Quicrun 860 - wiring and setup

[Westside Charlie]

I'm confused about how to set up my QR 860 ESC. This is part of a Traxxas 2.5 electric conversion where I'm installing a 775 motor.

I really just need a buddy check that what I'm assuming, and what I need to do is correct.

This ESC has six wires for hook ups, plus a switch and the connector to the receiver. The six wires are:

2 yellow
2 blue
1 red
1 black

So, the two blue/yellow pairs are for motors. Since I'm only using one motor, I won't be using one of these pair. Does that sound right?

The red and black wires, therefore, must be for connection to the battery. These wires have no connectors, so I'll be soldering the connectors of my choice - probably Dean plugs. I'll probably use a single battery -- a 5000mah 14.8 v lipo, rather than two batteries (7.4v each) in series.

What are pros and cons of one battery vs two?

I haven't had to do much soldering on my previous few builds, so that's a bit new, and I want to be sure I get it right.

Any advice and feedback is welcome.

Thanks!

 

[Chumley54]

1. Just tape off the extra pair of motor wires. I am using this ESC on my dual motor CLodbuster.
2. Dual versus single batteries.

Single takes up less space, less wiring, less connections, less weight. A large capacity single battery will get quite large.


Dual can give you higher capacity (MAH) or higher voltage. 2 batteries in series, add the voltage...Two batteries in Parallel, add the maH capacities. 2 Smaller battteries may be easier to fit than a single larger battery. For larger vehicles (like my Clod Buster), 2 cells allow me to distribute the weight better front and rear.

Single battery packs can be internally 2 (or three cells or more) in series, and 2 or more cells in parallel.

A battery listed as 2S1P is 2 cells in series. Your typical lower capacity Lipo is this, 2 x 3.7 volts = 7.4 volts
On the higher capacity cells, you may see 2S2P - 2 cells in series, those two groups in parallel....2x3.7v=7.4 volts per group, 2x3000Mah groups = 6000 mah.

So depending on the size and voltage battery you buy, they may already be like 2 batteries, just in one convenient form.

The problem comes in when a really cheap battery pack uses too small gauge internal conductors which have higher resistance than a pack usng thicker gauge wiring.

 

[Westside Charlie]

Thanks for your prompt and clear feedback, Chumley54. I finally got all the electronics working and taped on all the parts to conduct a quick run test in the driveway.

Now I have to find clever ways to secure the receiver, ESC and battery. Given the space available, I am planning to pick up a 4S 14.8v Lipo, rather than two 7.4v.

I currently have an 18-tooth pinion installed because I'm thinking I want good torque. However, with so much power from the 775, I'm thinking I'll be better off with a 24-tooth pinion, if I can get that to fit.

Thanks for your help!