Introduction: How to Build a Full-sized All-Terrain Tracked Vehicle From Junk (the Ultimate Bug-out Vehicle)
I made this Instructable and video to share one of my recent projects. This is a homemade, tracked, all-terrain vehicle, built almost entirely from scrap metal and junk that I was able to scrounge from parts boneyards and scrap piles. The entire project, from gathering junk to putting the final touches on the paint, took me about a year-ish to complete. I call it "The Tank." It does have a few other names... Like "Frankentank," "Tankenstein," and "littering fine in potential" haha.
I've always had a love for the ruggedness of tracked vehicles and the plan to build one has been in my mind for many years. However, when doing my research, I couldn't really find anything like what I had envisioned. So, I formulated a plan in my head, and started trying to gather parts as I needed them. This conglomeration is the final result!
I never drew up any designs or plans. It just wasn't reasonable when I didn't really have an idea of the parts I'd have to work with from month to month. Overall, I'd say that I'm fairly pleased with the final result regardless.
I hope that you might find some inspiration, or just some interest at the very least, from this project. If you would like to see more of these types of things on this page and on my YouTube channel, then please let me know. I would love to be able to make things to share with you guys regularly, and that's a goal I'm working towards.
So, I'll try to be thorough with my explanation in words, because (like a dummy) I didn't get any pictures of the building process as I didn't have any intentions of making a video or an Instructable... Lesson learned! Document everything because you just never know! So if I'm unclear on anything, or something doesn't make sense I will be more than happy to clarify for you if you let me know in the comment section.
The building wasn't necessarily difficult as far as figuring out how to put things together. I mean, I have no formal training in engineering or mechanics, and I was able to figure it out. The true work behind this project is in simply moving things around by hand and the tediousness associated with creating the sheer number of parts in this beast.
As far as tools go, you don't really all that much. Anyone who has the most basic (but essential) of metal working tools can pull this off with relative ease.
The power tools I used were as follows:
4.5" Angle grinder
110v Arc welder
Mini drill press
Battery operated drill
Sheet metal shear (optional)
Skillsaw (also optional to cut the aluminum floor panels)
I won't go over the hand tools and such (e.g. wrenches, tape measure, etc...) because I don't feel like it's entirely necessary. You certainly won't need anything special though.
As far as materials go, they're vastly interchangeable, so I would encourage you readers to check out the video I made if you'd like to get a better understanding of the parts I used. I didn't have many choices of parts in my case so I just made do haha. There were much better solutions to many of the problems I encountered, but that's where you guys can learn from my mistakes and make this your own if you build something like this for yourself!!
Step 1: The Tracks
The tracks are the main feature of this vehicle obviously, and they are also the most time consuming part. This is where I had to bite the bullet and buy almost all of the parts I needed for them simply because it would be nearly impossible to find the 212 ft. of 2 in. x 1/8 in. flat bar needed anywhere outside of the store. Along with those 106 1 ft. long steel plates that need to be cut out, (if you have a cut-off saw, I envy you here) you also need to drill 4 3/8 in. holes in each one, AND 4 more holes in the rubber itself to mount them! As I said, the tracks are definitely the most tedious part. Don't let that scare you though! It would absolutely be possible to get them done in under a week if you work hard for several hours a day. Just keep your mind on what you'll have when you're done!
Along with those plates you'll also need some way of keeping the tracks from simply rolling out from underneath of you as you drive. Here is where I tried to be cheap and go with an original plan of just using 2 in. angle iron and welding them onto into the plates before shaping them one at a time with couple of pairs of channel-lock pliers and an angle grinder with a flap disk. They simply weren't big enough to keep the track on the boogies when turning. So, (still being cheap) I cut them off of every other plate and and used 1 1/2 in. x 1/8 in. flat bar pieces that I bent in "U" shapes in my bench vise to create taller 4 in. guides. So far, so good!
The grand total amount of metal used for my 53 total feet of track was as follows: 142 ft. of 1 1/2 x 1/8 in. flat bar, 212 ft of 2 in. x 1/8 in. flat bar, and 18 ft. of 2 in. angle iron. Hopefully that math is correct...
Please see the accompanying photos or the main video if you'd like an image of exactly how I put them together.
The rubber was collected from one of my local rock quarries. The rock crusher belts eventually wear too thin in places for them to be used in the machines and when I inquired to my areas rock pits they were very willing to just give me an entire belt at no cost including delivery. The original belt was about 80 feet long and 36 inches wide. I cut the track out of the belt with a simple utility knife and it really wasn't that bad to work with. The rectangular cutouts where the teeth engage the track are 4 inches long and 6 inches wide. I think the tracks took me about 9 hours each to cut out by hand from start to finish, but I left them a couple of feet longer than I thought I'd need just to be safe.
Obviously I needed to find a way to link both ends of the track together. Rather than make an overly and unnecessarily complicated connecting plate that probably would've been too weak anyway, I simply used some longer bolts and overlapped the rubber by a couple of links as demonstrated in my drawn illustration. I think that's all with the tracks themselves!
Step 2: The Drivetrain and Frame
The engine is a 3.9 liter V6 from a 1992 Dodge Dakota that was in pretty rough shape. The engine has some leaky rings and so it does burn a small amount of oil, but I couldn't really care less. Did I mention that it was also free??
Now, in the interest of simplicity and time I decided to go the most direct route possible when mounting the engine. Rather than building a carefully measured frame and cutting the engine mounts out of the truck or even fabricating my own, I decided it would be much easier to leave the engine and transmission together in their cozy little truck frame and just cut the whole chunk out to set into the simple tank frame made from 4 in. C-channel. I think that was the best way to do it.
You've probably noticed that it's a mid-engine vehicle. Having the engine in the middle has some advantages. The weight is more balanced, there's more working room, and it kept the profile of the tank shorter while keeping comfort in the cab area. Accommodating the different engine placement was easy because everything that I needed to control the engine was just lines and wires. It was a matter of just moving and placing flexible things.
Step 3: The Means of Control
This step will be covering the control of the vehicle in general. The main difference that needed to be addressed between the old truck workings and the tank was the difference in steering methods. Tracked vehicles use a type of steering called "differential steering." Meaning that the tracks will move at different speeds to turn.
Slowing down each track independently is actually a very easy thing to do with the parts that I already had available from the rear-wheel-drive pickup truck. The pickup had a certain type of differential (the big bulb on the rear axle where the driveline enters), called an "open differential." You can find out what kind of differential your vehicle has by putting the vehicle in gear, jacking up both rear wheels, and spinning one of the wheels by hand. if both rear wheels turn in opposite directions with very little resistance then you have an open differential. This is what you want for a vehicle like this. I won't be going into the other differentials because that's a whole other Instructable in and of itself.
A differential works by using a gear assembly to divide the input speed of the driveline evenly between the two wheels. It's a necessary function for standard turning in a conventional 4-wheeled vehicle. We can use this function for steering with no modification because by using a hand brake to slow one side of the differential, the difference in speed is given to the other side. So, braking the left side will yield a left turn, and vice versa.
All I needed to do was mount two master cylinders in the cab and assign one to each side of the brakes with some super long brake line leading to the rear axle. Apply pressure, and BOOM DONE! The next thing ya know, you're turning left and right with ease!
I went with a simple setup of mounting the cylinders under my seat, so a rearward pull of one of the levers turned the vehicle to the same side as the lever I pulled. It seemed like the most natural way to do it.
For the brake master cylinders, I used a pair of clutch master cylinders that would each fit a 1992 Toyota 4-Runner. While brake master cylinders are technically bigger and displace more fluid, because I was only controlling one side with each, volume was never a concern.
The throttle was quite simple as well. I just bent and shaped a long length of 1/4 in. tubing from the gas pedal to the throttle on the engine. I simply ran a piece of well lubricated cable all the way through this line and attached it at both ends. I used the original pedal from the truck because I had it on hand.
The clutch... I really wish that I had gotten an automatic transmission and didn't have to worry about this... But, oh well! The concept is basically the same as it was for the brakes. It's a hydraulically actuated clutch, so all that was needed was another master cylinder and pedal to press it. This time however, I used the brake master cylinder from the Dodge and built a simple pedal assembly from scrap metal that I had lying around. While we're on this topic I'd like to address the elephant in the room... shifting. I can't do it from the cab quite yet. It's not a big deal though as I have no desire to go faster than you saw in the video because I'm not sure how fast the tracks can turn and I'm not willing to find out quite yet haha.
For starting I just mounted the trucks ignition switch to my control panel. There was never an issue with the wiring because I never disconnected any of it. There simply wasn't a need to.
And that's all for there!! We can now start, move forward and backward, turn, and stop!
Step 4: The Body
Okay, so it officially moves, but now it needs to look cool too! The design inspiration came from a vehicle called a "Ripsaw." It's the worlds fastest tracked vehicle. I would encourage you guys to look it up!
The cosmetic frame was made out of whatever I had laying around after I got the functionality completed. Most of it is 1 1/2 in, angle iron that I got in the form of these strange temporary structure pieces that were basically just 12 ft. long, 4 ft. wide welded rectangular frames. I got them free from my neighbor who has tons of them lying around and wanted to let some go. Throughout this project I definitely was quite lucky with my pursuit of materials.
The rollcage around the cab area and the side parts of the nose are made of 1 1/4 in. steel well pipe, with the forward-most cross piece of the nose being constructed of 3 in. x 1/4 in. walled round tubing left over from the sections I had to remove from the axles to shorten them. It's definitely strong enough to take an impact if need be.
The silver decking panels that you see in the bed, the upper deck, and the floor of the cab are all aluminum cattle trailer floor panels. They're interlocking and quite strong, so they suited those needs very well. The bed panels and the upper deck panels are removable as well to allow access to the engine and the rest of the internals for large repairs or even replacements.
The last parts to be put on were the sheet metal side panels. I cut them out of some thin galvanized steel that was originally glued to 3/4 in. plywood for horse stall and barn siding. I was fortunate enough to be able to borrow a double-edged sheet metal shear which made the job MUCH easier and safer than using an angle grinder with cut-off wheels. Galvanized metal can be nasty stuff for your lungs if handled improperly. I used some 1 inch self-drilling metal-to-metal screws to fix the sheet metal in place, taking care to measure and mark the distance between each screw to make sure everything was even. Little details like that can go a long way for the attractiveness of the final project.
Hopefully that covers that. The body style I created was just what I chose and what I thought looked good. I can't tell you exactly how to build it, or what to use, but hopefully telling you about my experiences can give you some guidance on creating your own if you ever plan on building something this ridiculous.
Step 5: In Conclusion
Congratulations! You made it to the end! There is just so much information to talk about on a project of this magnitude and I'm pretty sure that I touched on everything. Hopefully I answered any and all of your questions or curiosities on this thing. I had such a blast building this thing and I learned SO much that I was hoping some of you other makers out there might be able to use in your own projects to make things a little bit easier.
As I said in the beginning, my main goal in sharing this project with you is my hope that you'll take some inspiration and possibly look at your next project a little bit differently. The world is full of parts, bits, pieces, and stuff that others may find no use in or have no drive to utilize in a new creative way. That leaves nothing but opportunity for us! There was enough "junk" lying around to build almost an entire working tank for goodness sake! Even if you're not a maker, I hope you were left with something to think about after reading this.
So, I guess that about wraps things up! If you enjoyed this adventure, then please consider showing it here and on my YouTube channel. I'm planning to do frequent projects with this same mission and scavenger mentality in mind. I love making this content for you guys to enjoy and I have a long term goal to try and make a living at it if I can, so your support means everything. Every "Like" and Subscription goes a long ways.
Thank you all for your time and I hope you enjoyed!!
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