Mobile Manipulator Robots for Un-Bounded Rapid Prototyping

Mobile manipulators for infinite rapid prototyping

Giant 3D printers are cool, but they have fundamental limitations: the parts they can build are limited to the volume of their finite workspace. Let me propose an alternative. What if we gave mobile manipulators a "toolbelt" of rapid prototyping utensils so that our general purpose (home!) robots are effectively on-the-spot machinists capable of building almost any CAD design?! Actually, there's some compelling evidence that we're closer to this vision than one might imagine. In the interim, I think there's some great low-hanging fruit around this idea.... if only there was a diligent robotics researcher (i.e. not me) to pursue it. Any takers?

In the last few years, we've witnessed a number of "smart tools" for us meatbags. These tools let an ordinary person (like me) do precision manufacturing without precise (micro-meter) control. Some of my favorite examples:

HandiBot CNC Cutter HandiBot CNC Cutter

The Handibot is a man-portable CNC cutter that will cut or carve complex shapes (arcs curves, holes, or even straight lines) into any surface upon which it is placed.

User-Guided Precision Router with CPU Assist 

This router localizes itself on a piece of wood and helps guide (and correct) gross human motions to produce precision cuts over a large area. Developed by a group of MITers and presented at SIGGRAPH.

FreeD hand-held milling machine 

FreeD is a handheld milling machine that turns on-and-off the milling bit based on where where the bit is in 6-DoF space (obtained via Polhemus). This lets a person move it around in freespace, while a computer controls the actual cutting.  Also developed by a group of MITers and presented at UIST.

3Doodler Handheld 3D printer 3Doodler Handheld 3D printer 3Doodler Handheld 3D printer

The 3Doodler is a handheld 3D printer. It's sorta like a glue gun, except that it melts and extrudes ABS plastic. It was done by WobbleWorks (including Peter Dilworth, the roboticist that brought us Troody), and had an amazingly successful Kickstarter. Oh, and here's a cool tear-down.


Just like a human... you could give these tools to virtually any mobile manipulator to instantly turn the robot into a precision manufacturing machine -- often with better precision that the robot's own actuators. And don't forget: The robot could also possess it's own on-board 3D printer to build new tools on demand!

This idea certainly isn't new -- it was discussed often during my grad school days, which virtually guarantees that it has been a topic of conversation for a few decades. But the key is: you don't even have to imagine. We're at the stage where these technologies are quite approachable, as the above technologies demonstrate.

In fact, Bosch (the company behind the iconic Dremel) was a participant in Willow Garage's PR2 Beta program. During the program, and with very little fanfare (and no press coverage?), Bosch engineers had their PR2 use a dremel to mill a piece of wood -- and it's all released as open-source in the pr2_dremel ROS package.  Workshop paper at IROS 2011.

Bosch PR2 using a Dremel: Mobile Manipulators can be used for rapid prototyping  Bosch PR2 using a Dremel: Mobile Manipulators can be used for rapid prototyping  Bosch PR2 using a Dremel: Mobile Manipulators can be used for rapid prototyping


In the future, your robot could to build (and recycle?) almost any household object for you! I think this idea is ripe for prototype demonstrations. I'd love to see someone make it happen!




Some people mount pens and even cutting tools to their hexapod walking robots, enabling them to do CNC. Example video: Hexapod Robot CNC Router - Cutting 3D face

"Geoweaver" is a recent experimental extruding-3D-printer with legs, effectively giving it an infinite build area. It even automatically compensates for sloping ground. Here's a video of that: Geoweaver: A Walking 3D Printer Hexapod