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Old 01-13-2009, 10:25 PM   #556
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Originally Posted by Danny/SMC View Post
I never understood why 12th scalers use 16 gauge wire as this limits the voltage under load.
It's more a matter of the ESC-to-motor wires (and the jumper, if it's used.) 16ga wire mitigates any potential spring effect thicker wire might apply between the chassis and pod.

Or...most dedicated 1/12th scalers are just epically picky freaks Your call.

That said, I've got one of your batteries in my 12R5 now, and I, too, found the wire a pain. Slicing off the shrink wrap that extends out of the battery case helped.
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Old 01-13-2009, 10:41 PM   #557
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The wire on the single cell is 14 gauge not 12 gauge. I know 12th scale racers like 16 gauge wire but this pack is also being used in Oval and they use 12 gauge so we made the wire 14 gauge.

I never understood why 12th scalers use 16 gauge wire as this limits the voltage under load.

I would be interested in seeing the actual voltage drop under load of 16 vs 14ga wire. From what I understand you need to get quite a bit above the amp loads a 13.5 or even a 8.5 will pull from battery to see any issues. And if voltage drop under load was a big concern we wouldnt use connectors at all. I am pretty sure the voltage drop/resist. of the Deans connector is a pretty big factor as is the short shunt of high ga wire.
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Old 01-14-2009, 07:37 AM   #558
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So what are you guys at 360 doing with respect to running 1S Lipo/13.5 with 4Cell/NiMh/17..5 cars ?

Are you making it a separate class ?

If not, are you making the 1SLipo cars add weight ?



Not looking for opinions on why it should be one way or the other, just curious what your doing at 360 at the moment.


We are currently running them together. And we are not adding any weight. Deciding the weight min. is critical to the success of running LiPo. So far the Speed Merchant cars sre the heaviest at about 705grams w/ LiPo, so we will take that under consideration and maybe look at 710 to 720 grams as the min. wt.......It's still a work in progress. Very minor detail thou as we move along with this technology.

We simply do not want to hurt the performance side of the LiPo advantages with punch and overall speed compared to the 4 -cell set-ups. Right now, the cars are running close in lap times w/ little wear on the tires and equiptment. I usually gear up 2 teeth from my 4-cell set-up to my 1C set-up.............Example: 76/47 with 44mm tires for 4-cell/17.5 and 76/49 for the LiPo/13.5 set-up.


........And so again, we're allowing both confirgations to run together with great success and many are taking advantage of the LiPo simplicity.

Hope to helps...........Happy Racing!
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Old 01-14-2009, 09:44 AM   #559
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The chain is only as strong as the weakest link....
the voltage drop difference in the 2 different size wires you mentioned is moot . Guage is (for us anyways) a current thing . Not a voltage issue. the drop would have to be measured over 100 feet of wire. not over 4 inches.
12th scalers are also worried about weight .. well,, atleast we were when we were using round cells. The efficiency of all the electronics now... omg . Fat wire is really only needed for the low winds. You could run 14 GA. wire on a 13.5 T/C and it would be just as fast as one with 12 GA. wire. No problem.
P=I squared * R. Hwat in the wires used to be an issue with brushed motors , an easy solution then was bigger wire. we just dont need it now.
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Old 01-14-2009, 09:57 AM   #560
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If voltage drop isn't an issue with smaller wire then please explain why a sub-c pack with a small jumper wire has higher IR and lower average voltage than pack that uses battery bars with no wires ?

At the IIC Vegas one of our racers was using some weird style Bullet connectors and he decided to hard wire and gained a 10th of a second. The connectors he was using were brass which I know is not a good connector so may the difference between gold plated copper wouldn't of been as big.

When racing seriously you should care about everything to try and make your car as fast as possible. I have always wondered why the use of 16 gauge seemed to eb the way to go. There is some good flexible 12 gauge out on the market.
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Old 01-14-2009, 10:15 AM   #561
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There is some good flexible 12 gauge out on the market.
Check out what I post above from TQ racing. His wire is super flexible that won't cause tweaking of your cars.

http://www.tqracing.com/rc_products.htm
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Old 01-14-2009, 10:23 AM   #562
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As john mentioned, the weight is another aspect. I saved over 12 grams just removing the deans connector and the stock wires and replacing them with trinity bullet connectors and 16ga wire.

Under full race conditions the wires dont even get warm so to me... I doubt there is any real limitations being hit with them. Now if I was running a 5 turn or something, that may be different. I am running 13.5 with the LiPo, and 17.5 with 4 cell... in an 8 minute run with the 4 cell I drain betwee 2200 and 2400 mAh from the cells.

So doing the math 300mA was drained from the cells per minute. (18Ah) I am pretty sure these fine wirecount count 16ga wires can handle an 18Ah/4.7v draw no real voltage drop over a few inches of it. The lack of wire heating is a dead give away at how efficient these wires are at these loads.

And many things can contribute to a .10 decrease in lap times. What about the weight saved from going away from the connections and doing a direct connection?
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Old 01-14-2009, 10:49 AM   #563
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So options are to run a receiver pack(yuck) or a booster unit (something else to deal with) or sacrifice the servo speed and go back to a normal setup. For those that are running speedos with no booster or receiver pack, the steering servo is only seeing 3.5V or so. If this is acceptable we can adjust our unit to work with no additional things needed also. We are still watching how this plays out and what everyone wants. It is currently engineered to maximize performance with 4cell. We are on the track today looking at it and making the adjustments.

Slower servo is acceptable?

With our current suggestion of using a receiver pack or booster and leaving our red wire in and power switch off, we are getting all the power possible to the motor. As long as we can still get all the power this is an easier solution for spec motors. If we get to faster motors and start using more of the battery capacity in a race I think a receiver or booster will be needed to get it all. We have run a 2.5turn in a 1/10 TC with the single cell and it is pretty impressive. We will see how the battery liked it over time. I can also see 1S with a 13.5 or 17.5 in a TC being the speed real beginner stock should be.

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Old 01-14-2009, 11:00 AM   #564
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The bigest reason that I run the smaller wire is space. Back when we only ran two wires to the motor you could run the bigger wire without any real problems. Now, we're stuffing 3 wires plus a sensor harness through the pod and it can get packed up really fast with 12 or 14ga wire.

It's no secret that wire gage, wire length and any connectors are going to hurt performance. From what I've seen wire length and bad connectors are the major contributors.

It does get me thinking about trying to fit some of that fat wire in the car again though. Then again, I'm not trying to wire my house with this stuff.
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Old 01-14-2009, 11:07 AM   #565
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Originally Posted by TeamTekin View Post
So options are to run a receiver pack(yuck) or a booster unit (something else to deal with) or sacrifice the servo speed and go back to a normal setup. For those that are running speedos with no booster or receiver pack, the steering servo is only seeing 3.5V or so. If this is acceptable we can adjust our unit to work with no additional things needed also. We are still watching how this plays out and what everyone wants. It is currently engineered to maximize performance with 4cell. We are on the track today looking at it and making the adjustments.

Slower servo is acceptable?

With our current suggestion of using a receiver pack or booster and leaving our red wire in and power switch off, we are getting all the power possible to the motor. As long as we can still get all the power this is an easier solution for spec motors. If we get to faster motors and start using more of the battery capacity in a race I think a receiver or booster will be needed to get it all. We have run a 2.5turn in a 1/10 TC with the single cell and it is pretty impressive. We will see how the battery liked it over time. I can also see 1S with a 13.5 or 17.5 in a TC being the speed real beginner stock should be.

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+1

I know lots of pros and above average drivers feel the delay in some 2.4 ghz conversions and I would imagine they would baulk at a slower servo for the same reasons. Personally I've run WGT and 12th with no booster or rec pack and have no problem with the servo speeds, but while I consider myself above average, I was never one to notice a delay when I went from FM on my Helios to the spektrum module in it.

As for beginner speeds I think you're right. It kinda goes back to the argumenet that there are too many pro drivers in the stock classes. If we had 17.5/1 cell as stock, I imagine we would see less of that.
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Old 01-14-2009, 12:14 PM   #566
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So Fred, do you have the red wire pulled for your ESC when using the booster?

I am thinking I cooked one of my boosters already by leaving the red wire in, and the ESC turned off. I did some playing around and noticed that the booster got hot, and after doing some diagnostics I see its voltage output is almost just at where the battery voltage is... so its dead.

I am just trying to figure out what the key is for a novak GTB. Is it - Red wire out, ESC power switch on, Voltage booster On? or Red wire in, ESC Switch off, Voltage booster on?

Anyway, attached are pics of how I mounted the Trinity bullet connectors for my BMI. This makes it easy to charge, and easy to connect/disconnect.
Attached Thumbnails
SMC 4000/25C/3.7V single cell Hardcase pack.-img_3673.jpg   SMC 4000/25C/3.7V single cell Hardcase pack.-img_3675.jpg   SMC 4000/25C/3.7V single cell Hardcase pack.-img_3676.jpg   SMC 4000/25C/3.7V single cell Hardcase pack.-img_3677.jpg   SMC 4000/25C/3.7V single cell Hardcase pack.-img_3678.jpg  

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Old 01-14-2009, 12:40 PM   #567
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I would be interested in seeing the actual voltage drop under load of 16 vs 14ga wire. From what I understand you need to get quite a bit above the amp loads a 13.5 or even a 8.5 will pull from battery to see any issues. And if voltage drop under load was a big concern we wouldnt use connectors at all. I am pretty sure the voltage drop/resist. of the Deans connector is a pretty big factor as is the short shunt of high ga wire.
I know the difference is probably not much but there is one. It can easily be compnesated by better car setup and driving but if you take 2 equal cars and drivers the one with the shortest wires and better connections should be a bit faster.

I've been matching cells for over 20 years and everyone use to and still get caught up in numbers on the cells. This is why I alsways wondered why 12th scalers cared about packs numbers when they use small wire that limits power.

Novak sent me a 7.5 BL motor with smaller gauge wire inside and they also included 16 gauge wire for me to use for the battery and motor connection. They told me this would smooth out the power band and it's what they used in offroad.

I bet if one of the best stock 12th scale racers was to use good flexible 12th gauge wire and start beating everyone you would soon see many go that route. What I have noticed with RC racers is that they really seem to try and copy what others are doing. I have seen this with some of the top sponsored guys as well. It's monkey see monkey do but sometimes this is not the best thing to do.

If I would race 12th scale stock I would use 12 gauge and solder directly to the pack wires. This would give me the lowest possible resistance. Since I race offroad I use connectors as speed isn't important in mod offroad as I can always motor up or down.
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Old 01-14-2009, 12:45 PM   #568
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So Fred, do you have the red wire pulled for your ESC when using the booster?
I'm running a Tekin so it might be different with the Novak. With the RS I have the red wire pluged in on the receiver.

If you let the Lucas (smoke) out of your booster with the positive in on a Novak then it might be a good idea to pull the red wire and give it a try.

My guess is that there is some kind of ground loop happening with the booster grounded to the battery. Never had a problem with receiver packs back in my Novak days.

Novaks have red Lucas in them by the way. Haven't seen one go up in a long time but they shure are pretty when it happens.
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Old 01-14-2009, 03:35 PM   #569
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the larger wire has its advantages. It can handle more current for a longer period of time. The lengths of wire we use the resistence is insignificant to voltage loss but at the sost of mass. Also in tern the smaller wire would heat up under high amp loads that would cause increased voltage drop. We simply dont require that kind of power.
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Old 01-14-2009, 10:07 PM   #570
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Just got back from my first race with the 13.5/1c setup.

Now I want to state that I am running very light, a little over 700 grams, but this setup rips !! I was less than a tenth off fast lap and behind a tenth for the first min of a run. After that it was the same as a very competitive 17.5/4c setup. The pack did smooth out a touch from begining to end but couldnt tell you were. I made a pretty big bobble early in and had to drive the hell out of it but I cought him with 3 laps to go. Very big advantage at the end of the run. I had plenty in the tank but just ran out of time and luck.

Anyway, thanks for a killer pack. Now I just have to bring the car up to weight and see if it still shines. But I do like it light, very little tire wear !

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Last edited by PartTime; 01-14-2009 at 10:27 PM.
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