Contest Entry Beetlejuice

[WGhost9]

Abstract: Beetlejuice is a beetle-shaped hybrid vehicle. It will be able to travel by either wheel or foot and navigate by either sonar or remote control.

Inspired by the Chiba Institute of Technology’s robot, the Halluc 2, I am building a roller/walker hexapod called Beetlejuice. The wheels, powered by continuous servos, flip up to bring rubber-tipped feet down on the floor. The legs will be powered by 333oz/in and 168 oz/in servos.

Beeltejuice will initially use an Atom Pro 28 controller for initial testing but will then be upgraded to an Axon microcontroller. It will include four sonar sensors for autonomous navigation but can also be controlled remotely via a PS2 controller. Beetlejuice will also include a series of multi-colored LED’s for a psychedelic effect.

I will begin fabrication this week, by laser cutting the plastic plates, and CNCing the shell for the back of the robot. I will be cutting the back from high density foam, which I will then lightly coat in epoxy resin. I will then take the epoxy painted foam shape and vacuum form over it with a plastic sheet. I am planning on a rapid fabrication time for this robot and will hopefully start programming a finished product within three weeks. Too optimistic? We shall see…

YouTube - Beetle Robot

YouTube - Beetle Robot

[Shevek]

That looks awesome! I'll be anticipating some updates

[elios]

Wow. that thing looks amazing. will be a great achievement when complete.

[Matt]

I hereby declare this project as awesome! :P

[WGhost9]

Well, I have begun the CNC process for creating the vacuum plug. Thorough research has found that CNCing the positive mold (aka plug, in vacuum forming parlance) would take considerable time and money were I too use wood or plastic. Even balsa can only be milled at a rate of 30 inches per minute or less while also costing considerable sums of cash.
So I have found a high density Styrofoam that is relatively cheap (about 30$ for twice what I need) and can be milled at the breakneck speed of 3 inches a minute. Unfortunately, it is likely to melt when vacuum formed, so I have taken the positive mold and painted a thin layer of tooling epoxy over the surface in the hope of providing heat dissipation and structural integrity to the mold should it begin to melt. Below are some before and after pictures of the mold covered in epoxy.

In addition to the foam plug, I have successfully CNCed the negative mold for the rubber wheel out of a small piece of sugar pine.

Tomorrow I will begin the process of vacuum forming onto this mold and report back the results. By the way, thanks for all the nice comments . It is nice hear such positive feedback.

[WGhost9]

Well the epoxy covered Styrofoam failed to vacuum form for multiple reasons; One, the vacuum on the vacuum former was broken and, two, the high-density Styrofoam melted far worse than anticipated. I will try again with CNCing SignFoam3 next. SignFoam is supposed to be a temperature resistant, low-cost, and high-density foam which should provide far better results.

[jes1510]

Awesome, awesome, awesome, awesome, awesome. Did I mention this is awesome? Definitely keep us updated on this project.

What about covering the plug with fiberglass?

[ScuD]

Or milling a negative plug, casting a plaster mold (cheap, heat resistant) and then vacforming over it?

Might be harder to get a good finish on a negative mold, but you can easily sand out imperfections on the plaster cast

[WGhost9]

Fiberglass is a valid option I am considering. As per plaster, I am told by the plastics experts down at Tap Plastics that plaster doesn't vacuum form well. On the other hand, I have a barrel of plaster left over from a family member's project that I was given permission to use, so I may try that if all else fails.

[ooops]

Wow, awesome project!
Keep the updates and pictures coming.