THE YARD MULE ELECTRIC DUMP TRIKE

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


wheelbarrow of wood

I need a much better way to move stuff!

Living out on 160 secluded acres, we enjoy a self-sustaining lifestyle that includes growing our own food and cutting our own wood supply for heat during the 8 months of Northern Ontario cold. Having worked the land for 7 years now, I have identified the tasks that take up most of my time and energy, many of which involve moving heavy stuff from one point to another.

Firewood harvesting and moving dirt are the two tasks that often involve the most physical labour and lost time because you can only move so much at a time in a wheelbarrow or yard cart. We also live on land that is made up on large hills in all places, so a wheelbarrow of firewood can be a massive undertaking if it has to come up a 2000 foot long steep hill.  We have considered an ATV, but didn’t like the thought of dumping $10K into a high maintenance gas powered machine that would leave ruts in the yard and do a lot of tasks decently, but none really well.

This is how the “Yard Mule” idea came about!

I wanted a vehicle that was made for hauling, would run well for my entire lifetime, not leave ruts in the yard, and never lack in either pulling power or hauling capacity. I needed a vehicle that would stand up to the abuse I can throw at things and never let me down, and I wanted it to be clean, silent, and inexpensive to both build and operate. Am I delusional? Is it possible? Well, let’s find out!

YardMule concept sketches

Working out ideas for The Yard Mule.

I work out all of my ideas the same way, using a pen and paper. Some people have asked, “why not learn CAD and do it that way?” Well I actually do use SolidWorks for a living, and I am good at it, but when it comes down to working out ideas, I say nothing beats a comfortable chair, a pen, and some paper, and that is how I will always work out my ideas… drawing board style!

Like everything I create, the Yard Mule went through many iterations over the few years I have been considering building it. Originally, I intended to take an old snowblower apart for the gas engine and then drive an auto differential with it, but the thought of polluting my nice quiet wilderness with that noisy, clanking, oil spitting beast just didn’t seem right. I then worked out the gear reduction required to move 1 ton under human power up a hill, and although the math certainly worked out, I realized that I would be less efficient that moving smaller loads one at a time.

The only logical answer was electric power.

Electric motors are far superior to gas engines in every possible way now. You get all your torque at the lowest RPM, there is almost no noise, maintenance is low, and power to weight ratio (not counting batteries) is much higher. Of course, the world is just starting to go through fossil fuel withdrawal, so the selection of mid-size DC motors is somewhat limited right now. I did find a few though, so I was off to scavenge for parts to build my ultimate yard vehicle.

ford f150 rear differential

An old Ford F150 rear differential.

On one of my trips to the local dump, I noticed a burned out truck laying on its side in the area where the volunteer firefighters do their training. It was an old Ford F150 that they had lit on fire to practice on, and it was soon to be towed to the car yard. I had one day to take what I wanted form the burned up hulk, so I went home and grabbed a bunch of hand tools like a hacksaw, large hammer, pipe wrench and all the other tools of mass destruction I could find. I wanted that rear differential!

You can certainly save yourself the work and just purchase a rear differential from a car scrap yard for a hundred bucks, but I live a long way from town, and wasn’t afraid of a little sawing on a nice afternoon. Ok, it was actually a LOT of sawing, and after 4 hours, I still had to roll the damn thing through the bush and then lift it into the back of a trailer! Hey, it’s all good, and that’s why I am still fit. If you are afraid of hard work, then DIY is probably not going to be your game!

ford f150

A typical older Ford F150 Pickup.

This is the model of truck that this differential came from. I am not sure of the exact year, but this photo matches exactly to the truck I spent 4 hours hacking the rear differential from. Even the hubcaps are the same. I was hoping to identify the model to get the gear reduction, but didn’t really need to since I did a test to find it as shown later.

differential connection

Looking at the universal joint mount.

So now that I had a hefty rear differential and a type of propulsion to use, the puzzle was how to make the two if the m work together. A car engine drives the differential through a drive shaft running perpendicular to the axle, but in this case I didn’t want to use a drive shaft as it would really not be necessary in a vehicle like this. Looking at the universal joint mounting housing that remained, it was obvious that I could just mount a sprocket directly to it face, as it had 4 bolt holes and a flat front mounting surface. This was good.

remove lugnuts

Removing the rusty lug nuts.

This differential was not only old, but it was set on fire and then left exposed to the elements for a year, with all protective oil or coating burned away. Yeah, there was rust! When I removed the hubcaps, a pound of rust chips fell out, and the lug nut studs looked pretty rough. I added some penetrating oil, and them them soak for a few hours as I only had a tire iron to use.

For those of you who don’t know how I work, I use only hand tools, and work outdoors. I own a hand drill, angle grinder, basic AC welded and that’s all. Everything I do, and all of the DIY Plans on this site were made using only these tools. Tackling a rust truck differential with only small hand tools may seem crazy, but I totally enjoy the challenge, and that’s what keeps it fun for me.

remove rusty brake drums

The rusted and seized brake drums.

The lug nuts required some good kicks on the old tire iron, but they did eventually come loose. The brake drums on the other hand were really bad! Both drums totally rusted out and seized both to the hubs and to the brake pads, which were probably melted in the hot fire.

To get these loose, I used a 10 pound sledge hammer, bashing the outer face all around until the rust let go of its weld like hold on the brake pads and hub. It took a few hours!

dodge ram rims

Some huge wheels I found online.

On another project I am building (Autonomous Yard Robot), I found some Dodge RAM wheels for sale for a steal, and picked them up. These are stock rims with decent tires, measuring 32 inches in diameter. I ended up with 4 identical wheels, but the robot only needed two of them, so this worked out perfectly. Of course, things are never that easy, and Dodge rims do not just fit right onto a Ford hub.

That’s what angle grinders are for!

centering hub width

Measuring the hub center bore.

Car rims are centered to the hub in two ways. The firs method is by the center bore, which is a protruding ring off the face of the hub that matches the bore in the rim. The second method is by the lug nuts, which are tapered in shape to place the perfectly center the rim when they are tight.

rim center width

The Dodge bore is too small for the Ford hub.

I think that the center bore was really created to stop us from sharing rims from one brand to the other. There is a secret “Non-Standards” committee in existence that does nothing but think of ways to piss you off and make sure that similar items that should work together actually do not. In this case, they made sure that Ford, Chevy, and Dodge rims do not work together at all.

But like I said before… that’s what angle grinders are for!






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