Who can build one of these?? Cuz i want one!

weeba2kv said:

stupid

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Very insightful. Thank you for your input.

Honestly I am not sure how well a little 30mW 532nm would work but You could use a 100mW 532nm module and add a small line diffraction lens to it for about the same price as those two small ones:
100mW 532nm Green Laser Module (3V 11.9mm) - Worldwide Free Shipping - DX
AixiZ 60° Line Generator for 12x30mm Housing, AixiZ

These could be made into a low profile waterproofed case with several high powered neodymium magnets behind a rubber layer to hold it in place and be remote activated by something such as this:
Wireless Remote Control Switch Set (DC 12V) - Worldwide Free Shipping - DX

Power for the remote trigger and laser could be 3/6/9 4.2V batteries with a driver designed to drop the voltage down to 4.2V for the laser module. You would likely get hours of runtime off this setup per charge and if made well it could take some serious vibration without damage.

A 100mW module could pose problems if you use it while rolling but all you would have to do is slow down and maybe stop and wait for the road ahead to clear before you flash it on.

I think the idea of using a laser is awesome and I am going to pitch this idea to my Dad who is a truck driver also.

Thanks for the links buddy!!! Thats exactly what Im needing n thanks for taking the time and trouble to link me up...

IR laser, CCD camera, and a dichroic bandpass filter so only the IR gets through.

Makes it so much easier during daylight, Unless you like wearing glasses with green filters.

I second the laser and a line generator, but you need two of them that intersect to define a altitude at a given distance from the truck.

Line gen makes it one heck of a lot safer.

NHTSA and DOT and most state law bans any color other then red, yellow, or white on anything.

But green is the best bet.

This is a special dichroic filter. It makes sure the camera or the eye only sees the green laser:

http://www.ebay.com/itm/Precision-I...595?pt=LH_DefaultDomain_0&hash=item518b1f9843

Using a 532 nm bandpass dichroic with the green laser reduces the amount of power you need.

Daylight solar energy is about a kilowatt of energy per square meter, of which say 5-10% is visible light. Your fighting a huge amount of background light.

Now for the rules. This is a no-no legality wise. For a one-off no one will say anything till you hit some one on a bridge. You may or may not damage their vision, but at that point its their word against yours, and you loose in court. Mass production is another legal matter. It is a eye hazard at decent powers and up close to the laser.


Steve

Regardless of laser dangers and visual detection vs using a camera, there are some very basic problems with this idea:

Consider you put a line projector on the highest part of your truck, how are you going to keep it level? If you brake, the line will point down, if it accelerate it will point up - just like you headlights do, although many modern ones have a mechansim to limit this problem already.

Also, it would not work if the road isnt perfectly level. Lets say there is a slightly download slope leading into and underpass you will need to get through. As you drive down the ramp into the underpass the laser line will be projected too low, missing the edge you are trying not to hit by a long shot.

If there is any incline in the road leading towards an underpass, the laser line will be projected too high, highlighting the upper edge of the pass falsely leading you to believe your truck will not fit under it.

I'm not famliliar with american road signage, but in western europe its very common for the clearance height to be indicated on signs long before a tunnel, underpass or anything else that limits vehicle height.

I have been thinking over this since it was initially discussed and I no longer think it would be very feasible. For a 532nm, the output required would have to be too high to be able to be seen from any kind of distance. The whole idea in general is just not a good one since you have too many risks involving the law and safety. Now that I think about it, I do not recall seeing an underpass/tunnel that lacked a clearance indication. Your best bet would be devise a method of being able to quickly measure your truck's highest point since it would vary for every load.

The one situation where this might actually work would be if you approached the problematic height limit and got just so your tractor was nosing up to it(basically stopped) and hit your laser then. You still run into the issue where most times the road leading up to it could not be flat.

As for braking and accelerating changing the line's position, that wouldn't matter at all since you know when you are breaking/accelerating so you can know not to base what you measure at the instant to be true.

Camera; too much vibration, too much equipment, less doable than a laser.

Basically, find a quick way to measure the max height of your rig and use that instead XD

Old oil field trick: measure your load height, write this on the windshield in grease pencil to remind you. Simple is better.

So many above are missing the OP's point of his cars being scratched by trees' low hanging branches, NOT by some sneaky overpass, and I for one have never seen a tree with a low clearance sign. Something like this https://www.laserglow.com/BLG could be positioned with the focus fixed and the angle of the module fixed, so that where the beam falls when activated is more or less where it needs to be every time.

I don't see how laws or safety are really an issue here. You have a diffused laser beam of a relatively low power, being used by an industry professional to predetermine the location of an object. Like oh-so many things in today's society, as long as you don't get caught by the wrong person with the wrong agenda, this could be a useful tool.

I think its an even worse idea to be shining a laser at every low tree as you drive. I think the power required to project a line bright enough to be useful outside in the daylight would make it dangerous. Don't get me wrong, I am not saying he is a careless guy but I am saying that accidents happen and who is to say it couldn't shift on a large bump or from a branch nudging it and point right into someone rearview mirror and flash blind them as they drive. Though the risk may be pretty low, nobody has the right ever to endanger other's lives.

Its not a diffused beam its a concentrated bar of laser light that would have to be pretty high power to be visible for this use. Also, he may be a trained professional truck driver but he is not trained with lasers.

Its just a bad idea and there is a reason nobody ever made these in mass production. Believe me, we are not the first people to come up with this idea. There has to be a better way to do this.

EDIT: Also, the whole "as long as you don't get caught" mentality is what gets people hurt all the time. Its illegal for a reason bro.

?? Lol ... Dude. Apex? ??
Here. Let me bring u up to speed on the situation.
We know how high our load is.
We do t k ow how higb the tree branches are 1000 miles away on a street we never drove down.
We dont know how low the bridge iS now that 2 feet of snow is on the ground.
We dont know and People ARE DIEING Because we dont know.
Cars are getting knocked off trucks
Branches knocked down into the roadway traveledby fast moving motorcycles. Cars etc

There is No law restricting the placement of a laser on a truck 13.5 feet above the thousands of teenagers running aroundwith them.

My God!?? Lol ...

Just in case anyone ever diid get dilusionally off on what im doing with auch lower power laser than teenagers are running around with .. Its a mounted laser pointer... 13.5 feet above the ground. That can be switched on for a few seconds to paint low hanging objects and Make The World Safer via preventing them getting knocked down into the path of motorist .. Et. Etc etc.
No laser coursEs required.. No electro strato brozo techno anybody necessary to operate it ok? Just a flip of a switch.. It shoots a beam .. It shows something is low. .. Truck stops beam stops. No damages.. Nobody gets hurt.
Lol
It takes more than a good idea. N some of the folks on this forum are looking at an opportunity to use their know how to make this world a safer place and some decent $$ for doing it.
Dont worry about the level , i just need a housing a visible beam 50 meters out sourcing a 12 volt system.. One of u guys put that together before i do n ill buy it from you for a lot more than its worth ! Message me if u r up for it.

You could go to home depot and pick up a laser level, replace the red with a green module, and use Nd magnets to hold it in place. The level should allow for uneven surfaces and movement, provide a line at the highest point, and i would suggest the remote turn on. Granted you will be stopping before underpasses to check, and there shouldn't be too much visibility during the day to other people. Especially since you wouldn't be running it for longer than 5 seconds.

Im sure you know being a truck driver, you guys get pulled over alot so...user beware.

B52 said:

There is No law restricting the placement of a laser on a truck 13.5 feet above the thousands of teenagers running aroundwith them.

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If there isn't a law covering it, there will be one made, just as there will be if there is a serious incident involving kids and lasers. We've already seen what has happened in lieu of people shining lasers at aircraft. Anyway, most of those lasers are acquired because it is hard to regulate such devices, not because there isn't a need or want to, or even attempts to do so. Furthermore, fixing a laser on a moving vehicle is just asking for negative attention and problems.

Just in case anyone ever diid get dilusionally off on what im doing with auch lower power laser than teenagers are running around with .. Its a mounted laser pointer... 13.5 feet above the ground. That can be switched on for a few seconds to paint low hanging objects and Make The World Safer via preventing them getting knocked down into the path of motorist .. Et. Etc etc.

Click to expand...

Your idea is good in concept, but still hazardous, even 13.5ft above the ground. Even at laser shows you're not supposed to have the laser less than 3 meters above the heads of people. What about when the beam intersects a road on a hill further down the road? Or a building? Or reflects from a shiny surface like a metallic pole? The places you'd use such a device, where trees hang low, are usually in areas in close proximity to buildings, poles, and people. So at the power levels you're asking for--a visible beam--all of the above are real visual hazards.

The laser you're talking about not pointer, it's a high powered laser device that spreads a cone of light out to illuminate objects 50 meters away, and be visible from below the beam source. That kind of power can flash-blind, distract, or even injure people.

It takes more than a good idea. N some of the folks on this forum are looking at an opportunity to use their know how to make this world a safer place and some decent $$ for doing it.
Dont worry about the level , i just need a housing a visible beam 50 meters out sourcing a 12 volt system.. One of u guys put that together before i do n ill buy it from you for a lot more than its worth ! Message me if u r up for it.

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Then build it yourself. Assume the liability for the hazard it poses.

You can just buy a cheap green laser from eBay that runs on 12V. Pass the beam through a cylindrical lens (try using the 12mm FL lens here) that you can adjust by positioning it in front of the beam until you get the cone you like. Glue it down, seal the system up from the weather and you're done.

I completely disclaim any of the information above. Use at your own risk or liability.

Use high power flashlight with good throw on a stick with a switch in the cab. Cheap...easy...and legal.

Here ya go:



Pressure sensor - Wikipedia, the free encyclopedia

The sensitivity of the strain gauge should be adjustable from the cab to filter out small road induced wiggles and only detect large deflections.

So now you have detected low tree branches what next? Stop in the middle of a possibly busy street? Get out and trim them? Back up and find another way?

Sorry for sounding so negative. These questions should be addressed along with the problem.

I actually am pretty darn sure it is illegal already in the US to mount a laser externally on a vehicle, especially a commercial vehicle.

Anyway, in theory the laser idea would be your best bet still. You would just have to be beyond careful when using it. Though now that you mention low temperatures I am rethinking a green laser being the best option. Green lasers perform extremely poorly in anything below a standard ambient.

Quote:
There is No law restricting the placement of a laser on a truck 13.5 feet above the thousands of teenagers running aroundwith them.
END QOUTE.

Respectfully disagree.

21 CFR 1040.1 Subchapter J
Covers the use of lasers in public for commercial use pretty well.

OSHA has some laser rules as well, including following ANSI Z136.1 guidelines about lasers and moving vehicles.

You can build one for yourself. If you sell them commercially or sell a kit, that is another matter and they must be type approved devices at that point. 1040 covers the commercial sales aspects.

IR laser based vision systems for vehicles exist. However they are all designed to be "eyesafe" and thus have average powers less then Class 3A. (AKA 4.95 mW)
This means they are generally infrared and have a display in the cabin. You might want to look into them as they have rangefinders and will give you a 3D map of the objects in your path. However they are not at all cheap. I would imagine if your hauling 10 Porsche roadsters some one might pick up the tab.

Steve

Bill King said:

Here ya go:

Pressure sensor - Wikipedia, the free encyclopedia

The sensitivity of the strain gauge should be adjustable from the cab to filter out small road induced wiggles and only detect large deflections.

So now you have detected low tree branches what next? Stop in the middle of a possibly busy street? Get out and trim them? Back up and find another way?

Sorry for sounding so negative. These questions should be addressed along with the problem.

Click to expand...

Ok so now he can know 1/100th of a second before a tree hits the roof of a car. Either that or he slams on the brakes and rolls at super low speed under a tree and stops and backs up if the sensor goes off. That's not realistic. On top of that, the telescopic pole would be ripped off on the first tree that touches it.

Laser system: Driving, sees a tree or bridge ahead, glaces around for pedestrians and makes sure he wont hit a car in front and quickly flashes the laser to check the height. With enough power from a laser this all could be done from a reasonable distance away giving him enough time to change lanes or safely stop the truck. IMO, this is far more useful than a "oh shit I'm going to hit that tree" sensor.

I don't think IR would be a practical undertaking seeing as it would require far more equipment and cost. I do think a 632nm or a 445nm laser running through a line generator would produce the effect you are looking for. It could be designed so that the aperture would restrict the width of the generated line as well so you wouldn't have to worry as much about the beam where it extends out to the sides past your target. I also think that using a strobe driver on the laser may also improve its safety since then even if its output were higher the chances of eye damage would be reduced. On top of that a rapidly blinking line may be even more visible than a steady one.

The system has the potential to be dangerous but if used correctly and cautiously I think risk could be minimized. Basically, if the risk of getting into trouble with the law was worth it to you then I think the whole idea is doable.