Hello Everyone,
I am in the field of mechanical engineering and I am aiming to get very accurate cuts from my laser. For some of my applications a laser can do what a mill cutter cannot: very thin cuts and cuts with sharp angles. I performed different test cuts and my machine is good enough to do what I want to do. Then, I started to evaluate how to position accurately a cut on a workpiece (with an accuracy better than 0.5mm just to give an order of magnitude). I started using a camera placed above the work bed, but the picture is too blurry to be precise even with a 8MB camera (I created a post about this). Then I decided to use a head mounted camera with a cheap 2 MP camera. With this type of camera it is easy to see all the details you need. I evaluated the head mounted camera feature from LB V1.4 which is an experimental feature and this is not the way to go for these kind of application either (I created a post ). Then finally I decided to use the head mounted camera with a crosshair (some people are using a laser crosshair to position their jobs but the laser beam is too thick for what I am looking for). Some people here are asking for the camera crosshair functionality but LB is not offering today the possibility to have a crosshair overlay in the camera view. Therefore I evaluated two different solutions: a crosshair reticle mounted on the camera and a software crosshair using an external webcam application. I would like to share my findings as it can perhaps help you and can be helpful to some extent for LB to improve their product.
The conclusion of my evaluation is that having a crosshair in the camera view is a precondition for accurate positioning but this is far to be enough as LB is suffering of many weaknesses that needs to be solved to get something really handy. Nethertheless you can achieve what you want, you have to go very carefully and slowly with the bare minimum offered by LB.
Solution 1: Using a crosshair reticle in the camera. I will not detail how to make it here but it is rather complicated to build a compact system due to space limitation and collision risks wih the machine structure. The main issue is that once you have your crosshair in the LB camera view, if you want to enlarge the “camera control” window to get a larger picture, the Width/Height ratio of this window is not locked. Enlarging keeping the same ratio is difficult and you end up with a deformed picture. Then I identified several LB limitations that I will describe below with the second solution based on a webcam software.
Solution 2: Use a webcam software with a crosshair overlay. This is rather simple to implement and allows a very accurate positioning. You can jog the machine where you want. With the “Laser offset” in the device setting menu you can compensate the difference of position between the laser position and the crosshair position. This is working well and I can cut now where I want. This is the bare minimum. That being said, once you are at this point, you start to see all the LB limitations that are hitting you:
- “Frame”, “Center find” and “Print and cut” are not compensating the position offset (Print and Cut TBC) (major/severe issue)
- you can jog very accurately to a position, you can save it. What is missing is a button to directly save the jogged position in the “Saved position” list (minor limitation)
- you cannot display the list of the “saved positions” in the LB workspace. It means you can probe your workpiece but you have to manually draw all the positions one by one in the workspace. (very ennoying/frustrating because you could do much more with this)
- As you are not using the head mounted camera postioning system for all your jobs, you don’t always need to apply the Laser offset. When you are switching to a new job, nothing is indicating in the UI that the Laser offset is On or OFF. And “Frame” is not helping you as it does’t compensate the offset. You are easily cutting somewhere else. What is missing is an indicator that the offset is ON/OFF and a way to directly turn it On or OFF.
- Don’t use AT ALL the LB camera alignment wizard with a head mounted camera and an external webcam software. You are going to be in trouble if you use the “update overlay” LB is not designed to have two types of camera installed in the machine and to swtich easily between them in the machine context.
These are my main findings, it is not an exhaustive list. The conclusion is that adding an overlay with a crosshair in the camera view is a precondition but it is not enough as it is the global process to probe a workpiece/several posiitions that has to be considered. Today you can use an external camera sofwtare but you need to be extremely cautious using the “Laser offset”. This function is OK but only for a basic usage.
Hope it will help you and happy to get a feedback if I have missed a function that could make this process easier. I am using LB V1.4. I checked the improvements in LB V1.5 but nothing has been done yet in this direction .