Friday, March 8, 2013

Tuning and Upgrading NINCO 1 Slot Cars

By Michael Ashton

The first NINCO 1 cars were introduced to the U.S. market in early 2009. These cars were NINCO's version of the "crash resistant" or "entry level" class of slot cars, intended specifically for home racing. They were priced somewhat less than the Sport line of cars and came equipped with a low-power NC-11 motor, rated at 16,000 rpm and 100 gcm of torque, making it ideal for younger and/or beginner slot enthusiasts. To reduce cost, the cars are produced without an interior, a plastic drive pinion and plastic rear axle bushings. However, unlike cars in this classification from other manufacturers, NINCO 1's have dark tinted glass (as opposed to black painted glass) and relatively high quality and detail in the body decorations.

In addition to being very good cars for kids and beginners, NINCO 1's turned out to be ideal for digital slot racing. The lower power and higher level of control are well suited to the more frenetic conditions that result from having four, five or even eight cars running simultaneously on a two-lane home track. And they exhibit superior performance when running on a NINCO N-Digital track without the magnet using the more aggressive professional throttle profile.

Because the NINCO 1 line is designed for a more casual home racing environment, the cars tend to run quite well out-of-the-box for their intended purpose. However, this should not belie the fact that, as with just about any modern slot car, they can be tuned and tweaked to provide measurably increased performance. This article will present a series of tuning measures that can enhance both level and consistency of performance over a spectrum that ranges from subtle to momentous. The measures themselves range from the relatively mundane: fiddling with magnets, to downright life-changing: upgrading the motor. The goal of this exercise is to establish (or perhaps uncover) tuning methods that can maximize the potential of the NINCO 1 class for the broadest appeal to slot car enthusiasts possible.

The car that will be used throughout this exercise is the NINCO 1 Renault Megane Trophy N4, pictured below.



Replacement/upgrade parts that will be used at various stages of tuning are shown in the following photo.


From left to right: the NINCO NC-13 EVO motor; the NINCO ProRace Suspension Guide and ProRace Braids; PineCar tungsten putty weight (ballast); and at center-bottom: two BRS [Hobbies] bar magnets; and finally, a NINCO standard brass 9 tooth in-line pinion (for the NC-13 motor). All of the above parts were provided by BRS Hobbies for use in testing.

Pictured below are top and underneath views of the Renault Megane Trophy N4 in its stock configuration. This includes a 9 tooth plastic pinion, 27 tooth in-line crown, the standard spring suspension guide with relatively stiff copper braids and a quite powerful bar magnet positioned just behind the motor, underneath the pinion. All NINCO 1's come with 20 mm x 10 mm front and 20.5 mm x 11.5 mm rear standard NINCO rubber. The red thing between the front axle and the motor is the N-Digital decoder chip.


In order to observe and document any effect of the tuning measures, it is essential that a performance baseline be established for both magnet and non-magnet operation of the car it its stock configuration. That baseline is represented by the recorded lap times listed in the following table:


Lap times will be recorded for each subsequent individual tuning action and compared to the respective (magnet or no-magnet) baseline data to determine its effectiveness. Basically, the tuning measures will be applied and left in place which will allow the lap times to reflect a cumulative effect. The BRS bar magnets will be the only exception and will be removed after the NC13 EVO motor upgrade. In addition to the measurement data I will also provide subjective evaluation when appropriate, especially for situations where lap times may not tell the whole story.
 

Testing was performed on my 60' relatively technical NINCO N-Digital track. All lap times were recorded while using the N-Digital professional throttle profile. For those not familiar with N-Digital, the professional profile would be analogous to 11-12 volts maximum on an analog track with a relatively steep response in the lower region of the throttle curve.


ProRace Suspension Guide and ProRace Braids

The first tuning measure is to replace the stock (standard) spring suspension guide and copper braids with their NINCO ProRace equivalents. This is something that I recommend for any NINCO car that is going to be raced competitively. The longer ProRace guide flag provides increased stability, especially in the turns, and the softer, more pliable tinned ProRace Braids allow the guide to sit lower in the slot while providing superior electrical contact. This is especially important for N-Digital racing where the control data are transmitted via the slot rails and there are many joints and gaps in the rails which the more compliant ProRace Braids seem to handle better.

For those who have not changed a guide/braid assembly before, or who may have encountered problems when doing so in the past, the following is a short, illustrated step-by-step example of one approach to the process:

A new NINCO ProRace Suspension Guide comes with two pre-cut sections of ProRace Braid material. If you don't have the pre-cut braids, or if you are replacing worn braids in an existing guide, cut two sections of ProRace Braid material that are between 22 and 26 mm in length.


Note on braid length: I have recommended a range of length above because specific track characteristics may dictate the actual required braid length. For example on N-Digital tracks, if braids are too short, cars may hesitate on dead strips. The best advice here is to experiment in order to find a braid length that is optimal for track(s) that you run on.


First, use thin needle nose pliers to crimp the end of each braid section as shown in the two photos below. The crimp should be about 2 mm in length.


Make sure that the un-crimped end of the braid section is tightly woven and has a clean edge that is not frayed. If the end is frayed, you may need to pinch it close to the end with the needle nose pliers in order to be able to insert it into the "eye hole" of the guide.

Carefully insert the end of the braid into the eye hole. I find that tilting the braid slightly and inserting one corner first while pushing down on that corner works best, as shown in the following photo.


Once the braid is inserted into the eye hole...


...push it all the way down with your forefinger until the crimped end contacts the top surface of the eye hole. Make sure that strands of the braid at the crimped end cannot contact the suspension guide's spring.


Then, holding the guide flag between the thumb and forefinger of one hand, and holding the crimped end tight against the eye hole with the other hand's thumb, bend the braid toward the underside of the guide's base with the other forefinger, as seen in the two photos that follow.


Repeat the previous steps with the second braid section so that the result looks as depicted in the next two photos.


I find that poking a scribe or similar sharp, pointy tool into the eye hole helps to form a hole in the braid material that makes it easier to insert the metal ferrules on the end of the motor leads for the first time.


Once the guide/braid assembly is inserted into the guide holder in the chassis, while holding the chassis with the fore and index fingers of both hands (as seen in the following photo), use your thumbs to press down and forward on the braids.


 This will loosen the weave of the braid material and fan them out in a tapered fashion as seen in the following photo. This insures maximum electrical contact with the rails. Once again, this is essential for good operation of the N-Digital system.


Finally, make sure that the braids are angled downward at about 30°, as shown below.


I find it to be much easier to connect the motor (or decoder chip) lead wires to the guide with the guide removed from the chassis guide holder. There is also less danger of breaking the guide holder due to the high force that may be necessary to press the ferrules into the eye holes. So, whenever possible, I recommend removing the guide (if it is installed) and sliding the motor leads down through the guide opening in the chassis. Then reinstall the guide after the motor leads are attached.

When preparing the motor leads to receive the ferrules, strip the insulation to expose bare wire that is about twice the length of the ferrule. Insert the bare wire into the ferrule as shown below.


Next, bend the section of wire that extends through the bottom opening back against the outer surface of the ferrule.


Holding the guide assembly with one hand, use the forefinger to press up against the braid to prevent it from being pushed down through the eye hole when the ferrule is inserted from above. With the other hand, insert the ferrule into the top of the eye hole and use the forefinger to push the ferrule down into the eye hole. Note that the exposed lead wire is facing back toward the braid.


Normally the ferrule can be pushed all the way in by hand using this method. However, if the fit is very tight and the ferrule will not go all the way in, use small needle nose pliers as shown below to squeeze the ferrule all the way in while keeping the braid from being pushed out of the eye hole. Do not use excessive force here.


When both leads are attached with the ferrules pushed all the way in, the result should look as depicted below. The guide can now be installed with the leads properly threaded up through the chassis opening.


With the ProRace Suspension Guide installed and adjusted it was time for track testing. The car was run for three 25 lap sessions, first with the stock magnet installed and then without the magnet. The results are shown in the following table:


There was a slight improvement in lap times, however, given the limited testing the result cannot be seen as conclusive. Subjectively there is no doubt that the car drove better. Especially over the bumps, gaps, undulations and lane-change sections of the NINCO/N-Digital track. As previously noted, installing the NINCO ProRace guide and braids should be S.O.P. for a N-Digital track.

BRS Bar Magnet 

The next tuning measure is the replacement of the stock NINCO bar magnet with (two) BRS bar magnets.


The stock magnet that is installed in the NINCO 1 cars is very powerful. In fact, I believe too powerful for the majority of the NINCO 1 cars — especially those with a low ride height. And its position located just in front of the rear axle serves only to further intensify the overwhelming down force. In the case of the NINCO 1 Renault Megane Trophy represented in this article, I can run the car around my 60' N-Digital track at full throttle with the exception of one R1 hairpin curve, even when using the professional throttle profile. I don't feel that this is what the majority of slot car racers, especially digital racers, are looking for.

A single BRS bar magnet has approximately 25% of the down force of the stock NINCO magnet. So, two BRS magnets stacked vertically and placed in front of the motor should provide something less than 50% of the effect of the stock magnet. This would seem to be a more reasonable approach to increasing traction. The following photo shows the two BRS magnets secured just in front of the motor mount by hot glue. This is a secure installation that does not alter the chassis and is easily removed at any time.


With the BRS magnets in place, the car was returned to the track for another series of three 25 lap sessions. The resulting lap times are shown in the third row of the following table, just below the original mag and no-mag baseline.


Obviously the lap times are slower than the stock magnet baseline. The real point here is that the BRS magnets installed in this fashion provide a significant reduction in lap times over the no-mag baseline. Cornering speed is noticeably faster, however, the driving experience is much more realistic than that of the NINCO magnet. It is now necessary to reduce throttle through all the turns and it is possible to occasionally slide the back end out without encountering the calamitous "snap" spin out that is characteristic of "stuck down" magnet cars. I believe that this is a significant tuning measure that enables a NINCO 1 car to become a credible magnet slot car and much more exciting to run.


NINCO NC-13 EVO Motor

The NINCO 1 line of cars was originally intended to satisfy the requirements of the beginner or less experienced slot car user, and all indications are that it does this quite well. However, the high level of detail and quality of the NINCO 1 exteriors also made them attractive to the more advanced user. So, it's not surprising that a number of the more serious slot enthusiasts who bought NINCO 1 cars eventually became dissatisfied with the lower power drive train. And then, NINCO released the NINCO 1 PLUS series of NINCO 1 cars that feature an enhanced chassis design that includes an angle winder drive train previously found only in the SPORT series, and the NC-9 Sparker motor — rated at 20,000 rpm and 145 gcm of torque — instead of the usual NC-11. This created even more demand for an upgrade path for the existing NINCO 1 cars to a performance level on par with the NINCO 1 PLUS.

Enter the NC-13 EVO motor. Created as a drop-in replacement for the NC-11 with specifications virtually identical to the NC-9 Sparker. So, this next measure can't really be classified as tuning. The stock [NINCO 1] NC-11 motor will be replaced with the NC-13 EVO motor. This is better described as an upgrade. The NC-11 is rated at 16,000 rpm and 100 gcm of torque. The NC-13 is rated at 20,000 rpm and 135 gcm of torque. Both at 14.8 volts.

Shown below is the NC-13 EVO motor installed in the Renault Megane Trophy chassis, fitted with a NINCO standard 9-tooth brass pinion. Note the replacement of the plastic bushings with NINCO #80407 brass bushings. This is not really critical to overall performance, but because the wheels were loose and needed to be glued onto the axle, I took the opportunity to change the bushings while the wheels were removed. Also note that the BRS bar magnets were left installed for the first round of testing with the new motor.


With the NC-13 EVO motor installed, after some initial break-in, the car was run for three series of 25 laps for each of three configurations of magnet (225 laps total). The resulting lap times for each configuration, compared to the baseline, are shown in the following table:


Not surprisingly, the addition of NC-13 EVO motor creates a much different car from a performance standpoint.

The combination of the NC-13 motor and the stock NINCO magnet effectively make the car a "magnet missile". However, my feeling is that, even with the increase in power over the NC-11 motor, the NINCO magnet is still too strong for the car. But performance was more realistic and a higher degree of driving skill was required when compared to the stock motor/magnet configuration. As always, this is a matter of preference.

The BRS magnets were a different story. Performance and handling were much closer to that obtained with the combination of BRS magnets and NC-11 motor. Very good speed through the turns but not at the expense of a feeling of control. The big difference is greater speed on the straight sections owing to the increased power provided by the NC-13. Overall the car was fun and exciting to run this way without being stressful.

Running without a magnet yielded lap times that now place this car squarely in the middle of the NINCO 1 PLUS line of cars. The Megane Trophy has its own unique handling characteristics, most likely due to the in-line drive train versus the angle winder of the NINCO 1 PLUS cars. But there is little doubt that the NC-13 motor provides the necessary upgrade path to be compatible and competitive with the line of NINCO 1 PLUS cars.


Tungsten Putty Ballast

The final tuning measure is a novel method of adding ballast (weight) just about anywhere in a slot car. Tungsten putty is a very dense (i.e., heavy), malleable putty that can be formed into any shape required. It can be pressed into "nooks and crannies" of a chassis (or body) and it will conform to the shape of the receiving space. Once pressed into a given space, it tends to stay secured in that space. If necessary, it can be secured further with any adhesive that can safely be used in the chassis or body, such as hot glue.

Note: There is a caution on this product's packaging that states: "Wash hands after use. Keep away from mouth and food." Make sure that these instructions are followed by anyone who handles this putty.


 In the Renault Megane Trophy, a very effective place to add weight is in or around the "V" shaped chamber just behind the guide holder that is formed by two reinforcing ribs. This is highlighted by the three red arrows in the photo below.


The first step in using tungsten putty is to knead the whole piece by working it with the fingers until it becomes very pliable and does not flake or crumble.


Step two involves estimating the amount that will be required and braking that off as a smaller piece. The amount does not have to be exact at this point because small amounts can be added as you progress. Once again, work the separate piece with the fingers to make it as pliable as possible.


Finally, form the selected piece into the approximate shape of the area into which it will be pressed. This could involve rolling, flattening or any number of possible shapes. In the case of the Renault Megane Trophy, I formed it into several small balls and pressed them down into the chamber behind the guide holder until it was protruding from the top. I then used the tip of a very small flat head screw driver to press it further into the chamber while also smoothing and rounding the top surface. The result is shown below. Based on the weight of the original piece, I estimate the weight of the installed putty to be 8 to 10 grams.


With the tungsten putty in place, it was back to the track for another series of laps. Three sets of 25 laps first without the magnet and then with the stock NINCO magnet installed. The lap times below compare the cumulative tuning/upgrading to this point with the addition of the tungsten putty.


Obviously the powerful NINCO magnet obscured any effect that the putty (or any other ballast) might have. However, when running without the magnet, the effect was subtle but measurable. And there was a discernible increase in headroom when going through the corners. 


In Summary

The following table lists the performance results of all the tuning and upgrade measures, grouped in the order of application:


With all the previously described tuning and upgrade measures in mind, Brian Swanson of BRS Hobbies has proposed two NINCO 1 racing classes:

The first would be named the NINCO 1 SPEC class, which is a stock NINCO 1 car with the addition of NINCO ProRace Guide and ProRace Braid. The only options would be the choice of a 9 tooth or a 10 tooth brass pinion gear and tungsten putty added to the chassis for ballast. No other modifications to the chassis or body would be allowed. For Ninco tracks, the Laprene compound tires would be allowed as replacements. For non-NINCO tracks, a suitable compound rear tire of similar dimensions may be used.

The second would be called the NINCO 1 SPEC PRO class and would be based on the same rules as the SPEC class. The difference would be the upgrade of the drive train with the NC-13 motor. And, given the above test results with the NC-13 motor, the NINCO 1 Plus cars will very likely fit into this class.



So, even though the NINCO 1 slot cars are considered entry level, they still have a lot of potential. If you have one or more NINCO 1 slot cars I strongly recommend trying any or all of these tuning measures.

__Michael Ashton