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

Converting a SCX Compact Slot Car to Carrera Digital 143

By Michael Ashton

SCX Compact 1/43rd scale slot cars are among the best ready-to-run cars available in this scale. And although SCX has not released any new 1/43rd scale cars recently, they are still available in a few stores and on the Internet, if you are willing to search both diligently and persistently. I happen to have several SCX Compact NASCAR COTs that run quite well on the Carrera GO!!! track, so I would really like to add them to my growing stable of D143 cars. In order to do this they must be converted to the D143 system by installing the Carrera D143 decoder chip. This article is a brief step-by-step account of how this can be done.

Preparation

Look here to see a list of the minimum tools required for this type of conversion, tips on preparation and some cautionary advice that may help avoid mistakes. I rate this conversion as somewhere between low and moderate difficulty. Basic soldering and minimum modeling skills are recommended.

The Steps

After selecting a SCX Compact car to convert, and obtaining a Carrera D143 decoder chip/motor assembly, the first thing to do is compare a typical D143 and SCX Compact chassis side-by-side. This will allow planning to determine exactly where to create the opening for the D143 emitter and mounting post for the D143 circuit board.

The following photo shows a typical Carrera D143 chassis on the left and the SCX Compact chassis to be converted on the right. The D143 chassis does not have a decoder chip installed because the motor/chip assembly was removed and will be used in the SCX Compact conversion. There are three primary steps that must be accomplished for a successful, reliable conversion of the SCX chassis to D143:

1. An opening must be created in the chassis floor, in the correct location, that allows the emitter on the decoder chip to communicate with the sensor on the D143 lane change and lap counter track sections.
2. The decoder chip must be connected electrically to the pickup guide and motor terminals.
3. The decoder chip must be secured to the chassis floor so that no movement is possible.

Again, looking at the photo below, the yellow arrow points to the D143 chip mounting post which accepts a screw that holds the chip tightly in place. The red arrow shows the chamber which forms the opening through which the emitter communicates with the track sensor(s). In my opinion, the most secure chip installation and accurate digital performance will be achieved by duplicating these two structures in the SCX Compact chassis. So that is exactly what is going to be done here.

The Process

The first step in creating the opening for the D143 chip emitter is to determine the optimum location on the SCX chassis. The two important coordinates are: 

1. The distance from the center line of the chassis to the center of the opening. Ideally, we want the emitter to travel directly over the track sensor.
2. The distance from the leading edge of the guide flag (guide pin in the case of Carrera) to the center of the opening. The correct distance here ensures that the lane change flipper will activate prior to the arrival of the leading edge of the guide flag. Too long a distance could cause missed changes or even collisions with the lane change flipper.

In actual practice I have found these measurements to be not so critical. Just try to locate the opening as close to the position in the Carrera chassis as possible while still allowing for a secure chip installation and connection. The following two photos should provide a good depiction of where I drilled the hole in the SCX Compact chassis. Note that the leads that connected the motor to the copper strips leading to the guide pickups have been clipped.

To create the chamber for the emitter opening I used a short piece of 3/16” styrene tubing. The height of the chamber should be gauged to enable the D143 chip to sit level (i.e., no tilt) when the emitter is fully seated inside the chamber. Cut the chamber one or two mm higher than needed so that it can be adjusted by sanding the top after being glued in position.

The notch shown in the previous photo is needed because the opening in the chassis floor abuts the reinforcing rib that runs along the outer edges of the chassis. This allows the chamber to be centered on the opening without cutting the reinforcing rib and possibly compromising the structural integrity of the chassis. The chamber is glued in position using two-part plastic epoxy, mainly for that glue’s superior strength. See the photo below.

Below we see the finished chamber, sanded to the proper height and painted to match the chassis.

The mounting post is fashioned with a similar method. I used a short piece of 1/8” styrene tubing. Fist cut the tubing to the approximate height. Then use the D143 chip’s mounting screw to “self tap” into the post. Then remove and reinsert the screw several times until it is relatively easy to remove. Mount the loose post to the D143 chip through the chip’s mounting hole. Now you can test fit the position and height of the mounting post by seating the chip’s emitter into its chamber. Sand the end of the post, if necessary, to achieve the level orientation previously mentioned. Next, with the post still screwed to the chip, apply glue to the end of the post and place the post/chip assembly into position on the chassis floor with the emitter fully seated in the chamber. Apply pressure until the glue has set and then allow the glue to fully cure. Finally, gently remove the mounting screw and finish the post by applying epoxy all around the base. Painting to match the chassis is a finishing touch. The finished mounting post and emitter chamber are shown in the photo below.

Now that the D143 chip mounting structures have been created, it is a fairly straight forward process to install and connect the chip/motor assembly into the SCX Compact chassis.

Shown in the following photo is a typical D143 decoder chip/motor assembly. When converting a car to D143 my preference is always to use an existing D143 decoder chip/motor assembly when possible. The SCX Compact motor will work, but the D143 motor is known to be a good match for the decoder chip.

However, one characteristic of this assembly that presents a problem for installing in the longer SCX Compact chassis is how short the connecting leads are and, therefore, how close to the motor the chip resides. In the standard Carrera assembly, the positive output connection lead from the chip and one lead from the RF noise reduction capacitor are connected to the motor can as highlighted by the red arrow above. A common lead from the motor can, in turn, connects to the positive motor terminal. So all three wires are effectively connected to the positive motor terminal via the motor can.

Moving the chip’s positive output lead and the capacitor lead connections directly to the positive motor terminal, as shown in the following photo, allows the chip to be moved almost 1/2” farther away from the motor. This provides the additional flexibility in positioning required by the SCX Compact chassis.

Normally at this point the D143 chip’s input leads would be soldered to the copper guide pickup strips to complete the electrical connections. However, in this particular conversion I decided to install a quick connect micro plug assembly which allows the chip/motor assembly to be easily installed and removed. This allows the chip/motor assembly to be moved among different cars that have the plug assembly installed. This is a relatively simple process where the female (jack) is soldered to the chip’s input leads and the male (plug) is soldered to the copper pickup strips, as shown by the yellow arrows in the previous photo. If you don’t want to install the plug assembly, just solder the chip input leads directly to the copper guide strips.

The following photo shows the final assembly with the motor snapped into position and the D143 chip secured by the mounting screw with the emitter seated in the chamber.

This side view shows the emitter fully seated in its chamber (yellow arrow) and the chip sitting relatively level, secured by the mounting screw.

A view of the underside of the chassis shows the orientation of the emitter in the chamber.

One final recommendation: the SCX Compact cars perform very well on the Carrera GO!!!/D143 track. However, if your layout contains banked curves (as mine does), it will probably be necessary to eliminate the sharp square profile of the guide flag’s leading edge, as it tends to catch on the bottom of the slot on these track sections. The red arrow in the following photo highlights the SCX guide leading edge after being “nipped” and smoothed over with some light sanding.

So, it required a little effort, but I’m convinced that the final result was worth it. The SCX Compact cars in general look good, are quite true to scale and handle very nicely. If you are able to acquire, or already have one or more of these cars, and think that you would like to run them on a Carrera D143 track—go ahead. You won’t be disappointed.

A video of the SCX Compact Toyota COT converted in this article, running on a Carrera D143 track can be seen here.

_Michael Ashton