Newbie- Robot arm for foam and clay sculpting

[fxrtst]

Hello,

I'm new to this forum. I hope some persons in the know can help me if you can find me, this is a huge commmunity (169,000 members and a huge selection of threads!).

Let me first introduce myself. I live in Los Angeles and have worked in the motion picture industry creating make up effects for nearly 20 years. Early in my career I started as a animatronic engineer. Basically you are given an item and expected to make it walk, talk or make toast. I know the basics of servos and controllers thru a PC or RC. The rest of my career involves make up effects being applied to actors to age them or turn them into a monster or alien etc. LOL!

A year ago I bought my first rapid prototyper called the Vflash. I mainly use it for printing make up designs created by an organic sculpture program called Zbrush. I also build film and tv robot replicas and this machine helped me reproduce parts. A Nextengine 3d scanner is used for aquiring actors heads hands or bodies.

Well now I've been bitten by the prototyping-replicating craze. I recently saw this video on youtube YouTube - Sculpting a Large Bust of Bethoven
The concept of sizing up a 3D mesh is extremely useful to me. After doing some research I found several companies that sell second hand 6 axis robot arms. It only needs to carve foam and clay, maybe aluminum parts on occasion. Research has shown that Robot Master and Mastercam together seem to be the easy approach to getting these things to work.

OK so enough commentary. Here are my questions.

1) What size of an arm do I need? Since this thing is only milling foam and clay. I need speed and accuracy. Mill 4 or 5 foot blocks of foam and clay. I don't need a huge 2 ton robot arm.

2) I need it to change tools and a coordinated 7th axis rotary table (any info on this working with Robotmaster would be helpful)

3) Source for foam blocks so I can price them.

4) Does the robot arm need the large refrigerator (computer, controller? Not sure what it is) attached to it? If so how does Mastercam and RobotMaster running on a PC connect and control the robot arm (or does it?)

5) Alot of these robots are built for Palleting and arc welding and painting. Are milling attachments universal to find and add to an exsisting robot arm? Source or link?

6)Thanks for your time answering to a newbie

Will

[awerby]

Hi Will, welcome to the Zone! It sounds like you're pretty much up to speed with the modeling side of all this, but new to the machining end. There are several reasons why more people don't use robot arms for
carving, although it has been done to some extent. First off, they don't have much mechanical advantage or rigidity. Both are things that really help when dealing with carvable materials, and the harder the materials are, the more you need them. The arm in your video wasn't exactly a light-weight machine, but it was only capable of carving light-weight materials.

The second factor is the software. In order to take advantage of all those potential axes, you need some very powerful CAM software. It didn't look like the toolpath being executed in your video was any different from something that would run on a regular Cartesian machine with an additional rotary axis, but you would have to pay a lot more for the software that would tell it what to do. The math just gets a lot more complex with each rotary axis you add, and if all the axes are rotary, you're locked into some pretty expensive software.

The third factor, and the one that's kept me from jumping on some good deals on robot arms that have come up, is safety. Okay, I confess I'm a chicken, but I'm still a live chicken.

I've seen regular routers do odd things unexpectedly, but have fortunately been out of their reach when they misbehaved. These robot arms, however, aren't confined to an easily observable danger zone; it seems like they can easily reach out and smack you - in which case, you'd stay good and smacked...

But if you're undeterred by any of this....]

OK so enough commentary. Here are my questions.

1) What size of an arm do I need? Since this thing is only milling foam and clay. I need speed and accuracy. Mill 4 or 5 foot blocks of foam and clay. I don't need a huge 2 ton robot arm.

[I think you might, if you're to get an accurate surface. And I've never heard of anyone milling clay; I don't think that would work too well if it was wet, and if it was dry it would be hard on tooling as well as extremely messy.]

2) I need it to change tools and a coordinated 7th axis rotary table (any info on this working with Robotmaster would be helpful)

[You might call Robotmaster and ask them about that.]

3) Source for foam blocks so I can price them.

[Here are some links:

Foam Sheet: General Plastics Manufacturing Company

Elliott Company, Manufacturer, Fabricator, ELFOAM, Polyisocyanurate and Polyurethane Foam Products

Dimensional stability, machinability-Precision Board Plus HDU ]






4) Does the robot arm need the large refrigerator (computer, controller? Not sure what it is) attached to it? If so how does Mastercam and RobotMaster running on a PC connect and control the robot arm (or does it?)

[MasterCam is just a software program; it writes the toolpath G-code program but doesn't directly run a CNC machine. It seems like Robotmaster is essentially a plugin to MasterCAM that allows it to deal with the peculiarities of robot arms, but it doesn't actually run the arm either. I think you'd have to rely on the original (refrigerator-sized) controller/driver for the arm you selected to interpret the code and actually move the arm.]

5) Alot of these robots are built for Palleting and arc welding and painting. Are milling attachments universal to find and add to an exsisting robot arm? Source or link?

[There are reasons, touched on above, why they aren't used for milling very much, but there are companies that will provide spindles for them. Here's one: PushCorp - The Leader in Force Control Tooling ]



6)Thanks for your time answering to a newbie

Will[/QUOTE]

[No problem, Will - let us know if you really get one of these things, and how it goes with that, okay?]

Andrew Werby
ComputerSculpture.com — Home Page for Discount Hardware & Software

[mcphill]

Look here for a software solution:

Milling Robot - CAD/CAM for ABB Robots

You feed it "normal" 3-axis gCode, and it will convert it to robot script. It only works on certain ABB robots, though. You can also find a source of used robots (they have a US location too) here:

industrial robot,industrial robots,abb robot,robot part,pick and place,used robot,kuka robot,fanuc robot,global robots UK,robotic system,robotics equipment,robotic system integration,industrial robot UK,industrial robot UK

Budget will be a factor. The software is around $7500, the robot will run from $5000-20000 or more, depending on size, capacity, etc.

As for tools, I would think you could attach a "normal" router to the end of the robot, and go from there. You state you need automatic tool changing - that will be a stretch unless you are really creative in mechanical design...

[fxrtst]

Thanks for the incoming info. After a little more research I've found a chap in Australia that does the same line of work as me and has adopted some of the same techniques that i am trying to start here in LA. He uses a Thermwood 5 axis router. The advantage of the robot arm is on mid scale objects you can move all the way around the object as opposed to the Thermwood where you are forced to bisecting (or more) the object to be milled. Not a problem just a little more time consuming:

http://www.youtube.com/watch?v=3_ZzD...?v=3_ZzDVA-PuE


Andrew, I did in fact find several You tube videos showing car companies milling a form in foam, covering the foam in 3/4 inch of clay and re-routing that for a clay surface that could be smoothed or extra detailed applied by craftsman. John Cox in Australia also uses the same technique here:

YouTube - Thermwood - 5 Axis CNC Router at John Cox's Creature Workshop
YouTube - Thermwood - 5 Axis CNC Router at John Cox's Creature Workshop creating Big Girl Character
Any really good leads on where to find used version of one of these machines, so I cost compare. Thanks in advance.


Will

[GaboSana]

I believe the robotic arm has unlimited activities that it can do. I too am seeking to purchase a industrial arm to carve on wood, concrete and metal. In italy, they use the arm to carve on marble, making statues. That is amazing. [Does anyone know about the robotic arm? A place to purchase affordably, cause I've been seeing high end in the 80,000. I could affor maybe 20,000 or less.

[mcphill]

Originally Posted by GaboSana Does anyone know about the robotic arm? A place to purchase affordably, cause I've been seeing high end in the 80,000. I could affor maybe 20,000 or less.

Did you follow my link?

Used Industrial Robots sales and purchases: ABB, KUKA, FANUC available at Global Robots Ltd

20,000 what? US Pennies? Lira ; ) Euros?

[awerby]

But that doesn't include the software you'd need to actually get them to do what you're talking about, nor the integrated rotary tables pictured in those videos.

Andrew Werby
ComputerSculpture.com — Home Page for Discount Hardware & Software

Originally Posted by mcphill Did you follow my link? Used Industrial Robots sales and purchases: ABB, KUKA, FANUC available at Global Robots Ltd 20,000 what? US Pennies? Lira ; ) Euros?