Cross hair for shooting

we dont really have the choice of programming the robot to line up a shot and so on with the reflective tape, we dont really have a great programmer there new to it. my question is is it possible to just program a cross hair on the camera where the balls land, would it be easier this way to code?

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Well for the driver station to accurately display where the balls will land, you need to know the distance they will travel. Usually this is done by using the vision targets, but if you don’t have that option, I don’t see a way to do this as described. After getting a feel with the robot though, drivers can kind of guess where the ball will go, but that’s not always super accurate.

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My memory is extremely spotty on this, but when I was a driver in 2012, I am pretty sure we had a crosshair on our camera feed. We also had vision targeting, but only for speed.

Edit: posting this to maybe help jog someone else’s memory/get a sanity check–I am not sure if we actually had that crosshair!!

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Yes but not how your thinking of it. To do that you need position, or distance and angle. If you can sense all of that accurately and know enough to transpose that via cross-hairs then your know enough to do any kind of vision. your best bet with no additional programming may be just a light that you can shine on the target for alignment.

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The simplest solution would probably be to pick one spot on the field, ideally next to a hard surface you can line up against. Then you can tune your shooter for that particular shot’s range and elevation. Then you can tape a piece of transparent film with a crosshair literally painted on over the driver station’s monitor roughly where the center of goal is when you’re in your spot.

It’s not a great solution but it involves minimal programming.


The “camera feed + sticky tape + pencil” method of adding crosshairs is tried and true, oddly enough.

You may also want to consider a flashlight.


As the user Chris_is_me said flashlights are great. A lot of teams used them in 2016 so their drivers could line up their shot. Essentially you adjust it to shine on a certain area of the goal and know when your light hits said area your shot is accurately lined up.


Came here to say this, find a shot that works well for you, mark a center line for the goal and another horizontal line that matches a field object(bottom of the goal, etc) to set distance. Or other markers to help get into the right spot. Running into field objects is another good way to set a known distance from the goal.

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Here is an idea, I prefer driving from seeing the robot not a camera as much as possible.

You could use a square beam flashlight and rotate it so a point is up. This can be angled to the flight path of the ball. This will allow the driver to lineup easily without looking away from the robot. You can use a spike or relay to toggle it on or off, allowing it to be legal. I don’t currently have the product that we used, Andy mark has one but my experience with it isn’t the best. Basically you want a bright, 12v LED flashlight with a square reflector.

This solution also fixes distance issues, since the light diffuses as you get farther away so based on the square size you can gauge distance.

We used something similar in 2016, with great success. My team didn’t come up with the idea, so I cant really take credit. You can see us using it here at 1:45 ( we also used it to line up from the outer-works but I cant find a video of it.

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First things first. When you place your robot in the “ideal” location for shooting into the goal and you take 10-20 shots, how much “spread” do you get? If the spread is as big as your target or greater, no aiming method will guarantee the ball goes into the goal.

Highly recommend the “Photon Cannon” alignment method of using a flashlight and just use that.


in 2012 we had a pneumatic launcher

the programming was set up so that we had several positions to line up in and a cross hair to align the launcher arm with the desired hoop.

Then we would press the button for that position and it would fire the solenoid for x many seconds to achieve the distance.

This worked really well for us as a low resource team. We could even consistently score autonomous with great care from those who set the bot on the field. The only issue was we had so many different autonomous programs and it was a pain to set the desired one.

My team just made it in a art program and then just put it wherever we wanted digitally on the camera feed.

You could program a crosshair on the camera view, but it would honestly be easier to put a sight directly on your launcher. I recommend picking up a standard 3-dot sight or red dot from an airsoft shop or the like. They’re precise enough to aim at targets from over 100 meters, so you should be more than fine for the close ranges in the competition. You’ll need to dial in the scope (sometimes called doping the scope) to make sure it’s set up for the ranges you will be firing from. Just know that if you fire from closer than the selected range on the scope you’ll need to aim low and if you fire from further ranges you’ll need to aim higher.

I wasn’t there for it but I believe in 2016 our team put blue painters tape on our driver station laptop. They acted like crosshairs and apparently they worked relatively well

In 2012 our camera was exposed to be hit by stray shots so we took an empty plastic jar (peanut butter, I think), cut out part of one side, and turned it over to cover the camera and its mount. I am not sure why, but some one was hot gluing something to the jar (may have been to tie down a wire) and purely by chance a thin line of hot glue dripped, stretched and dried vertically over the opening through which the camera was looking. It turned out to be perfectly placed on the driver station feed for guiding horizontal alignment to the goal.


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So, never having played with airsoft Scopes, do they cast a focused beam like a laser pointer? We are using Cross hairs on the limelight, but possibly having something more world help.

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