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Old 02-09-2009, 09:32 AM   #751
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The nominal voltage for a single cell lipo is obviously 3.7v but what are the voltages after a full charge at the start of a run and the voltage of the cell after a 8 min run?

Just trying to work out if my esc (GM V3R, yeah i know bottom of the ladder esc but it make my mardave go like hell) would still be working at the end of the run. I know it runs fine about 4.1v (voltage of gp3300 cells after a run when put on discharger) but having just tried a 3 cell pack with 3.86v the esc and pt briefly lit then didnt work at all, the servo was fine though.
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Old 02-09-2009, 09:41 AM   #752
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4.22 would be at the start, not sure after an 8 minute run though.
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Old 02-09-2009, 10:25 AM   #753
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Originally Posted by jrp View Post
What speedo are you running ? With the LRP Sphere, you need to run it off of the battery, then into the speedo (like it was a receiver pack), otherwise the speed control senses low voltage and cuts motors signals, thus the dumping feeling.
Novak GTB 4 cell SS. No dumping feeling at all through the race.
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Old 02-09-2009, 02:40 PM   #754
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Novak GTB 4 cell SS. No dumping feeling at all through the race.
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Old 02-09-2009, 03:04 PM   #755
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iI just ordered the 1 cell lipo...got a race on Sunday I will post results soon after!!!
So how did it go?

DK
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Old 02-10-2009, 11:10 AM   #756
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So how did it go?

DK
we race over at jonesboro arkansas and the just had a bad ice storm about two weeks ago so we just got word that they just got power again so we will be racing Sunday if everything works out....I will post results soon after.
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Old 02-14-2009, 10:45 AM   #757
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Once the speed control cutoffs get changed I think the flat feeling will go away. In testing done by Donny Lia he tells me that the pack will run fine for 6 minutes but after that it starts to feel like it's dumping but there is still plenty of capacity in the pack. I think under acceleration the voltage dips down below the speed cutoff so it backs off the power to motor to keep it for the reciever. So basically for 8 minute 12th scale to work properly it will require updated speed controls.
Both of the speedos I have can have the VCO disabled..
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Old 02-14-2009, 02:22 PM   #758
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I think what Danny is referring to ( please correct me if I'm wrong) is not the user settable lipo cutoff voltage. Most esc's have a separate preset voltage (set by the manufacturer) that must be maintained for the receiver/servo to function. When the volts drop below this point the esc limits the power to the motor to maintain rec/servo function. The lipo cutoff is there strictly to prevent over discharging.

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Old 02-14-2009, 03:23 PM   #759
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I think what Danny is referring to ( please correct me if I'm wrong) is not the user settable lipo cutoff voltage. Most esc's have a separate preset voltage (set by the manufacturer) that must be maintained for the receiver/servo to function. When the volts drop below this point the esc limits the power to the motor to maintain rec/servo function. The lipo cutoff is there strictly to prevent over discharging.

Scott
No , you are correct! But as a serious racer I can realize when I need to take it off the track. I shut mine off. My son whom is six however... Oh it's on now!
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Old 02-14-2009, 10:23 PM   #760
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how do i setup up a sphere to run on a single cell lipo in 13.5 1/12th? esc settings, booster(would the tq cells one work) or reciver pack?
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Old 02-15-2009, 06:24 AM   #761
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Originally Posted by SPC Racer View Post
how do i setup up a sphere to run on a single cell lipo in 13.5 1/12th? esc settings, booster(would the tq cells one work) or reciver pack?
I put the voltage cut off on nimh because its lower then 2cell lipo, not sure if it even works though.
Start with a 3.15-3.2 roll out and the speedo set with 2,6,3,0. I have used a 4cell rx pack of 150 mah and now a booster. The booster is cool cause I dont have to charge two packs for one car but the rx pack did work just as well. I wired a switch inbetween the speedo and booster and turn just the booster on.

DK
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Old 02-16-2009, 06:20 AM   #762
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I'm running a Novak GTB 4 Cell SS/Novak 17.5 BL and was wondering what people had for rollout? I started with 88.5mm and that seemed a bit low. Trying to get in the ballpark before fine tuning at the track. Thanks.
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Old 02-16-2009, 07:22 AM   #763
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I'm running a Novak GTB 4 Cell SS/Novak 17.5 BL and was wondering what people had for rollout? I started with 88.5mm and that seemed a bit low. Trying to get in the ballpark before fine tuning at the track. Thanks.

The rollout for 17.5 really depends on the track. I'm finding that on some tracks the motor won't overheat even when it's overgeared. So, with 17.5 I've ended up around 90mm. Use laptimes to gear up or down from there and turn the timing all the way up on the motor for single cell 17.5 and light weight.
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Old 02-16-2009, 07:59 AM   #764
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75x36 track I settled on 3.52 rollout. Tried 3.62 but it was a touch too much so went back. Timing was cranked on both motor/speedo. Ran ok. Wouldnt load the motor as much in the corners with the 3.5 roll out. Next will try dropping the timming on the motor and a 3.6 roll out.



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Old 02-16-2009, 02:50 PM   #765
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Questions??

How are people finding their laptimes compared with 4cell on the same circuits etc.

Preferably with different motors.

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