel or similar to check range of motion.

Thanks Bobo
Wikipedia comes through again. I have looked over that page lots, imagining my product with each of the different spring mechanisms.
My client is wanting to drop developing the pneumatics for now and to focus on “Tension springs within the arms” (wiki name). Does anyone has know of any examples of “Tension springs within the arms” being used in current products.

I am expecting that there will be a lot of trial and error when we get to prototyping, and looking forward to it. :slight_smile: