Mobile Sauna For On-The-Go Relaxation

July 30, 2021 by Bryan Cockfield 6 Comments

While it might be nice to imagine owning a cabin in the woods to escape from society, complete with an outdoor sauna to take in the scenic views of nature, most of us will be satisfied with the occasional vacation to a cabin like that. For those trips, or even for long-term camping trips, [Schitzu] and a group of friends thought it would be nice to be able to ensure access to a sauna. For that, they created this mobile, timber-framed sauna that he can tow behind his car.

The sauna is built out of a combination of spruce and Douglas fir, two types of lumber with weather-resistant properties. For an additional layer of protection, the frame was varnished after assembly. The walls are filled with baked cork for insulation, and heat is provided by a small wood-fired oven placed in the corner of the sauna with a stove pipe plumbed through the roof. Performance of the sauna shows good design too, as it can heat up quickly and performs well in all of the tests so far. The final touch on the mobile sauna was to finish the roof with some solar panels in order to gather some energy for long-term camping trips and also to ensure that the roof was protected from rain and weather.

The sauna is designed for two adults to sit in, but it will also accommodate a single person to lay down and sleep (presumably when not using it as a sauna), so the entire trailer actually makes a fairly capable mobile camper too. With the addition of a panoramic window, anyone can take in the sights as well as someone with their own permanently-located sauna could, which is a win in all of our books. If you’re looking for a mobile sauna that’s a little more discrete though, be sure to check out this one which is built in the back of a white panel van.

How To Modify Your Car Stereo For Bluetooth Or Aux-In

July 28, 2021 by Lewin Day 42 Comments

If you’re an automotive enthusiast of taste, you can’t stand the idea of fitting a janky aftermarket stereo into your nice, clean ride. Flashy, modern head units can spoil the look of a car’s interior, particularly if the car is a retro, classic, or vintage ride.

Thus, we’re going to look at how to modify your existing stock car stereo to accept an auxiliary cable input or even a Bluetooth module. This way, you can pump in the latest tunes from your smartphone without a fuss, while still maintaining an all-original look on the dash.

Fundamentals

A simple Bluetooth module designed for wiring into car audio systems. There are two wires for 12 V power from the vehicle, and the audio signal is sent out over the RCA plugs. The RCA plugs can be cut off and the module hard wired inside your stereo if you have room. Cutting off the plastic case can help too.

Depending on your choice of audio player, you may prefer a 3.5 mm aux jack, or you might want to go with Bluetooth audio if your smartphone no longer has a headphone port. Whichever way you go, the process of modifying the stereo is largely the same. To achieve your goal, you need to find a way of injecting the audio signal into the head unit’s amplifier stage, while making sure no other audio sources are getting sent there as well.

Whether that audio source is a 3.5 mm jack or a Bluetooth module doesn’t matter. The only difference is, in the latter case, you’ll want to buy a Bluetooth module and hardwire it in to the auxiliary input you create, while also splicing the module into the stereo’s power supply. In the case of a simple headphone jack input, you simply need to wire up an aux cord or 3.5 mm jack somewhere you can get to it, and call it done.

This guide won’t cover every stereo under the sun, of course. Edge cases exist and depending on the minute specifics of how your original car radio works, these exact methods may or may not work for you. However, this guide is intended to get you thinking conceptually about how such mods are done, so that you can investigate the hardware in front of you and make your own decisions about how to integrate an external audio input that suits your usage case. Continue reading “How To Modify Your Car Stereo For Bluetooth Or Aux-In” →

The Case Of The Mysterious Driveline Noise

July 14, 2021 by Lewin Day 31 Comments

Spend enough time on the automotive classifieds and you’ll end up finding a deal that’s too good to pass up. The latest of these in one’s own case was a Mercedes-Benz sedan, just past its twentieth birthday and in surprisingly tidy condition. At less than $3,000, the 1998 E240 was too good to pass up and simply had to be seen.

The car in question. Clean bodywork is too tempting to resist, even if there are mechanical issues.

The car was clean, too clean for asking price. Of course, a test drive revealed the car had one major flaw – an annoying hum from the drivetrain that seemed to vary with speed. Overall though, mechanical problems are often cheaper and easier to fix than bodywork, so a gamble was taken on the German sedan. The first order of business was to diagnose and rectify the issue.

Characterise, Research, Investigate

The first step to hunting down any noise is to characterise it as much as possible. In this case, the noise was most noticeable when the car was traveling at speeds from 40 km/h – 60 km/h, present as a vibrational humming noise. The location of the noise source was unclear. Importantly, the noise varied with the speed of the car, raising in pitch at higher speeds and dropping as speeds decreased. Engine speed had no effect on noise whatsoever, and the noise was present regardless of gear selected in the transmission, including neutral. Continue reading “The Case Of The Mysterious Driveline Noise” →

The Nuclear Powered Car From Ford

July 8, 2021 by Al Williams 42 Comments

We think of electric cars as a new invention, but even Thomas Edison had one. It isn’t so much that the idea is new, but the practical realization for normal consumer vehicles is pretty recent. Even in 1958, Ford wanted an electric car. But not just a regular electric car. The Ford Nucleon would carry a small nuclear reactor and get 5,000 miles without a fillup.

Of course, the car was never actually built. Making a reactor small and safe enough to power a passenger car is something we can’t do even today. The real problem, according to experts, is not building a reactor small enough but in dealing with all the heat produced.

Continue reading “The Nuclear Powered Car From Ford” →

Can The Solenoid Engine Power A Car?

June 26, 2021 by Bryan Cockfield 12 Comments

[Emiel] aka [The Practical Engineer] makes all kinds of fun projects in his fully-featured shop, and one of his tangents has been building a series of solenoid engines. These engines mimic the function of an internal combustion engine, with each solenoid acting as a piston. The only problem with [Emiel]’s concept engines, though, was that he never actually put them into a vehicle to prove their effectiveness. This build finally proves that they can work at powering a vehicle.

The project starts with a new engine. [Emiel] chose a V4 design using four solenoids and an Arduino-based controller. After some trouble getting it to operate properly, he scavenged a small circuit board he built in his V8 solenoid engine to help with timing. With that installed, the solenoids click away and spin the crankshaft at a single constant speed. The vehicle itself was mostly 3D printed, with two aluminum tubes as support structures to mount the engine. Even the wheels were 3D printed with a special rubber coating applied to them. With a small drive train assembled, it’s off to the races for this tiny prototype.

While the small car doesn’t have steering and only goes at a constant speed, the proof of concept that these tiny electric engines actually work is a welcomed addition to [Emiel]’s collection of videos on these curious engines. Of course they’re not as efficient as driving the wheels directly with an electric motor, but we all know there’s no fun in that. If you haven’t seen his most intricate build, the V8 is certainly worth checking out, and also shows off the timing circuitry he repurposed for this car.

Continue reading “Can The Solenoid Engine Power A Car?” →

Retrotechtacular: Discovering Aerodynamics With The Chrysler Airflow

June 16, 2021 by Dan Maloney 31 Comments

When you think about it, for most of human history we’ve been a pretty slow bunch. At any time before about 150 years ago, if you were moving faster than a horse can run, you were probably falling to your death. And so the need to take aerodynamics into consideration is a pretty new thing.

The relative novelty of aerodynamic design struck us pretty hard when we stumbled across this mid-1930s film about getting better performance from cars. It was produced for the Chrysler Sales Corporation and featured the innovative design of the 1934 Chrysler Airflow. The film’s narration makes it clear why the carmaker would go through the trouble of completely rethinking how cars are made; despite doubling average engine horsepower over the preceding decade, cars had added only about 15% to their top speed. And while to our 21st-century eyes, the Chrysler Airflow might look like a bulked-up Volkswagen Beetle, compared to the standard automotive designs of the day, it was a huge aerodynamic leap forward. This makes sense with what else was going on in the technology world at the time — air travel — the innovations of which, such as wind tunnel testing of models, were spilling over into other areas of design. There’s also the influence of [Orville Wright], who was called in to consult on the Airflow design.

While the Airflow wasn’t exactly a huge hit with the motoring public — not that many were built, and very few remain today; [Jay Leno] is one of the few owners, because of course he is — it set standards that would influence automotive designs for the next 80 years. It’s fascinating too that something seemingly as simple as moving the engine forward and streamlining the body a bit took so long to hit upon, and yet yielded so much bang for the buck.

Continue reading “Retrotechtacular: Discovering Aerodynamics With The Chrysler Airflow” →

Electric Vehicles Could Be The Grid Storage Solution We’ve Been Dreaming Of

June 7, 2021 by Lewin Day 157 Comments

As nation states grapple with the spectre of environmental and economic losses due to climate change, we’ve seen an ever greater push towards renewable energy sources to replace heavier polluters like coal and natural gas. One key drawback of these sources has always been their intermittent availability, spurring interest in energy storage technologies that can operate at the grid level.

With the rise in distributed energy generation with options like home solar power, there’s been similar interest in the idea of distributed home battery storage. However, homeowners can be reluctant to make investments in expensive batteries that take years to pay themselves off in energy savings. But what if they had a giant battery already, just sitting outside in the driveway? Could electric vehicles become a useful source of grid power storage? As it turns out, Ford wants to make their electric trucks double as grid storage batteries for your home.

Continue reading “Electric Vehicles Could Be The Grid Storage Solution We’ve Been Dreaming Of” →