Unofficial VEXU question: LASER aiming?!!!

So worlds just ended so we really shouldn’t bother Karthik and GDC at this point, let them take their vacation.


Is laser aiming legal in VEXU?

VEXU allows any electronics, and non-destructive laser is absolutely electronics!!! This might be a complete game changer, because it would make VEXU’s aiming so much easier!!

Guys, face it. VEXU nothing but net is completely a different game from VRC nothing but net. VRC will be an effort looking for elevating partners, while VEXU will certainly fill up high goal and low goal in autonomous with the across field launching!!! Can’t wait to build VEX version of FRC 2012 high speed conveyor belt launchers!!! 10 motor launcher rule!!!

I wasn’t around for 2012 so I’ve never heard of this, but it seems very interesting. Do you have an example?

No, I ask about lasers virtually every year, you cannot aim them up, for safety reasons.

You can aim them out with a limited chance the head ref tells you off anyway.

What if you 3D printed some sort of cover for the existing vex flashlight that would focus the beam onto one small point? That would work similarly to a laser, and would be completely legal for vex U.

What about the use of Lidar? My FRC team is using them this year and they work really well.

Doesn’t the L stands for Laser?

Will a laser bounce nicely off a net or would you point at the walls and pipe?

So wall bots may not be good, but “get in the way bots” could disrupt the laser distance pretty well and cause premature shooting and missing in auton. Buff up that aluminum or steel until it is nice and shiny! It would react to ultrasonics too without the shine.

Some Mylar or rainbow prism tape as “non-functional” decorations could also work to reflect light back in weird ways too.

Most LIDAR systems use IR lasers, which don’t really affect the human eye (at least not at weak wattages), those would probably be OK.

But you won’t be “aiming” with them as IR cannot be seen.

TO BE CLEAR, a horizontally mounted LASER should be legal and should be useful in aiming.

This is wrong. Don’t hurt yourself.

Caveating it with the low wattage comment doesn’t make it correct, because that it true of all EM Radiation.

There are definitely portions of the IR spectrum in which IR lasers’ harmful effects (on eyes/retinas) are similar to those of visible lasers.


Would this be legal for VRC High school? Could it be considered nonfunctional decoration if the laser pointer does not touch any of the game objects?

I feel like having a laser or IR would not be a good idea just for safety reasons and if you want to use it for a decoration it can not have any match bearing uses so the point of using it would not be worth it.

You have answered your own question. If you are aiming with it, it is functional.

In the past my club has had robots that used lasers pointing at the ground so they can line up for autonomous. These lasers would be turned off before the match so they were considered non functional during the match. We had numerous officials say it was ok to use lasers like this. But we were always told that you couldn’t have the laser on during the match and that it had to be pointed down and be mounted close to the ground when it was on so nobody would get hurt.

The power requirements for a LIDAR that could damage your eyes in short exposure far exceed the cortex’s output. The ones that are more powerful also have a high enough frequency that they do not transfer much energy. There should be an rating on the unit. Class 1 is safe.

It is also irrelevant since LIDAR does not play nice with clear, reflective objects like the field perimeter. It produces noisy readings. If you have the processing power to use a LIDAR there are better sensors to use.

Speaking as someone who used a laser for aiming in FRC 2012, the reason it was useful was because our robot could sense when the laser reflected off the reflective tape on the backboard, so we used it for turret aiming.

As VEX does not have any kind of vision-tracking target, using a laser in this situation would just be for the human eye to see where you’re aiming. If that’s the goal you might as well just use a Photon Cannon. It would be much easier to see on the goal then a laser dot, and much safer.

Even if a robot actually carrying a laser and running around is ruled illegal, teams should still be able to do laser aligning before the start of match… Remember Karthik ruled laser aligning and other prompt methods of precisely positioning a robot before a match legal.

So… design some sort of mechanism to snap in a laser and aim your launcher precisely at the goal, and then take it away. This should be legal. In VEXU auton shooting without moving base should be commonplace.

I believe that both of the statements about LIDARs in this quote are wrong.

[INDENT]1) I think the Cortex is able to deliver as much as 4 amps on an output port. I don’t want to spend any amount of time looking into a laser converting a significant part of 4 amps into visible or invisible radiation; particularly if that laser’s electronics might store energy before emitting powerful pulses.

“short exposure” is pretty darned nebulous. Thermal and photochemical retinal damage can occur very quickly (not much total energy deposited) at some visible and invisible wavelengths. OBTW, how do I know if an invisible laser is on, so that I can limit my exposure, especially if I’m a bystander?

  1. LIDARs can be built from lasers that operate at pretty much any frequency. I have firsthand knowledge that contradicts the assertion that LIDARs operate at high frequencies (high relative to what?).
    Sweeping statements other than “Class 1 is safe.” about whether Laser radiation is/isn’t safe, are a bad idea; and even a Class 1 label should be taken with a grain of proverbial salt.

OBTW, read the fine print on the devices’ labels. Some devices emit Class 1 levels, but contain higher/dangerous levels inside their cases. Crack one open by accident, or on purpose, and you could be in trouble.

OBTW again, I have looked into the subject in the past, and to the best of my knowledge, no USA agency checks manufacturers’ assertions about what class their laser devices belong in. I can imagine that a few manufacturers might label theirs incorrectly.

Bottom line: Don’t hurt yourself (or me, or a baby in the stands/pits, or a teammate, or …).


Along the lines of this recommendation, I suggest simply putting a couple of landmarks on your robot and then lining them up with a landmark on field.

Basically, make a gun sight. If one or both parts of the gunsight is a hollow stand-off beam, or some other straight tube, I think it will be just as good as anything you can implement using a laser pointer.

For a robot that needs to be lined up before it moves, I’ll also bet that the slop in VEX motors’ internal parts, the slop in drivetrains’ external gears/chains, the slop in wheel/axle interfaces, the flex in robot chassis structural members, and the normal variations in field (and tire) surface conditions will all combine to create path differences that make any alignment improvements you might get because of using a laser instead of using a simple mechanical “gunsight”, irrelevant.



Ok, I will agree that this is enough amperage. The Hokuyos we use in a lab I work in needs .7A at 12V.

What I meant by this is that the internal mirror has a large angular velocity so that the point created by the laser is illuminates a particular object for a short period of time, which lowers exposure.

Of course it is, it is a whole lump of variables that I did not want to account for. I could say that “very quickly” is equally nebulous, but risk management is a huge topic that is difficult to implement. I have only ever done a semester of research on LIDAR systems, and even then I was just looking at optics and controls. I am no expert, but just because it says “laser” it is not necessarily dangerous.

This just sounds paranoid. What advantage would manufacturers gain from injuring their customers? LIDARs from reputable companies and of a proper classification are safe to use in the application they are designed for. Sure, some LIDARs have a higher level of EM radiation in the housing, but you are not in the housing so it is irrelevant. If you are using the LIDAR improperly, it can be damaged, just like everything, and then it should be shut off. It is outside of its safe operating parameters. If one is used it would require the team to know how to properly and safely install and operate the LIDAR. I do not believe that a LIDAR would be particularly useful for VEX competitions, but it irks me that people are so quick to mash the “it’s dangerous!” button. Yes, all things carry some risk factor.
Also the appeal to emotion:

has a whole Wikipedia page on it.
VEX is an introduction to engineering, risk assessment is a important aspect of design. Be careful, don’t be stupid.

This is a much better option and is significantly cheaper to use. There are a lot of different types of iron sights too, so you can experiment to see what works best for this application.
If you desperately want to overpay for lining things up, go to Walmart and get an optical sight. Or even better, build your own. I have done this before using parts I pulled out of a disposable camera. It is a little finicky, but it is possible to get some magnification.

But will laser aiming actually help that much? I see that in will help you in horizontal aiming, as long as you are not to far off to the side.

But in the vertical direction Lasers, imho, would be next to useless. The balls will not travel in straight line - they are to slow for that. They will take parabolic trajectory with high point being a function of the exit velocity. If you plan to use visual clues you literally need to have a ballistic chart plotted against distance to the target.

If you plan on staying in the base and shooting all driver preloads you may as well just use a kind of leaf sight, because you don’t care about vertical component.

I thought that pretty much every VEXU team will think about employing some sort of computer assisted vision to correct their fire :slight_smile: