mini RC tank body for Arduino, N20, lego tracks by BuiltBrokenGlued

Last crawled date: 3 years ago

Hi,
take a look at my other designs https://www.thingiverse.com/BuiltBrokenGlued/designs
Remixed from https://www.thingiverse.com/Mkhand_Industries.
MK2 tank here https://www.thingiverse.com/thing:3068121
Longer, wider to store the 1400mah battery inside the tank.
Order:
Idea
Remix
Updates
Process build
Idea:
I have wanted to make a Tiny tank but I planned on using 1400mah 3s batteries that I have lying around. I usually crash my quad copter (more practice required) and I wanted something else to use the batteries up as well as get into FPV at some point.
The base for the tank is using Lego Technic 30cm tracks along with 1x 1400mah battery. I am planned on using N20 12v 1200rpm motors running off a Arduino and L298n driver.
The L298n will be on the left (nearside UK) with a area allowing for passive cooling of the driver.
I am hoping with the small motors that the current draw is low and the cooling does not heat up the PLA around the l298n too much.
The l298n cooling fin has been cut down to allow better fitment inside the body - see pictures.
I will write an arduino code to allow the PWM signal of the RX to control the tank. This should be a 6 channel setup. This can allow extra functions to be added into the arduino code at a later date, i.e. servo rotating turret, dimmable/flashing leds, adjustable percentage of usable speed (full throttle stick but 50% max speed) etc.
Remix:
I wanted to have a tank design so I have remixed the design by https://www.thingiverse.com/Mkhand_Industries.
I have removed the tank tracks and made the turret support a little higher to allow the battery to fit underneath a removable lid. The Turret has been increased in scale from the original file.
The inside has been hollowed out to allow a Flysky FS-I6 micro receiver, Arduino nano, battery and a l298n (adapted) to be fitted into the case.
Updated 05/07/2018
I printed the chassis base then mounted the N20 motors. Sorted out the drive and idle wheel size to put the correct tension on the tracks. Mounted the L298N motor driver and soldered the N20 motors direct to the board. I am using XT60 connectors as these fit my 1400 mah battery.
Hot glue the L298N driver into the base frame. Wire up the motors to motor A & B on the L298N. It doesn't really matter if they are not wired up the same, the arduino code can make them run in the correct direction. screw in the battery connector to the + and -. The arduino + & - will be wired in, in a later update.
Updated 18/07/2018
The twin throttle does work but I have found that I tend to have it on full 100% (Variable) all the time. The motors being 1200 rpm are great for speed and are ok but trapped grass in the tracks stops the tank. I will be looking for some 300 rpm motors for off road use.
The design is compact and could be made quite a bit smaller with a smaller battery and using a standard square box body. This is something I will do at a later date.
Updated 19/08/2018
See pictured - I have attached the L298N to a 3s lipo battery and used the 5v off the L298N to power the arduino and the RC receiver.
I have found though that the 5v supply from the L298N may affect the arduino and causes a small amount of interference to the PPM input.
It is running off an arduino code but it is a little glitchy, I'm still learning.
I hooked up a 1400mah battery and drove this home from my local park around 500-600 meters with no heat issues (motors,L298N) affecting the PLA print.
https://youtu.be/aqVu5qaTH8I
I have printed the turret to include a cheap VTX camera and a 9g servo for side to side movement. The camera does work though it has interference from the 5v Supply of the L298N. I haven't tried the servo as yet.
The cut out should rotate enough to allow a good range of movement for the turret allowing the cable to come straight through the top plate.
Update 26/08/2018
MK2 tank https://www.thingiverse.com/thing:3068121
designed for ESC and 3s battery
Update 30/12/2018
Added 3 files for the Upper Chassis.
These split the tub and the front gun for beds that may be too small. The GUN and TUB can be printed separately or there is a file with the gun inside the tub.
Process:
2 x N20_Front_drive_wheel.stl - These are super glued onto the N20 motors
1 x Chassis_Base_MG_Tank_N20.stl - The L298N driver and RX is hot glued in. The N20 motors with wheels are super glued in.
2 x Rear_608s_bearing_idle_wheel.stl - These are super glued onto 608RS bearings. The bearing are then attached to the tank using a 90mm length of M8 studing (or a M8x90mm bolt and nut) and a nut on either end.
See picture.
1 x Upper chassis MG Tank N20.stl - I printed off some little 2mm x 8mm x 2mm rectangles and super glued them to this part to locate the upper chassis to the bottom chassis. It is temporary while I carry on with the design.
1 x Top plate MG Tank N20.stl - This is glued to the Upper Chassis and allows for the RX to slot through at the rear.
1 x Turret Rear MG Tank N20.stl - This houses the 9g servo that allows the turret to move from left to right. The entry hole for the servo may need a little trimming. I hot glued this in due to the print not holding the servo tight enough. You will have the trim the servo screw holes so they don't come out the side of the turret. ( I haven't done this pictured do to the print not being finished)
1 x Turret Front MG Tank N20.stl - This houses the VTX camera. it is hot glued in place.
NOT PRINTED AS YET
1 x Guns MG Tank N20.stl - these are printed together using a 2 mm brace that gets cut off after.
If you have any questions please ask, I'm open to improvement and ideas.