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Originally Posted by Origineelreclamebord
(=3-gear mid-motor)? How does it drive?
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I do use the 3 gear transmission. I think it drives well, but my driving ability limits how well I can tell. I'm typically back of the A main level at my local club (before and after making my own car). When I first made it, it was very clear that it how lower inertia -- it starts turning in very fast, but in a stable way. I find it generally easy to drive. The biggest challenge for me is the lack of setup sheets. It really shows how good or bad I am at setup. I lately have found that extending the wheelbase and moving the weight rearward helps. I find that helps making it a bit lazier, which helps with my middle aged reflexes.
I ended up making it about 2 mm shorter wheelbase than a B4.2 (by accident), so I suppose that I'm just finding that stock might be right.
I don't think that the 3/4 gear makes such a huge difference, but don't have back to back comparisons on the same car to really tell. Having said that, I focus on 17.5 classes, and they have lower gear ratios, which lowers torque reactions to motor acceleration, compared to typical mod gear ratios. I always feel like my mod car (same design) wants to kidnap me and murder me, so maybe that's the 3 gear and higher gear ratio at play...
Quote:
Originally Posted by Origineelreclamebord
Have you thought about reinforcing the weak areas of the 3D print with some layers of fibre mats and resin?
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I haven't really seen the need, in my project. With PETT and some of the newer materials, overall strength isn't such a big deal. But I find areas with stress concentrations are not doable with 3d printing, like hinge pin pivots and shock tower mounts. Reinforcing doesn't help much in those situations, as tearing out threaded holes and crushing from hinge pins it a stress concentration issue, unless I'm missing something.
Having said that, I would try it in a second, if I could figure out a way it would give me a genuine performance increase. I think there is a compelling reason to use CF shock towers because of how high the mass is, even if I don't currently.