Series connector

[Superbasher]

Well i can't find a tutorial/instructions on how to make a set of connectors so that i can run 2 packs in series on my Mamba max. I don't want to guess as i'm going to be using a high cell count (10 cells) so does anyone have a guide on how to do it? (I tried searching and couldn't find anything)
Cheers
Matt

[Patrick]

This is made by BrianG on this forum
http://www.scriptasylum.com/rc_speed/_lipo.html
Go down a little bit to the part that says "Battery Pack Wiring".
Click "Use 2 series-connected battery packs" a picture should come up of how you'll want to wire it.
Basically join the positive wire of the first pack to the positive wire on the ESC.
Join the negative wire of the first pack to the positive wire of the second pack.
Join the negative wire of the second pack to the negative wire on the ESC.

Some people (including me) make an adapter to join the two packs together, so you can easily go back to using 1 pack. To do that you'll need 1 female plug and two male plugs (assuming your using a plug with both wires in the same plug eg. deans, tamiya, powerpoles etc)

Oh, and I recommend putting that site in favorites. It comes in handy for a lot of things, especially the top speed estimator part.

[Superbasher]

Thanks for that patrick, it makes it seem pretty simple. that speed calculator looks good, but unfourtunately it doesn't have the internal gear ratio's for a T4, and i don't know what it is.
Matt

[BrianG]

If you find out what the ratio is, I will add it. All I need are the tooth counts, not the ratio. Better if I have a schematic diagram of the tranny to be sure there aren't any other gears affecting the ratio.

Also, if you know the available spurs for that truck, I can add those as well.

And this goes for any vehicle you'd like to see added.

[Superbasher]

I can't really find much, but from http://www.teamassociated.com/ae/t4/t4_specs.htm
It says that the internal gear ratio is 2.6:1 - Is that the right one?
Matt

[BrianG]

Well, the T4 online manual can be found here. I'm donwloading it now and see if I can verify that. If I can, I'll at least add the tranny ratio to the calculator...

[Superbasher]

I entered it with the cells i am going to run and my current gearing. 68mph? i wasn't expecting that fast lol, and 85 on 21/87, wow!

[BrianG]

Well, remember there IS a disclaimer that speeds will start being less and less accurate after 45-50mph. Around there, wind resistance starts to play a significant role. However, it is all but impossible to calculate exactly how much, so just keep that in mind...

[Superbasher]

I was thinking that might have something to do with it, plus i think my bearings might explode...

[BrianG]

What are you using for values to get those speeds? Hint: enter the values into the calc, click the "forum export" button, and copy/paste the results into your post.

[Superbasher]

Differential Ratio: 1
Transmission Ratio: 2.6
Other Ratio: 1
Spur Tooth Count: 87
Pinion Tooth Count: 17
Total Voltage: 12
Motor KV: 5700
Tire Diameter (inches): 4
Tire Ballooning (inches): 0.25
Motor Current Draw: 0
Motor coil Ω: 0
Spur/Pinion Ratio: 5.12 : 1
Total Ratio: 13.30588 : 1
Tire Circumference (inches): 14.14 inches (359.08mm)
Total Motor Speed: 68400 RPM
Vehicle Speed: 68.82 MPH (110.55km/h)
Effective Speed Rate: 5.73mph/V (9.21kmh/V)
Effective KV Value: 5700
Motor Torque: Amperage not specified...
Final Torque: Amperage not specified...


The amps and ohms etc i'm not 100% sure on so i didn't include them.

[BrianG]

For top speed measurements, the current (and the resulting kv drop) will be fairly low anyway, so it's not vital. The amps/ohms are more for figuring max torque the motor will produce.

What motor are you running that will revv over 68,000 rpm?! :wow:

[Superbasher]

Mamba Max 5700, they put the 65,000 rpm limit in to be safe, it can really take a bit more.

[lydiasdad]

http://www2.towerhobbies.com/cgi-bin...?&I=LXNKY9&P=7

[Superbasher]

Originally Posted by lydiasdad

http://www2.towerhobbies.com/cgi-bin...?&I=LXNKY9&P=7

Thanks for that, no point ordering a pre made one though as tower charge british citizens hurrendous amounts of money to ship stuff.