My company wants to move over to robotics and they want me to make it happen. Where do I start??

Welcome to the forum!

If you are looking for a Robot guy then it would be preferable to find someone with experience with your application. If you want to do machining, routing, or laser cutting then ask for someone who has done that before.

Here are a few questions to ask yourself.

How important is accuracy? You mentioned holding a precision of .06mm. A good industrial robot can be repeatable to .06 mm but will never hold accuracy to .06mm. For cutting plastic and sheet metal to a high accuracy then you would be much better off purchasing a CNC. There are also CNC laser machines you can purchase that would be much more accurate than a robot. Have you considered a CNC?

What type of EOAT are you wanting, Drill, Spindle motor, gripper? There are components you can purchase but generally you have to design the mounting plates yourself that attach the motor or gripper to the end of the robot. Then you either need to machine the mounting plate yourself or hire a machine shop to do it for you.

What about electrical controls? Do you have any experience with wiring, 3 phase power, VFD's, I/O? Someone will have to wire power to the robot, wire power to the spindle motor, setup the VFD and IO.

What about Safety? Do you have any experience with industrial safety, guarding, E-stops?

Where is it that you are from? The term to search for is Robot Integrator, Systems Integrator, or Robot Programmer.

If you do a search for precision vs accuracy and look at the bullseye pictures that will give you a good mental image of repeatability vs accuracy. Robot manufactures don't publish accuracy because robots aren't very accurate and it depends on many factors out of their control (such as payload). Generally you can expect an industrial robot to have accuracy around 1 mm. Some are better, some are worse.

For EOAT you just need to select a reputable company that makes spindles and lasers, then fabricate a mounting bracket to attach them. Make sure that the mounting is accurately made and use dowel pins. VFD = Variable frequency drive. That will be needed to control RPM on a 3 phase spindle motor. I/O = inputs and outputs, generally 24 VDC signals to control other devices or receive input from other devices. For example 24V output could control a solenoid valve for a gripper to open or close. Or a 24V output could go to a VFD or motor starter to turn a motor on. 24V input could come back from the VFD to say that the motor is actually running.

E-stop is an electrical safety device, red mushroom head button that stops the robot. If you have other devices like spindle motor or laser you would want to stop them also. Robot not running into wall could be done by safety rated software that limits position. You can review RIA for robotic safety standards.

Honestly, there are not a lot of resources out there for industrial robotics. This forum is the best place to get information. The more you get into it the more specific you can make your questions and get good quality answers back on this forum. Each industrial robot manufacturer has a proprietary system and programming language so it will be important to have the manual when you purchase a robot.

Good luck!

Repeatability vs Accuracy. The "target shot" graphic is particularly useful. Robots are good at repeating motions exactly the same way every time -- even if the motion is wrong, it will be wrong in exactly the wrong way time after time.

Basically, if you hand-program the robot, and keep tweaking the programmed positions until the path is "perfect," that "perfection" will be repeated to within the repeatability limits of the robot forever (or until the robot begins physically wearing out). If you try to go CAD-to-Path, you're immediately in the "accuracy" enviromnent.

Also, compared to CNC machines, robots have a lot more backlash. If you programmed a mathematically perfect circular cut, it'll turn out to be slightly oval. This can be corrected, but requires trial-and-error.

Robots also have much less rigidity than CNC machines. A robot with a cutting laser will be much more accurate and repeatable than the same robot using a spindle, b/c the spindle will induce "recoil" forces that are not very consistent.

I have one of these self-correcting router tools, and one of my ambitions is to find a way to strap it to a robot to do large-scale CNC-ish operations without struggling with the robot accuracy issues. But it'll probably remain a dream forever...

HawkME and SkyeFire , I would like to bring a bit of nuance on the Repeatability vs Accuracy thing. And I invite you to correct me if you think I'm wrong.

Everything that was said is right, but in the case a 2D cutting on a sheet of material, the precision of the part create should be quite good if it's not too big of a part. The absolute precision with respect to the base of the robot won't be good, but the distance between the points should be quite good. In other words, as long as the "XY" plane is define properly and the part is not huge, the cutting path could be shifted 1 mm on the sheet itself, but the part should be quite precise. In a case like that, we are kind of in the middle of the realm of repeatability and precision. Especially in the case of a 2D model where you don't switch for one configuration to the other on the same part.

This is just my personal experience working with offline programming software as we constantly struggle with robot accuracy, we even developed a calibration method using a laser tracker to improve robot accuracy. But if you are working in a quite small work area of an existing piece or if you are cutting on a plain sheet, a good frame definition should do the trick. Especially if the goal is to cut parts to build a lamp.

dodkipod First of all, welcome to the world of robotics. It's such an amazing field where you will learn new things every single day. This forum is, in my opinion, the best resource on the web in the field of robotics. There's a lot of very knowledgeable and active members.

I don't want to look like the guy that push his product (I'm not a sales man, I don't get any commission or anything) but a good way of getting your feet wet without breaking the bank and/of breaking anything physically speaking would be to use a simulation software to get started. There a few software that gives you free trial. You can create your station, create the program, run it in the simulation environment and generate the real robot program at the end.
Some robot manufacturer have their own specific simulator:
ABB -> RobotStudio
Fanuc -> Roboguide
But some are also robot agnostic:
RoboDK, RobotMaster, Octopus, etc.
This is exactly how I started robotics about 10 years ago. I downloaded a trial version and learned a lot (I also did a whole lot of virtual robot crashes! Good thing I was not playing with the real robot!)

RoboDK even have a direct link with Fusion 360, you can draw you laser cutting path in Fusion and automatically transfer it to RoboDK, it will then convert it to a usable robot program in the language required by your robot controller.
Most of the robot simulators will have some kind of Wizard to help you create complex program without requiring the complete robot programming knowledge of an expert.


Have a great day and good luck.

Pay very close attention to safety, especially if you are putting a laser into the equation. There are ISO standards for robot safety, and RIA (Robotic Industries Association) standards as well. Of course, to obtain copies, they will want you to pay for them. Welcome to the wonderful world of robot safety. If you want to buy a new robot, many if not most of those manufacturers are also integrators. You might expect to pay a premium for their services, though. But they should know their own robots and do a good job. Spend the time to clearly define what you will need very specifically from your proposed system. It is very difficult to give a customer what they want when they really do not know what they want. Or if those wants are often changing. Oh, and did i mention SAFETY?

Jeremy you are correct on the nuance of accuracy. It really depends what they are trying to do, small area vs large area, and if dealing with cutting forces from a bit vs laser. The laser tracker calibration makes a huge improvement in accuracy but definitely adds cost.

It will still not be as rigid and have more backlash than a CNC. All depends on how good is good enough.

I forgot to mention that some robot brands have enhanced or "absolute accuracy" options. ABB calls it absolute accuracy. It is a special calibration method for the robot which takes into account things like deflection of the arm and such. ABB also has "advanced shape tuning" for things like cutting holes and what not. I am sure that some of the others have their equivalent.

HawkME Thanks for the confirmation.
And just to clarify, I was not suggesting that a laser tracker system was the solution for this process, just that precision is such an issue that, for us, it was worth developing a solution for it.
But so that you know, the laser tracker is only needed for the calibration process, therefore we have partners that can come on site with their laser tracker for a few thousands dollars. It can generally be done in a day or less (smaller the robot, faster the process). You end up with a calibrated model of the robot (kinematic including flex under payload. * Not under applied force). You can use it to created filtered programs for the robot using our software.
This way you don't need to buy the expensive toy that is a laser tracker.

they use positionally accurate robots (HA or ABS variants)

And/or additional 3rd-party calibrations, like SARCA , or a lot of trial-end error fine-tuning on their CAM programs. Or just raw experience on the part of the CAM programmers -- there's various tricks you can use to minimize the effects of robot inaccuracy over small areas, and with experience you can figure out how to "hide" the worst effects in areas that aren't very obvious, or are easy to post-process "blend in" with some sandpaper.

Also milling foam won't create the cutting forces that wood or metal would. A sculpture could probably be off by a millimeter and a person wouldn't notice.

Robots are made from parts. and all those parts have tolerances (including length of joints!). As long as tolerances are within some limits, those are all good parts and can still be used to make robots. But this still means that every robot made will be slightly different from each other and therefore not a perfect match for model used in software (all robot of one type use same software model, there is no individual tweaking).

So what was just described are so called standard robots (STD). Making tighter tolerances would work better for accuracy but it would mean way more rejected robot parts.

In case of KUKA, robots, two "fancy grade" options are available: HA and ABS.

HA robots are like STD but made from carefully handpicked parts (every part is tested and every now and then you get one that matches design perfectly or at least a lot closer than average part).

So right from the start HA robots (high accuracy) are more precise since they match model much better than average robot units (STD).

This is why if you want HA version, you need to order it as such. To be an HA version, arm must be MADE from those perfect parts which can only be done in the factory. Plus it is not like those fancy grade parts are just sitting around, it takes some time to gather all perfect parts (must run some volume production). in other words if you want HA version of some rare model, it may tage some extra time....

But that was only the first step. The next step is to better measurement of the arm under load to make unique "fingerprint" compensation.

All this means HA robots are like STD but more accurate and a bit more expensive and a bit longer lead time. HA is the top notch, there is nothing better in commercial, volume robots.

Then there are ABS robots. They are basically STD robots in terms of parts tolerances. And while parts are same as standard (and therefore have same tolerances), these robots do get measured to get that compensation "fingerprint" (known as PID file), just like HA models. They get pretty close to HA but without special/rare parts. And unlike HA units, ABS upgrade can be also done on site - just need to measure robot, not rebuild it with rare parts.

Fanuc also offers a high accuracy "Signature" calibration.

When routing wood the robots accuracy doesn't necessarily change but you get effects from vibration, chatter, backlash,cutting forces that can affect the cut quality.

If you can afford higher accuracy then I strongly recommend it. Also buy good quality motors and cutting tools that are specifically made for the material you are cutting.

Wood can be done with good results but requires effort and some trial and error.

Any machining with a robot on any material harder than styrofoam should probably be assumed to need some "spring passes".

There's no hard number for accuracy, although you can generally get the data for a particular robot model from the manufacturer. But that will generally have caveats for payload, inertia, and reach distance, among other things.

In my experience, a 10:1 ratio between accuracy and repeatbility has been a decent general rule of thumb. This assumes no steps have been taken to improve accuracy.

Hi,

that is not a problem you don't have robotic knowledge . There is a big evolution in robotic world to permit anyone to use a robot.

This may imply avoiding complex robots and have a look at robots solution like universal robots, where programming is very easy (you can teach using it on their website) . But that really depends on your needs.

From my opinion, RoboDk is the tool you need for your application, you can first evaluate your project with it and then buy required hardware.

Steph