Progressive banking

[ratfink03]

Does anyone have a technique for building progressive banking on oval for 12x6x3/8 MDF. Thinking of maybe 5 to 12 degrees.. Tks

[HomeRacingWorld]

[ratfink03]

What I meant by progressive banking is that lane 1 on inside track would be 5 degrees banking and lane 4 would be 12 degrees in turns.. From inside lanes to the outside of lanes in the turn. thanks

[slotguy]

Hi ..I built a few banked ovals and banked them and found that when you get 5 degree of banking it carries from top to bottom of the turn I think you would make the turn not being flat from top to bottom and causing the track surface to roll as you go from lane 1 to lane 4 .but if you want the turn to form a natural bank cut a little off each side of the turn this will cause the str8 to aim outward and when you pull both sides in it will cause the turn to form the bank. Be careful not to go to far because the mdf will break .just going by pass experience in building my tracks

[RichD]

That method for making banked turns works well, but the banking will not be progressive. I did see an article on building a true progressive turn, but I did not bookmark that. If I recall correctly the builder did not finish the track in any case. As a practical thing a slot track does not need much banking, after about 15 degrees most cars will be able to take the corner flat out. One way to get the effect of progressive banking is to use a finish with more grip on the outside lanes. One of our tracks is finished with regular flat latex paint, but the outside lane has an added coat of clear polyurethane for extra grip. Mixing an abrasive with the base paint might be another way to get more grip.

[ratfink03]

Thanks for everyones input.. great ideas to ponder on !!!! thanks

[Nor Cal Mike]

Progressive banking as you propose would require a compound bend which would be pretty hard to do with conventional slot track materials. I remember seeing one that Luff did that mimicked a track in Europe but his was flatter on the outside than on the inside. His method was to actually bend to sets of curves from separate pieces of wood whose outer and inner radiuses met in the center of the curve. I didn't care for it myself. It had a sharp break there the inner outer sections joined. But Luff is an experimenter and his creation was pretty close facsimile of the real track. The craftsmanship required to successfully carry it out was impressive so I do take my hat off to him for that.

You might be able to do what you want by pulling the banking in the conventional squeeze method but when cutting out the actual wedges that you will screw the surface down to, cut a bit of concaved arc into the wedge. Then you would very carefully pull the wood surface gradually down screwing a little bit at a time while working your way around the curve. But be warned that the wood will likely give most at it's weakest point which is at the bottom of each slot. That will likely give you slots that will have been pinched at the top in the process so sanding may have to be done to open them up to 1/8" again.

You project may be trial and error to get it done. Will it be worth it? Only you can be the judge of that. If you are concerned about equalling lap times, I find that the times across my oval are not all that different given that the inner / shorter / sharper curved lanes require a lower speed to negotiate so the lap times mostly come out in the wash. Any differences can easily be made up through lane rotation between heats.