Robot for CNC Wood Milling

[Andreas Renz]

Hy Guys,

I'm new in the RobotWorld and I'm looking for some advice. I have a small Woodshop making Furniture and Woodenobjects. I have quite some experience in 3 Axis CNC Milling with Fusion 360. Now I would like to buy a Kuka Robot for bigger and more organic Objects. I could buy a Kuka KR15/2 with a KR C1 controller and I would like to stay on Fusion 360 if possible. Am I on track???
Do you have better ideas or recommendations? Is the Kuka 15 strong enough for efficient milling?

Thanks for any input.

Andreas

[Johannes @ Robots in Architecture]

Hello Andreas,

I wouldn't recommend a KRC1 robot, first of all it's limited in regards to memory, but to my knowledge it also does not comply with the current machine safety regulations. So at least in Germany you couldn't set up a new KRC1 robot legally, you could just replace a robot in an existing cell. That might be different depending on where you are. I'd go for at least a KRC2 ed05 (runs Windows XP, supports USB sticks, larger memory, etc.)
We had some fun milling with a KR16 robot and a cheap Kress 1050 spindle which actually worked quite OK. If you've got the space for a larger robot, it actually shouldn't be more expensive than a used KR16 or similar and with it's higher weight it should be more accurate (less vibrations) while also allowing you to produce larger pieces and mount stringer spindles.
Most nice spindles with a HSK holder weigh more than I would feel comfortable mounting on a 15kg robot.
Through KUKA|prc you can postprocess your Fusion G-code into KRL.

Best,
Johannes

[Andreas Renz]

Hello Johannes,

thank you very much for the answer. Helps a lot. I already noticed that larger robots really are not more expensive, but space is a issue (at least for the moment). But as you recommend, I will definitely look now for a Robot with a KRC2 ed05. Now I have to make some space and go on.

Best,
Andreas

[SuperFly]

Giving the fact that more than 2 years have passed since the initial post on this thread, I would like to get an update if you've managed to get yourself a robot? I think a lot of us started dreaming about having a robot after the Terminator movies. At least, that was the moment when I started thinking about ways how to get it. It brings me a lot of happiness when I hear that there are people who are as passionate as I am about this. There is nothing you can find about robots at www.gardenfurniture.co.uk, but you can definitely find some of the best garden furniture available on the market.

[Woodboss]

Hi Johannes.
Where can I find out more on how to process GCode into KRL using KPRC?
That would potentially release me from the constraints of my little 300X400 router, and let me use my Kuka KR200 for cutting, welding etc toolpaths generated using DeskProto.
Best regards,
Charles.

[Johannes @ Robots in Architecture]

Hello,
It's pretty straightforward, we include a custom postprocessor for Fusion 360 that generates files that you can then read through a component that comes with KUKA|prc.
We've also got a generic G-Code component, but as G-Code is only poorly standardized it might need some adaptions to work.
What CAM-software are you planning to use?

Best,
Johannes

[Woodboss]

Hi Johannes,

I've not found a component in my KPRC relating to G code. Perhaps It's only included in the professional version?
DeskProto CAM software is my favorite, really user friendly and with a helpful forum - I found Fusion to be a big can of worms...
I've not done anything (yet) with postprocessors.

Best regards,
Charles.

[Johannes @ Robots in Architecture]

Hello Charles,

Yes, it's only available in the member version. If you want to give it a try, send me an eMail (johannes@robotsinarchitecture.org) and I'll provide you with a temporary license!

Best,
Johannes

[harueg]

Hello Johannes
I've just read through this post. For the safety issue, are the KRC2 robots safe ? I thought you need some " safe edition " from Kuka.
The videos from Karl show a great trust in the safety of the robots. My thinking was, that there is always a cell needed.
I gladly noticed, you've added the KR200 comp to robots configuration.
Are/will there be splines as output in KRL supported. I heard this would eliminate some path precision problems.

Best regards and happy Easter

Harald

[harueg]

Me again

Can it be that I didn't find anything easy to define the tool diameter offset ? Do I have to to offset a line with d/2 and use that line for TCP ?  What about depth cuts ? The same, multiple lines copied in Z direction ?
What G codes would get imported ? 

Thanks again

Harald

[Johannes @ Robots in Architecture]

Hello Harald,

Most safety regulations are national, so what I'm writing may not apply to you. In Austria, a robot is considered an incomplete machine that then needs to be certified once it's equipped for its particular task. Often, that means building a cell around it. In particular when you are milling, for me the main risk is not so much the robot but flying debris, broken milling bits etc.
KUKA also sells software packages that provide extra safety features.
In our case, we are operating robots within the scope of research and development, so there are no specific requirements in that area.
Regarding videos that you see online: There are probably multiple rehearsals before doing anything potentially dangerous.

And regarding your other questions: Spline output is supported but not necessarily recommended as the CAD-splines do not match exactly the robot-splines. And tool offsets etc. need to be considered in your CAM software or your Grasshopper pathplanning!

Best,
Johannes

[harueg]

Hello Johannes

Thanks for your in-depth answers !
For tool path planning, there is no grasshopper module for that ? This would be a mere offset in the 2,5 D range, but in 3 D with a ball mill, you would also have tool contact point, which differs from the TCP.  Are there any plans to implement anything like this ?

Best and thanks

Harald

[Johannes @ Robots in Architecture]

Hello Harald,
With KUKA|prc we only act as the interface to the robot. I'm not sure if there is a mature CAM plugin for Grasshopper, but of course people have realized extremely complex scripts for milling that incorporate all these features. It's just that they are often very focused on one specific application, rather than generic purposes by other users.
We - as Robots in Architecture - have no plans at the moment to develop CAM solutions that are natively integrated into KUKA|prc. We would rather provide slick ways of getting toolpath data from a dedicated CAM plugin to KUKA|prc.

Best,
Johannes

[steenblikrs]

I am trying to plan a robot cell for my university. We are thinking about getting two KR210's and an LBR iiwa for collaborative working. I am wondering about standard end effectors, or  End of Arm Tooling (EOAT). I have seen people using Sematek brand, but I am finding it difficult to find a quick price quote for such things. Is there a market where I can compare different brands, etc? If there is anyone with a recommendation of a good supplier I would greatly appreciate it.

Someone else recommended a  9kw hsd spindle with hsk63f tooling, but I am not sure of a reliable outlet for purchasing any of these options, nor am I aware of the other elements I will have to purchase in addition to the spindle itself.

Thank you for your help in advance!

[Johannes @ Robots in Architecture]

Hello,
Unfortunately that's a major challenge for robotic arms, there are hardly any standard tools, usually you need to build at least an adapter plate to e.g. mount a gripper to the robot. UR had a pretty good idea with their UR+ platform (https://www.universal-robots.com/plus/products/?) however even that does not contain prices.
That's one of the reasons why robot integrators make good money, as they offer a package price and deal with all the details. Of courses that's quite a bit more expensive than doing it by yourself.
Regarding the spindle: Usually you need the spindle and a fitting inverter. The opening/closing/cleaning... of the spindle is done via pressured air, so you need digital outputs at the robot and connect them to valves. Often, the spindle also needs a 24V power supply, e.g. for the fan or for operating certain buttons. And a lot of cables!

That should give you an idea, the complexity of the integration of the spindle depends mostly on the chosen inverter, many of them are a huge pain to program. Especially with a spindle I would recommend to get one without too many fancy functions that you don't need but make the handling more complex.

We're currently using an HiTeco spindle, I've also seen plenty of HSD spindles. For robots, they usually recommend the long-nose variants.

Hope that helps a bit with estimating the effort of integrating a spindle!
Best,
Johannes