Posts by TheFabricator

    I plan on fitting DMM Absolute encoders to the Yaskawa motors and using their new EtherCAT servo drives. I am working on a LinuxCNC configuration that is specific for six axis robots. It will have dynamic compensation and singularity detection.

    I agree that the duty of care lands with the employer. What kind of employer would let an incapable person operate a welding cell if the parts where critical without any previous experience. I dont know what kind of company the OP works at, but in my workshop I would not let a guy weld parts that I was not 100% certain that they could do the job.

    Formal education does help but I have employed people who are qualified that I would not let weld certain jobs. They had the paperwork but could not do the job well enough - either because they were lazy or just not capable. Maybe the OP's employer has faith in him to pick it up.

    Could I compromise and put Air craft Stripper all over their existing paint jobs, scrub it off and repaint at that point?

    Yes, yes you can. They are your robots do as you like. Although I would not put paint stripper on them, it could end up inside a gearbox or melt the wiring.

    If they were mine I would de-grease, sand back the areas that need repainting, maybe a light sand on other areas. Remove all cables that might be in the way or at the least mask them and tie them back. Mask the servos, connectors, pivot points and anything not to be painted like end effector mount and apply a decent etch primer and then a top coat. I am sure you could do that easily with spray cans if needed.

    I have a UP6 in need of repainting. When I finish my LinuxCNC retrofit I will repaint it properly.

    I find it funny that people smart enough to have a robot are not sure about how to secure it down. Sometimes you just need to go with your gut feeling and beef up the factor of safety, its not like Grade 8.8 M20 bolts are expensive. Replace the M8 bolts with something bigger like M16-20 or do that and chemical anchor the bolts to the concrete.

    I want to build and program the robot as far as possible in the same way as it is done in industry. The robot should have six servo motors for a free choice of the orientation of the effector. Which parts should I buy for this? Should I buy some small servo motors and 3D-print the arm parts and program the controller with an AVR chip? If so, which servo motors should I buy, how should I wire the servo motors, etc? And I don't want to do it with Arduino at all, because I want to learn how something like this is done in the industry.

    As a basic beginner you need to start small. Well I did not and spent 10K on a used six axis robot but looking back I should of started small.

    Have a look here,

    Chris has plans for a open source small six axis robot. It can be 3d printed or you can buy an aluminum part kit.

    If you don't have a ticket, they shouldn't have you welding at all tbh - now I know regulations differ but that's pretty dangerous. I've been dealing with a welding robot for almost a year now and just got my ticket, but I've been lucky enough to have a fully experienced welder operating the thing while I just program and troubleshoot.

    I'd ask your company for a welder.

    I think its a long stretch to say its dangerous to have him welding without a ticket. I am a trade qualified boilermaker but I have employed plenty of guys who can "just" weld. Once I teach them the basics they can produce "safe" welds in a couple of hours. Is it ideal - No but thats the real world. Will they kill anyone - again No because the weld I have them do are not critical. One of my brothers is a pressure welder. All his welds are x-rayed and if any defects detected he grinds the weld out and re welds. But they ARE critical welds.

    As far as learning how to set the welding parameters for the welding robot goes, nothing comes close to real world practice. Get hold of some scrap metal and go to town with different settings. Try different angles, travel speed, wire speed and amperages. Produce some welds and talk to your welders about how the welds look. Once you get some good looking welds try breaking them apart. Look at the penetration and for defects like porosity. Also pay attention to the sound the welder makes while welding. Good welds have a "sound" and when you hear something different its time to have a good look at the weld.

    Also these days its easier than ever to learn the basics of welding. Spend some time on Youtube and you should be able to learn the very basics in a couple of hours.

    I have spent considerable amount of time researching retrofitting old industrial robots with new control hardware.

    A few things,

    LinuxCNC will work but not in its current state. It is not designed for six axis robots, well not yet!, See my retrofitting thread,…546-motoman-k6sb-retrofit , I will in the next year finished my six axis robot configuration for LinuxCNC.
    The main problem with LinuxCNC is it does not allow for the dynamics that a open chain manipulator imposes. I have written some components that do that and detect singularities and such.

    The biggest hurdle you will face with your ABB manipulator is re using the AC servos. As long as your current servo drives use industry standard control signals then you should be OK.


    I am new to robot programming but not to CNC machines,

    With the Inform II language used by the NX100 controller, Am I able to program a request for a external servo to move to a certain position? If not how would I go about moving a external servo to a position I want to define and have the program be able to play back that command.

    Any help will be greatly appreciated.

    Ok I will read up on position control, I will be using modbus but I can use Digital I/O with this drive it seems.

    How do robots usually program external output movements into their programs? Can I request a position command and have the servo go to it or is the ability to program the output more limited.

    I have a Motoman robot with Inform II programming language.

    Thanks for the reply,

    I am using a 1kw Hiwin AC servo that has a Hiwin D2 servo drive.

    I plan on using the servo to move my robot on a linear rail I have built. The robot and track will be used to weld trusses. I plan to move the robot to a working position, hold it there while the robot welds all of the weld seams in its working envelope then move it to the next position and repeat.

    The drive has a modbus compatibility, Digital pulse-direction interface and analogue ±10 V interface, Position control, speed control and torque control, Inputs/outputs can be parameterised.

    Hi All,

    I posted this in the Yaskawa forum but I might get some responses if I make the question a bit more general,

    How can I go about controlling a AC servo motor to move to a position and hold using I/O communication from a robot controller?

    Can someone please give me some kind of idea of what steps I would need to go through.

    Hi all,

    I have read on this forum that it is possible to control a external servo using the I/O communication from the NX100 controller,

    How do I go about doing that? I understand I wont be able to use it as a external axis, I just need the servo to index the robot to a working position and hold it there.

    Hi All,

    I am looking for guidance in the design of an open source robotic controller.

    I have many older robots, Mostly ERC era Motomans that are in good condition mechanically but the control hardware is horribly obsolete.

    What I would like to accomplish is to design a robot controller compatible with ROS Industrial that can control the kinematics of my six axis robots.

    Can anyone recommend any books or resources that can give me an idea of what is needed to control a industrial six axis robot.

    I am fully aware that each robot will be different, different servo motors, different kinematics,

    I would like to have hardware in place to be able to control six axis robots from all manufactures, not necessarily in factory form, as with my Motomans the Yaskawa Encoders on the motors do not have a standard pulse output.

    I will change the motors to standard ac servos that output a common encoder signal.

    I realize this is a big undertaking but once finished will allow me to deploy mechanically old, good robots that I can buy for scrap value.