Slot Car Track Wiring Machine Machine

TRACK CONSTRUCTION Part 5

Wiring and Power Supplies

Contents

Turning the power on and off

Extra power supply info added January 2009 and extra fuse info added November 2012, minor changes March 2016

Slot Car Track Wiring Machine Machine Gun

Jan 10, 2008 Here's the track wiring used by BSCRA (British Slot Car Racing Association) clubs and many non BSCRA clubs in the UK Controller plugs are to be BS 546 3-pin, 2 amp type, wired as follows: Wiring for various different types of controller explained in more detail here Chris. Pachinko (パチンコ) is a type of mechanical game originating in Japan and is used as both a form of recreational arcade game and much more frequently as a gambling device, filling a Japanese gambling niche comparable to that of the slot machine in Western gambling. Pachinko parlors are widespread in Japan and usually also feature a number of slot machines (called pachislo or pachislots. Below is a nice, standard wiring diagram for a 4-lane layout. High Resolution PDF Track Wiring.

There are two ways I could cover trackwiring - either give a detailed explanation of why a particular size of wire is needed,or just give a simple guide to what to do. No doubt some readers willjust want the simple approach, and others will want the reasons, facts figures,graphs etc. I aim to provide answers for both sort of reader - read on forthe what to do guide - the reasons, facts figures,graphs etc are in the next article in this series.

For those who don’t want tomess around with the reasons why things work here are a few quick guide-lines ontrack wiring that should provide a reasonable amount of power. It assumesa normal club size track, running BSCRA type cars. For lower powered cars theprinciples are identical, but lower thinner wiring will suffice. A lot of clubs now useelectronic power supplies in place of batteries - these rules apply equally wellto both (but I won't keep repeating 'battery or power supply').

1) Use separate feed wires fromthe negative battery terminal for each lane. Although a SHORT length(less than a metre) of VERY THICK wire from the battery to the pointwhere the wires separate is tolerable the general rule is DO NOT USE COMMONRETURN WIRING.

2) Obviously the positive wiringhas to separate fairly near the battery to go to the separate controller sockets. Ideally use separate feed wires fromthe positive battery terminal for each socket. Although a SHORT length(less than a metre) of VERY THICK wire from the battery to the pointwhere the wires separate is tolerable.

3) Keep the wiring from thebattery to the controller sockets as short as possible.

4) Keep the wiring from thecontroller sockets to the track as short as possible.

Slot Car Track Wiring Diagram

5) Keep any wiring from thebattery to the track as short as possible.

NOTE For tracks where the driversrostrum is next to the track (like most tracks) 3,4 & 5 can be achieved byputting the battery under the track close to the middle of the rostrum.

6) I would recommend at least 5power feeds for a 30m / 100ft lap length TAPE track. (4 might be adequatefor a very compact layout.) More feeds are needed where the lap length is longer( as a rule of thumb, one feed per extra 6m/20 ft. of lap length).

7) For braided tracks asingle power feed may well be adequate for tracks up to around 30m / 100ft laplength a second feed will be needed where the lap length is longer.

8) Run the first set of extrafeed wires run from from the main power feed to a convenient point about halfway round the lap length. Its important to keep these wires short, so forexample if the feed wires can be 5m shorter if they connect 5m from half wayround, then go for the shorter wire. The extra feeds should be distributedevenly round the lap length.

9) Separate feed wires are neededfor the positive and negative side of each lane.

10) Use 2.5sq.mm cable (ring maincable or similar) for track wiring (including extra power feeds) (but somethingmuch thicker is needed where VERY THICK wire is recommended)

Slot Car Track Wiring Machine Machine For Sale

11) Connect up the tape / braidas a continuous loop round the track - a break in the connection increases theresistance considerably.

Making cars run forwards without blowing controllers!

The current BSCRA standard has the cars wired so that when looking down on the car in the direction of travel thepositive braid is on the right. Most imported American ready to runcars, standard home set cars (Scalextric,Fly, Ninco etc.) are also wired to go forward when the positive braid is on theright.

(The original Association standards since they were first published in 1961 was positive on the left. BSCRA will be changed over to the 'plus on the right' standardon 1 Jan 2003. )

At first you might thinkthat the wiring options shown in either of the lefthand parts of Diagram T would make BSCRA 2003 and 'Scalex etc.' cars go forward. Wellif you use a resistance controller either will work. If you try to use atransistorised controller, the wiring with the big green tick will work fine andyour car will go forward. However the wiring on thelower part of Diagram T will blow up your transistorised controller and none ofyour cars will go anywhere (even on a correctly wired track) until yourcontroller is repaired (Probably with a new transistor). On the right handside are the equivalent diagrams to make the cars go backward ( which isonly rarely used).

Why does it make any difference to your controller whichway the track is wired? Looking at the controller socket the standard wiring(Top of Diagram T) has the E terminal (the brake) wired negative and the Lterminal (the power connection) wired positive. Transistorised controllers aredesigned to work this way round. Looking at the lower half of Diagram T, you’llnotice the E terminal (the brake) wired positive and the L terminal (the powerconnection) wired negative.Thisconnects the transistors back to front, so they will not work, and unless youare very lucky they are destroyed (this happens far quicker than you can unplugthe controller, and faster than a fuse can blow.) Unfortunately there is nosimple change that can be made to a controller to get round this problem - theonly simple solutions are to wire the track properly or use a resistancecontroller. (unlike transistors, resistors work exactly the same whichever waythe current is passing through them.)

Using the track in the opposite direction

Do you always want to run the track in onedirection? Running in the opposite direction giveseffectively a different circuit to race on - some layouts work well in eitherdirection. It's sometimes more difficult to drive a track in one direction thanthe other - bends that open up are often easier to drive than ones that tighten(the Oaklands Park circuit is a good example of this) There are potentialproblems with running backward. Cars will deslot in different places inthe reverse direction so themarshalling positions will often be significantly different, and there can be ahigher risk of cars landing in awkward places (like under the bridge). Some ofthe imperfections in trackbuilding upset cars much more in one direction than the other.

Slot Car Track Wiring Guide

If you want to run either type of car withouthaving to rewire each car, or you want the option of running either way roundthe track without swapping over the wires on the car - the track needs to be wired to allow either. Manyclubs now run both types of car, unless you are quite sure the track will onlybe used for one type, I recommend the track is wired top allow both types ofcar. It mightappear easiest just to connect the battery / power supply the other way round -unfortunately this produces incorrect controller connections (as the lower half of DiagramT). The right way to do it is to swap over the connections to the lane on thetrack side of the controller socket as shown in Diagram U. (Cars wired to 2003standard will run in the reverse direction with the switch in the 2002 position.Cars wired to 2002 standard will run in the reverse direction with the switch inthe 2003 position.)

I’ve shown a two pole switch, it willalso work with relay(s) or plug/sockets. These are carrying the full power tothe cars so

(a) The switches, relays, plugs/sockets need tobe of a suitably high current rating (20 amp. for strap cars)

(b) The power wiring must not be extended anymore than absolutely necessary or else there will be voltage drops in thewiring.

This means the switches, relays, plugs/socketswill almost certainly need to be under the track. If you envisage frequentchanges between the wiring polarity, its convenient to use relays and have theswitches at race control. (Switches on the drivers rostrum are an option - thismakes it easier for the sensible drivers - but gives more opportunities to theless sensible for messing about.)

IF the track polarity is reversible, the lapcounters will also need to be suitable for running in both directions - this iscovered in the Lap Counter article.

The 'power on/off' shown in Diagram V wouldusually be a relay contact. This should be mounted between the power supply andthe socket as shown. This removes power from thecontrollerwhen track power is turned off which can be very useful if a faulty controlleris plugged in. (Putting the power on/off on the 'N' lead (the blackwire in Diagram V) would still turn off the track but would leave the powerpermanently connected to the controller)

The power relay should havecontacts rated to carry the maximum current a car will take. 20 amps per lane isadequate for BSCRA cars. A separate contact for each lane is ideal. A separaterelay for each lane is a good idea - it allows individual lanes to be switchedoff which can be useful in holding cars on the start line. These relays areavailable for a few pounds each, and are commonly used in full size cars.

The fuse shown in Diagram V protects the trackwiring and minimises damage to controllers in the event of a faulty (orincorrectly wired) controller or other dead short circuits. Domestic 15ampfusewire (0.5mm) or a 25 amp plug in automotive type fuse is suitable for this fuse - practical experience is that thisdoes not blow in normal use - even with 25g armatures - even with the sort ofshort circuit exhibited by a chassis sparking on the tapes as it goes round (yesI hope that's not normal use)- but it does blow instantly when somebody plugs ina controller with the E and L terminal are shorted through the brakes. Just incase you were wondering - a couple of cm. of 15 amp. fuse wire has negligibleresistance compared with the rest of the track wiring, so it will not slow thecars down. You might be surprised that experience shows therating for fusewire is so different to automotive type fuses, it'sprobably got something to do with how fast they blow on overload but Ihaven't investigated the reasons in depth.

Some American tracks use a 10amp. circuit breaker wired into the brake connection (see Diagram X). Thisprovides similar protection for incorrectly wired controllers, but doesn’tprotect against other short circuits. It's also likely to have a small resistancewhich may slightly reduce the brakes. Incorrectly wired controllers are amore likely problem - particularly as many American tracks depend onseparate croc clips for each wire rather than a 3 pin connector. (With separatestud connections, the careless competitor has the opportunity to wire up hiscontroller wrongly every time he plugs into the track. With a 3 pin connectoronce the plug is wired up right you cannot go wrong.)

The standard wiring for the studson American tracks is

L pin - To Battery Positive -White Stud

E pin - To Battery Negative - RedStud

Slot car track wiring machine machine for sale

N pin - Power to car - Black Stud

It would suit slot cars very wellif the voltage arriving at the motor was always the same whenever you put yourthumb hard down. So why isn’t that just what you get on any slot track?

There is a popular misconceptionthat copper wire has no resistance - this is not true - the first thing tounderstand is that copper wiring has resistance and that resistance is enough toreduce the voltage to your car by a very noticeable amount. There is also amisconception that car batteries produce a constant voltage under varying loads- this is not true either - the voltage drops with increasing load. Generally, electronicpower supplies provide a more constant voltage than a battery. Thecombination of these voltage drops is the reason the lights on your full sizecar go dim when you turn over the starter motor.

Slot Car Track Wiring

In fact it doesn’t matter much if the power available isexactly equal all the way round the track (Good job too because there's nopractical way of making it exactly equal all the way round as I’ll explainlater). Certainly adequate power is needed all the way round, but less power is'adequate' in a bend where you cannot put your controller full downthan on a straight where cars are accelerating on full power. As long as thepower available on any particular part of the track is the same every lap, itjust becomes part of learning the track .... Drivers learn to deal with thedifferent levels of power just as they learn to deal with different radii bendson different parts of the track. The voltage from some club batteries go downslowly by half a volt during a 3 min race, and the drivers naturally compensate(by braking a little later and applying a bit more throttle in corners) withoutrealising they were doing it. What drivers cannot compensate for is power goingup and down by the split second depending on how much power the other cars are taking.

Separate wiring to each lane is important. If the wiringis common (see 'wrong!' half of Diagram W), when one lane is drawingpower the voltage to all the lanes will drop by say 1 volt. So thepower to all the lanes will go up by 1 volt when one car brakes, and the poweron all the lanes goes down again when the driver on one lane puts his thumbdown. With separate wiring each lane has the same voltage available regardlessof what the other lanes are doing! (see left hand half of Diagram W)

The maximum power available to the car is limitedby -

(1) how much power is lost in the resistancebetween the car and the battery / power supply.

(2) the power available at the battery / powersupply.

The next article in this series explains whatsort of wire to use, why, and includes some graphs to show what happensall the way round the track. If you just want asimple what to do guide go to the top of this page.

The power for the cars comes from the track powersupply - traditionally this was a car battery with some sort of charger. These days the use of batteries is less common. High currentelectronic 'regulated' power supplies are available at reasonable costand are often used without a battery. For home set type carslow cost unregulated power supplies can be used.

A 12 volt car battery is a good source of highcurrent dc at a fairly constant voltage, and was the standard choice for manyyears (although they are now less common). The battery needs to be recharged otherwise it'll go flat fairlyquickly. The voltage from a battery is at best only fairlyconstant. The combination of clapped out batteries and poorly regulatedchargers, that used to be all to common, produces disappointingly largevariations in voltage. In fact poorly regulated chargers can quicklyconvert a good new battery into a clapped out one!

So what do you need in a battery charger?
(1) A trickle charger will do the battery no harm,and will recharge it eventually. This means only a few amps of chargingcurrent, and unfortunately means that high powered cars will drain the batteryrather much more quickly than the trickle charger can replace it.
(2) A higher current charger that turns itself off very quickly when full chargevoltage is reached. This is how traditional car charging systems work, andin the early days of slot racing car parts were the most common way of doing it.
(3) A constant voltage charger set to the correct float charge voltage for thebattery (13.8v is usually recommended forbatteries with lead/antimony plates, 14.2v is usually recommended for batterieswith lead/silicon plates). An electronically regulated supply is usuallyused - ideally 10 amps per lane (e.g. 40 amps for a 4 lane track) so you candeal with any motor, but many clubs manage with considerably less.

So what do you need in a power supply (withoutbattery)?
You need a power supply that can give each motor the maximum current (amps) itneeds. That means the maximum motor current multiplied by the number oflanes. Here are some examples
(1) For high power cars 20 amps per lane is needed - so a 40 amp supplyshared between two lanes etc. will do nicely.
A 75 amp supply shared between 4 lanes seems to workfine.
(2) For group 12 powered cars 10 amps per lane is needed - so a 40 ampsupply shared between four lanes etc. will do nicely.
(3) For Falcon powered cars 5 amps per lane is more than adequate - so a 20 ampsupply shared between four lanes etc. will do nicely.
(4) For home set type cars 2 amps per lane is more than adequate - so a 4 ampsupply shared between two lanes etc. will do nicely.

Slot Car Track Wiring Machine Machine Parts

Is a higher current power supply aacceptable?
YES Motors only take as much current as they need. For example if alow power motor running at speed needs half an amp then it'll only takehalf an amp even if the power supply is capable of supplying 100amps.
Even for home set use it makes sense to buy a big enough supply to cope with thehighest current motors you are likely to want to run. Cost is a reasonfor not going too far above the current you need.
Higher current power supplies will put more current into a fault, so protectionagainst faults is important.

Does lap length makes a difference to what powersupply is needed? No (except possibly with digital tracks) - BUT extrawiring is usually needed for extra lap length.
Some electronic power supplies can be connected in parallel satisfactorily,some cannot. The best way to avoid this problem is to connectsupplies to lanes individually - so for example if you have two 40 amp suppliesfor your 4 lane track connect two lanes to one power supply and the other twolanes to the other power supply as shown in the diagram below.

NOTE - The blue wire'x' in the diagram is often necessary to get the lap recorders working- the power supply to the cars will work properly if it omitted.

There seem to be plenty of suitablepower supplies about. For example, the BSCRA Nationals track currentlyuses four Rapid Electronics 40 amp switch mode power supplies (part number85-1828) - two lanes from each supply and no batteries. The output voltageis adjustable, they are used on the fixed 13.8 volt setting for championshipracing, but for charity events lower voltages are used.

Adjustable Voltage Powersupplies with an adjustable voltage are often used on slot tracks. Manyclubs simply want a fixed voltage, and never make use of the voltage adjustment.Adjustable voltage provides a useful way of reducing power, for example whenopening a track to the public (see section 7).

Capacitors - some tracks(particularly in North America) use large capacitors connected to the powersupplies. I haven't measured the supply on a track with these fitted soI'll only offer a theoretical observation. The capacitors will maintainthe the track voltage over very short periods (fractions of a second) of highcurrent load, which can help with the peak current when starting from rest. They should also be useful for reducing ac ripple (ac ripple was a problem with simple mains frequency transformer power supplies,but shouldn't be a problem with switch mode power supplies). There is noguarantee all power supplies will start up with capacitors connected.

Homeset power supplies
Many home set tracks come with a low costunregulated power supply. These are suitable for their intended purpose,but can present problems for the enthusiast who wants consistent power to hiscar.
The problem with unregulated power supplies is that the voltage goes up and downas the current changes. Think about what happens when two cars share thesame unregulated power supply. One car taking current reduces the voltagefor the other car. When one car suddenly stops taking current (as it willwhen the brakes are applied, or it falls off) the other car suddenly gets morevolts. At worst this means when one car falls off the other one getsenough extra power that it also falls off ! This can be described as apower surge problem.
A regulated power supply (asdescribed above) is a great solution to these problems. A low cost solutionto this power surge problem that makesuse of these unregulated power supplies is to have a separate onefor each lane. The voltage still goes up and down depending on how muchpower the car is taking but the driver is unlikely to notice. Drivers have no trouble in learning to drive acar on 13 volts in corners and 10 volts under low speed acceleration. Theyare looking at the car not a voltmeter! Consistent voltage differences are justpart of learning the circuit. The diagram below shows the right way toconnect them (separately), also for clarity I've shown the wrong way to connectthem (in parallel).

NOTE - The blue wire'x' in the diagram is often necessary to get the lap recorders working- the power supply to the cars will work properly if it omitted.

Basic Slot Car Track Wiring

Chris Frost

Building the track surface

Cutting the slot

Painting, laying braid or tape

Lap Counting

Wiring resistance explained

Back to Track Building start page

No liability is accepted forthe information on this site or any use to which it may be put

Building the J & L Raceway
~ Part 1 ~

Building a Home Slot Car Track

Text by Larry Geddes - Photosby James J. Van Scoter

Slot Car Track Wiring Machine Machine Reviews

If you’ve finallymade the decision to rout your own track, but you’re a little intimidatedabout getting in over your head, don’t worry. It’s actually not that difficultonce you get started. Although we have some prior woodworking experience(which helps), this is our first track, & we’re pretty pleased (&surprised) with the way it’s turned out so far. The track plan is prettysimple, which helps make it easier to build. The simple design should alsomake it a fairly fast track, which was one of our goals (We admit to beingspeed-crazed morons at heart). The bank & the bridge both add somecomplexity, so if you prefer a flat layout, it should be even easier foryou than it was for us. So, for your own trackbuilding edification, hereis a brief description of HOW WE DID IT. We hope that you enjoy it &can use it to develop some ideas for your own layout.

The first thingyou’ll want to do is to accurately measure the space you have availablefor the track, & then make a large-scale drawing of the space &the track plan. Our space is 11’9” x 19’3”. The larger the drawing, themore accurate you can make it. Use a scale of 1/10 or 1/8. Remember thosedrawing lessons from high-school geometry, where you had to draw a lineperpendicular to another line using a compass & straightedge? Thosetechniques will come in handy here (so I hope you paid attention). Youwill also need a decent plastic protractor, a mechanical pencil with 0.5mm lead, a good eraser, like a Pink Pearl, & a few sheets of 20” x30” posterboard.

You can also usea drawing program on your computer, such as Microsoft PowerPoint, but thefinal drawing should be on paper. Besides verifying that the track willindeed fit into the space, the drawing will show the exact length of allstraights & the degrees of arc (curve angle) of all curves. This informationis necessary when cutting out all the pieces. If the design you want won’tfit into the available space, you’ll just have to doodle around with ituntil you come up with a variation that will fit. It’s better to find thisout now than later!

It is at thisplanning stage that you want to finalize the lane spacing (ours is 4”)& the minimum curve radius (ours is 18”). This will dictate what scalecan be run on the track, & how the track will drive. Also give somethought to how much aisle space you need around the outside for drivers& turn marshals. Your plan should also include a bill of materials& a work schedule. Our situation dictated buying material & workingon construction over a period of many weekends.

The actual trackbuildingbegins with a suitable table on which to mount the roadway. We built aplatform of ¾” plywood on 2x4 stringers, supported with sawhorse-likelegsets. The plywood deck overhangs the 2x4 framing about 10”-12” all around,so that the deck can be contour-cut to match the roadway without cuttinginto the framing. This is optional - if you like, the table can simplyhave square corners. This provides some space for scenery, but will makeit harder to reach across the track, & harder to run around thetrack (like between heats). We initially built the table 30” high, whichwould be fine for a flat track, but later lowered it to 20” to allow forthe height of the risers necessary for the bridge & bank, & alsoto give better visibility. It may seem like a waste of plywood, but a continuousdeck such as this allows you to attach risers anywhere on the surface,& also gives you a reference plane from which to take height measurements.Our main table is 6’ x 17’6”, with a 4’ x 7’ wing table on one side.

The roadway ismade from ½” MDF (medium-density fiberboard). Our local lumberyardsdid not carry this thickness & had to order it for us. It is the idealmaterial for routed tracks. It is easy to machine, has a very smooth surface,& is surprisingly quite flexible. Cutting the straights is of courseno problem, just clamp down a straightedge to guide your saw, but the curvesare a little more involved. The outer edge must be smooth & truly circular,& the curve angle must be very specific. There are 3 special jigs thatwe made to produce the curves, one to lay out the inner & outer curveedges with a pencil, one to rout the outer edge (after rough sawing), &one to guide the saw for the radial end cuts, governing the curve angle.Drill a 5/16” hole in the MDF panel & secure a bolt or threaded rodin the hole with jam nuts to provide a fixed center for all 3 jigs. Thefinal step after all jigwork is done is to remove the bolt & saw outthe inner edge freehand, just following the layout line. The completedcurve blank should resemble a piece of plastic track, only larger. If thedesired curve won’t fit on a single sheet of MDF, make 2 curves of halfthe curve angle & splice them together permanently. We had to do thisfor the donut section of our track; it is 6 feet in diameter.

The straights are actuallyhalf-length, so that the pieces can be spliced together into subassemblies,each one consisting of a half-straight, a curve, & another half-straight.These subassemblies are then routed separately, then spliced together end-to-end,so that the final joints occur in the middle of the straights. The routerjig we used for the first (outer) slot has 2 rollers (These are 1-3/16”OD ball bearings mounted with bolts; you could probably use replacementrollers for patio doors.) that must always follow the outer edge of thecurve; it just won’t work against the inner edge. Handling the track insubassemblies allows the roller jig to follow outer curve edges only, regardlessof whether the curve is left-handed or right-handed. We routed the slot.350” deep. This will accept any guide, even a Cahoza, the deepest we couldfind.

It shouldbe mentioned here that the spacing between the rollers on the router jigis important, because it will determine how much wider the outside guttersare in the curves than they are in the straights. This gutter-wideningeffect happens automatically, & is a function of the jig’s geometry& the curve blank radius. The further apart the rollers, or the smallerthe blank, the wider the gutters become in the curves. Our outside guttersgo from 4” on the straights to 6” in the curves, & with a curve blankof 36” radius, the jig required a roller spacing of 23.8” to achieve this.All our curve blanks were about the same radius, so this roller spacingwas used on all curves. If your curve blanks vary in radius, but you’dlike to maintain the same gutter width on all curves, you must build yourroller jig with several different mounting holes for the rollers, so thatyou can select the appropriate roller spacing for the curve you’re workingon.

Since the outergutters get wider in the curves, the inner gutters naturally must get narrower.Our roadway width is 20” on the straights, giving us 4” gutters on bothsides. In the curves, the outer gutter grows to 6”, as mentioned, withthe result that the inner gutter has to shrink to only 2”. In order toend up with a decent inner gutter, we added 1” to the width of the roadwayof all curves, making it 21”, & giving us a 3” inner gutter, whichwe feel is adequate. The 1” step where the straights meet the curves wereblended in later with small triangles of MDF.

Once the firstslot has been routed in all subassemblies with the roller jig, the routeris removed from this jig & set up in the other slot jig, this one having2 guide pins that guide the jig using the first slot. This pin jig is usedto rout all the remaining slots, with the pins following the previous slotin succession. The pins in this jig are slightly under 1/8” in diameter,about .120”, so they slide freely in the slot, but without too much play.Unlike the rollers in the first jig, they are spaced only 4” apart, becauseno additional widening effect was desired on the inner 3 lanes. The slot-routingjigs require a certain amount of extra material at the free ends of thestraights, since the slot can’t be routed all the way to the end (Bothrollers must be against the edge at the start & finish). Each half-straightis therefore initially cut with 24” of extra “waste” material added toits length. A starter hole is drilled in which to start the router bitfor each slot. After all routing, this waste material is simply cut offso that a straight of half-length is left. The slot spacing is maintainedwith the pin jig in all subassemblies, so the slots WILL line up when thesubassemblies are joined. Trust me!

If you plan onusing braid instead of copper tape, the braid recesses must be routed afterall slots are cut, but before the waste material is sawed off the straights. You will probably have to either contact a track builder to obtain thespecial cutter required for this, or have a tool grinding or machine shopmake one for you. The braid should end up slightly below the track surface,about .010” - .015”.

An interestingside-effect of using this approach to slot routing (elliptical routing)is that the transition from straight to curve is not tangential, as itis in plastic track, or track routed with straightedge & trammel. Itis actually a spiral, with the straight turning into the curve in a constantlydecreasing radius, until the final curve radius is reached. This meansthat the cars will not be subjected to a sudden change in direction, butwill undergo a more gradual change when entering & exiting the curve.We believe this feature will make the track very fast & smooth driving.

The bank was actuallyquite easy to make. The basic principle is that you start with a curveof smaller angle than on your track plan, then just push the two attachedstraights toward each other until the desired curve angle is reached. Thebank will pop up by itself. In our case, we wanted the bank to have a curveangle of 200 degrees after bending, according to our drawing. We cut thecurve blank to 190 degrees & pushed the straights together the final10 degrees to obtain the desired 200. We also made the blank 3” largerin diameter than that called for on the drawing, to allow for shrinkageduring bending. We arrived at the before-bending figures by experimentingwith a 180-degree curve-&-straight subassembly that was to be usedelsewhere in the track, taking before-&-after-bending measurementsto see what to expect. The straights leading to the bank should be elevatedseveral inches above the table, because the inner edge of the bank willwant to dip down below the level of the straights. If it pushes downagainst the table, it can cause some deformation of the straights, whichcould result in “launching ramps.”

Once you reachthis point, you’ve pretty much got it made. All that remains is to splicethe subassemblies together & mount the roadway to the table on risers.All our splices are ¾” birch plywood, 3” wide, spanning the widthof the roadway, & secured with countersunk #8 flat head wood screws,ten per joint. The risers are mostly made from leftover scraps of MDF,with 1x2 cleats top & bottom to attach to the roadway & table.They are made in two parts, so that a little adjustment is possible, similarto the supports found under a typical commercial track. Short risers areripped from 2x4s & placed on edge. A certain amount of fiddling willbe required to determine the dimensions of the risers & the final roadwayposition. We used temporary supports to prop up the roadway (paint cans,blocks of wood, etc.) that could be moved around & changed easily duringthis stage. When the last riser is finally in place, the hardest part oftrackbuilding is over. All the rest is fairly cut-&-dried.

Before any paintingis done, drill holes next to the slots for electrical taps to be addedlater. We will be using .0015 x 5/16” copper tape & tapping it with#6 - 32 flat head brass machine screws let into countersinks at each hole.We are using 3 tap locations spaced equally around the 55-foot lap, oneset of taps every 220”, so that there will never be more than 110” of tapebetween the car & the track power.

Frankly, we arenot too familiar with how braid is terminated at the tap locations. Wedidn’t investigate this because we didn’t plan on using it. We would recommendcontacting a track builder to find out the specifics, & what methodwould be best for a home track. We felt that tape would be adequate fora home track that will not see the amount of use (or abuse) of a commercialtrack.

Our next installmentshould wrap up the rest of the project, with paint, copper tape, &wiring. We hope we have inspired you to dust off your imagination, fireup your power tools, & give it a try. We’d also like to thank PaulKassens, the Old Weird One himself, for letting us share this with you,so - - - Thanks, Paul!

(OWH Webmeister note: Thank you Larry &Jeff!!! :-)

Larry Geddes & JamesJ. (Jeff) Van Scoter
email: geddes@erie.net- vito98@erie.net

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