T3-2011
Just getting back to RC cars thanks to my 9yr old son (it’s the best excuse I could find to tell the wife). Having a background in engineering and motor-racing I have some issues with some of the assertions/beliefs I have seen as being taken as gospel.
Anti-Roll Bars The design of the AR is poor, it seems one targeted more for convenience and looks than function. The spec of the material used is not appropriate for the task in this application.
The task of the ARB (in simple terms) is to transfer some amount of the suspension movement from one side to the other.
So let’s look at the T3’11 with the shocks and springs in place, and to make the point really clearly we will use the 1.6mm bar. Now try compressing the suspension on one side with your hand and watch the other side to see what happens. Exactly ! Almost nothing happens, at best you may have seen a twitch and that was it. Ah, you say the springs are too hard, ok - so try the 2.4C on the front and you’ll still find nothing happens.
Ok, so the observation is clear, so what’s wrong.
Well the design here uses the 1.6mm spring steel as an arm extending back from the AR cross bar back to the drop link (it’s all one piece of metal suitable bent after all). Compress the suspension on one side again and take a good look at the arm and how much curvature is now visible. The curvature is alot worse for the 1.2mm bar. Well if the arm is bending it cann’t be transfering force to the other side, so the more it bends the less force it transfers.
So if we were to persist with this design, the bar would need to be in the order of 3mm thick before it would show any signs of working correctly.
As for the rear, it would need to be thicker still as the rear arm length is about 15% longer than the front.
Compare the T3’11 design to a typical race car design.
In most competition race car designs the arms are very unlikely to bend, and the adjustment comes from the mounting position of the drop link on the arm and a small amount of twist in the bar itself.
Conclusion The current design is next to useless, for it to work with the current design of anti-roll bars, the bars would need to be much thicker, or the length of the arm much shorter. eg Diameter = 3-4mm or Arm length = 10-15mm and this may need to be matched with new spring rates (probably softer).
look forward to comments.
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