CNC Milling with a Fanuc Robot

[MBX5]

Hello... We are a robot integrator and want to experiment with a Fanuc robot and a spindle to attempt some CNC milling / drilling, etc. I know that most 6 axis industrial robots arent repeatable enough, or stiff enough to use for milling applications....however the robot I want to experiment with is a Fanuc S430iCF - it is an extremely stout, extremely stiff robot with a very heavy payload - I think it is stiff enough to do some light duty machining....the repeatability is something I can deal with...I should be able to get +/- .008 with it which should work fine for us.

We dont really know much, if anything, about CNC machining - we considered buying a standard VMC for our in-house needs, but wanted to try this robot first to see if it will do some of our machining for in-house projects....most of our tolerances arent too strict so we can probably live with most of what it can do...

We have to select a spindle motor.... I have Fanuc servo motors here but most cap out at about 2hp and 3000 rpm...I have some other larger motors that are about 5hp and only 2000rpm that I suppose I could step up..?

My question is for general aluminum machining and possibly some mild steel, what kind of HP and RPM should I be looking at? I want to avoid spending $20k on a spindle and drive if at all possible... I would like a pneumatic collet (for auto tool change) to use 40 taper adapters, much like with what Pushcorp has...

I plan on using what I develop in Solidworks to run through either Robotworks or RobotMaster post processors to get the robot code....

Any spindle advice and info would be appreciated...

Thanks!

[Andre' B]

I have written exactly one program for a robot and that was in school, some old worn out Puma, so given that.

I would look at a high quality die grinder.
www.airturbinetools.com
They have some that are intended for the kind of use I think you are looking at.
Probably start with one at the slower RPM end of their selection.

I would start programming it so the cut is a lot like how a human would use a die grinder with a carbide burr to cut AL, lots of light passes.
Basically high speed machining techniques.

YouTube - VIBRA-FREE High Speed Aluminum Machining

YouTube - VIBRA-FREE High Speed Aluminum Machining

[boilerbots]

I have seen Kuka robots sold that for just this type of application. Maybe you can get their specs and then find a spindle that matches what they where using.

I saw them running demos in Japan last year, but the demos where machining wood.

[boilerbots]

Maybe you can find out some information from this site and their videos.



This is not the robot I saw, I think this could mostly be done without the rotary table.

[PhoenixMetal]

Hi MBX5, well while the robot may be capable of doing what you want, I don't think this is the best route to go. The power and versatility of machining centers comes very much from the software that is used to generate the toolpaths.

Great machining CAM software like MasterCam is the most important portion of the machine+control+software equation in my opinion. It is through this software that you look at your part (that you may have created in solidworks) and decide what pattern the cutter will take, and here you get to tweak myriad different settings and options that come together to make intelligent toolpaths that create your part.

I don't think that any of the popular CAM software packages have the capability to write code that a robot would follow.

So, trying to do machining with your robot, you will be working way harder than necessary, having to reinvent the wheel by figuring out how to program all the different toolpaths. At best, you would be able to come up with some really rudimentary toolpaths - perhaps equivalent to what people do who manually type out their G-code to run their machines. But you will not be able to pull off the highly sophisticated work that comes effortlessly from using a great CAM software package with a machining center.

Used machining centers are really, really cheap these days since there seems to be about two auctions every day from automotive-related plant closures. If it is important for you to add this capability, I'd recommend you just get a machining center. Trust me, there will be a tough enough learning cure with that alone - let alone trying to figure out how to program a robot to emulate one!

[TylerRobertson]

Originally Posted by PhoenixMetal Hi MBX5, well while the robot may be capable of doing what you want, I don't think this is the best route to go. The power and versatility of machining centers comes very much from the software that is used to generate the toolpaths. Great machining CAM software like MasterCam is the most important portion of the machine+control+software equation in my opinion. It is through this software that you look at your part (that you may have created in solidworks) and decide what pattern the cutter will take, and here you get to tweak myriad different settings and options that come together to make intelligent toolpaths that create your part. I don't think that any of the popular CAM software packages have the capability to write code that a robot would follow. So, trying to do machining with your robot, you will be working way harder than necessary, having to reinvent the wheel by figuring out how to program all the different toolpaths. At best, you would be able to come up with some really rudimentary toolpaths - perhaps equivalent to what people do who manually type out their G-code to run their machines. But you will not be able to pull off the highly sophisticated work that comes effortlessly from using a great CAM software package with a machining center. Used machining centers are really, really cheap these days since there seems to be about two auctions every day from automotive-related plant closures. If it is important for you to add this capability, I'd recommend you just get a machining center. Trust me, there will be a tough enough learning cure with that alone - let alone trying to figure out how to program a robot to emulate one!

Phoenix - you're absolutely right, but that's where Robotmaster software comes in

It's a total conversion software for Mastercam which allows you to use any of the machining techniques found in Mastercam, on your industrial robot. It has built in functionality for avoiding kinematic errors associated with robots, as well as controlling external positioners (gantries, rotary tables).

It works really really well for exactly this type of work, and a considerable amount more.

[TheBigJW]

Originally Posted by TylerRobertson and a considerable amount more.

Is what your going to pay once you start using Mastercam. Dealers crank prices once they get enough users on board. Our dealer upped their price list almost 40% a couple of years ago.

If you are in Canada you will save a substantial amount if you can somehow buy through a US dealer.

John

[TylerRobertson]

Originally Posted by TheBigJW Is what your going to pay once you start using Mastercam. Dealers crank prices once they get enough users on board. Our dealer upped their price list almost 40% a couple of years ago. If you are in Canada you will save a substantial amount if you can somehow buy through a US dealer. John

Guess where Robotmaster is developed