Slot car racing for the rest of us

I’ve always wondered about the slot car craze of the 70′. I heard so much about it. But I never did understand its lure. Unlike RC flying, slot car racing provides a racer with only one degree of control. You go fast, or even faster, until your slot car derails, and flies off a track.

Classic slot car racing

After I bought a starter kit recently, I now appreciate why classic slot car racing can be a hobby, and not just a toy. I get that at the enthusiast end of the spectrum, die-hard collectors and racers build elaborate custom tracks and cars. I know that at the toy end of the spectrum, cheap slot car kits are available for $30 to keep toddlers entertained.

But the majority of potential customers for slot cars do not belong to either end of this spectrum. There is a reason why slot cars soon faded from the popular stage. Most casual users find the experience thrilling only for a brief moment. After an initial adrenaline rush, the game soon become repetitive and one-dimensional for casual users.

Table of Contents

What’s missing in slot cars for the rest of us

In 2013, Anki Drive almost brought about the second coming of slot cars. But it too quickly faded into oblivion. I think I know why, based on my own first-hand experience. You see, I bought Anki Drive on the spot when I first saw it at a store. There was something irresistible about these iPhone-controlled miniature cars. Unlike classic slot cars, these let you roam with two degrees of freedom. And you could engage in virtual battles with opponents. Everyone who raced Anki Drive at my house found it thrilling.

Anki Drive cars controlled via iPhones

But the entertainment value of Anki Drive did not last. I think two reasons explain it. For the VR generation, video games such as Final Approach was much more immersive, offered more variety of game plays, and provided real-time competition against online friends.

Final Approach VR – air traffic control

For people such as myself, the lack of tactile feedback on control surfaces made the game play of Anki Drive imprecise, inconsistent, and therefore unattractive. While it featured physical cars, its tracks were flat, virtual and non-customizable, further subtracting from physical immersion. For more info on Anki Drive, see iFixit’s Anki Drive teardown.

The flat track pad of Anki Drive

Unique appeals of classic slot car racing include building physical tracks, controlling cars with tactile feedback, seeing cars fly by at surreal scale speed of 1,000 miles per hour, and hearing a cacophony of noises made by motors, wheels and tracks. Add to these the thrill of seeing one’s painstaking labor pay off, resulting in superb racing circuits created from raw track materials. Also do not discount the feeling of accomplishment derived from maintaining, fixing and upgrading one’s slot cars, in a fierce competition to one-up friendly competitors.

Slot cars running at the equivalent of 1,000 mph at 1/64 HO scale

Other unique features of slot car racing fascinate enthusiasts, but bore casual racers such as the rest of us. For instance, the lack of reverse drive and lane changing actually enables an enthusiast to single-mindedly focus on the throttle, to strive to consistently drive a car through steep turns at the maximum speed possible, just short of causing a spinout and thus derailment. For us casual racers, spending hours to perfect such turn maneuvers is a torture. And having to get up to pick up and replace our spun-out cars is not enjoyable. While four people can race on a four-lane track, no one is truly racing against others. Classic slot cars do not interact with one another, unlike real-life racing. Every racer is really just racing against their own personal records. This again fascinates enthusiasts, but bores the rest of us.

I have some ideas about what to do, with respect to issues I raised. I will talk about them at the end of this article. But first, I’ll document some of my experiences that you won’t find elsewhere online. Some of these pertain to a particular brand of HO-scale slot cars and tracks I bought. Some have to do with lack of accessories for casual racers such as myself. I modeled and 3D-printed these missing accessories. Readers with similar tracks and cars may download my 3D models, and print them on their own printers.

Unboxing the Super International set from AFX

I needed a slot car setup for small parties, for racers who may have never laid hands on slot cars. I wanted something more elaborate than a boring, circular racing track. And the more racers it accommodates the better. This would not be a permanent installment, so the setup needed to be disassemblable. Usually space is at a premium, so the smaller the slot cars the better.

All of these considerations led to the Super International raceway set from AFX. This is a 1:64-scale model which in slot car circles is known as an HO-scale. AFX is the same as Aurora which is the same as Racemaster. I won’t go into details that you can easily find online. Try this encyclopedia of terminology for HO-scale slot cars. You can find plenty of enthusiasts discussing slot cars at SlotForum. For commercially-available slot cars, check out the 1:64 shop and the YouTube channel of the king of slot cars.

The Super International set from AFX

This set alone is enough to set up a race track for small parties I had in mind. It comes with enough track materials to re-create 18 different international circuits, including the famed Suzuka circuit depicted on the box. Four slot cars and four controllers come with the set. Everything I need for my parties is in this box.

An assembled track is shown below. It accommodates four slot cars simultaneously. The circuit does take up considerable floor space. But this is already the smallest scale available commercially. Larger scales such as 1:43 or 1:32 would take up even more space.

Suzuka circuit assembled per instructions

A hobby, and not a toy

The AFX set I bought is a hobby-grade pack. This set is often glued or fastened to large plywood tables for permanent use. Despite what the box says, this set should not be bought and given to a small child, for assembly and use without adult supervision. While it is almost infinitely expandable with myriad compatible tracks, cars and accessories from Aurora and other compatible brands, these parts often require repair even fresh out of a new box. I have more to share about such repairs shortly. But for now, it suffices to say that if you want toy-grade slot cars, you are better off buying much cheaper alternatives on Amazon. Those, however, will be mostly one-off kits that are not compatible with anything else, and thus not expandable or customizable.

I will soon show you some of these manufacturing and assembling defects I mentioned. This hobby is like most hobbies – it requires time and skills. I think folks tolerate these defects, because this hobby is a niche market today – beggars can’t be choosers. But more importantly, none of required repairs are beyond an enthusiast. Repairs and enhancements of tracks and cars are simply a part of the hobby.

But first, I want to establish that most of what I got from the set are beautifully made. These tracks and cars have stood the test of time. Here are some track pieces. These are well-designed and well-manufactured. Connections between pieces work well, and pieces fit tight when connected.

Beautifully-made track pieces

Furthermore, these HO-scale slot cars are also beautifully designed and manufactured. They are tiny, yet they have great details, run surprisingly well, and are basically indestructible. I figured that these cars would be flying off corners. I figured they’d be hitting stone tables, glass doors, and other unforgiving surfaces. And I would need spare cars at parties to make up for broken ones. Indeed, cars flew off tracks every 30 seconds in the hands of inexperienced merrymakers. They in fact did hit hard surfaces repeatedly at incredible speeds. But surprisingly no cars have sustained any damages at all so far.

Indestructible slot cars

So, what are some of the issues I found and addressed? Let’s start with minor annoyances. About half of track pieces come with oil slick on their surface. Many Amazon reviews alluded to the same, but I did not pay these allegations much thought when I made my order. After all, just wipe them off with a towel already – I figured. But boy, was the oil slick annoying. I didn’t realize that I had this issue at hand, until mid way into assembling a racing circuit. Oil got everywhere. I had to take apart all pieces, and thoroughly inspect and clean those affected.

Oil slick on surface of some track pieces
More oil slick on the back side

The track piece shown below has a severely bent metal rail. But it turned out cars run just fine over these two marked sections. Pickup shoes on the bottom of slot cars seem to make contact with the rail alright.

Bent track rail

One of the four cars from the set came with a missing front tire. The seller had Aurora send me a tune-up kit that contains among other spare parts two front tires. I received nothing but great service from both the seller and Aurora. The missing tire was the only issue I could not fix myself.

One car came without a front tire

This beautiful Ford GT didn’t run well out of the box. After comparing it to other cars, and lifting the body from the chassis, I realized that one wheel rubbed against the car body while turning. On that chassis, the gear spacer circled in green was installed at a small offset such that one wheel was closer to the chassis than the other one. Perhaps the gear spacer could be moved. But I simply swapped in another chassis from an F2 car from the Super International set.

A rear tire rubbed against body

The chassis I put into Ford GT had a pickup shoe that did not move right. About 5 times more pressure was needed to squeeze this pickup shoe, compared to the other side. Initially I thought the spring under the metal strip was not right. But then I realized that the metal slot circled in yellow below was ill-positioned.

Metal slot for the pick-up metal strip was ill-positioned

It turned out the printed circuitboard wasn’t properly seated. It took me a while to push the PCB into the right place, such that the metal slot is moved back to the right location.

PCB board was not originally seated flush against chassis

I also bought an AFX Infinity Raceway set. This is a great deal. The set can be had for the equivalent cost of the two exquisite Formula N cars that came in the set. So everything else in the box was basically free: track pieces, track accessories, power supply, and two controllers.

AFX Infinity Raceway set

However, the connector from the power supply made no contact with the track. I forcefully pried open the top cover, and found misshaped internal support. I then applied some epoxy to provide equivalent support to the two metal contact strips.

Metal contact strips were not properly supported

Look, I do realize that this level of maintenance is not for everybody. I did say this was a hobby, and not a toy. Even though it says on the corner of the box shown above, “for Age 8+”, this is honestly not for 8 year olds without adult supervision.

If you have not been scared away yet, and are still with me, then the rest of this article is for you. I think of the rest of us as “casual hobbyists”.

3D-printed cable bridge for 4-lane tracks

As a casual slot car hobbyist, I wasn’t going to mount a circuit on a huge table permanently. Unlike die-hard enthusiasts, I wasn’t going to drill holes on a tabletop, and route cables away from tracks into the table. So, the first thing I had to deal with, when I laid my 4-lane track on the floor, was the three cables trapped inside the Suzuka circuit, circled in yellow in the picture shown below.

What to do with cables trapped inside a circuit?

This circuit includes raised track sections. So I rerouted cables under a support bridge. That may work for this circuit. But no other international circuits in this set feature raised tracks. What is one to do with these cables?

I found no accessories online from Aurora to deal with this issue. Perhaps other brands such as Auto World with compatible tracks do sell cable management accessories. But I simply designed a cable management bridge in OpenSCAD, and printed it out on the same day. Ain’t it beautiful?

3D-printed cable management bridge for 4-lane tracks

The bridge clips onto tracks the same way guardrails clip onto tracks. Now these cables won’t come into contact with cars during races. I haven’t had time to prep for upload to Thingiverse. For now, if you want to print it yourself, grab this STL file.

3D-printed carrying case for four 1:64 cars

The next issue I encountered, as a casual hobbyist, was the lack of carrying cases for slot cars. Die-hard enthusiasts build display cabinets for their large slot car collections. I just needed a few feeble storage boxes for my tiny collection. Yeah, I made one myself, with space for four 1:64-scale slot cars, plus a tune-up kit. This box is based on a storage box by Aaron Newsome at Thingiverse model 82533.

3D-printed carrying box for 4 HO-scale cars, plus one tune-up kit

Again, I haven’t had time to prep for upload to Thingiverse. For now, if you want to print it yourself, grab this zip file. There are three STL files. The one with thin walls is what I printed. With Prusament PVB, they come out semi-translucent. There is another STL with thick walls, and a third one with intermediate wall thickness. Rotate the 3D model in your slicer to fit your print bed as needed. The box “prints in place”, meaning that these hinges are printed, in place, already pre-engaged. This box fits my Prusa i3 MK3S print bed.

3D-printed support platform for iPhone SE2

As a casual hobbyist, I wasn’t going to spend hundreds of dollars buying lap counters. There are people who wire a PC or a laptop to serve as lap counter displays. There may be Raspberry Pi solutions out there as well. But I simply went with the LapTracker app. This app has not been updated in 4 years. And it is quite buggy. But it’s the only lap counter app out there. I found that as long as I did not use my fingers to move virtual detection boxes, it more or less ran reliably.

I designed a support platform for my iPhone SE2. It places the phone at just the right height, such that default configuration set by LapTracker places the four virtual detection boxes over the 4 lanes. As I mentioned, if I so much as move one detection box by one pixel, the app starts to register false triggers at random.

3D-printed support platform for iPhone SE2 for LapTracker
3D-printed support platform for iPhone SE2 for LapTracker

I have plans to make trivial changes to the support platform, so that its height becomes adjustable, for different mobile phones. The phone clip can be generalized as well. But I haven’t got time yet for that. So, if you happen to carry an ancient iPhone SE2 like I do, grab this zip file.

The Suzuka circuit with 3D-printed accessories

Here are some pictures of the Suzuka circuit complemented by these 3D-printed accessories. Together they are now a complete party package.

Complete party package

Disassembling a circuit for transportation to a party

Now I’ve got to transport my racing circuit to a party. I break the circuit up into only 13 chunks, and not completely down to individual track pieces. I label each chunk for identification later.

Labeling sections of a circuit during disassembly

You can now wrap the two sections of each chunk with painter’s blue tape. Stick all of them into a luggage for easy transportation.

At your destination, it won’t take much time to piece back these chunks.

Track clips

Track clips keep your track pieces tightly connected. Tightly connected pieces present smoother racing surfaces and better electric contacts between connected rails. Track clips are invaluable when you need to pack up disassembled chunks. It protects these chunks, preventing pieces in them from being shaken loose during transportation. Loose connections are prone to bending, when shaken during transport, or handled by people later.

One hundred track clips were barely enough, to keep the 13 chunks of the Suzuka circuit together.

There are no high-quality pictures online showing how these clips actually work. So I took a few pictures. Yellow circles below highlight the two connection points to be clamped with track clips.

Circles highlight where track clips go

Following illustrates a connection point before, during, and after application of a track clip.

How to clip two pieces of track together

Why slot car racing becomes boring fast

I mentioned that slot car racing becomes boring fast for casual racers. The monotony of the race is one key reason. I already cited the lack of lane changing and the lack of car-to-car interactions. I also mentioned the razor-thin zone between a speed that derails a car, and a speed that causes one to lose a race. This tiny zone is further exacerbated by the insane speed at which 1:64-scale cars run.

Just how insanely fast do they run?

Instead of citing unrelatable numbers to you, I’ll just repeat the same video I’ve already shown you. Take some time to appreciate how fast these cars run. They are running at slightly below derailment speed. These cars run so fast, partially thanks for magnets on chassis that keep cars glued to tracks.

Actual speed of 1:64-scale slot cars

If these slot cars were to run at scale speed, the race would look like shown below. This video is slowed down 10 times to simulate a bird’s eye view of a real F1 racing.

10x slow motion showing equivalent scale speed

I have tried to invent new racing types, in an attempt to make races more interesting to casual racers. Most of these inventions failed. One of them was “see-who-manages-to-finish-last”. The idea was to force racers to make their cars crawl as slow as they could, without physically stopping a slot car on its lane.

This turned out to be quite hard, as cheap controllers from a set usually have inaccurate and non-uniform potentiometers. Thus it was difficult to keep the throttle almost open, without cutting off current supply to a lane. In addition, slot cars running at a near-stall speed tend to run out of momentum at turns, when one of their pickup shoes loses contact with a rail. Now one has to walk over to the car to reseat it before it would run again. Nonetheless, this and other weird race types did provide some temporary relief between monotonous “fastest-lap” and “shortest-total-time” races.

Be mediocre by placing 2nd

One race type I invented turned out to be popular. Folks did not seem to tire of this race type. I called it “be-mediocre-by-placing-2nd”.

As you can guess from the name, the winner isn’t the first person to finish a predetermined number of laps, say 3 laps. You also don’t win by finishing last, say coming in 4th in a 4-lane race. Beating the 4th car fails to make you a winner either. Instead, you win by placing 2nd at the finishing line.

This race type is magical, because it re-introduces car-to-car interactions that has been missing in slot car racing.

A racer needs to track where the pack is, throughout predetermined laps. One needs to adjust speed in relation with everyone else. This combines elements of traditional “shortest-total-time” with those from “see-who-manages-to-finish-last”. Here is a video of an actual race.

Beyond new race types

Partygoers obviously don’t bring their own custom slot cars to casual races. They pick up whatever car is given to them. But every car is slightly different, even if they are of the same class. Then there are dozen types of slot cars that can run on these 1:64 Aurora tracks.

To make party races fun and even-handed, I have come up with a set of rules that appears to work well. It eliminates, to a large extent, unfair advantages resulting from differences in cars, controllers, and lanes.

Slot car racing rules

  • There is a race every 15 minutes
  • 4 drivers vote on the type of race to run
  • Each driver picks a lane, in order…
  • … and then a car, in reverse order
  • Practice until race starts
  • Swap cars and/or lanes with consent
  • Those in line for the next race pick up derailed cars
  • Botched races can be restarted once

I have additional ideas involving physical contacts in races. These should introduce even more variability and interactivity into races. Perhaps I’ll write about them one day.

About Xinhai Dude 辛亥生

The name Xinhai Dude 辛亥生 is a pun in Chinese, as it means both “he who was born in Xinhai” as well as “he who studies Xinhai”. I had an ambitious plan to write something about the great Xinhai Revolution of 1911, thus my blog But after an initial flurry of activities the initiative petered out. One day I will still carry it through. But for now, this website has turned into a conglomerate of my work on various topics of interest to me, including travel pictures, RC model airplane flying, inline skating, ice skating, classical music composition, science fiction short stories, evolution and atheism.
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