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Your #1 Tuning Tip - Time To Cough It Up!

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  • #61
    If you are building a proxy car make sure it's bulletproof. Everyone of my proxy car that have required some work by the race organiser or track host has suffered in some slight way and performance has not been as good as when I built the car. Do not assume someone who has never seen your car will lavish the same care and attention to detail.

    Do things like grind 3 flat spots on the rear axle for the wheels and gear grub screws to get a better grip. Add a tiny bit of solder to the lead wires where they go into the guide. Wrap electrical tape around the lead weights to keep them in place.

    Think "What can go wrong" and do something about it.




    • #62
      The back half

      Now that you have thoroughly covered the front end of the car, what about the back? OK, one place that is often neglected is the rear bearing carriers. Even in the and SCX pods, there is flex between the motor mount and the rear axle. This can cause minor gear mesh problems during a race that will eventually destroy one gear or the other. Stiffeners should be glued in between the bearing carriers and the motor mount. Straight, short 1/16" wire hot glued or CA glued in place will do the trick. I have seen sheet styrene used as well. Anything you can do to make this area rigid will help deliver power to the track.


      • #63
        Here's a few tips on getting the body weight down.

        Use a dremel to do the initial grinding to get lots of plastic off the body.

        I use the warm to the touch approach. Hold the outside of the body exactly where you are grinding and when it gets warm you know you have ground enough off. If the car body starts to go red and your hand hurts you know you have ground too much off so take things gently. I use quite a few different bits in the dremel to get into some of the tight spaces, especially across the back and front of the body. Spend a lot of time on the back of the body as you want as little weight behind the rear axle as possible. The same goes for the roof if you have a coupe or sedan as this really helps to get your centre of gravity down low.

        Sometimes you may want to keep the front untouched to keep that part of the car body strong enough to withstand accidents but so far I haven't had any problems in all the proxies I've entered.

        Occasionally hold the body up to a light so you can see through the plastic. You are looking for any spots in the body that are lighter (body is thin enough to let some light through). This is where you have ground enough off so don't grind any more there.

        Use a coarse grade sandpaper to finish the job.

        Using this technique I cut my D-type Jag body down from 30 grams to 15.

        I also use lightweight interiors for all my cars. With the D-type the driver is cast into the body but it's only one driver and steering wheel, not a complete interior so I'll probably leave him alone.

        You can also cut down the interior glass if you are really keen but all you are saving is 1 or 2 grams at the most. Hardly worth it unless you are cutting down a windscreen on a roadster

        Have fun but remember to take things easy when grinding, it's easy to gat carried away and put holes in the body. You don't want that as body filler is heavier than plastic which defeats your exercise.




        • #64
          To make a good tire truing station I used a tech block, with a piece of sheet metal glued across the back where the rear tires touch. Then I have some sticky sand paper that goes on aluminum sanding blocks for hobbyists, they come in different grits, it kind of looks like yellow emery. I stick that to the sheet metal. Then I have a close to perfectly square sand station. I copper tape the front of the tech block and run power to it.

          Do not sand the tires before making sure the chassis is straight.
          Do use WD-40 on the sand paper, as this reduces heat build up from friction that can warp your tires, and make them bigger so that they fall off the rims easier.
          Do not rock your car side to side, just hold even pressure, and keep the car straight.
          If you have a car with a motor pod that rocks, try your best to keep even pressure on both tires.
          On cars with plastic rims, sand the rims smooth and true first before sanding the tires. The tire will sit on the rim nice and true. Do not sand too much off, just enough to get rid of flashing and any unevenness.
          Check your progress with dial calipers. You want both tires exactly the same.

          Clean your tires before race with WD-40, as junk builds up on them, do not sand them clean once trued. If you are not allowed to put anything on the tires, just use your thumb, and a paper towel. You can usually push the dirt off with some friction.


          • #65
            I have a circular track, routed, approx 70 cm in diameter and painted with an abrasive paint (ferrodore which is what the Sydney Harbour Bridge is painted with). The texture is like very fine sandpaper.

            30 minutes in both directions with the back of the car gently sliding around the track will wear down any high spots in a rubber tire, an hour if they're silicone. Perfect results every time because the slight weight transfer on a slot car means the tires are slightly tapered, not perfectly square. Have a look at the tires of one of your well used cars and you will see the rubber is worn more on the outer edge. With a flat surface to true your tires you can only get a square edge, not tapered. Looks good on your inspection block but doesn't equate to real racing.




            • #66
              A good trick in tuning I learned from my R/C days, is to place the slotcar on a tech block, and lift the front end up with the back side of an X-acto knife from the middle (the slot). From that perspective you can see if one wheel lifts up first, and that tells you if your chassis of front end adjustment is tweaked.


              • #67
                Originally posted by Robert Livingston View Post
                Guides are a good place to tweak RTR cars to go faster. On the Scalextric guides, I do what Dansula says, but I also re-thread the braid so it is one long pigtail rather than two short pigtails. The downward pressure of a longer braid is less than two shorter braids. Results is the same electrical contact, but less spring pressure pushing upward on the front end, so you get less front end bounce, and you reduce or eliminate front end de-slots.
                Which pigtail do you make the long one (the front or rear pigtail)?



                • #68
                  Front for me. But try both and see which works for you.


                  • #69
                    Front, so it looks more like a normal guide.


                    • #70
                      Cheap skates: Re-use your aluminum / magnesium rims!

                      So for what ever reason it is time to put on new tires. You are cheap, like me, and don't feel like spending more $$$ on rims. Here is a tip for you.

                      Remove the old tires and then soak the aluminum or magnesium wheels in nail polish remover (acetone). Put enough nail polish remover in a small sealed container to completely cover both rims and then let it sit for a hour or two. Pull them out and scrape the area with your fingernail. Presto the glue comes right off the metal rims.

                      BE WARNED! Don't do this with plastic as the acetone will eat the plastic rims!


                      • #71
                        Too late Diff, this tip was posted a few weeks ago



                        • #72
                          Where can I get one of thoes...?

                          Where can I get one of thoes...? I think I'm just messing my tires up
                          Originally posted by Alta_Racer View Post


                          About the best improvements can be made with round grippy rear tires IMO.



                          • #73
                            Your tubes

                            What size tube do you use to fit the guide shaft? The evergreen website has a dozen or so different diameter tubes. And can you use the .093" tubes for axel spacers too? This is a great find for me, thanks for the tip!

                            Originally posted by dr vanski View Post
                            To ensure I spend more money on cars, and less on guides, I try to use stock parts when ever possible. Most stock guides are really sloppy and rock laterally, fore and aft, as well as vertically which doesn't make for an ideal interface with the slot.

                            I shim my guides with Evergreen styrene tube. I cut a slice that's just the right size to limit vertical travel which seems to eliminate all the other axes of play considerably.

                            Once I've fitted the piece, I use CA glue to attach it to the shaft of the guide. Sure, you could accomplish much the same thing with a screw in guide, but this fix uses less than a penny worth of materials.


                            • #74
                              The INOX secret is out

                              The easiest trick to do to shave a half second or more off your lap times is to use INOX on your car braids and track rails. I`m from OZ ( Sydney )and was in the marine trade and have been using inox products for the last 20 years.They all work a treat , but i never thought of using inox to clean and protect the track rails. ( i have Carrera track - so i really never thought of using anything on the rails ). Thanks to you Mr Flippant !!


                              • #75
                                Grapite powder

                                Also , a little puff of Graphite powder in the slot every metre or so of track works really well too. Being a dry lubricant - dosen`t attract the dust. Like all lubes , don`t get it on the track surface and if you do just use a damp cloth to wipe it up. Jason.