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Sensored Motor Question

Sensored Motor Question

Old 08-27-2013, 03:50 PM
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Just received a new to me buggy (xxx4 G) and a Viper 6.5t motor for it. The esc I installed is a MMP. I am having a hard time currently with the sensor wire that I have as it is too short. I hooked up everything else for setting steering, esc etc and accidentally hit the throttle on the tx. To my surprise the motor ran normal (without the sensor wire), I do have the esc set to smart sence for the sensored motor. I took it out just to see what kind of speed the buggy had with the 6.5t and I was surprised as to how slow it was. My question is since the wires for the sensored motor is not plugged in am I losing speed? My SCTE has a 3800kv Castle in it and is definitely faster than this much smaller and lighter buggy with the 6.5t (which is about 6100kv). I know gearing could be everything just do not see it getting much better. So hopefully it is due to the wires being unplugged. If you lasted all the way through this novel I thank you for your time!!
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Old 08-27-2013, 04:09 PM
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Originally Posted by jayman69 View Post
Just received a new to me buggy (xxx4 G) and a Viper 6.5t motor for it. The esc I installed is a MMP. I am having a hard time currently with the sensor wire that I have as it is too short. I hooked up everything else for setting steering, esc etc and accidentally hit the throttle on the tx. To my surprise the motor ran normal (without the sensor wire), I do have the esc set to smart sence for the sensored motor. I took it out just to see what kind of speed the buggy had with the 6.5t and I was surprised as to how slow it was. My question is since the wires for the sensored motor is not plugged in am I losing speed? My SCTE has a 3800kv Castle in it and is definitely faster than this much smaller and lighter buggy with the 6.5t (which is about 6100kv). I know gearing could be everything just do not see it getting much better. So hopefully it is due to the wires being unplugged. If you lasted all the way through this novel I thank you for your time!!
Sensor wire really plays a roll at the low RPM, it is to tell the ESC what position the rotor is in relative to the stator. Once it spins up it is not as big of a deal. The motor might run pretty good at all RPMs for you, but I would advise getting a long enough cable to run it, you will get a smoother low end and the car will not cog (if it even does that now) at lower speeds.

As for the top speed you get, it could be gearing, could be limits set on the ESC, could be the EPA on the radio. Just take each thing one at a time and rule it out.
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Old 08-27-2013, 04:51 PM
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The mmp automatically switches to sensorless mode if the sensor wire is unplugged. Most escs will run fine without the sensor wire installed. As stated above, it will just be a little rougher at the bottom end. You will also loose any can timing adjustment.

Did you program your endpoints? Could be a reason why its slow. A 6.5t should still be fast no matter where the timing is at, unless the gearing is extremely low or epa isn't right.
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Old 08-27-2013, 04:54 PM
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Originally Posted by KainK View Post
The mmp automatically switches to sensorless mode if the sensor wire is unplugged. Most escs will run fine without the sensor wire installed. As stated above, it will just be a little rougher at the bottom end. You will also loose any can timing adjustment.

Did you program your endpoints? Could be a reason why its slow. A 6.5t should still be fast no matter where the timing is at, unless the gearing is extremely low or epa isn't right.


I have the epa set to 125% and it has a 18t pinion. Going to take it up a few teeth right now. The motor has 15-45* for timing and right now I have it set the way it came, 30*.
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Old 08-27-2013, 04:54 PM
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I did set the esc to the remote as well
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Old 08-27-2013, 05:04 PM
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Set max EPA, reprogram to the radio and see what it does. also might want to check castle link to make sure all settings are right.
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Old 08-27-2013, 05:22 PM
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Originally Posted by novice racer View Post
Set max EPA, reprogram to the radio and see what it does. also might want to check castle link to make sure all settings are right.
Just did all of that and used the castle link. After putting the 21t on it picked up some good speed. Forgot to mention earlier that I did get the small sensor wire plugged in temporarily and did not notice a change.
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Old 08-27-2013, 08:26 PM
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Well smart sense is supposed to start it on sensor and then transfer at higher speed. so maybe it only goes a certain amount higher than the sensored speed. and because it didn't have sensor it just limited itself to that amount of RPM.
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Old 08-27-2013, 08:55 PM
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Originally Posted by jayman69 View Post
I did set the esc to the remote as well
DO NOT set your epa to max. Use 100% and recalibrate the esc to the transmitter. Nothing more, if done properly you now have maximum power. If you then turn up the epa and the car is faster then there was an error in the transmitter calibration.
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Old 08-27-2013, 09:07 PM
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Originally Posted by asc6000 View Post
DO NOT set your epa to max. Use 100% and recalibrate the esc to the transmitter. Nothing more, if done properly you now have maximum power. If you then turn up the epa and the car is faster then there was an error in the transmitter calibration.

I will take a look at that tomorrow, I believe the epa stopped at either 100 or 125. I will adjust accordingly tomorrow, thanks
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Old 08-27-2013, 09:08 PM
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Originally Posted by novice racer View Post
Well smart sense is supposed to start it on sensor and then transfer at higher speed. so maybe it only goes a certain amount higher than the sensored speed. and because it didn't have sensor it just limited itself to that amount of RPM.
Not too sure, I will be getting a longer lead and tie it in correctly, thanks
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