Dynastinai V1.5

Dynastinai V1.5

"You may be wondering, why the red suit? Well, that's so bad guys can't see me bleed!"
- Dynastinai V1.5, Deadpool theme (?)

  Dynastinai V1.5 is an upgrade version of my first 3lb modular combat robot, Dynastinai. Most of the parts are reused if not, modified/upgraded for better performance.

  I was taking a break from Robojacket duties since I have been busy with preparing for graduating/ graduate school plans. I wasn't planning to work on improving this battlebot until the week before the competition. I saw the announcement on Facebook about the upcoming event on March 30th and thought, "Why not?".

Goals for this upgrade was to:

• improve most of the flaws experienced from 2018 Motorama
• fix everything and revive the robot into functioning state within 1 week
• compete in Robojackets 20th Anniversary Competition
• have fun

Parts I used for this build (replaced/added from old design):

Chassis extension piece	Onyx + Kevlar
New horizontal weapon	AR500
Weapon ESC	BL heli 35A brushless ESC
Drive motors	1000 rpm 12V DC brushed motor
Drive motor controllers	Scorpion Mini
12V BEC	TUZ 12V 3A step-down regulator
Battery	3S 850mah 45C * 2 in series

CAD model was done with Autodesk Inventor

Top view showing internal electrical components and the chassis extension piece

  I decided to only use the horizontal weapon module for this competition since I haven't got a chance to fix the vertical weapon's severe vibration problem from the previous competition. I only had 1 week to complete the project, which was not enough to fix it.
  Minor modifications had to be done to the chassis to fit the new DC brushed gear motors for drive, which were larger and heavier than the precious choice. It would have taken too much time to 3D print all the new chassis parts so I took it to mill and milled down sections of the chassis.

  Larger capacity batteries (3S 850mah * 2 in series) compared to the last design (3S 500mah * 2 in series) were used to make sure the battery don't become fully discharged in the middle of the fight.

Invention Studio's Markforged now supports Onyx!

New horizontal weapon partially assembled

  Improvements done to the electrical systems plus the chassis extension piece increased the total weight of the robot. Thus, I had to redesign the weapon to stay under the 3lb weight limit. 3/16 inch think AR 500 plate is water-jetted and then belt grounded for polished look. New weapon weighs about 290 grams, which is slightly less than 20% of the total weight of the robot.

Painting the suit in red

  To make sure bad guys can't see it bleed Dynastinai has more intimidating look, I spray painted the robot with red and gave it a glossy coat. Painting & coating only added approximately 5 grams overall.

Chassis extension piece (black rectangular thing on top) and shock absorbing pads showing

  During the last competition, the weapon stopped working after a huge hit exchange with the opponent. Upon examination, I was able to find out the weapon ESC wouldn't work and I figured it would be a good idea to protect the fragile electronics with shock absorbing pads. This is why I made the chassis extension piece to give more spacious room for the electrical components plus the pads. Now, all electrical components are either floating via wires inside the chassis or have protective pads surrounding them to separate them from external impacts.

12 V bec exposed

  I heard successful stories in online forums about overvolting DC brushed motors and be fine with doing so. So I supplied 24 V to the 12 V rated DC brushed drive motors and practiced driving. It seemed to work fine for about 10 minutes but soon, one of the motors failed. I blame myself and no one else. I changed out the burnt motor and added a 12 V step down voltage regulator (only 3 grams!) and hooked up to the drive. The system worked flawlessly after this.

Only approx 1 gram lighter than the 1360.78 gram limit (3lb), the weight is impressively optimized

Matches:

1. Dynastinai vs. Crispi

  Crispi was a drum spinner type battlebot from Robojackets.

Fight never happened and I won by opponent's forfeit.


2. Dynastinai vs. Oreo

  Oreo was a wedge type bot. I decided to head on attack in on all directions to practice driving with minimal weapon spin but felt bad for over doing it. It was my first fight and since I was too eager to test the robot, I didn't notice the opponent unable to drive after several hits and kept on attacking before the opponent tapped out.

3. Dynastinai vs. Daddi

  Daddi was a horizontal spinner type bot. Mid cutter. I tried to attack the opponent's sides and rear to avoid sustaining damage to my horizontal module. Also felt bad at the end. I didn't notice the opponent unable to drive after several hits and kept on attacking before they tapped out.

4. Dynastinai vs. Furi

  Furi was a drum spinner type bot from Robojackets. In this fight, I wanted to test the weapon spin up to the maximum speed and see what's gonna happen.

5. Dynastinai vs. Impulse Response

  Impulse Response was a horizontal spinner type bot. Under cutter. I tried to attack without giving enough time to spare in between hits since I figured the weapon spin up time for Impulse Response would be slow due to large weapon and relatively small motor. This didn't work out very well since my weapon spin up acceleration wasn't great either - another aspect to improve in the future. Also, I was quite worried since Impulse Response had greater reach in terms of weapon so I decided to attack on its sides and its rear. This turned out to be quite effective.

6. [Final] Dynastinai vs. M.A.D.

  M.A.D. (Mutually Assured Destruction) was a horizontal spinner type bot. Mid cutter. I tried to attack its sides and rear to avoid getting hit. After exchanging few punches, I was unable to spin up the weapon fast. Later I noticed the heat shrink covering the weapon motor ESC and the foam pad surrounding it were partially melted. I believe the ESC got overheated and failed to function properly in the middle of the fight. This will be fixed in the future.

  At the end, Dynastinai won 1st place with 6:0 win to loss ratio.

Workbench view at the end of the competition

Sustained damages

  Visually, only the wheel guards and the horizontal weapon module sustained damages throughout the event. This may not seem a lot of data to analyze but I learned a lot about where to fix/improve in the next iteration of Dynastinai. Thank you members of Robojackets who worked tirelessly in organizing this event! Awesome job and hopefully they will host another competition in the future.

Improvements for future interations:

• complete optimized remodeling of the chassis
• botkits 22mm planetary gear DC motor for drive system
• larger diameter weapon for greater reach
• faster weapon spin-up time (lower KV, higher torque motor (?))
• beefier weapon ESC
• beefier wheel guards