ROUTING BANKED TURNS
Banked turns are relatively easy to build. (See Illustration #7A - 7B - 7C) Cut out a "horseshoe" shaped piece of thin cardboard like the drawing to see how easily this is done.) It took Hasse, Ogilvie, DaPron, the Tunkels (and former track builder Chris Dadds) a lot of trial, error and experience in order to learn how to construct wide, high-banked turns and get them ultra-smooth so cars donít "launch" going in or coming out of the turns. In the case of wide King layouts and Hillclimbs (which have a high bank which can drop as much as three feet from the top straightaway to the lower level where the drivers stations are located) it is sometimes necessary to have three different radii all in the same turn. Damon uses a router affixed to a pre-determined radius point to cut the outside of all his turns and bank pieces.
This gives an ultra-smooth outer-edge which he later uses as a "guide" for his special router "plate" (See Illustration #8 & #9) to cut the first (outside) slot. Once heís cut the outside lane, leaving a 6" to 7" gutter, the roller bearings are removed; a special pin bar installed, and he uses the first routed lane as a guide to rout the other seven. This method is called "elliptical routing" - pioneered by Hasse Nilsson - and gives modern tracks much smoother entrances and exits to the turns. Look at the difference between old, sixties tracks and modern layouts and you can actually see the difference. Old tracks started a turn at the very end of a straightaway and the next straight started right at the end of the turn. With elliptical routing, the turns start sooner and go further. Elliptical routed turns are not 90 degrees to the slot like the old layouts.
If youíre not able to use Damonís method of cutting the outside radius of turns, youíll still have to lay your turns out and scribe a pencil line using a radius point far enough back to get the amount of turn you wish. You can use a sabre saw to carefully cut this radius, but should you use this edge as a guide for your router youíll need to use a belt sander and get the curve as round and super-smooth as possible. If this not possible, attach the router to your radius point and having someone hold the radius guide point while you slowly and carefully rout the slot.
CAUTION: When routing the slots, run the router in one direction only - preferably forward. Never pull the router backwards. This can change the radius point and cause the slot to become too wide. Always rout the curves and high bank pieces while still flat. Also rout for your braid recesses before you assemble the track sections and rout the straights. NOTE: Routing braid recesses requires a special router bit (See Illustration #10) which has a pin which rides down in the slot and the slot is the guide for the router. If you have access to a local machine shop they can make you one of these.
Modern track braid and wire- available from several and is available in wider widths and varying thickness. Most track builders now use nickel-plated copper braid which is 9/32" or ľ" wide that has more strands and is smoother than 60ís variety. This carries the current better and cuts down somewhat on wear and tear. Braid recesses must be carefully routed so the braid will actually rest .010" to .015" BELOW the racing surface. NEVER have the braid flush with the top of the surface, especially in the turns, as tire wear or gears too close to the track, etc. (This is why you should ALWAYS tech cars prior to BOTH practicing and racing!) Flush braid tends to "peal" up the leading edge, causing constant repair headaches. There is a braid available through a company in San Antonio, Texas, called Magnatech, which is a combination copper-steel. While a bit more difficult to install, and with a slightly higher price, the advantages are numerous. With Magnatech braid you get five to seven years of life and donít have to replace the braid in the turns nearly as often as you will with standard copper variety. Another advantage to copper-steel braid is that you can use neodymium magnets - called "traction" magnets - affixed to the bottom of cars. This virtually eliminates the need for the application of traction substances (called "glue" by its devotees) and does away with the mess associated with "glue." Weíll discuss glue in a later chapter. If you want information on Magnatech braid, contact former TOA Board Member Jim Honeycutt at (210) 308-6909 or 210-981-2419. Also, H.O. and 32nd scale cars already use magnetic attraction. (See www.slotcars.net, www.scalextric-usa.com and www.wizzardho.com for examples.)
Once youíve routed all your turns and bank pieces itís time to construct the straightway. To save time, add "guides" on the work table to hold the 1" x 4" x 40" (or 41") supports (See Illustration #11). Once in place, roll carpenterís glue across the top edge of these supports and carefully lay the pre-trimmed 40" or 41" wide straight section so the outer and inner edges are even and flush with the edge of the surface. Using your lane guide, (See Illustration #5) install staples with your pneumatic stapler, putting at least one or possibly two between each mark youíve made for the lanes. If you donít have access to a pneumatic stapler, pre-drill and countersink holes in the same places youíve marked. Fasten the running surface to support brace pieces using 1" sheet rock screws. Youíll also need to glue and sheet-rock screw the 2" x 4" end cap pieces where the sections are joined together with the bolts.
On the King track Damon built for me, he pre-trimmed both ends of the MDF sheets to give much straighter, smoother edges for the joints. His straightaway sections were actually only 90" in length once he trimmed 3" from each end. Once all the straight sections were completed the track was assembled. The legs were temporarily installed - then he installed the bottoms, one section at a time. As the bottom was completed on each section, the adjustable legs were permanently attached by gluing and screwing to the bottom piece. If you do not wish to install a bottom to the track or your straight sections, go ahead and glue and screw the adjustable legs at this time. Do not tighten the adjustable leg bolts until youíre satisfied that the top surface is where you want it and the surface is smooth and level. Youíll tighten and add a sheet rock "locking" screw once you are satisfied with the overall surface layout and do this just prior to painting.
CAUTION: Sheet rock screws have a razor-sharp point! Be careful or youíll get extremely nasty cuts should you rake an arm, hand or finger across one! Any exposed sheet rock screw which extends down below the surface and could cause harm later should be knocked off. This is done easily by hitting sharply with one or two hammer blows to bend it - then scrape it off or pry it loose with a screw driver or the end of your claw hammer.