Mato Toys Tank Gun Modification

I purchased a few 'Tank Guns' from Mato Toys that some of the other Mech Warfare guys have used in the past. These are designed to be used in remote control model tanks which is apparently a popular hobby in some parts of the world.

This gun is much smaller and lighter then the airsoft gun I used on Second Amendment but its firing rate is extremely slow and disappointing. Another competitor at the Mech Warfare 2010 event had modified this same gun for a faster firing rate so I set out to discover the modification myself.

Here is the Tank Gun in all its cheapness glory. It is a slightly different form factor from Mato Toys product image but everything important seems to be the same.

Here I have removed the motor and one side of the gun's casing. We can see the inner workings of the gun. It works almost identical to the spring airsoft gun I used on Second Amendment. This gun uses a much smaller motor with many gear reductions to pull back the gun's spring/plunger.

Here is a picture of the modification I made. Normally the pinion is press fit onto the end of the motors shaft. I simply tapped the pinion down the base of the shaft. By repositioning the pinion like this it is simply bypassing two of the gear train's gear reductions increasing the guns firing rate.

The modification couldn't be simpler and was immediately obvious once I opened up the gun. Any negative long term affects on the motor or gear train is still unknown and requires some testing. Use at your own risk.

Second Amendment OverHaulin'

I have started work on a new Mech, Gold Rush, but that does not mean Second Amendment will be retired.

An overhaul of SA's chassis is first up on the list of improvements. It will be replaced by a more traditional 'sandwich' style chassis that will have less parts and be lighter.

I want the legs to remain the same so I have created some brackets to easily adapt SA's old legs to a new chassis.

I am also in the process of designing a new turret that will be used on both SA 2 and my new mech Gold Rush.

All other components of SA will remain the same.

Second Amendment takes the gold in Mech Warfare at Robogames 2010

Second Amendment's New Amble Gait

SA Improvements Underway

Attending the CIRC Bot Brawl was a great proving ground for SA. Myself and the Mech Warefare participants in attendance learned a lot.

A few things that I observed:

Circuit protection
SA's camera and transponder are unprotected from stray bbs.

Gun Wiring
Wiring is a mess up on the turret. Will need to look into some better wire management.

Turret Mechanical Limits
Turret unable to aim down making it impossible to shoot low mounted targets on close mechs.

Fine Turret Control
My fine turret control needs to be finer. Will make aiming much easier.

Small Camera Image
The camera image on the drivers end is much too small. Needs to be full screen.

Large Step Length
Need a larger gradient on step length. Will make positioning and aiming easier.

Ugly Target Panels
Would like to dress these up to match the robot. Possibly add some Upgrayd Labs logos or some kind of made up paramilitary decal.

Kodak Zi8 Pocket Video Camera

I have been in the market for a decent camcorder for a while now. All my previous video work has been through the built in iSight web cam built into my MacBook. Obviously that was not an idea setup. Poor quality vido, poor audio and awkward positioning being the main issues.

I wanted something that was small sized and portable, did not require a lot of gear, decent indoor video quality, and in the 200 dollar price range. The three cameras that fit these requirements included the Flip MinoHD, Creative Vado HD and the Kodak Zi8

Hands down the Kodak Zi8 really stands above the rest. Features including:
- 1080p video with 16:9 aspect ratio
- SD card slot
- External microphone jack
- Image stabilization
- Removable battery

I have uploaded a short test video to YouTube of SA walking that I took with the Zi8.



I plan to use this camera to keep this blog updated with my progress on Second Amendment, offer some coverage of the events I attend, generate some how-to and project videos and document any projects Team Upgrayd works on in the future.

Attending the CIRC Bot Brawl

On March 6th the Central Illinois Robotics Club will be hosting a robotics competition event.

Competitions at the event will include various sumo divisions, autonomous line flowing, autonomous maze completion, combat robots (1lb and 3lb divisions), best in show, and a few short Mech Warfare demonstrations.

I plan on attending and bringing along Second Amendment my quad mech to participate in the Mech Warfare demos. Also I will probably enter SA into the best in show competition. The focus of my best in show entry will be around inverse kinematics and walking gait sequences.

Date - March 6, 2010
Location - Lakeview Museum, Peoria, IL
CIRC Homepage
Bot Brawl 2010 Information

Improved Quad Walking Gait Sequence

Second Amendment's gait was functional and that is about it. It was clunky, mechanical looking and inefficient.

SA's gait was very simplistic. Basically alternating diagonal sets of legs would be raised and moved. While this works it is sloppy and prone to wondering (unable to walk in straight lines). Also, due to program structure, SA was unable to both walk and turn at the same time. These things had to be improved!

Enter the ripple gait. SA is now programed with an eight step ripple gait (leg up and forward, leg down, move body forward 6x). In addition it is now possible for him to turn while walking opening a great amount of possible body translations.

SA Shaping Up

Second Amendment is really coming together.



Just a quick rundown of everything that has happened from the last update:
Revised leg configuration
Test gun mount idea
Test ammo hopper
majority of mechanical components painted
optimized walk sequences
and more!

Meet Second Amendment The Quadruped Mech

Second Amendment (SA for short) is a Quadruped Mech being designed and built for the Mech Warfare competition at the 2010 RoboGames.



SA's Specs:
Mechanical
- A mix of Lynxmotion SES parts and custom machined aluminum parts.
Electronics
- Lynxmotion SSC-32 Servo Controller
- Xbee Wireless Communication Kit
- TRENDnet Wireless Internet Camera Server (TV-IP110W)
Software
- Python Programming Language
Weapon
- Modified CyberGun Defender Electronic Full Auto SoftAir BB Gun

Updates:
SA's previous updates have been documented in the Trossen Robitcs community forums in this thread.

Videos:
A few videos of SA can be viewed in my YouTube channel.

I will continue to post small updates in the Trossen Robotics thread and periodically update this blog with posts detailing major advancements.