Servo - November 2015

maintenance needs at an event. He’s also a big strong guy, which ends up very useful if we’re taking a couple of heavyweights to an event. Rick owns his own sheet metal fabrication shop, so he has some tooling and fabrication skills that he brings to the team. Rick also handles much of the maintenance and repairs at an event.

Olin: Can you tell us a little bit about your sponsors and any material support they gave you for building Tombstone?

Billings: Team Hardcore Robotics has a long standing sponsor arrangement with NPC Robotics. NPC has provided me with drive motors and components and various engineering services for several years. They have played a big part in our success, helping us to win the ComBots Cup (twice!) and place highly at every RoboGames event. Great products from a great company!

Our newest sponsor for BattleBots is Innovation First International — the parent company for VEX robotics. IFI has created some of the most commonly used electronic speed controllers in robotics today. Three of the top four bots in this year’s BattleBots tournament were running IFI products, and most top teams rely on their electronic components. I have relied on IFI speed controllers for every single combat robot I have built.

Olin: How do you build your robots? What tools and processes do you use?

Billings: This depends a lot on the weight class. In the larger classes,

I tend to use welded 4130 steel tubing for the frame, with armor either bolted on (for non-contact areas, say the top and bottom panels) or welded on (something where contact is likely). Welded steel tubing is really pretty strong for its weight, and makes it relatively easy to address major damage at an event. I’ll take some extra tubing and a welder, and we can pretty much fix anything that happens on-site, even major problems.

In the smaller classes, welded steel just ends up too heavy to work with, so I would end up using machined aluminum framing. This isn’t as easy to address at an event, unless you simply make a lot of spare parts to change out in case they are needed. But it tends to make more sense from a weight management point of view for the smaller classes.

Olin: What can you tell us about Tombstone’s weapon system?

Billings: The weapon motor is an Etek-R and is geared for about 2,800 RPM, which pulls about 1,000 amps at spin-up. Obviously once spun up, it is drawing much less, but not something I have measured. The weapon bar’s weight is between 65 and 75 pounds.

Olin: Is there anything new or innovative on Tombstone?

Billings: Most of the different systems used on Tombstone were basically identical to my previous HW Last Rites. But the frame for Tombstone was all new, to better take advantage of the heavier 250 lb category. The frame for Tombstone was almost 20 lbs heavier than for Last Rites. Also, with the active arena for BattleBots I had to plan for more to deal with than just the opponent.

With the killsaws and hammers, I had to armor up the top and bottom to handle this. I added a 0.1 inch titanium panel top and bottom, which should have been enough to deal with a killsaw ride or two. Luckily, I didn’t have to actually test how well it would have worked.