LRP ESC and Motor Tips
R&D, LRP electronic GmbH
Generally speaking, a smaller rotor improves driveability (smoother) and gives more topend but the downside is slighly lower efficiency and less torque. Temperature isn’t much different.
unfortunately no comparison possible between powerprofiles of SPX StockSpec and boost profiles SXX StockSpec is possible!
The reason is that algorithm works differently and SXX StockSpec clearly makes more power.
Lowering the timing on the motor (e.g. changing from insert “oo” to “ooo” or “oooo”) will of course lower the motor temperature, but you sacrifise power in higher rpm range slightly and may need to alter gearing to reach enough topspeed again.
kV rating is not affected too much by sensor timing, therefore we don’t give different ratings for different timings. So you can go with 7100kV for 5.0t at -10° (oooo insert) as well.
standard in all X12 motors is 12.5mm rotor, Tamiya specially requested a 12.0mm rotor in their new motors but ourselves we stick to 12.5mm as we feel this is the best allrounder!
4.0t with LiPo is VERY fast and not the wind I’d recommend to use with LiPo’s… common winds for LiPo use in a touring car is 4.5 to 5.5, 5.0t seems like the best compromise and is what I’d recommend.
Also on brushless motors it is important to oil the bearings from time to time, wrong gearing or wrong adjustments (timing or speedo) may also cause excessive heating which can result in bearing failure.
I assume you run TC, correct? If so, I’d start with profile 5 and lowest motor timing (e.g. “oooo” insert) and then increase from there and check motor temperatures (they should be below 90°C). (LRPSXX TC Spec)
Marc is currently testing quite a bit, so he switches back and forth between Tamiya (LRP SphereTC OEM version) and SP speedos. I’ actually not sure what he used at the last race but I know that Jilles won with our speed-control…
paralleling capacitors is/was only required if the capacitor was of bad quality, with a good quality (single) capacitor it’s not required and therefore not worth the hassle to add another one
We have tested with many different capacitors and so far our original type, which is a very expensive LowESR version “Made in Japan”, worked best. None of the other (bigger & smaller) we tried worked better. So in my opinion there is no point in trying other capacitors.
Especially stay away from the flat “SuperCapacitors” as they don’t work well.
As for the gearing at the Worlds with the X12′s:
- we ran 4.5t
- lowest timing setting (oooo), which seems to work best anywhere!
- gearing ~8.6:1
- powerprofile 3 on the speedo
Remember this was with 6 cells.
As for the temperatures, anything below 100°C is fine!
The X12′s does get fairly warm on the outside as it makes a lot of power and also transfers the heat well from the inside to the outside due to the clamped stack. But we have a magnet with a very high temperature grade, so until no solder starts melting there is no danger.
Source: forums of rctech.net