Jimmy's Northline Raceway Frequently Asked Questions (FAQ)
Most recently asked questions are at the top of this list
Overall discussion of A/C power system used by Jimmy : Link
Diagram to add diode into car wiring : pdf
Bill's question: How tall do you make your guardrails and walls? Response from Jimmy : First know that 3/8" = 1 foot in 1/32 scale. The top of one Armco guard rail is no less than 24" up from the ground (3/4"). The steel rail heights themselves are 12" (3/8") tall. Double barriers have two rails touching each other in between, or have a 2" (1/8") space. Guard rails are 14 ft long with 3 places to secure posts. End posts are inset to produce a 1 1/2' overlap of the guardrail. Posts are 6" dia. cement filled pipe (3/16), or 6"X 6" wood post or I-beams (3/16). A wall on track is 32"(1") tall to 36" (11/8") high for corner workers, or 40" tall (1 1/4") for spectators. The walls are min 1' thick (3/8") at impact points of the circuit and about 8" (1/4") thick at non impact areas. Track side banners are 30 to 32" tall so you can get an idea of the wall heights in ref photos. Note that big outside walls at Daytona and other oval banked tracks have walls 5' to 6' tall. That's about (1 7/8" to 2") tall in 1/32. I was torn with what to use as a height for my concrete walls because I did not want cars hidden, so I used the 1" tall in areas where the wall would block a view. and 1 1/8" elsewhere. I cut poster board to the height I wanted, plus 1/2" for track thickness. I glued and stapled the first strip to the 1/2 thick particle board track edge leaving the correct height standing vertically above the track surface. Then I glued on more strips of poster board onto that first strip until I got to the correct thickness for the wall. Work toward to outside to keep from reducing the distance to the slot. I used clothes pins to keep them together until the glue dried. I stippled the backs of business cards with soft splotches of light gray, white and tan paint, then flicked black specks of thinned paint on it with a tooth brush. Each card must be cut the appropriate wall height. I glued these business cards, no two alike, to the outside of the walls. They are the right length and the joint between gives the illusion of an expansion joint. No messy painting on the track itself. It's mostly all done on the bench. Next day I capped the top of the wall with a layer of spackling compound used to patch walls prior to painting. About 10 hours later I used 250 paper and sanded a radii into the painted business card at the wall tops to smooth the spackling into the wall. Puff the tiniest amount of black chalk dust on the top of the wall and streak downward with a small paint brush to weather it. Finish with a coat of Testors Dull Coat.
Question : Just how smooth do the slots have to be after routing? Are imperfections tolerable by the cars, or should every wiggle/imperfection in the slot be sanded smooth? Response from Jimmy : I carefully free hand routed the slots in Northline Raceway, so I had many jogs to fill, but most guys are now using Luf Linkert's flexible guide system : www.oldslotracer.com Nothings perfect so you still will need to sand the slots smooth and straighten some severe jogs in the slot that can cause the shoe to catch. The secret to routing free hand is the fact that sanding the slot afterward gives you a smooth surface regardless of slight jogs. A jog of 1/32" disappears quickly. 1/16" may have to be filled I used a piece of plexy plastic less than 1/16 thick, that could flex to do turns wrapped in 100 grit paper to start. Wear gloves, or by the 2nd lane you will stain your track with blood. No need to follow up any finer. To repair bad jogs, first sand smooth one side of the slot at the bad jog. After pushing a 3/32" thick piece of cardboard wrapped in masking tape into the sanded and cleaned slot, fill from the top, the remaining rough jog left on the opposite side. Use Plastic Wood type wood filler, Bondo or, J&B Weld epoxy paste. The waxy surface of the masking tape will allow you to carefully remove the slot filling card board the next day. If you cleaned out the bad side of the slot well enough the epoxy or plastic wood will remain in the jog. Sand the top of the track level and then sand the repaired side gently with a 80 grit, followed by the 100. Put pressure on the repaired side of the slot only, and let the side you smoothed out earlier be your guide. This is easier than it sounds, and besides the cars shoe is more tolerant of jogs than you would think, as long as it is smooth. As for wavering slots, as long as they are smooth, they are not an issue at all for cars. You never see it through the car's actions at all! Of course with 7/8" or 3/4" between some slots in this system, you better not waver more than 1/16" total anyway. A trick that I use... by laying the copper tape evenly over the slot, and not following the wave, no one but the car will ever know you are not the perfect wood track builder.
Question : There seems to be two schools of thought on wood track bench work. One is as depicted in Luf's how to CD and the other is shown pretty well on some of the track building forums. Luf's is a flat table type section of plywood that is used as the base for securing the routed track sections. The other is an open frame work of 1" x 4" boards. So, I'm not sure what the obvious choice should be? Response from Jimmy : Remember that with the table top method, you will have zero access to the bottom of that track once you pin it down. I've been under my open bench work a million times tweaking or rewiring connections, or trying new ideas. But, not if I had screwed it down to a table. Another negative to table top building is that you can only pin it down from one direction, the top. Open bench work not only allows you access, but during construction, as you force things up and down, you can add or subtract bracing very easily since you can screw it horizontally to cross members under the layout without a table in the way. Also, with a table, bracing has to be cut to fit perfectly between the table and track to get the right, banking or finished height. With open bench work, the bracing can be rough cut scrap, pushing the road bed up to where you like it, then screwing it to the bench work cross members beneath. If too high or low, simply undo it, make the adjustment, and re-screw it. With the table top you need to cut another brace to fit. This is huge guys, on tracks your size. If you don't have your mind set on the table top, then choose the open bench work. It is harder to get started, but once you get the top of the bench work cross members positioned, height wise, within 4" of where the final track may lay, than it will be easy to brace up the track to what ever elevation you want. Not to mention it will be lighter if you have to cut it up to move it later. Ken's track on the Professor Motor site is built on a bed frame of 2X4's crisscrossing every 3'. Cross members bridge those 2X4's in areas where the track flows over it. The 2X4's are more stable and far cheaper than 1X4's. 1/2" scrap plywood bracing pushes the track up and down glued and drywall screwed to these cross members. Very easy and cheap. This whole assembly sits on 18 stacked up milk crates. Some train guys construct a 1/2" plywood table as their datum to build and measure up from with big access panels cut out of it. Cost more in plywood, and is not as accessible, but it's not as bad as not being able to get to the bottom of your track. A modular track, built in sections that sit on a table, would be very portable, but would give unwieldy access and be the hardest to build. Also, twisting the MDF track work up and down might torque each section out of square. You really have to torque the MDF or particle board down hard onto the bench work to get it to bank and pitch. You would have to screw the sub frames down to the table from beneath and hope it doesn't change it's configuration when you go to undo it for access. I don't have any experience with this modular idea, but I do know that there is a lot of pent up energy waiting to unwind if I ever was to cut the bench work beneath my track. Hope this doesn't set anyone back in their plans but these are things that I learned by doing. I really only went to open bench work because all my infield scenery sections and pit areas are modular, so that I can take them to my desk and model them more easily. I'm really glad I went that route because, I found I needed to get access under there a lot more than I thought I would, both during and after construction.
Question : Is the track coated with any type of clear coat or sealer or just paint? Do you think clear coating aids in traction ? Response from Jimmy : I tested 3 different paints on wood straight sections that I added to my boy's plastic slot car track 20 years ago. We ran the test panels for two years. Results will surprise you. Polyurethane did not grip well, traction wise. Latex which guys are talking about using today did not last back then, but the traction was good. For me, traction and resilience won out. A mix of Flat black and Flat white Rustoleum gave the best wear and traction over the two years. My track has one primer coat of white Kiltz sanded (Kiltz oil, never latex since it's unsandable). One coat of Rustoleum Oxide red primer sanded to 400 grit, one coat of pure flat black, again sanded, then one coat of three different shades of the black and white mix to replicate different years of paving. Then I airbrushed speckles of tan, light gray and brown. Finally I air brushed a light black wear pattern where the real cars would have left their mark. I also made a roller out of a tire wheel and axle and added skid marks with diluted flat black. Phew, I had forgotten I did all that, but the Rustoleum has been great! Nothing shy of Gumout softens it. Stinks as it's drying though, but I can't be happier. Guys say that MDF starts out smoother, so the coat of oxide red Rustoleum primer sanded might be eliminated. I used particle board which was far courser. My friend has a polyurethane clear coated track and I'm sure the Rustoleum is giving better traction.
Question : I'm planning to lay out my design on MDF, route the slots, then cut out the track from the rest of the MDF. This way I will end up with a small number of fairly big sections of track as you described in your first entry in the FAQ. Have you found that the slight amounts of banking that you describe impact the alignment of neighboring track sections? Response from Jimmy: All of my 1,040 feet of slot were cut free hand with no guide, so it was no problem for me to route 6" to 8"of uncut slot at the joints where sections come together. This was done after the sections were joined, banked, then glued and screwed down to the bench work. If you leave 3" to 4"of uncut slot at each end of the track sections you can blend the lines for routing smoothly together and guarantee that the slots across each of the mating sections transition smoothly. The size of banking that causes you to have to account for a revision to your design "in blank" are the huge steep turns that we remember on commercial raceways and hobby shops. This form of racing is great but we must categorize them not as scale model car racers, but more the old school flying wing racers looking for the thrill of speed. They endeavor to whip out a lap as fast as mechanically possible with little regard for realism once the cars are in motion. Thus the desire for huge banked turns. You can only drive on them one way, and that's at full speed. Even though they are cool to see and add to the speed, what they subtract is realism and an opportunity to use the large area they take up to design in more linear feet of racing in a given area. This is well and good for that style of slot car racing, but scale model car racing, as on Northline Raceway, is for those who desire to recreate actual vintage races with fine scale model cars which are on more realistically banked turns. You can pack more racing in the same space with scale racing, which would eliminates these huge banked turns because they are so out of scale. A more prototypical degree of banking will rarely require you to change the track cut out so that your finished track matches your plans. The amount of banking that we used most on our scale model raceway is no less than .5" of slope for every 9" of run measured anywhere along the width of the track from the inside to the outside. We have found that if you have less than a 1/2" to 9" pitch, fishtailing cars can put a wheel off the outside of the track edge or lean on a guardrail or wall. This is assuming that you use the space saving 2.75 to 3" of outside gutter dimension we discussed earlier. Note that Northline Raceway has two banked turns with a light banking of 1/4" of lift for every 9". At both turns it causes the outside cars to lean too hard on the walls and Armco railings, and the inner cars to fishtail too much. Although most of the turns have the .5 to 9" minimal pitch, banking all the way up to a Daytona style turn is cool and realistic, but it does use up more space. This type of banking is possible only if the track cut out is routed, then made to have it's apex angle enlarged because the dimension between the entrance and exit to this banked turn gets smaller as the ends are pulled together and the banking formed. Luf Linkert's site www.oldslotracer.com has a great example of this on a wide routed track. Although it is too extreme for me, it shows how it's done, and how much space it takes up. On a narrower scale width track like ours it's easier. On Ken's Raceway Club track, included in the Professor Motor collection of Michigan tracks, www.professormotor.com/kens.shtml the biggest banked curve with an outer radii of 2 1/2' was banked after the entrance and exit were firmly screwed to the bench work about 24" before and after the start and end of the turn. This 1/2 particle board was banked into submission after the routing was done with no accounting for a change in the turn as it was drawn. Wedges were glued and screwed beneath the track to pin down the banked track permanently. Off hand, I believe it was banked at almost an inch across the 11" width of the roadway. The whole curve itself was tipped up an additional 2" above the bench work at it's highest point. The particle board was straining but we did it. The light .5 to 9" banking at all the turns on Northline were done the same way. Oh by the way, the other turns on Ken's Raceway were left un-banked and are very difficult to drive. I would bank every turn on a routed wood track today.
Question : The lane gutter width, (defined as the distance from the outer-most slot to the edge of the track surface) keeps rearing its ugly head, Jimmy. I have read everything you have written at the Professor Motor site, and if I had to summarize, it would be as follows : Allow as little as 1.75" gutters on the straights, and as little as 2.75" - 3" dimension in the corners, when using retaining walls. Most of the forums I have read recommend anywhere from 5"-6" for a gutter width for the outside lane (for full car rotation) and around 2.5" for the inside lane. Jimmy, the gutter size has a huge bearing on track design and/or board size. What is your recommendation? Would/did you allow for full-car rotation in the outer lane? Or, are you for containing the race surface with barriers to the 2.75-3" gutter distance? Response from Jimmy : Normally the gutter dimension (the distance between the track edge and the nearest slot) must be enlarged at turns. Especially, since cars fishtail more readily because faux gravitational devices (magnets) are not attracted to wood. Some builders design huge skid aprons (5 to 6") which I think can be avoided. Yes, the gutter dimensions you quoted are what I used, mostly because it's important to me to fit the most track into a given space by keeping the turns narrow. We did this by taking into consideration the attitude of the track surface at the corners. We can control the amount of car fishtailing by changing the banking, and inclination of the track. Thus keeping it narrower. Before forming an opinion on how wide the turn must be to allow for drifting cars, understand that 4 physical things will affect the amount of fishtailing that takes place at each turn. 1) The radii or size of the corner. 2) The inclination up hill or down hill at that corner. 3) The rate of speed a car enters the turn. 4) How important is it for you to get as much track into the space allowed? The most efficient track design may necessitate a banked turn or a concrete wall or Armco barrier at the outside of some turns to keep the layout compact. The extreme opposite of course, is a design allowing room for a wide skid apron dimension, which gives cars room to drift way out. For the sake of space and realism we designed Northline raceway to avoid this by banking turns. Cars fishtailing greater than 45 degrees to the slot may look cool to the majority, but not only do real cars not do that, (modern rice burning drifters not withstanding) but it is by far the slowest way to do a lap. Not to mention getting in another racers way since a good driver keeps a solid grip on the road. Northline Raceway has soft banking at almost every turn to stop guys from big drifts and possibly cutting others off from doing a fast lap. Even though the lanes are cut so that two cars can get by, if the lead car is an idiot driver that fishtails wildly at every turn, the car behind may not get the room to pass. So, I intentionally banked tighter turns to keep drifting down, and it really worked. The bonus to reducing drifting is that it makes it possible to keep the turns narrow. Remember that nothing eats up usable track space like wide turned skid aprons! By using 1/2 chip board or MDF, a robust framework, construction glue, and drywall screws one can torque sections of pre routed track into a grade that pitches toward the apex of tight turns pretty effectively. It does not take much to create a bit of banking which avoids allowing cars to drift way out. Just 3/8" measured vertically between the outer edge and the apex makes a big difference. Sometimes, after forcing the routed track to bank, the slots pinch closed a bit at the surface so you may need to widen them back out with a piece of 1/16 plastic wrapped in sandpaper. The attitude of the track surface is every bit as important as how much apron you give an outside car to fishtail. Banking, twisting, pitching, torquing, rising and dropping. All these terms are used by race drivers when describing real race tracks. Since you are building your own track out of wood, why not add these different features to your scale track? On plastic track guys continually drift around the same way at each turn. Why would you want the same thing on your custom track? On a wood track, besides being able to fit more racing into a given space by custom designing turns to fit the space, banking them differently gives drivers even more cool features to drive through.
Question : Will the Vintage Cox thumb controllers work well with AC on a big oval using 1/24 pro track chassis or what controllers do you recommend? Response from Jimmy: Although this sounds bias it's a fact. I always recommend the Professor Motor line of controllers because they have today's technology in materials and circuitry, and give consistently superior control. I'm confident that the vintage controllers all can be made to work on A/C without a problem, but the added expense of buying new P/M controllers pays off in the long run. There is no reason though, why you could not start with your Cox controller and move up to one of the better P/M controllers later. If $ is tight, that's the way I would go. However, just like racing our 60's cars vs. today's robustly engineered, injected polymer cars, there is no comparison when it comes to reliability, durability, and ease of service, or upgrade. In regards to the Pro track 1/24 chassis, I have not found any chassis yet that doesn't run well once the diode is added to the cars circuitry. I can't say that I've done the revision to that particular chassis. But, I'm positive that if it runs OK on DC than the addition of the diode into the chassis, and another into the track circuit to ( or from ) the controller, will give you a car with realistic control on AC. Do the same for a second car, but with the diodes reversed, and it's polarity at the shoe switched over, and you guys will be able to run two cars in one slot. It will not just double the fun on your racing nights, but compound the realism and excitement twice over, then squared again.
Question : My track is a much faster oval than your Northline track, I would like to add a second set of switches on my plans to allow cars the choice of returning to the regular slots when ever they want to, rather than being forced back into the faster passing lane at the end of the fast lap. Do you see a reason not to allow more switching like the digitals tracks do? Response from Jimmy : Your track may lend itself to switching back two places on the track, but I can think of 2 reasons that it may take away some of the realism. First, it may get choppy and hard to keep the racing going. A second lane change area doubles the chances for that one guy not cooperating (or upset at another driver) to disregard the lane change discipline required for all to have fun. But on your fast oval that rockem - sockem action may be what you like. But second, and more importantly, you know that the drivers will learn quickly to stay in the lower faster lane on the oval and not switch out of it. No one will take the high road, and that will be the only way anyone can pass. The difference between cars and / or drivers is rarely great enough to overcome the difference in length that an outside lane on a big oval creates. My opinion is that with guys hogging the fast inside lane and not forced to go back to the longer regular lane, trailing cars will rarely have enough speed to overtake them on the outside. Especially because, on an oval the cars ahead never need to brake. My opinion ... force the guys out of the shortest way around the track by cutting the faster second slot back across and into the regular outside slot. If drivers are allowed to choose to stay in the fast lane, than the majority of your oval races could look like nothing less than a fast parades.
Question : Do you use just one train transformer for the whole track? Response from Jimmy : Yes. We started with a small Lionel 20 watt AC transformer and it ran 8 cars fine at full speed but it was straining when all the cars were running slowly behind the pace car. The circuit breaker built in would trip and quickly reset. A few times we felt slight surges if two cars went off at once. About a year ago, I bought a used 90 watt Lionel transformer, 1950's vintage, at a train show and we now have more than enough power for 8 cars at any speed, plus we can vary the voltage from 4 to 18 volts and it has built in circuit protection that resets automatically. All this for $28.
Question : What model diode did you use for the cars and the controllers, and where do you wire them in the controllers? Response from Jimmy: We have not found a diode that does not work for the AC two car system. The ID numbers on the sides of what we order from Digi-Key www.digikey.com is 1N4004. We got a batch of 200 for about $20 and they were delivered in a few days. The Digi-Key order number is 1N4004GITR-ND. Individually they seem to sell for about 17 cents each. Of over 75 cars that we've installed diodes into, we have only had two that were bad from the start. We have not had one go bad in a car while racing. I'm told that diodes are heat sensitive, so solder the diode with the minimum heat necessary. That may be what went wrong with the two of ours that did not work. As for the controllers, the diode can be put in line anywhere up or down stream of the controller in the black or white side of the circuit. The controller's diode should not be put inside the controller or on the leads between the clips and the controller. Wire the diode for each controller in it's black or white line under the track. This is because the diode inline with the A car controller must be in sync with the diode in the A car. The B car diodes must be in sync with each other also, but running in the opposite direction than those in the A car circuit. If a diode were installed inside, say the A controller, it will be in sync with the diode in car A and work fine. But, if that controller with its A situated diode inside, was unclipped and hooked up to a B car station, the diode in the controller will not be in sync with the B car. Again, to avoid complexity, hook up the controller diodes under the track or you will end up with a set of dedicated A and B controllers, and you will be unable to clip any controller at any station. Note : Never connect the red controller lead. It must be disconnected at the alligator clip or under the track. If not, a dead short will occur when the controller is hooked up and the car sharing the lane is energized. Lastly, we've used Professor Motor controllers for thousands of hours of reliability and optimum control. These PM controllers have efficient diodes built into them. It is important to note that when using this type of controller for the AC two car system, vs. wire wound resistor controllers, the polarity must be changed at the controller on the B car only. This is easily done by hooking up the black lead of the B car controller to it's white terminal and the white lead to the black terminal. We did the flip-flop of polarity under the table so that at the B stations the white post is wired to black and the black post is wired to white. That way any controller could be used at any A or B station. When using old fashioned controllers with wire wound resistors this flip-flop is not necessary. The above sounds so confusing, but bench test the system on a short piece of straight, and when you get the combination right I guarantee you will get a rush seeing four cars independently running in two slots! And, you did it yourself for very little money.
Question : I want to plan a second place on my track that allows lane changing to give drivers a second place to pass. Your large track only has one lane change area, wouldn't another lane change area add to the passing? Response from Jimmy : Actually it would create less opportunities to get by slower cars. More critical is that it would add to the complexity. It would reduce strategies associated with passing and blocking that we've tried to achieve on Northline raceway. Remember that switching without the time to think will make the racing look chaotic. Racing here really does become a mind game with good experienced racers. The digitized, magnetized, homogenized, lane change systems today seem too hectic and chaotic. Each car looks more like a streaking bug, thrashing to cut each other off with no racing strategy involved at all. I have found in 4 years of having so many drivers coming to our track that the less complex the smoother the fun. Even the one lane change area seems to overwhelm many at first. Note that Northline has a 140 ft. lap, and even with that distance to try and pass many times cars are still neck and neck when they have to funnel together at the hairpin to change lanes. If you were to design two places on a shorter track where cars were required to chicane down (into single file to avoid shunts as they crossed lanes) then that leaves even less of a lap to get by your adversary. Not to mention that most race stopping pile ups happen at our lane change hairpin. Two places that cars can cross lanes will compound the number of race stopping shunts. As an example of my having to reduce complexity, I am not a big fan of microprocessors wired into the track doing all the work for drivers, but I am having to rethink and rewire Northline's pit lane electronics to be more automated. This because guys could not learn to flick a simple shift lever in the right direction upon entering the pits. This lever flicking was to put the car in neutral (as in real racing) and signal the system for either fuel, or the longer required fuel and tire stop. Afterward, a timer would give the team manager's green signal for the driver to leave the pits. Drivers were prone to mess up a good race thrashing the shift lever around. A huge amount of past work was wasted. I had relays galore wired to the leather booted Escort turn signal levers that I set up to look and act as shift levers. Ice age electronics my sons call it, but it looked and worked great. Except for one thing...It was too complicated. I'm afraid that I need to make everything that happens, when a car stops in it's pit, to happen automatically. Oh well, good idea, but too hard for guys to use under pressure. Moral of the story...design to the more user friendly, simpler side.
Question : I was wondering what you use for lap timing or how you run races when you have two cars in the one lane? Response from Jimmy: We start large fields behind an independently controlled pace car to gather the 7 other cars together for a disciplined race start. The pace car has sirens and lights that automatically go out after it drives into the pit lane as the field comes up to the starting line for the green flag. As for the microprocessor controlled lap counter, Infer-red sensors installed in a recess cut into the slots, from beneath the track, detect each race car's guide as it shoots past. This is a bit more complicated with the pit lane and passing lane system because each car has three ways of passing the start/finish line. A car could do a lap as it goes through the pits, so that has to be accounted for by adding sensors through the slots in pit lane . Also, since the cars have a second way to do the course, the passing lanes have to have sensors in them to track cars going past the start/finish line in them. So, for racing 4 cars there are 11 sensors tracking their laps. 4 for the regular slots, 3 in the 3 passing slots, and 4 in the slots through the pit lane all wired in parallel. To complicate things further, since we run two cars in one lane, we now have to account for the second set of race cars, or the "B" cars, with minor revisions to their shoes. The "B" car has a 1/16" slot cut into it's shoe and the micro processor can actually identify it as different than the "A" car that runs a standard shoe. We tested it thoroughly and it's amazing that, with out fail, the system can detect the two different cars flashing past the sensor at full speed while running nose to tail. However, the system will not work with transparent or white colored shoes. My son Andy is a graduate electrical engineer and is still developing this slot car tracking system that he designed from scratch. His latest changes will also track each car's location for the caution light system around the track. We broke the track into 8 zones and installed the same infer-red sensors at the head of each zone to track each car as they race through every zone. Should your car crash, you simply push an amber button and the last zone that your car successfully passed through begins to flash yellow caution lights across that whole section of the track. This quickly and efficiently signals the other drivers and corner marshals that there is a "car down" in that zone. Very important when so many cars are racing around the track! I think Andy plans on selling the system for other wood track owners to use when it gets finished. Building a large scale race track has it's own reward. You will have a lot of fun. If I can be of any more help to you let me know. Have you discovered Luf Linkert's site yet? It's the #1 site for wood track owners. www.oldslotracer.com/index.html
Question : We know that you use a 12 volt solenoid and return spring connected to a bent 1/8 steel rod to guide the shoe from one lane to the other. But, when you run two cars ("A" and "B") in a lane. Both run very fast and near one another. Say car "A" is first and "B" goes through second. But, both cars run nose to tail. How do the drivers of car A or B put on the switch and not disturb the other car? How the does the switch "know" who wants to change the lane and who does not want to do it? Can the A driver send a different signal to the switch than the B driver? Response from Jimmy : Good question. The problem of a driver holding his lane change button down too long sounds worse than it is. Both A and B driver's buttons are wired in parallel to the same switch. Nothing fancy is needed. The decisions are totally up to the driver. If driver A wants to be kicked off my track, he can just keep holding the button down as driver B goes through the hairpin turn where the lane change switches are. There must be discipline in any form of racing. The decisions are totally up to the drivers. If they just change lanes blindly, they are going to ruin the race. Anyone model racing with two or more cars per lane must adhere to the same common sense rules that apply to all forms of racing, or be black flagged. We are not making toy cars fly around here! We are miniature racing. We are replicating an actual car race of a period with the finest scale models that we can build or buy. I have seen some guys digitally racing with more than one car per lane. The cars seem to be flying around like magnetized bumble bees stuck to the track. The track's electronics on some sets, does the thinking for the drivers. The only time they do look like real race cars is when they pick them up to look at them! The secret to a good routed track with two cars running in the same slot with each controlled independent is that it needs to have the lane changing area designed just past a chicane, or hairpin. This way, just before the switches, the track necks down to force the field of cars to go through slowly in line. Something the plastic tracks cannot provide. This not only minimizes shunts that occur as cars cross other lanes, but it allows the time to make a decision as to whether to stay in the regular lane or cross to the passing lane. The way we race, if a slower car is blocking, 1) the slow driver really should let the faster car pass. No different than what is expected in real racing! 2) the faster car needing to pass should drop back as he comes to the switch because he not only has to negotiate the hairpin turn slowly in single file, but he needs to see which side the car in front decides to choose to race on. If he drops back a bit, no one can pass him from behind because the field of cars were forced into single file to get through the tight hairpin or chicane. Like real racing, he sees which side of the roadway the blocking car chooses as it leaves the turn and he takes the opposite side. This careful planning allows him the whole next lap, to beat the other car back to the lane switching area. Each time the cars slow and regroup at the hairpin, or a chicane, that decision is made again. No different than what Mario Andretti needed to do at hairpin turns each lap of every race he ever ran in. If a driver on a track with two cars in one lane, does not race as the real cars do, than he deserves not to race with a track such as this. He should go and spend money to buy a digital set that does the thinking for him as he buzzes the cars around mindlessly, in an unrealistic way. It will still be fun for a short while.
Question : With your idea of keeping the tracks width to a minimum I see that a larger layout is possible, but fishtailing in the corners needs more width to the track. How wide do you find it needs to be not to allow cars to, "lean on the guard rail" for added speed. What dimension did you use from the outer most slot to the outside edge of the track on your turns? Response from Jimmy : It would be helpful to refer to a drawing of my track to get a feel for how the following dimensional increases to the 1.75 spacing between the outside slot and a wall has on a high speed drifting 1/32 model car. At turns where we do not get any contact at all the 1.75" space is increased to 3". This is at the Carrousel, Hairpin and Daytona banking. The degree of the turn affects whether the car can lean on the wall and increase speed. The tighter the turn, the more the leaning car benefits. With 3" a driver can touch the wall, but the attitude of the car is such that speed is scrubbed off. Now at 2.75" a car can lean on a wall and it's a wash, speed wise. A definite increase in speed on big turns can be gained when the 1.75 space on the outside of the turn is reduced to 2.5" or less. Note that this increase in speed is gained on sweeping turns at a good clip. On sharper turns than 18R" it gives a car leaning on the wall a huge advantage. To not help the outside car, you can design the track edge to be <2.75" from the outside slot but not build a wall or Armco rail for the car to lean on. The tires will simply fishtail across a skid apron and not gain a big speed advantage. However, the reason we are trying hard to keep the track design narrow in turns is to create a larger overall layout. The space reserved for skid aprons takes up usable space. For reference, the above mentioned 3" spacing of outside slot to a wall, or guard rail, gives total clearance. If the car touches because it is drifting that hard the driver is scrubbing speed off. The 2.75" dimension at the last corner before the Cork Screw and at the last part of the "D" turn before the up hill straight makes a car at speed bang the wall or curb marker and does not really help it. In the Esses the three turns have a spacing of 2.5" from slot to the outside edge of the track. The middle 180 degree turn has a wall that hard charging cars do lean on, but the other turns have curb markers that the cars wheels ride up on so drivers need to back off or they upset the car. At the last sweeping turn after the pit entrance, before the main straight, the outside car gets a dramatic advantage by leaning on the wall. This dimension is only 2.25" or less as it drives toward the start finish line. If I could redesign my track, the only thing I would change is this last turn. If the 2.25" was 2.75" the car on the outside would not get such a boost from the wall. Not only should the track width increase at turns on the outside, but the inner most slot has issues with apex markers less than 2" away. Although 1.75" of absolute min space between the walls of my main straight and the outer most slot have never, ever been a problem, it's important to note that this dimension must enlarge as the inside car reaches the next apex. Especially if it is a tight turn because the long wheelbase cars like NASCAR or Trans-Am models drag their rear wheels inboard of the front. This makes the rear wheels hit the apex markers and deslot at slower speeds. At fast speeds the rear end fish tails out so that it isn't as obvious. So my point is, that not only should the 1.75 min spacing between the outside most slot grow to clear scenery for fishtailing, but the inside may need to enlarge also to clear tight apexes at slow speeds. The gap of 2.75" between slot groupings has never been a problem. I left it that dimension thru almost every turn on Northline Raceway. Although cars can lean on each other, they tend not to be able to get that pendulum swing and bang hard to nerf outside cars off like with 3.25" and 3.5" standard spacing. Works great with kids.
Question : How was "Ken's Track" shown on the Professor Motor Michigan Slot Racing Directory made to be 80 ft of racing in so compact a space? Response from Jimmy: The track I built with my Nephew Ken, (Ken's track is here : link) is exactly 6' X 15' long. There can not be a linear inch more track laid into a layout of that size than what we got out of that space without overlapping roadways. The slots are only 2.75" apart in the straight sections with 1.5" of track on each side to clear walls. That's a total track width of 8.5" minimum needed to run (3) 1/32 scale cars. The track has been running for over two years with no issues at that width. Of course the roadway widens at turns to allow for drifting. These narrow straights allow for many more linear feet of track in the same space and the roadway looks more to scale. No lane changing was designed into it because it was set up to be built by (3) 14 year olds. For simplicity I designed Ken's track to be the "cookie cutter" style. There are two ways to build a track and each should be designed that way from the start. The simplest is cookie cutter style. The second is individual sections for the more complex road courses. Northline raceway (Jimmy's track) was made in individual pieces and fastened to bench work that was already built and set for the change in typography. For Ken's track, the road way was cut by the boys, cookie cutter style, right out of 4 X 8 sheets of 1/2 particle board fastened to 2X4 framing with milk crates stacked 3 high for legs. To start, the 4X8 sheets are all fastened together with 4' X 6" sections of 1/2" plywood glued and drywall screwed together from underneath. This huge flat table top sits loosely fastened to it's bench work, which are 6 sets of 3 milk crates, drywall screwed together, that are fastened at the top with 2X4's and 3" drywall screws . These 2X4's act as a perimeter frame with cross members that support the particle board top. After priming this table top, the roadway is traced on to the top of it, slots routed and then most of the track cut with a reciprocating saw. The road course is then lifted, banked or tipped on the bench work where ever possible. At many places the track is purposely not completely cut out so that it retains its rigidity yet torqued and upset enough to keep the roadway from looking flat. It does not take much twisting to make it more interesting than a flat road course. Using drywall screws and liquid nail glue, the lightly twisted, undulating, torqued and banked turns are fastened in place with glued and screwed gussets of wood that retain the roadway just the way you want it. The change in elevation adds dramatically to realism. It's much easier to do than it looks, thanks to the invention of the common drywall screw and Liquid Nail Glue. The remaining infield, of the 4X8 sheet, stays in place screwed and glued to the track framework. This will act as a base for the 2" pink Styrofoam that gets glued to it, and shaped up to meet the undulating track edges. The scenery and it's Styrofoam base is another story. The last hair pin turn at the long straight before the banking was made too tight (R3.5"). I recommend that it be made larger. Actually I would make that whole hair pin turn large enough to have it tuck under the turn adjacent to it. One turn would need to be raised and the other roadway go under it. But, it would then have had to have been cut from a separate piece of particle board to make the radius of that turn any bigger. But, that would have been too complicated for the boys. Since it was converted from DC to rectified AC the track is dramatically more user friendly, because it now has better conductivity between the brushes and copper tape since the voltage almost doubled. It is powered strictly with an AC train transformer and diodes. Because there is no need for running two cars in the same lane, there are no diodes required in the cars. Just in line with each controller. The AC system and Professor Motor controllers add greater control on tight routed tracks such as this.
Question : What are the advantages and disadvantages of running a track powered by an AC transformer vs. traditional DC power ? Response from Jimmy : Initially the importance of using AC over DC on Northline Raceway was only that by rectifying the AC signal, two cars can be made to run in the same slot with independent control. By powering the track with A/C current (a simple, old, used, cheap Lionel train transformer) and rectifying the supply with $.10 diodes in each car, plus wiring a diode in line with the Professor Motor controllers, we are able to send two separate signals to one lane. Where before we ran 4 cars, now we race 7 lead by a pace car that pulls into the pits at the start of each race. The cars run on twice the voltage for half the time which gives greater control. Especially on copper taped routed tracks. You can make a car creep into the pits or go balls out down the straight. Not only that, the oxidation on the copper is no longer an issue because the 12 to 18 volts burns thru the dust and oxidized copper film. No more warm up laps to break the copper in so that the cars don't stall. Hearing guys call out, "My car's stalled give me a push" is down 1000%. The cars have a unique growl as they go around, which everyone says sounds cool. However, a distinct issue is that the motors run warmer, but not hot. In the past 18 months we have thrashed 75 cars for 18 months of hard running with no ill effects. Another thing is that that you lose the brake system. Guys not used to running on AC will disagree, but we do not find this a disadvantage. It's not an issue since the cars run with greater control and good drivers know that the fastest laps are done with brakes off. A real hurdle has been that veteran slot car racers are used to gobs of wheel spinning torque as they enter a straight. The A/C system is more prototypical in that you must exit a turn as fast as you can to get the highest speed at the end of the straight. Because the car, as in real racing, comes out of a corner and into a straight with reduced torque, drivers find themselves using full throttle allot more with AC. It leaves guys not used to the lack of wheel spinning torque thinking the track needs more power. Real racers are on full throttle 95 % of the time too! Believe me the cars on AC can go plenty fast! Racing with AC takes time to get used to but it has turned out to be a remarkably more realistic way to run cars. Although old die-hards seem to take a while to get used to it, the new guys never notice a difference until we switch back to DC. As soon as we do, the cars revert to the jerky, wheel spinning, limited control that we've all been weaned on. Everyone says that they never noticed that racing on DC was jerky, until they get used to running on the AC system with a large field of other cars. I'm sure that it is not too unlike movie goers of the 20's who were perfectly happy with the jerky movies they thought were good enough to enjoy. That is, until they experienced the smoother running films of later years. After an hour of running on AC, all agree that it is a great smooth way to run cars. Also an advantage, if racers come over with regular cars, no diodes, you can put them right on the track and they can run perfectly one car per lane. With the same great sound and control. Unlike unique digital cars, it's no problem if guys come over to run regular cars. The quick addition of a simple diode allows them to participate in the races with larger fields of cars. Any standard car can be made to run two in one slot with the simple addition of one critically placed diode. Again, note that a car with no diode installed in it will run great on AC as long as no one tries to race a second car in that slot. The western Michigan chapter of GWLTRSCIOGB (Guys Who Like To Run Slot Cars In Other Guys Basements) drove across the state to try it a year ago. They loved it, and have been back for many more hours of realistic racing along with many other GWLTRSCIOGB's at Northline Raceway.
Question : Why are the slots bunched together in two groups on your track and why the lane changing feature ? Response from Jimmy : The slots are cut into Northline Raceway in two tight groupings to allow 4 (or more) cars to race on a scale width racecourse. This passing lane system we use can be designed into any home routed track that guys are currently planning with little or no cost. My thoughts 20 years ago was to get as much racing as I could in the space that I was allowed. Also I did not want a wide roadway that looked unrealistic. So, I experimented with grouping slots together. A narrower roadway allows for much more racing in the same space. In order to understand the advantages we need to compare the design width of a typical slot car track with one slot cut around the layout (which allows passing anytime) vs. a track designed with two ways cut around the course (allowing cars to pass only when on opposite sides of the road). If we were to design a track to race (3) 1/32 scale cars and they required an absolute min of 2.75" between slots to get by each other, and 1.75" on either side for min clearance to walls, than the total road way width on this imaginary straight would be 11.25". ( track width at turns should be expanded but for this comparison we'll compare the straight sections) Now lets bunch up each of the 3 slots to only 3/4" apart and cut a second way around the track for the cars on the opposite side of the roadway. In order to allow the 3 cars the ability to pass we must cut another group of 3 slots 3/4" apart that is 2.75" from the first group. Hey, the total width of this straight away is now only 8.75"! A 3 car layout who's straights are 8.75" wide can have many more linear feet of track designed into it than an 11.25" wide road, in the same space allowed! To pass, the cars must now change to the inside or "faster" group of slots. That is why the lane change feature is in place at the hairpin turn on Northline Raceway. Now, design a chicane on the track where the cars must go through single file (this minimizes shunts as cars change lanes) and create a lane change feature to allow the 3 cars the ability to run on the inside, or "faster", group of 3 slots. Design the track so that when the cars running in the "fast" lanes go one lap around and get back to the narrow chicane, their slot is cut to guide them back into it's original slot. This negates drivers hogging the "fast" lanes, or quickest way around. A driver who switches into the fast lane knows he has but one lap to pass his adversary who stayed in the original group of lanes. If you are racing realistically, the slower car lets you by, or he may change lanes too and try to continue to block you. It gets to be a race with in a race to get to the chicane first to gain control of the passing situation. Not too unlike real racing. Now add the AC power system we use, where with a single 10 cent diode per car two cars can run with independent control, or spend the money and go digital, and you now can race 6 cars on the same 8.75" roadway. You have a track that looks realistic, because it is 23 scale feet wide rather than 30 feet. And, you get way more track in the same space you started with. That is why Northline Raceway looks as large as it is. The narrow width track allowed much more track in the space that it occupies. If you design your layout with a passing lane you now get the exciting ability to dice with other cars to gain the lead, rather than just blindly driving by. You have designed a track that has a passing feature built in so you can have more than one car in each slot. This doubles the fun on the same track. Without cutting the passing lanes a second car could not pass the car sharing his lane. You are now running 6 cars for the same money (AC System) on the same narrow width. To race 6 cars the conventional way would require a track width of over 20 inches! You have designed the most racing that you can get into the space allowed, with the most cars, in the most exciting realistic way, on a scale width roadway. This is only an outline of how I use the passing lane system at Northline raceway. It by no means is a "how too" report. I will be happy to answer any more specific questions anyone may have.
Question : How do I build a mechanical switch and how does it force a shoe from one lane to the other? Where on the layout is the best place for this switching to take place? Response from Jimmy : I modeled my pit switching idea from a scrap book that I kept since I was a kid. I had pictures of a huge club track in California that had a pit lane turn-in back in the early 60's. It was my fantasy track that I always dreamed of mimicking. I designed my own switch assembly when I began laying out the ideas for my track. Each crude switch assembly consists of a 90 degree bent rod (.125" welding rod) that I hammered flat at the top. This flattened end sits up along side the slot hidden in a recess. When the hammered rod would swing out into the slot, the car's shoe would strike it and be forced into the Y that leads to pit row. This rod is supported by two slot car chassis bronze bushings that are set in a block one inch apart. At the lower end of the .125" rod, beneath the bushings, is formed another 90 degree bend about one inch long. This bell crank arm gets tugged by a 12 volt solenoid with a return spring in line to pull the bell crank back. In a neutral state the spring holds the flattened section at the top of the bell crank rod tucked into the recess carved out along side of the slot just forward of the Y. If power is not provided to the solenoid, then the car will go by the bent rod unhindered. If power is applied to the solenoid, then the bell crank gets pulled to bring the top flattened "flag" out across the Y in the slot to direct the car's shoe into the side that sends the car into the pits. Very crude by today's standards. But it has been very, very dependable so far. More effective than I had hoped for! I think the secret to keeping 7 switches working properly all these years was to lubricate with graphite dust vs. sticky oil. The biggest hurdle to laying out a good lane changing feature is to design your track in such a way that the Y in the track happens at a place where the cars need to be accelerating but not going so fast that they can't handle the fork in the road. In this way each car has a better chance of "jumping the gap" when power is interrupted as the brushes cross over the Y. At the end of a turn before a big straight would do well. Also it is advisable to design a place on the layout where cars will be doing a minimum of passing. This is to minimize the spectacular crashes that sometimes occur when cars drive across other lanes to get into the pits. If I were to do it again I would certainly look into the efficient switching devices that are now available to model railroaders. Some sort of combination of RR switch and a "flag" going up into the slot would be in order. Countless hours were spent testing my system until I had a device that was trustworthy and robust enough. Using a device that already had the solenoid ready to work would have been the way to go.
Questions : How do I minimize the tarnish on copper tape that affects how well cars run until it gets burnished off by passing cars? Why did you choose to use copper tape vs. tinned braid? Response from Jimmy : The copper tape used as the conductor on my track was not my preferred choice because of oxidation that occurs on the copper vs. tinned braiding. I have become very familiar with the difficulties of getting a run started when the dust and oxidation builds up enough to stall the cars. A side note: I had to use copper tape because on my track the car's wheels actually ride over the copper tape of the adjacent lane. My goal was to keep the track a true 1/32 scale width. To accomplish this, my lanes are clustered together in two tight groupings. Both groups of lanes have slots cut less than 1 inch apart with 3 1/2 inches between the two groups. To allow for passing a slower car, I designed in the capability of changing out of the regular lanes (the outside group) and into a slot that is cut on the opposite side of the track (the inside faster group). As long as the slower car blocking you doesn't change lanes too, both cars can battle for position without contact for the full lap. I could not indent the thicker tinned braiding without upsetting the traction of the slot car in the next lane. And, the braiding was too wide. Copper tape allowed the neighboring lane's tires to run smoothly over it. I have found two things that help lighten the problem of cleaning off the build up of power starving residue. But, neither procedure solves it. First a 50/50 mix of Orange Clean and white vinegar, wiped over the track leaves the track surface clean for good traction. It also removes some of the tarnish off of the copper. The vinegar is used in antique restoration to clean brass and copper. The Orange Clean is sold by the Oxy clean guy on TV. When I saw him dip a penny in it and it came out clean, I knew I had found something. When one uses the O/Clean straight it leaves a film that a rinsing with water easily removes. But don't do it!!!!! Never ever, ever allow water to touch the copper or it will increase the rate of oxidation ten fold ! I have learned the hard way. Once water touches it, you can dry it till you rub thru the paint. It will accelerate the tarnishing of the copper. The vinegar 50/50 mix seems to reduce the film residue as well as clean the copper. The O/clean & vinegar solution does not affect my track paint or the bond of the copper tape. I used Rustoleum flat paint as my track surface and the concoction does it no harm. I also have found that the vinegar makes a great cleaning solution on the brushes. But beware that it can remove decals and will slowly discolor lacquer paints. That is why I hesitate to use straight vinegar. I don't know what the long term ramifications on the copper adhesive may be. For troubled spots I have been known to polish the copper carefully with straight vinegar. The second idea I found effective is to run older vintage cars first to polish the track clean. The older tinned brushes tend to have less problems with conductivity. Although they still stumble around for a few laps, at least they stall less. Once they burnish off the oxidation, the track will be more user friendly. The newer cars like the FLY's have pure copper brushes that tend to stall once they pick up any corrosion. Especially, I've sadly found out, on my large track, where the laps are so long they need to be cleaned every 10 to 15 laps. Oh well, It's still a lot of fun !
Questions : Were plans to build the track purchased, or how was the track design developed? Response from Jimmy: In response to your question, I did not buy the plans for my track, I used ideas from 30 years worth of scrap book track plans. I designed my layout on CAD and then after priming 4X8 sheets of fine 1/2 particle board with oil base Kiltz (not the unsandable water base Kiltz!) I traced the full size paper drawings on to them. I routed it out 1/4 deep with an 1/8 bit, but I would do it 5/16 deep now because of deeper shoes . However, if I had to do it over again today, I would butt up all the primed 4X8 MDF sheets edge to edge across the space it actually was going to sit in the basement and start laying out the lanes in full scale right there on the floor. It sounds more tedious but you will not only get as much track as your space allows, you will be able to tweak turns that are too tight or aprons that are to narrow to allow fish tailing without problems. You will end up with a tighter track but a package that fits more racing into your allotted space. Also you will get to skip the tedious task of tracing your plans down with stacks of carbon paper. Remember that any 2-D drawing won't allow for the added inches of board you need as the track rises and drops. The best thing about home routed tracks vs. plastic is that you can build in great elevation changes. With fine particle board it is not hard to just glue on an extension (braced underneath) to the portions of track that don't meet because of hills and valleys that make your connections between sections fall short. I ended up "tweaking" so many of my drawings that I'm sure I would layout my plans right down on the white primed 4X8 sheets with colored markers and a pair of dividers. Then, step back and take a look. Also note that you do not need to make perfect radius turns. The real race tracks don't so why should you? A sweep around a bend to fit your basement (and thus get more racing) is better than a true radius that doesn't. When you make revisions, do them in a different color. My Cork Screw turn ended up having 3 different colored tracks drawn on it over the original CAD design before I got it to look and fit right. Besides this gives you something to show your buddies before you start making saw dust. It may even entice them to help!
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