Here is the new chassis after printing, I’ve made a few changes to improve the strength where needed and cut some excess weight.
And side by side with the old chassis.
Mains cable and capacitor replacement
Before plugging in and testing this radio I replaced some choice components to improve the safety and reduce the chance of damage to other parts of the radio.
The original mains cable was the old twin core single insulation type and had become cracked and hard.
The capacitors replaced were the mains line-to-line cap, aerial-to-chassis earth and the audio output capacitor.
Cleanup and valve removal
The chassis was very dusty and dirty so I gently cleaned it with a paintbrush and vacuum cleaner.
At this point I also removed the valves for cleaning and inspection.
Stella ST105U
This is my first project in the world of valve based equipment and I’m very excited to be working on it.
I bought it as a non running chassis from eBay but it seemed to be relatively complete, missing only the outer body. This won’t be a problem as you will see since I intend to laser cut a perspex case for it.
Demonstration time
Setup and ready to wow some future undergrads
Will have to use a proper projector screen next time and see if that improves the colour / brightness.
The turret gets some paint
A dash of black n white paint and the turret begins to look like an apple product.
It was also at this point I 3dprinted a white ring to hold the red leds that form the eye.
Thoughts on robot wars
Well that’s my 1st robot wars competition over and done with and I can say I have much to improve on !
Movement – Servos modified for 360 degree rotation have lots of drift and thus slowly rotate when you want it to happen least. Use proper servos or motors and drivers.
Battery life – 300 mAh batteries are fine but excess weapon motor useage will deplete them. Locate the charging port to somewhere that’s easy to access for charging between rounds.
Amour – All cables *must* be projected from cut damage or you risk losing the round early as the green machine experienced.
Overall though I felt I did alright and got through to the 3rd round.
Video recording of the event by BEEES
This *is* my final form
This is robot being weighed and measured before the start of the competition
Chassis iterations
The next few updates shall be a brief collection of pictures I’ve taken during recent projects.
3 stages of chassis prototyping
Final chassis
Servo modification
This post is a few pictures showing the modification of SG90 servos so that they rotate 360 degrees rarther than the standard 180 left/right.
Bottom casing removed and you can see the control board, motor and potentiometer.
Here is the servo with the top half of casing removed. One of the gears has a pin that physically stops full 360 degree rotation so that must be cut off.
Small pile of gears and drive shafts.
My first attempt at soldering a pair of resistors in place where the potentiometer previous connected to. This is to trick the control board into believing it has not rotated far enough yet.
2nd attempt on the other servo, space is very limited when you put the end casings back on so you really need to shorten the resistor legs as much as possible.
And back together ready to act as drive motors for my robot.