Outer Limits 4x4 Board

Im looking for info on how to set up a air operated light bar (type of ram, what pressures to run etc). Ive done heaps of searching but cant seem to find much.

Ive heard of a couple of people purchasing a kit from the states but my searches have turned up zip.

Any info / links / pics would be greatly appreciated

noodle wrote:Im looking for info on how to set up a air operated light bar (type of ram, what pressures to run etc). Ive done heaps of searching but cant seem to find much.

Ive heard of a couple of people purchasing a kit from the states but my searches have turned up zip.

Any info / links / pics would be greatly appreciated

You can buy stuff from festo, rexroth, smc....i would run around 60psi but use flow controls on the cylinder (ram)....i would reccommend using flow controls that meter out so they control the flow of air out....hope this helps

If any of youre mates are good with tinkering, theres always small air rams available on ebay 2nd hand, then adapt that into a hinged mechanism. You can get away with it cheap with regulators from Supercheap, etc...

Thanks for your replys.

The tinkering side will be fine im just a little new to air systems.

So when the air is on the rams hold up, when the air is switched off they come down. Is this what you mean about having the flow controls releasing the air ? so they control the speed at which the bar drops ?

iam also interested in this so pics would be handy to see how people have done theres. (brackets and fiddly bits)

I'm also interested in any info and pics on this subject .

I think the flow control is there so the lights don't pop up too quickly as well .

I have a air ram for my lights. I've got it mounted vertical pushing the light bar around 90deg from pointing strait up to on the road, I run 100psi in my system it helps when at speed and the way my linkages are set up.

The size of the ram is also important cause to smaller bore and it wont have the force to push it up, and depending on the legth stroke of the ram will depend on how you set the system up

Gwagensteve has a rather clever system using a gas strut ( tailgate lifter style ). From what I recall it incorporates an over centre action, where the lights are held normally or "stored" by the strut.

It advantage over a pneumatic cylinder is that force is applied by the strut in both the normal and stored positions so the lamps cant flop around as would happen with a depressurised pneumatic cylinder.

Its not automatic as I'm assuming is your goal, but its a neat solution and might give you some ideas especially if your used the gas strut idea for static load and a cylinder only to "move" the lamps.

Perhaps PM him - he may have a pic or two.

MightyMouse wrote:Gwagensteve has a rather clever system using a gas strut ( tailgate lifter style ). From what I recall it incorporates an over centre action, where the lights are held normally or "stored" by the strut.

I have the same set up on mine

Im interested in this too.. anyone got pics too?

The ontrack Shriek truck has one on it, had photos on their site... might be worth searchin for

Hulksta wrote:Im interested in this too.. anyone got pics too?

http://carl.outerlimits4x4.com/ftopic14 ... ight=strut

It works fine, a bit of messing around getting the right angles to allow the spotlights to drop down to where i wanted, without the ram wanting to push up on the hinges rather than rotating, that picture is older and now has an off centre mounting to help take load and get a better angle.

It is a 2way ram but is not hooked up two way as yet.

It is running off a 3rd solenoid off my airlocker compressor, and being fed airlocker pressure, the ram is from an industrial machine so those pressures are more than acceptable, the ram does have an adj screw that puts pressure back on the side that you screw it to, as 100psi starts off pushing the lights up slow, as there is more weight levering on the ram when there just under horizontal, but as it lifts them it would slam them into the stops before adj the screw, but a regulator in line would solve the problem if id didnt have a screw.

For it to work the way i wanted the ram, which is for them to fold right down to vertical, it would have to be mounted more vertically, but i didnt want that down in my vision and it would get in the way of whatever gear i have on the back.

There are stops now welded in to stop the lights in the right upper and lower positions, i didn't want the rod at full extension being banged around by bumps shaking the lights, 2 rams is better as it does have a slight movement when their on, but minimal,

Thanks berad.
Very helpful

WHY DONT YOU JUST USE A LINEAR ACTUATOR-12 VOLT.ALL SORTS OF LENGTHS/TORQUE AVAILABLE.GOOGLE IT FOR YOUR CLOSEST SUPPLIER.

I can't comment on linear actuators, but I am aware that apparently pneumatic actuators don't like being stalled forever with pressure on them - so if your lights need pressure applied to keep them locked down, the ram might not be happy. Rams like to move something somewhere, and then move it back (that is generally stay in motion) which is why they are great for a process application but not very good for a light bar that nigh get used once a month, or something.

PS if the linear actuators (electric) are a screw flight kinda thingy then they are way preferable as once power is removed, just like a worm drive, they will lock in whatever position they're left in.

also, a linear actuator can be "tuned" to raise and lower your lights depending on your speed. That's going to be a pita with a ram- it's up or down - and if you need to lock them down to avoid having pressure on the ram constantly, then you're no better off than my gas strut, which is set and forget.

just some thoughts.

Steve.

I have done a bit of research into 12v Linear actuators (waterproof) but having not seen them on a rig before I thought there may be an issue with using them. hmmm might give it a go

noodle wrote:I have done a bit of research into 12v Linear actuators (waterproof) but having not seen them on a rig before I thought there may be an issue with using them. hmmm might give it a go

If theyre good enough for Mythbusters...

I think you could modify a wiper motor to do the same thing if you wanted. Cheap, plentiful, no air fittings or compressor required, just a threaded rod that moves them into whatever position you want....

I'd go for the strut and set it up over centre style and just have a handle to pull it down, that way the strut will either hold it down or up.
Not as automated as air cylinders but way simpler - and i work in a process environment and play with cylinders a bit and could get the gear and hook one up easily - id still opt for the strut
For air you'd need a reg - maybe depending on cylinder bore size selected - if you chose the correct size and leverage you could do away with the reg, air fittings for the cylinders (4 90 degree smc 4 or 6 mm would be fine), i'd run 2 cylinders - one on each side, a couple of inline restrictors - or flow control valves, a couple of tees, and a few metres of air line and a toggle switch.
If you wanted to run 2 cylinders, you'd be wise not to put your speed control valves on the cylinders individually as you'd need 4 and then there would be a chance they wouldn't be set the same and the unit would bind from side to side, instead run the air from the compressor to the switch, 2 lines out of the switch would have inline restrictors close to the tees, then go to tees which would have 2 lines for each cylinder.
You could also run a single acting cylinder which has a spring to hold the lights in one position and air to drive it to the other position.
Also not sure if you're aware but with the flow control valves they generally allow full flow in one direction and restrict in the other (unidirectional restrictor), they should usually be set up so that they restrict the exaust of the cylinder, this makes for smoother operation and the fact that they only restrict in one direction allows you to have a different speed lifting up compared to returning
Most industrial supply places should be able to help with parts - be warned some of them can be surprisingly dear.

Gwagensteve wrote:I can't comment on linear actuators, but I am aware that apparently pneumatic actuators don't like being stalled forever with pressure on them - so if your lights need pressure applied to keep them locked down, the ram might not be happy. Rams like to move something somewhere, and then move it back (that is generally stay in motion) which is why they are great for a process application but not very good for a light bar that nigh get used once a month, or something.

PS if the linear actuators (electric) are a screw flight kinda thingy then they are way preferable as once power is removed, just like a worm drive, they will lock in whatever position they're left in.

also, a linear actuator can be "tuned" to raise and lower your lights depending on your speed. That's going to be a pita with a ram- it's up or down - and if you need to lock them down to avoid having pressure on the ram constantly, then you're no better off than my gas strut, which is set and forget.

just some thoughts.

Steve.

True, i'll let you know how it goes, no problems so far been on and running for a few months, doesn't matter if it breaks its all in the name of what works best and for how long haha.

I opted for air instead of a simple strut because im lazy and hate getting out to drop them down for trees and other random obsticles, at the end of the day i can override the air and block the chamber off with the grub screw and they'll lock up or down.

We ran with the gas struts on the comp truck.. the ups and downs were..
Positives,
The constant force allowed for a more stable light bar.
Cost effective.
If you hit trees they would fold down instead of breaking something, but because the didn't go over centre they would pop back up automatically.
Less shite to go wrong

Negatives,
You had to put them up manually
Lower coolness factor.

There should be no problem whatsoever with using pneumatic cylinders for this application.

Speed can be controlled by simple flow regulators that screw into the cylinders ports then accept push in nylon tube, cheap and compact devices.

The end of the stroke is controlled by selecting a cylinder or cylinders that have adjustable pneumatic cushioning at each end of the stroke which slows down the last few millimetres of stroke to avoid a full speed crash and ware and tare on the cylinders and associated bracketry that supports the lights.

If you can grab the bracket that accepts the rod end of the cylinder (where the cylinder connects to the light bar) and rotate the light bar up and down with one hand then you should not require any more than a 40mm bore cylinder and may get away with a 32mm bore.

Alternatively two 25mm bore cylinders at each end of the bar should have enough force and will give a more rigid light bar when it is raised.

When the light bar is lowered have a lock pin fitted to hold it in place so pressure can be removed from the system.

If you want to get more technical then use a cylinder with a mechanical rod brake to hold things in place when raised. A suitable stop that stops the light bar before the cylinder reaches it's full extended stroke will suffice though.

You will not need any larger than 4mm pneumatic lines to run cylinders up to 63mm bore so if you keep this in mind all the components will be that little bit cheaper because they are at the small end of the pneumatic scale.

The pressure applied will determine how much force the cylinder applies the tube sizing will only determine flow rate and therefore speed of travel.

cheers

What about gas strut one side to hold it up and down (and allow pop down if you hit something) and air on the other side to raise and lower it

hmmm gas struts with an air ram i like how ever you would need to disconnect the air ram once up , or atleast de pressurise it so that the lights could fold down if they did hit something, otherwise the air ram will hold them there

cooki_monsta wrote:hmmm gas struts with an air ram i like how ever you would need to disconnect the air ram once up , or atleast de pressurise it so that the lights could fold down if they did hit something, otherwise the air ram will hold them there

This sounds like a good solution. Air rams to hold up or down, with a double acting cylinder to change positions. A 5/3 centre exhaust dual solenoid valve with a spdt centre off momentary action toggle switch.

You could also consider a switch to detect the rack in the UP position, so the lights can't turn on when they're not up - but that's probably getting silly.

Just plumb each outlet of the cylinder to the tank via pneumatic toggle switch
You will need normally open and normally closed (DPDT in leccy talk) as the air need to vent when the switch is released.
Ones up, ones down
The ram will remain in whatever position relating to last button you press, beauty is the air is not constant on, it's only used to change position.

-Scott- wrote: You could also consider a switch to detect the rack in the UP position, so the lights can't turn on when they're not up - but that's probably getting silly.

A lot of quality industrial rams have magnets on the 'plunger' inside the bore
Simply attach reed switches to the side of the ram for detection

Some rams also have springs inside, depending on what side of the 'plunger' it is on it will not require air to either extend or contract

Jees its getting all fancy now haha, only problem i see with a strut on one end and air ram on other is the ram will be fighting it when you want to lower the lights, but the bar could easily be made rigid enough not to twist etc.

berad wrote: only problem i see with a strut on one end and air ram on other is the ram will be fighting it when you want to lower the lights

Mount the strut 'over' the ram from clevis to clevis