Pnuematic ram operated light bar

[Gwagensteve]

There should be no problem whatsoever with using pneumatic cylinders for this application..... lots of good information about cylinders

My point is that a linear actuator can lock the lights in any position, and can be setup to finely adjust the angle of the lights, so they can be raised for speed and lowered for crawling/recovery etc. I don't think that's very easy with pneumatics.

If that's not important, I like the idea of a gas strut over pneumatic cylinder - It has some redundancy built in, and allows the ram to be depressurised when it's no required so improve reliability. I still think it's hard to go past the lock up/lock down ease of an overcentre mounted gas strut, but I agree that being able and lower the lights on the move is a nice idea.

Steve.

[-Scott-]

My point is that a linear actuator can lock the lights in any position, and can be setup to finely adjust the angle of the lights, so they can be raised for speed and lowered for crawling/recovery etc. I don't think that's very easy with pneumatics.

Infinite remote pneumatic adjustment wouldn't be easy, although there are some (expensive) products which could probably achieve it, but I agree that an electric actuator would be more likely to be a viable solution.

If you only want two "up" positions, it may be feasible to use a fixed (screw?) stop for the "forward" position and a second (short travel, large bore?) cylinder to create a retractable stop for the "rear" position. This would require the "stop" cylinder to be pressurised to maintain the second position.

Perhaps a hybrid option? Pneumatic ram to raise/lower, with a motor driven screw mechanism to create an adjustable stop?

[Patroler]

You can run a cylinder with several reed switches and a pneumatic brake on the rod set up to stop at the reed switch, although this is overly complex and requires some electronics to make it work, also air off would release the brake, you may have one reed switch part way and run the cylinder to the end of its stroke for the other setting - it aint variable in car only position to position - and if you wanted full variability you would be better off using the linear actuator.

[265grunter]

you may have finished it by now with an actuator and a switch and wire..............

[Weiner]

Just doing some research on linear actuators, what kind of force would be needed to move the lights when on say the freeway, and what length would be needed?

[265grunter]

the length will be determined by the length of the arm attached to the light bar.the arm should only move through a 90' arc ideally so if you put on a 50mm arm it will move half the length of say a 100 mm arm.get in touch with a supplier and tell them what you want it for.they can tell you what torque rating will suit you.a friend of mine used some big suckers to lift the entire roof and wall section on his houseboat [about a ton]he drew the idea and asked for something to do it and they did the rest.

[Weiner]

the length will be determined by the length of the arm attached to the light bar.the arm should only move through a 90' arc ideally so if you put on a 50mm arm it will move half the length of say a 100 mm arm.get in touch with a supplier and tell them what you want it for.they can tell you what torque rating will suit you.a friend of mine used some big suckers to lift the entire roof and wall section on his houseboat [about a ton]he drew the idea and asked for something to do it and they did the rest.

Thanks mate, I have emailed one supplier and hopefully I can find out