Mini-Dump Magnetic Remix

Update May 16 ‘24: Added the Arduino code to allow a PS3 controller to be used with the MiniDump. Also found that a NiteCore NL169R WITH USBC will give a little more umpff than Fenix but a little larger and doesn’t fit into battery holder as well. I can shove down and close my hood, but YMMV.

The Mini-Dump Truck is another excellent model by Professor Boots. It allows  remote control of a dump truck that permits you to control the speed and steering and also to raise and lower the dump bed. An added bonus is headlight control. 

This remix adds a magnetic latch for the hood and makes it very convenient for opening and closing. I've also added some modified code that you can try to try to prevent the dump bed servo from binding and using up too much current. 

The STLs for the hood and chassis are based on the December ‘23 release by ProfBoots of his mini-Dump model. It adds pockets for 4 x 5mmx2.7mm round magnets. These can be purchased from AliExpress and are common there as 5x3mm magnets. Most stores that sell 5x3mm magnets actually have them only 2.6-2.7mm thick. so my magnet pockets are 2.8mm deep. I’ve included the step files if you actually get 3mm thick magnets. You should also glue them in place. If you order from AliExpress you can find stores that actually show you the measured thickness to be about 2.6mm; to ensure you get what you need.

The magnetic latch works very well.. surprisingly well, actually.

I've also modified the code to try to make it a bit easier on the servo current required by normal operation. Comments are in the code. 

It can happen that the regulator will shut down if the current draw exceeds 2-2.5A. This can occur if two of the motors (N20, or servo) bind (or stall). Stall current of a motor can be up to 1A. The best way to ensure your servo does not stall is to ensure that the firmware does not try to make the servo go to a position that it cannot physically go. Thus, you need to ensure that when you put the dump bed all the way up or down, that it has some extra room to go up or down. Thus the firmware is limiting the dumb bed travel, not the physical model. Same situation for the steering. You can modify the dump bed endpoints in firmware (read the comments when loading the firmware in the Arduino IDE).

The video below shows my remix version of the mini-dump with some suggestions when building.

1. Added magnets to hood and chassis for ease of opening/closing hood
2. Modified code to ease current draw from dump bed servo