Originally Posted by brrrrm
Yes, you are right about the friction. I don't want to waste any going inward.
I race in a 540 class.
From what literature I read is that a formula-1 car creates so much downforce at 80 mph that it could drive upside down! However, using the equations provided in Wikipedia
, the downforce in rc car environment appears to be minimal. The cars are too small and the speeds are too low to have a significant effect. I wonder if anyone else has looked into this?
How did you go with the uprights?
Was the question about the uprights directed towards me?
I know I was asking for problems when I dropped a 6900kV motor...
Anywho, I just drove my TT-01 around my larger driveway using the outer perimeter as a "track" and experimenting with how it drives with only FWD (if you remember earlier I broke a dogbone). However, I ran into another problem. After 15 or so minutes when I went to pull the throttle harder, I heard a screeching sound. At lower speeds it would not do this, but when more load was put on the drivetrain, it slipped.
This wasn't the first time--and the first time I ruined a spur gear when a bearing fell out of place (I had taken out the rear diff because as I said earlier, the car is FWD. The rear bearing behind the spur gear fell off, and the spur gear misaligned. I am not doing that again...).
I opened my car up, and was awaiting a horrified sight of a ruined spur gear, but only a small bit of the spur gear towards the aluminum shaft was worn. It looked like I had taken a file to the spinning gear for a short time, as the small pieces of plastic were hanging off like frills.
However, my pinion gear was almost all the way down the shaft, and I could not pull it off. The bottom part of the pinion looked grinded as well... And the grub screw as gone, and the hole was NOT over the flat spot of the shaft--so this was lodged.
Looking in the space under the spur gear, I saw some small particles of aluminum and plastic... and the grub screw was in the area under the spur gear too.
I was able to get the pinion off when I put oil down the shaft, and took a pair of pliers and wedged the pinion off. When I went to put the grub back in the pinion, there was a lot more resistance, like there were also small particles down there too. Also the outside of the pinion gear where it was once smooth, is now specked pretty uniformly, like small little scratches.
I am trying to figure out what happened. I am thinking that the grub flew out, causing the pinion to travel up and down. However, the soft alloy on the outside of the pinion somehow grinded, scratching the formerly smooth area of the pinion while sending more metal in the shaft. This caused a buildup that lodged the pinion on the shaft, and this was at the bottom of the armature shaft, and consequently, grinded the spur somehow...
Does anyone else with a similar setup have this happen? I am thinking about getting a lower kv motor, but I feel like this will happen with any mamba I get. So this just makes me want to get a TA-05 even more...