Quad-Motor Electric Kart Gets A Little Too Thrilling

[Peter Holderith] has been on a mission to unlock the full potential of a DIY quad-motor electric go-kart as a platform. This isn’t his first rodeo, either. His earlier vehicle designs were great educational fun, but were limited to about a kilowatt of power. His current platform is in theory capable of about twenty. The last big change he made was adding considerably more battery power, so that the under-used motors could stretch their legs a little, figuratively speaking.

How did that go? [Peter] puts it like this: “the result of [that] extra power, combined with other design flaws, is terror.” Don’t worry, no one’s been hurt or anything, but the kart did break in a few ways that highlighted some problems.

The keyed stainless steel bracket didn’t stay keyed for long.

One purpose of incremental prototyping is to bring problems to the surface, and it certainly did that. A number of design decisions that were fine on smaller karts showed themselves to be inadequate once the motors had more power.

For one thing, the increased torque meant the motors twisted themselves free from their mountings. The throttle revealed itself to be twitchy with a poor response, and steering didn’t feel very good. The steering got heavier as speed increased, but it also wanted to jerk all over the place. These are profoundly unwelcome feelings when driving a small and powerful vehicle that lurches into motion as soon as the accelerator is pressed.

Overall, one could say the experience populated the proverbial to-do list quite well. The earlier incarnation of [Peter]’s kart was a thrilling ride, but the challenge of maintaining adequate control over a moving platform serves as a reminder that design decisions that do the job under one circumstance might need revisiting in others.

DIY Quad-Motor Go-Kart Is A Thrilling Ride

[Peter Holderith] set out some time ago to build an electric go-kart. That by itself is not terribly unusual, but where his project diverts from the usual is in the fact that each of the four wheels has an integrated hub motor.

It might not look it, but each wheel has an integrated hub motor.

This kart project is a bit of a work in progress, with [Peter] previously building (then scrapping) a failed attempt at a cheap suspension system. But it’s completely operational with all four wheels able to deliver a monstrous amount of power despite being limited by the power supply (a battery pack salvaged from an Audi Q5 Hybrid).

The kart might not look it, but it weighs 177 pounds (80 kg) with the battery and motors accounting for nearly half of that. What is is like to drive? “Nothing short of thrilling,” says [Peter]. It’s got no suspension and is pretty bare bones, not to mention limited in power by the battery, but [Peter] finds it a satisfying drive that nevertheless delivers car-like cues in the driving experience. The build isn’t done, and [Peter] plans to see if more power is available by switching battery chemistries rather than add more battery weight.

Building and driving electric vehicles can be remarkably satisfying, and it’s an area in which hobbyists can meaningfully innovate. Self-balancing one-wheeled vehicles for example look like a ton of fun. Heck, researchers have discovered that even rats seem to enjoy driving just for the fun of it.

This Go-Kart Rides On A Pallet

Many beginner woodworkers, looking to offset the introductory costs of starting a hobby, will source their wood from pallets. Generally they’re easily found and can be low or no cost, but typically require a bit of work before they’re usable in a project. [Garage Avenger] is looking to do something a little outside of the box with his pallet project, though. He’s using raw pallets as a chassis for a four-speed go-kart, partially for the challenge and excitement and also to one-up a Pinterest post.

Almost immediately, though, the other major downside of working with pallets arose which is that they’re generally built out of low-grade pine which is soft and flexible. Flexibility is generally not a good thing to have in a vehicle frame so plenty of the important parts of this build were strengthened with steel tubing including the rear axle, steering mounts, and a few longitudinal supports to strengthen the overall frame. After working out some kinks with ordering a few of the wrong parts, and mounting the steering box backwards, it was time to test out the four-speed engine (and brakes) on the the go-kart, making it nearly ready for the road.

To complete the build, some tidying of wiring and fuel lines was done, along with improving some of the non-critical parts of the build like the bucket seat. Of course, adding pallet spoilers and body kit puts the finishing touches on the build and the go-kart is finally ready to tear up the local go-kart track and the less-inspiring Pinterest projects. [Garage Avenger] is no stranger to strange vehicle builds, either. Although it’s a bit out of season for most of our northern hemisphere readers now, his jet-powered street sled is still worth a view.

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Giant 3D Printer Aims To Produce Life-Sized Boat

As 3D printers become more ubiquitous, the number of custom designs and styles of printers has skyrocketed. From different printing materials and technologies to the movements of the printing head, we’ve seen all kinds of different takes on these tools. But one thing that has been largely limited to commercial and industrial use has been large print sizes —  leaving consumer level prints to be split into several pieces to fit together later. Not so with this giant 3D printer from [Ivan], though.

The design goals for this build are to print an entire boat that [Ivan] can captain himself, and additionally an entire go kart chassis in a single piece. It’s part of a contest between him and another YouTuber and as far as we can tell he’s well on his way to completing the challenge. The printer will be able to churn through 4 kg of filament per day, and has a printable volume of 1000x1000x1420 millimeters, or just shy of 1.5 cubic meters.

While this video is just the first step of building the frame and the printer guides, we can’t wait to see the next steps in the process. It’s one of the largest 3D printers we’ve ever seen, at least outside of printers designed for building entire houses out of concrete.

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Mahmut's kid in a helmet, riding the go-kart outside on pavement

Hoverboard Go-Kart Build Is A Delight To Watch

Hoverboards have been an indispensable material for hackers building their own vehicles in the last few years. [Mahmut Demir] shows how he’s built a hoverboard-powered go-kart for his son. Unable to hack the board’s firmware, he instead set out to reuse the hoverboard without any disassembly, integrating it into the go-kart’s frame as-is. This build is completely mechanical, distinguished in its simplicity – and the accompanying six minute video shows it all.

This go-kart’s frame is wood and quite well-built, with the kind of personal touch that one would expect from a father-son gift. Building the vehicle’s nose out of a trashcan gave us a chuckle and earned bonus points for frugality, and the smiley face-shaped wheel is a lovely detail. As for the ‘hoverboard reuse’ part, the board is pivoted backward and forward, just as it normally would be. Rather than feet, the kart uses a lever that’s driven with two pedals through a pulley-string arrangement, giving granular speed control and the ability to reverse. It’s a clever system, in fact we don’t know if we could’ve done it better. You can see [Mahmut]’s son wandering in the background as [Mahmut] goes through the assembly steps — no doubt, having fun doing his own part in the build process.

[Mahmut] tells us he’s also added a remote off switch as a safety feature, and we appreciate that. We’ve seen hoverboards in go-kart builds before, as well as rovers, e-bikes, robot vehicles, and even mobility platforms. Truly, the hoverboard is a unicorn of hacker transportation helpers.
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Go-Kart Reverse Without The Pain

Go-karts are a huge amount of fun, but often lack the most basic of mechanical conveniences such as a reverse gear. You can’t start a small four-stroke engine in reverse, so their simple chain drive transmissions lack the extra cogs to make it happen. Enter [HowToLou], who has given his go-kart a reversing option by the addition of an electric motor.

It’s an extremely simple arrangement, the motor is a geared 12 V item which drives a V-belt to the axle. The motor is mounted on a pivot with a lever, such that normally the belt isn’t engaged, thus reverse can be selected by pulling the lever. A simple button switch applies power to the motor, meaning that the machine can travel sedately backwards on electric power.

We’re not entirely convinced by the integrity of some of his fixings and it would be interesting to see how much the V-belt wears under the influence of the pulley when not engaged, but as an alternative to a full gearbox we can see the point. But then again as regular readers may know, we’re more used to full electric traction.

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Fail Of The Week: Alternator Powered Electric Go-Kart Doesn’t Go

What do you give a six-year-old who loves going fast but doesn’t like loud noises? Convert a gas go-kart to electric of course! (Video, embedded below.) That goal started [Robert Dunn] of Aging Wheels down a long path toward a go-kart that almost, but doesn’t quite… work.

If you’ve watched any of [Robert’s] videos, you know he doesn’t take the easy path. The man owns a Trabant and Reliant Robin after all. Rather than buy a battery pack, he built his own 5S24P pack from individual LiFePO4 cells. Those cells generally are spot welded, so [Robert] built an Arduino-controlled heirloom-quality spot welder. Now while the welder could handle thin nickel strips, it wasn’t up the task of welding high current nickel-plated copper. When attempts at a solution failed, [Robert] built a system of clamped copper bus bars to handle the high current connections for the batteries.

If batteries weren’t hard enough, [Robert] also decided he wasn’t going to use an off-the-shelf motor for this project. He converted a car alternator to operate as a brushless motor. We’ve covered projects using this sort of conversion before. Our own [Jenny List] even wrote a tutorial on it. [Robert] unfortunately has had no end of trouble with his build.

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