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4x16 Track

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  • #16
    My Wife's HORacePro Slider (tm) banked oval track features braid that stands 0.010" proud of the racing surface. We (HOCOC) run regular pickup shoes on this track with excellent performance.

    Ed's personal Slider (tm) banked oval track features braid that is flush with the racing surface. Standard pickup shoes can be problematic on this track. To resolve this issue, Ed developed Braiders (tm). These are fingered attachments that are easy to install on standard pickup shoes. The Braiders (tm) work very well on Ed's track.

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    • #17
      I'm back in town...

      So, about templates! The photo below shows the end result. Now we flash-back...



      And here is how it all starts. Yes, this template is 23 years old. A bit battle-scared, but hey, thems are honorable scars! Evidence it has been used more than once. The pattern was developed using a computer drawing package, printed out full-size on a large format printer and then glued directly onto a sheet of 3/8 inch thick MDF.

      But you could do the same thing sketching directly onto the MDF. Draw your track with the margins and your template outline will be created at the same time. Do not be surprised if you end up erasing and re-drawing parts of your track, maybe several times. It is not as easy as it sounds! But when you finally get it right you're well on your way to success.

      My template was cut out using a router with a 1/8 inch diameter straight carbide router bit, using a compass and straight-edge. Some parts were sanded with a hand-held belt sander to create smooth transitions.

      You will note that this template is VERY curvy, with only one truly straight section. That was by intent. It was a deliberate break-away from the rigid geometries imposed by plastic track. Some of the curve radii exceed 30 inches. The tightest curve produces a 4-3/16 inch radius slot.

      The interior, concave curves are critical and must be made using a compass. Any errors will get magnified when routing with the large guide disks. Exterior, convex curves are much more forgiving. If the curve looks okay on the template it will look fine on the finished slots.



      The photo below shows the template in place on top of the finished track. It also shows my routers with their different size guide disks. Once the template is fastened down to a sheet of MDF each of the four slots can be routed in quick succession. Since I rout 1/8 inch diameter slots, I can rout full-depth in one pass. Each pass takes about 3 minutes. Even if you have only one router, and have to swap guide disks between passes, you should be able to do all the slots in less than an hour.




      A little closer look at the template versus the slots...



      And a little closer look at the routers and guide disks versus the template and the slots...





      All the skull sweat, cutting and fussing goes into making the template. Once you have the template routing perfect slots is a snap.

      More complex tracks may require more than one template. The track shown below needed three templates. That required some careful fitting to match up the sections, but that would have been necessary regardless.

      Ed Bianchi

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      • #18
        thank Ed!
        the freeform result is excellent.
        do you offset the router on the guide discs to one side or the other to make the braid recesses?
        speedy

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        • #19
          That was answered in the power rail spacing thread.

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          • #20
            Richard is right, but just in case you're lazy, like me...

            I have a router base set up to cut braid reliefs on either side of the slots, using the slot as the guide. Two pins, which are actually 3mm machine screws, fit in the slot and guide the router.

            Note how the pins are arranged. The pin closest to the router bit sets the spacing between the slot and the braid relief.



            You turn the router around 180 to rout the other braid relief.

            For more detail, go to the power rail spacing thread, as Richard suggests.

            Ed Bianchi

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            • #21
              aha! I remember now. cool, thanks for showing it here.

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              • #22
                I started looking into making a base like the one posted above. I have a working system, but the pin system gets rid of the need for a fence and I thought I'd give it a try. Can anybody recommend a pin I can use? My guide slots were routed with this:

                Harvey Tools

                which per that link is a 1/16 inch wide slot. To my surprise I don't have any screws or even nails small enough to get in there... A link or two would be awesome but if I know what to google that works too.

                Thanks
                Dave

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                • #23
                  You might try "music wire" or "piano wire". It is available in 0.059 inch diameter, which should work in a 1/16 inch slot.

                  https://www.mcmaster.com/#9495k92/=18d2sbw

                  Ed Bianchi

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                  • #24
                    Most well stocked hobby shops that supply the R/C airplane crowd should have this size of piano wire in stock.

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                    • #25
                      You might try a slotcar axle... cut some small pins... Try an AFX or Tomy front axle... Keep the polished end down...
                      The closer you can keep the pins, the better, especially when you get to turns. Do some experiment routing first...RM
                      Last edited by Hilltop Speedway; 07-05-2017, 07:24 AM.

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                      • #26
                        Getting back to the joint, why not route a tongue and groove joint and glue the sheets together?

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                        • #27
                          Routing a tongue-and-groove into the MDF would be a trick. I use 3/8 inch thick MDF. A 1/8 inch tongue would be rather thin and delicate.

                          I have done a tongue-and-groove assembly on 3/4 inch plywood underlayment. Turned out not to be worth the trouble. These days I use a lap joint. Simpler, stronger and -- if you don't glue it -- easily disassembled.

                          In any case, be prepared to shim your joints. Even a 10-thousandths mismatch is noticeable. And 20-thousandths is a distinct bump. Commercial sheet goods are going to vary in thickness. You might get lucky and get a close match, but don't count on it.

                          Ed Bianchi

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