THE YARD MULE ELECTRIC DUMP TRIKE

A ROBUST DIY ELECTRIC DUMP TRUCK MADE FROM RECYCLED CAR PARTS AND BASIC STEEL TUBING.


purchasing new steel tubing

A bunch of tubing from the steel supplier.

I seem to use a lot of square tubing around here on the homestead, making things and fixing things on a weekly basis. I used up all of my 2” square on a new set of stairs for the house last week, and also needed some 1.5 inch square and the 3/4″ angle iron to make the dump box. I drove to town and had the steel supplier cut several 20 foot lengths in half so I could transport them home in my old trailer, which will also need a bunch of tubing to make it road worthy very soon!

dump box framing

Making the Dump Box Frame.

Making a box from angle iron is fairly easy, but it was still fun and challenging since I had to do the welding and fitting on uneven ground. When you have no stable surface to work on, you just create a virtual ground, by using a level to set the first piece in place and then consider it the kingpin. It’s just like framing a 2×4 wall, you check the level, then place each piece in one at a time.

The super heavy duty angle iron box is probably overkill but this is a common construction steel, so the length actually cost less than the slightly smaller wall angle iron. With this dump box, I will be able to toss 100 pound rocks in there without fear of bending anything. Thick treated plywood walls will be easily replaceable every few years as well, so the dump box will outlast me!

dump box hinges

Making a set of sturdy dumping box hinges.

I worked out where to add the pivot point on the dump box so I would have a good combination of stability and balance so that the load would not tip accidentally but I could still manually dump a thousand pounds using a lever (to be added later). Once I found the point I wanted, I made a set of heavy half inch thick plates to act as hinges, welded directly to the frame and to the differential.

The 1 inch diameter bolts can also be easily removed so the dump box can be removed from the frame at any time. I may make other implements such as a wood chipper or mini sawmill, so it is good to have an easily removable dump box that can be taken off in a few minutes. Actually, the pivot point worked out so well that the dump box can sit fully tipped on the ground, and the vehicle can drive away from it once the bolts are removed.

dump box hand lever

This is the retractable dump box lever.

To dump the load, this 3 foot retractable rod extends from a socket welded under the dump box. Giving the operator plenty of leverage and control over the load when it is dumped. I also plan to add a chain to the dump box to prevent it from tipping all the way over. The chain will be easily removable so that the box can fully tip to the ground when it needs to be removed.

new foot pegs

Large foot pegs added to the frame.

The foot pegs were expanded to something a little more elaborate using some spare one inch tubing and grating I had in the scrap pile. Now the operator can stand firmly on the pad to get on and off the vehicle and there will be a little more protection for feet when crashing through the untamed Northern Ontario wilderness. Yeah, I plan to go deep into the back 40 to collect firewood this year, so the Yard Mule will be blazing new trails!

dump box locking pin

A Dump Box locking system installed.

To ensure that the dump box is always under control, I added a locking system that prevents tipping until the pin is pulled from the socket. The lever that moves the pin also has to be lifted from a guard that will prevent it from bouncing loose. Normally, I don’t go overboard on safety, but around here there are nothing but steep hills, so I don’t want half a ton of wood dumping out all over the road by accident. I won’t be the only operator of this vehicle, so I am making it friendly for everyone.

apple tree blossoms

The apple trees are now in full bloom.

I have been working on the Yard Mule for 2 weeks now, a few days per week, and the terrain has exploded into summer mode in a matter of days. Our yard is loaded with apple trees and various berry tries, and they are in full bloom. This means that I can pick apples for my breaks, and of course go back to chasing bears away from the yard! I have seen 2 new black bears in the area already. Perhaps I can teach them to weld? I have seen a bear ride a unicycle, so why not?

idler sprocket

Checking the position of the idler sprocket.

Just like most DIY trikes and recumbent bikes, you need to deal with the slack side of the chain. In the Yard Mule transmission system, there are two chains, and although you can adjust the final drive chain by sliding the pillow block bearing that hold the jackshaft, this in turn loosens the primary drive chain. To deal with this issue, I added an adjustable idler sprocket that will pull up on the slack side of the chain.

Since the rotation (as viewed here) is clockwise, the underside of the chain will be the slack side (non-drive side) that is not under tension. Because my motor controller includes a half speed reverse function, I also need to account for that scenario, which would put strain in the underside chain. To accommodate this, my idler system is stiff, meaning that it is adjusted and then locked, unlike a bicycle rear derailleur that is just spring loaded. I will explain all of this in much more detail in the actual DIY Plan.

fuel tank sheet metal

Making the fuel tank from some scrap sheet metal.

The scrap metal gods must be happy with me today because I found just enough random pieces of 16 gauge sheet metal to make a box to hold both batteries and the master cut-off switch. I call this the fuel tank since that is actually what it is, but in this case the fuel is 200 amp hours’ worth of clean electrons instead of 20 gallons of smelly, flammable petrol. Did I mention that I am not a fan of archaic gas burning engines?

fuel tank complete

The competed removable fuel tank with side door.

I made the fuel tank easily removable from the main frame so that I could swap put multiple battery pack if one day I required that. I should get an all-day run time from one pack easily, but since the ability to remove the tank only required a small bit of effort, it was worth doing it now instead of after the paint has dried. The side door comes completely off by just removing the two thumb screws on top.






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