The (Not So) Evil Traction Magnet

By Michael Ashton

Like most hobbies, the slot car hobby has its share of ‘religious beliefs’ that are constantly being debated, often vehemently. Routed wood vs. sectional plastic track; analog vs. digital; silicone vs. rubber tires. And arguably the most controversial of all — running with vs. without a traction magnet. Visit any of the major Internet slot car forums or a retail establishment or club that has a slot car track, and at least one of these debates will inevitably flare up. All of these doctrines tend to divide slot car enthusiasts into two opposing camps that defend their respective positions passionately. This article will focus on the traction magnet debate, affectionately known as ‘mag vs. no-mag’. It is important to note that any discussion of slot car traction magnets applies only to track which uses metal rails that will exhibit some degree of magnetic attraction (i.e., magnets will have no effect on a routed wood track that uses copper tape for its rails).

The vast majority of ready-to-run slot cars come with a traction magnet installed, usually somewhere between the mid point of the chassis to just in front of the motor in sidewinder configuration or the rear axle in in-line cars. These magnets usually fit into an open chamber in the cassis and are held in place by small tabs. Occasionally, as is the case with Carrera cars, the magnet is held in place by a screw-in holder which is very secure.

The majority of modern slot car magnets are made of neodymium alloy which has very strong magnetic properties. The magnet is attracted to the metal rails of the slot car track, therefore, creating additional downforce. Its purpose is twofold:

1. Encourage the car to stay in the slot.
2. Increase traction in the rear tires.

This will tend to enhance the performance of just about any slot car, especially those which exhibit inherently poor handling characteristics such as narrow width, high center of gravity and uneven weight distribution. The downward force of the magnet creates a drag effect which tends to slow the car in the straightaway sections but allows significantly higher cornering speeds which, in turn leads to faster lap times. This does not necessarily make a car easier to drive because it becomes more difficult to judge the limit of adhesion, especially at high speeds. When a car equipped with a powerful magnet exceeds that limit the result is very often a violent, ’snapping’ de-slot which could possibly result in significant damage to the car.

Slot car traction magnets come in a variety of shapes, sizes, and levels of magnetic force.

The following photos illustrate some typical magnet installations, highlighted by the red arrows.

A large flat bar magnet installed in front of the motor in a sidewinder chassis.

A button magnet installed mid-chassis in an angle-winder chassis.

A bar magnet installed under the motor shaft in an in-line chassis.

An in-line chassis with two magnets installed, in front of and behind the motor.

What’s the Issue?

There is a myriad of things that can be done to a poor handling slot car to improve its performance. This is generally referred to as ‘tuning’. Three of the most common issues are: 1.) de-slotting too easily (especially in the corners); 2). fishtailing (wide swaying of the rear end, also in the corners); and 3.) a tendency to tip (again, in the corners) due to high center of gravity (COG). All of these issues indicate the need for increased downforce and/or better weight distribution.

These issues can be dealt with in one of two ways — either by adding weight (ballast) to improve weight distribution and increase traction, or installing a magnet that creates enough downforce to effectively mask the problems. Generally speaking, the magnets that are installed in ready-to-run slot cars at the factory tend to be very powerful and positioned to provide maximum downforce.

So, what to do? Mag or no-mag? This is where things tend to get very serious because otherwise mild-mannered, rational people begin to lose their composure and end up divided into two seemingly irreconcilable camps. There are those who believe that all slot cars must have at least one magnet so that they can be run at the fastest speeds that the laws of physics will allow and handle as a ‘modern’ car would. Then there is the camp that believes any slot car — no matter how unwieldy — can be tuned to run well by adding weight to various points of the chassis, or changing critical components such as the guide or rear tires, or in extreme cases, replacing the entire drive train and/or chassis itself! For this camp, resorting to the use of magnets is a sign of weakness that brings one’s very manhood into question.

The Path of Least Resistance

My preference is to try to run without the magnet, whenever possible and appropriate. Once I become sufficiently familiar with a newly acquired slot car, I like to place it in one of three categories:

1. Cars designed to run without a magnet.
2. Cars that should run with a magnet.
3. Cars that run poorly without a magnet.

There are a number of slot cars that, although come equipped with a traction magnet, are actually designed to run without the magnet. For example, Slot.it, NSR and Ninco cars fall into this category. They perform very well with the magnet out-of-the-box, however, they also exhibit superior performance without the magnet and with little to no tuning at all. I almost always run these cars without the magnet.

There are certain classes of cars that I feel should be run with a magnet because it creates handling characteristics that more closely reflect the actual (1:1) car that they represent. LMP, certain GT sports cars and modern Formula 1 are in this category. This relates more to creating a realistic racing experience than improving handling and performance. Remember that this is my opinion.

Lastly, are cars that are designed to run with a magnet installed. These cars could be from any manufacturer and they may be able to run without a magnet on smooth, flat track surfaces, but usually require significant tuning and/or modification in order to obtain an acceptable level of performance. This is the category where I have occasionally found cars that I simply could not get to run well without the magnet, even after some of the most aggressive tuning tricks were applied.

One slotting enthusiast once told me that he absolutely refuses to ‘give in’ to the use of a magnet. That there is no such thing as the car that he can’t tune to run well with a little weight added here and there. Then he revealed his secret: he glued half a pound of lead to the underside of the chassis and turned the track voltage down to 9 volts! This is ‘tuning’?

Then there’s the guy who runs with three magnets creating so much downforce that the car sticks to the track when held upside down. Track voltage must be turned up to 18 volts just to overcome the drag created by the magnets and the motors sometimes catch fire! But the car never de-slots!

Now I’m not disparaging either of these approaches to enhancing performance. And, yes I may have exaggerated a little, and everyone is entitled to enjoy this hobby in their own way. But people at the extreme ends of things tend to become somewhat evangelistic and can occasionally get a little emotional when another point of view is presented. Nevertheless, I believe that there is a middle ground.

I have found that it is possible to tune a slot car using one or more relatively mild magnets, resulting in performance and handling characteristics that are quite similar to that of running without a magnet. Moreover, this car will afford the average home racer a wider margin for error resulting in more fun and less stress. There is no special talent needed and no voodoo involved. In fact, some manufacturers provide this capability in their cars straight from the factory. Carrera typically includes two bar magnets in their chassis. A wide magnet directly in front of the motor and a shorter one just in front of the rear axle.

The red arrows highlight the position of the two bar magnets in the typical Carrera chassis.

Both magnets are secured by a holder and include a metal shim that allows the magnet to be raised about 1 mm. This may seem like a trivial distance, however, it has a measurable effect on the magnet’s downforce.

The Carrera bar magnets. Shown with holders and shims.

This combination of magnets and shims allows the chassis to be configured to allow nine distinct levels of magnetic downforce.

I have performed many tuning tricks on my Carrera GT cars to get them to run well without a magnet on my twisty, bumpy Ninco track. This included adding weight behind the guide assembly, sanding the top of the mounting post bases flat and loosening the body screws to allow the body to float, and installing high grip urethane rear tires. Still, I can only describe the results as marginal. The cars were drivable, however, the slightest amount of excess throttle in the turns would result in a de-slot. It is important to note that the Carrera chassis has fixed front bushings in contrast to the slotted axle holders that many cars have. The fixed bushings are not an issue on a smooth flat track surface. However, they tend to cause the front end to bounce upward on a bumpy, undulating track surface such as Ninco. So, I decided to see what the flexible Carrera magnet implementation could do for performance.

With both magnets installed in their lower position (Shims on top) the car was quite ’stuck down’ and performed like an LMP on the track. By removing the rear magnet (yellow arrow in the above photo) and placing the shim below the mid-chassis magnet (red arrow above), I was able to achieve handling that was surprisingly close to that without a magnet. The car could now be run with much more confidence in the turns and the rear end was still able to drift slightly when powering through corners.

You are not limited to the stock magnets that are installed by the manufacturers. There is also a wide range of aftermarket traction magnets available. I found two such magnets, available from BRS Hobbies to be particularly useful because they are relatively mild and can be ’stacked’ together in order to create different levels of magnetic downforce in the same footprint in the chassis. They are the BRS bar magnet and BRS button magnet, respectively.

The BRS bar magnet

The BRS bar magnet, at 19 mm x 3.2 mm x 1.5 mm, is an inexpensive, relatively compact, mild strength magnet that can be glued into a wide variety of locations in a typical plastic ready-to-run slot car chassis. By stacking this magnet one over the other, Magnetic downforce can be added in meaningful increments. This is especially useful when a magnet is obviously required for a particular car but the stock magnet proves to be too powerful.

Two BRS bar magnets hot glued in a stack.

Similarly, many slot cars come fitted with a full-size button magnet which tends to be very powerful and cannot be easily raised using a shim. The BRS has the same 8 mm diameter as the full-size magnet so it fits into the same cylindrical compartment as the larger version. However, the BRS version is only 2 mm thick and has only about 1/3rd of the larger magnet's downforce. It too can be stacked for incremental levels of downforce.

The BRS button magnet

The Magnet Boneyard

Finally, don't forget about all those magnets that were pulled from cars that are now running no-mag. If you want to find out just how much of a purist a no-mag racer really is, ask him if you can have all his leftover magnets.

My leftover magnet stash proved once again to be a valuable asset. I recently acquired a Scalextric BMW E30 M3 as a companion to the same model that a slot racing friend has. Straight out of the box with the stock traction magnet in place, the car runs like an LMP. You can almost complete an entire lap at full throttle. We decided that we would like to run them no-mag in order to create performance that is closer to that of the actual car. However, when the magnet was pulled, initial testing indicated that this was going to be a significant challenge. The model is quite attractive and almost perfectly accurate to scale. Ironically, being faithful to the actual car's surfaces and dimensions makes this car very difficult to tune for no-mag racing.

As a slot car the BMW E30 M3 has many of the characteristics that virtually guaranty poor performance without a magnet:

• The car is tall and narrow, which makes for a high center of gravity.
• The front end is light with a relatively shallow guide flag.
• Rear tire grip was marginal, resulting in fishtailing.

With the magnet removed it was difficult to complete a lap without extraordinary caution and concentration. The first attempt at tuning was comprised of adding weight (about 15 grams of copper — don't like that lead!) behind the guide assembly to help keep the front end down and in the conduits on either side of the DPR chamber to address the tipping. Urethane rear tires reduced the fishtailing, however, the higher grip tended to exacerbate the tipping, which was the car's predominant problem.

BMW E30 M3 chassis with weight added (red arrows).

This made a marked improvement but the car was still too top-heavy. The rear end could not slide out in the corners and the car would tip far too easily. Not wanting to add any more weight I decided to see if a magnet could overcome these problems.

After experimenting with several magnet configurations using magnets from the stash, the best solution turned out to be a pair of Ninco bar magnets taken from Ninco 1 cars. Now these bar magnets are quite strong. Probably as strong as the stock Scalextric magnet that comes with the car. However, by carefully positioning the magnets and making them adjustable to control downforce they turned out to be ideal for this situation.

The following photo shows the area of M3 chassis where the replacement magnets will be installed.

The red arrows point to what are effectively two three-sided chambers on either side of the motor shaft. The Ninco bar magnets fit perfectly (snug) into these chambers. The next photo shows how the magnets were installed.

A magnet holder (strap) was created from thin, black styrene sheet. The holder is glued into the chamber and is tall enough to allow the magnet (red arrow) to be raised and lowered using shims (yellow arrows) and also to be easily removed from the holder. The magnets are positioned far enough to the sides of the chassis to avoid any significant drag while running on the straight track sections. However, when the rear end starts to drift in the corners the inside magnet shifts closer to the rails and downforce increases. The height of the magnets from the track surface can be adjusted to provide just enough downforce to allow the rear end to drift while keeping the car from tipping. Now this car can truly be powered through the corners without fishtailing or tipping.

Another benefit of this type of magnet implementation is the ability to tune two or more cars configured this way to have virtually identical performance as a racing group. By using the shims to change the height of each magnet in very small increments, lap times can balanced easily within tenths, if not hundredths of a second. This can provide very competitive and exciting racing.

Here is a short video clip of the E30 M3 configured with the dual traction magnets running on Ninco N-Digital  track.

So there. I admit it. I have more than a few cars that owe their enhanced performance to the judicious use of magnets. Try as I might, I could not get them to perform in an acceptable way (for me) by adding weight. But they all perform quite closely to similar cars that can run without the magnet. And now when they run around the track, instead of clenching my teeth as I approach each corner, I'm having fun. 


_Michael Ashton

N-Digital DPR Chip for SSD Slot Cars

I have always managed to live in places that can only be characterized as a slot car 'wasteland'. By that I mean that no one else within a hundred miles is involved in the hobby. No one to race with or tinker with the cars. Anyway, I recently moved from Southwest Florida to North Central Florida, effectively replacing one slot car wasteland with another. Naturally I assumed that my lonely isolation in the slot car hobby would continue. So you can imagine my surprise, followed by overwhelming joy, when I received a message through an Internet slot car forum from Ray.

Ray is a 1/32nd scale slot car enthusiast — just like me! Ray has a digital slot car track — just like me! Ray lives less that 30 minutes from me! I could not believe it. Another DIGITAL slot racer less than 30 minutes away! I thought that I was going to explode. But wait. Ray’s track is Scalextric Sport Digital (SSD) while my track is Ninco N-Digital. The two systems are not compatible, therefore, he can’t run his cars on my track and vice versa. Unless we are both willing to install digital decoder chips from the other system in our cars, we would have to borrow cars when visiting each other’s track. Not a terrible solution but I would be hesitant to race another person’s cars really hard in case I break something. And we would like to race our own better cars — not just beat up 'runners'.

Ah, but there is hope. For quite a while now most Scalextric and Pioneer slot cars come with a chassis that is designed to accept the Digital Plug Ready (DPR) Easy Fit decoder chip. Shown in the following photo, the DPR chip is mounted on a removable panel that fits into the underside of the chassis just behind the guide. The car is equipped at the factory with an analog version of the panel that passes power through directly to the motor terminals. Converting the car to digital is a simple matter of removing and unplugging the analog panel and replacing it with the DPR chip — without having to remove the car’s body. Truly plug and play.

So, I got to thinking, what if there were an N-Digital version of the DPR chip? That would allow Ray and me to run all of our DPR-equipped Scalextric and Pioneer slot cars on SSD, N-Digital and analog tracks without any modifications to the cars. All that we would have to do is plug in the appropriate DPR chip or the analog panel. Well, the only way an N-Digital DPR chip was going to exist is if I were to create it. So I did!

                                        ☯                    ☯                    ☯                    ☯                    ☯

The remainder of this article describes the necessary steps to fabricate an N-Digital DPR chip and what I learned in the process. The N-Digital DPR chip is a relatively simple DIY project with the only requirement being basic soldering skills. Tools and materials needed are:

• Low wattage (30 watt) pencil type soldering iron.
• Solder removal tool (solder sucker).
• N-Digital decoder chip (any version of the chip will work).
• Analog panel from a DPR-equipped Scalextric or Pioneer car (see the following photo). The white DPR plug must be removed and will be wired to the N-Digital decoder chip.

• Narrow heat shrink tubing for the lead wire connections to the DPR plug.
• 9 - 10 mm heat shrink tubing to protect the entire DPR plug assembly.
• CA adhesive (super glue).
• Two part plastic epoxy adhesive.
• Double sided adhesive foam pad or tape.

The first step is to remove the housing which contains the white four-pin DPR plug from the analog panel. This is easily done using the blade of a sharp hobby knife to loosen and pry the housing away. The DPR plug is removed from the housing in the same manner. Just be gentle and patient. The DPR plug, freed from the analog panel housing is shown in the photo below.

The red arrows point to the plug’s two pairs of input/output pins which are soldered together for analog operation. The solder on these pins must be removed by heating them with the soldering iron and then using a solder sucker to pull the solder away from the pins. The resulting plug should look as shown below.

The DPR plug is now ready to be connected to the N-Digital chip’s lead wires, however, the pins may be somewhat loose, allowing them to move inside the plug. Applying a small amount of viscous CA adhesive (super glue) to the base of each pin will keep them secure in their position.

The following two illustrations identify the pin positions of the DPR plug and the corresponding lead wire positions of the N-Digital chip. It is just a matter of soldering the N-Digital chip’s '+ guide' lead wire to the DPR plug’s '+ guide' pin, then the '- guide' lead wire to the '- guide' pin and so forth.

                     DPR Plug                                                                                                     N-Digital Chip

Cut the N-Digital lead wires to a length of about 20 mm. Then strip and tin the ends of each trimmed lead wire with solder. Before soldering to the pins, slip a 1/4” length of narrow heat shrink tubing over each lead wire. Now solder each lead wire to the pins according to the position identifications shown above. Push the shrink tubing over each solder connection so that it is completely covered and shrink the tubing using the hot soldering iron. Next, cut a 15 mm length of the larger (9 -10 mm) heat shrink tubing and push/stretch it over the whole DPR plug assembly. Shrink that tubing until it appears as shown in the photo of the finished project below.

One last point: the solder connections of the N-Digital chip lead wires to the printed circuit board (PCB) are notoriously fragile. I mixed some two part plastic epoxy adhesive and applied it to the base of each lead wire's connection to the PCB to form 'boots'. This will keep the lead wires from bending and being stressed at the solder joint. Finally, the finished N-Digital chip/plug assembly is attached to the DPR panel using double sided mounting foam tape or pads. The mounting pads suppled with the N-Digital chip are ideal for this.

The N-Digital DPR chip is shown below being installed in a Pioneer Camaro. This car has a full interior and somewhat restricted space above the DPR panel and the N-Digital DPR chip still fits quite easily. The chip has been installed and tested in a small but representative sample of Scalextric and Pioneer cars without any problems in either installation or performance.

So, if there are any N-Digital users still hanging in there, and you have a few (or a lot of) Scalextric and/or Pioneer cars that are DPR ready, then you may want to make one or two N-Digital DPR chips. It’s a fairly easy project that provides benefits that are more than commensurate with the time and effort required. At least Ray and I think so. We now have a small fleet of cars that is easily switchable among SSD, N-Digital and analog racing, without even having to remove the car’s body. All we have to do now is find the time to race.  

_Michael Ashton

Healing a Broken Wing (Slot Car That Is)

By Michael Ashton

This is how I felt after my Ninco Audi R8 Spider left the slot at high speed and massacred the rear spoiler.

The spoiler was damaged in the worst way possible. One strut was broken off the wing. And the mounting tabs for both struts were snapped off.

And if that wasn’t bad enough, the mounting tabs were still in the slots of the rear deck, held in place by the world’s strongest thermonuclear glue!

Stop Crying and Get To Work!

I really wanted to fix the spoiler in a way that results in a reliable repair that also maintains the aesthetic appearance of the car as much as possible. Not just gobs of glue all around the mounting slots to provide reinforcement. So here is what I did…

First cut a square notch in the base of each strut where the mounting tabs used to be.

Next, cut a short rectangular strip from a sheet of styrene plastic that is slightly thicker than the strut itself. The styrene strip should be about 6 to 7 mm in length and the same width as the notch that was cut into the base of the strut.

The strip should fit snugly into the notch, as shown above. The strip is going to be our new mounting tab.

The strip is then glued into the notch using two-part plastic epoxy cement. This type of glue provides a very strong bond between the strip and the strut. Note how plenty of glue is applied. This effectively encases the strip and strut in a cocoon of very hard glue. Don’t worry about the excess because after curing it will be sanded down to a smooth, even finish. The combination of support on three sides and the surfaces of the new tab coupled with the bonding and hardness of the plastic epoxy provides a very strong repair.

The existing mounting tabs had to be “routed” from the slots on the car’s rear deck. This was done very carefully with a sharp scribing tool and a hobby knife with a narrow pointed blade. Be very patient when performing this step. Once this is accomplished the newly fabricated mounting tabs can be shaped by filing and sanding until they fit tightly in the mounting slots. 

The following two photos show the repaired spoiler. The strut that was separated from the wing has been glued back in place with CA glue and appears to be quite secure. The underside of the wing and the struts were painted with Krylon Fusion Gloss Black. After the paint cured for 24 hours the struts were coated with Pledge Floor Care.

Not Perfect, But Very Good.

The new mounting tabs fit tightly enough in the mounting slots that glue was not required. So this car has a tear away spoiler — at least for now. If it does ever become too loose for a friction fit I can always glue it in place.

The repaired spoiler has held up well so far. Even through a couple of minor incidents. Therefore, I would recommend this type of repair for any wing of similar structure where the struts have sufficient thickness and surface area to allow it. It’s a bit tedious and time consuming, however, I believe that the preserved appearance of the slot car makes it worthwhile. Not perfect, but very good I would say. Anyway, if it breaks again, I’ll fix it again.

Now see how I feel…

_Michael Ashton

Building a 1/32nd Scale Slot Car: Group 44 TR3

By Michael Ashton

In my younger days I owned four Triumph sports cars, including a TR3. So when a Lindberg TR3 static model kit “fell” into my possession I decided to make my first attempt at building a 1/32nd scale slot car. At first I thought that I would make a replica of the TR3 that I knew and loved. However, as with many slot car enthusiasts, I am not particularly interested in street (non-racing) versions of automobiles. But if not my trusty old TR3, I wanted it to be something worthwhile historically.

After a fair amount of Internet research on who has raced the Triumph TR3 it became obvious to me that one of the Group 44 racing team’s cars would be a great example. Most notably the TR3 built and driven by Brian Fuerstenau. Along with the more famous Bob Tullius, Brian was a cofounder of Group 44 Racing. He was a self-taught automotive genius who could make Triumphs, Jaguars and many other sports cars of the era perform uncannily well. And he was a champion driver at the national level long before Group 44 came to be. Sadly, he died in 1993 when the T-6 aircraft he was piloting (his other passion) crashed.

One thing is certain: no matter what form of motor sport Brian Fuerstenau would have been involved in — whether at Le Mans or a dirt track in the Ozarks — he would have competed at the top level. I hope that my humble attempt at recreating his rustic ride as a slot car would have met with his approval.

© Copyright Don Struke. Used with permission.

© Copyright VIR History. Used with permission.

The Model

Notes on the Process

The basis for the project was the Lindberg Triumph TR3 static plastic model kit.

The body is reasonably scale accurate, however, it has only rudimentary detail. Now my modeling skills and experience are quite limited. Therefore techniques such as cutting, filling and reshaping body details are beyond my capability — at least for now. So I have to create the illusion of detail using the primary assets that I do possess, namely tenacity and patience. Following are some of the techniques that I used.

For me, the most difficult task was the creation of the tonneau cover. The TR3 cover is unusually difficult because it has multiple surfaces (top and sides) and must conform to a number of undulations around the entire cockpit. I experimented with several methods and materials including very fine grit wet/dry sandpaper and surgical tape. I literally stumbled on the solution that I used while wandering around a craft store.

Chalkboard tape has the ideal characteristics for the TR3 tonneau cover: It has almost perfect color and texture; it is reasonably malleable but very strong and tear resistant; it is self-adhesive which is particularly useful during the fitting process.

First cut a strip long enough to cover the entire cockpit, as shown below.

Next, remove the backing exposing the adhesive side and press the tape all around cockpit edges. This will leave an impression of the cockpit’s geometry in the tape. You can also trace the required outline onto the surface of the tape with a pencil before removing the tape. Remember, this is chalkboard tape — the pencil lines erase easily.

Now it is relatively easy to perform a rough cut of the cover with sharp scissors or a hobby knife. Leave extra material around the outline to allow for test fitting and subsequent fine trimming. The fact that this is adhesive tape that can be easily removed and repositioned helps immeasurably here.

Once the tonneau cover shape is correct and conformed to the cockpit edges, the tape adhesive around the edges is removed using solvent and a Q-Tip. The cover is then glued in position with a permanent adhesive. I used two-part plastic epoxy. Be careful to keep the glue away from the outer most edges of the cover to avoid marring the car’s painted surfaces.

I found it almost impossible to create the tonneau cover snaps using paint. I just could not create tiny uniform circles by any method. So, I used tiny pins that I found in the sewing and jewelry sections of the local craft/hobby store. The pins on the left were used to simulate the tonneau fasteners while those on the right were used for the windscreen snaps and the roll bar opening covers.

The heads of both pins were too large to my eye so I reduced their diameter with a Dremel sanding disk. Correct spacing was achieved by creating a template from a narrow strip of masking tape with the fastener positions marked equally spaced on a guide line. The tape was then positioned around the edges of the cover and marked with a sharp scribing tool. I used a pin vise with the smallest available bit to drill tiny holes through the template, cover and cockpit edges.

The pins were then cut to a few millimeters in length and pushed all the way into the holes.

Enough of the pin protrudes through the inside of the cockpit (not visible externally) to allow CA glue to be applied from the inside, avoiding any glue residue showing on the cover itself.

Another area that required a little ingenuity was the kick panel behind each door. The Lindberg body has only the faintest relief detail of this feature (see the following photo) and it was not symmetrical on both sides.

I probably made a mistake by not addressing this prior to painting the body. I tried several types of matte silver paint, but even after allowing up to week of curing time, the silver paint never dried properly and tended to rub off — even under the clear coat! Then I remembered that I had bought some silvered copper tape to apply to the rails of my track.

The tape had the perfect, durable finish that I was looking for and a very effective adhesive. I was able to cut the exact shapes that were needed and position it precisely on the body. To make sure that the bond would be permanent and could withstand rough handling I applied some two-part plastic epoxy cement along the inside of the lower and trailing edges. Finally, two coats of clear coat were added locally for protection.

Decals were home made, printed on Testors clear decal paper using a medium quality inkjet printer. I was able to zero in on the appropriate type sizes by test printing on plain paper, cutting out samples and tacking them in position on the body. The dashboard gauges are drastically reduced images similar to TR3 gauges available on the Internet. The finished decal sheet received a light coat of Testors clear coat and allowed to cure for at least a week prior to application.

Microscale solutions were used to optimize the decal application. Micro Set to apply and create good adhesion to the surface. Micro Sol to allow the decals to conform to surface details and minimize edge visibility by softening the decal substrate.

Ranking high under the topic of “the illusion of detail” is the highlighting of chrome plated fixtures. The Lindberg model has no chrome plated surfaces or parts at all. And I have never found a chrome paint that was able to create a realistic looking finish (although Testors comes close). Luckily there is a product called Bare-Metal Foil that makes realistic chrome detail on any model possible.

It is a very thin foil with an adhesive backing that is basically burnished onto the surface and then trimmed to the desired area. No special tools are needed beyond a sharp hobby knife, Q-Tips and tooth picks. Reasonable dexterity and patience are a plus.

The chassis used to make this model a slot car is the Slot Classic. This is a very simple plastic chassis with an adjustable wheel base, designed for the standard Mabuchi [type] FC-130 motor.

The chassis for the Group 44 TR3 is outfitted with:

• A ScaleAuto 10K RPM FC-130 motor. Very mild but appropriate, I think, for this model.
• Slot.it axles, gears and bushings.

• The guide and pickup braids are Ninco Standard Suspension and ProRace tinned, respectively.

• Aluminum setscrew wheels and resin-cast inserts are BWA.

• The inserts were first sprayed with automotive primer then finished with Krylon matte aluminum paint.
• Tires are Ninco Classic 20x7.

Other Details

The driver figure is made by MRRC. It is the same figure that is used in many MRRC models, most notably, the 427 A/C Cobra. The head was repositioned to a more natural attitude. The figure was first primed and then painted with acrylic paints.

The Lindberg TR3 body was primed with DupliColor white primer and finished with DupliColor Ford Pure White.

The clear coat is Pledge Floor Care (formerly known as Future). This provides an attractive finish and also protects decals and Bare-Metal Foil chrome accents. It is easy to apply with a 1/2” soft bristled art brush.

This article covers many of the techniques employed and issues encountered in the building of this slot car. Feel free to post any questions that you may have in the comments section and I will do my best to answer them. You may also have suggestions about better ways to do things which are, of course, welcome.

_Michael Ashton