2 way 12v linear actuators.
Turbo Mini Forums

Does anyone know a good supplier of actuators?

I'm after something with about 50mm of travel in both directions. So obviously it starts in 'middle' position and then can travel 50mm further out, or 50mm back in towards the body.

At a guess it needs to have a speed of about 20-25mm under load and the operating force i am not to sure of, i'm sure 40nm will be plenty though if not too much.

I could be having a brain fart here but how do you work out how much NM of force is required? It takes around 4kg of force to click in what needs to be 'actuated'.

How do you work out the require NM from that? ITs probably really simple, i just cant get my head around it on my tod.

This did start off general, now its abit techy.

Cheers, James.

What you building? Sounds intriguing.

I am just planning for the moment but i need to know that i can get the actuators and that they are not vastly out of my price range before i spend more time working out the finer details and putting it into practice.

Its an idea for an electronic gearshift on a sequential box. But at an affordable price.

maplin, 2 wire central door locking servo/solenoids, you would need two for what you require.

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

F = ma
a is accelleration due to gravity, about 9.81 on earth so you may as well say 10.

So F (in newtons) is approx 10 X "force" measured in kg.

Technically kg is mass (m), not force, but is so often mis-quoted as if it is a force, just multiply the kgs by ten to get Newtons.

NM (Nm) is torque, not force, ie, rotational force at a given radius.

Schrödinger's cat - so which one am I ???

Thanks Rod. Its abit clearer now and at least i can work it out. Not a bad guess up top though!!

Evo, i was looking at them but i cant help but think that they just aren't man enough.

Plus they do not self return, they have to have the polarity reversed in order to get them back into thier start posistion which would good for a gear change type mechanism. Unless it had some fancy switch work and that would be a pain in the ass.

Cheers, James.

there plenty man enough and when not engaged can be easily moved back and forth by a spring. tbo though for your intedned use i would think pneumatics would be better? or vacuum to be more precice.

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

I had thought of pneumatics although not on the vacuum side of things. It does sound like a very good idea in principle as there are plenty of options for pneumatic actuators and possibly quite cheap if you could make say a decent wastegate actuator work well.

Wouldnt be very hard to make a couple of micro switches operate a solenoid valve to send the vacuum to either side of the diaphram depending if you wanted it to push or pull or even to a totally seperate actuator.

The only thing i wouldn't be too sure of is obviously it would need to be sealed and one way to make it work under vacuum and how would you go about returning the actuator/diapram to its resting position if it is holding vacuum in one side?

Obviously it would also need a vacuum reservior big enough to not run out of vacuum under a period of say track driving. Especially if using a flat shift system. Although i cant see this being a big problem as i'm sure you will top it up more often that you actually think.

either a 2 way pneumatic ram or 2 1 way rams with biasing springs to suit :) if the gearbox input already self centres then a single 2 way ram and a pair of 2 way solenoids is all you need, and a vacuum accumulaor ofcourse.

if you can get away with a short stroke, the vacuum "freewheel" 2 way canister on the front axle of mitsubushi l200's will do. hell, you could even grab the 2 solenoids , accumulator, and one way valve too lol

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.