The Coffee Shop - For general discussion

[Ketchup]

Ok... now I’m super confused

Here’s my little diagram. It sucks because I’ve never made one of these before lol.
Red is positive, black is negative and gray is signal (it should be yellow irl I think, but I didn’t have anything yellow).
Also, note that both red wires coming from the ESCs are cut short.

Here's a better diagram:

 

[Ketchup]

Would the special connector be a tri-y harness or a y harness connecting the ESCs and then another to connect that to the bec?

Yep. Both ESCs and the BEC are all connected directly to the battery.

 

[Ketchup]

In this project that I am imagining that may or may not come to a flite fest Ohio near you in the future, I will probably use two sunnysky 2814 motors that will draw about 80 amps each so 2 100 amp ESCs to be safe. Then, I am planning to use 4-5 20g servos depending on whether I go for a rudder or not, and 2 13 gram servos for the flaps. With this setup, I’m wondering if two included becs will double the bec capacity or not change it, and if that will be enough considering that they are 100 amp ESCs after all...

You never use multiple BECs at once. At least with switching BECs it won't really work well. Normally on a twin you disable one of the ESC's BEC, but here you should disable both for a separate BEC.
The amperage of the ESC has no effect on the amperage and voltage of a BEC. They are two completely separate things, so a 100 amp ESC still might not supply enough power.

 

[Battery800]

You never use multiple BECs at once. At least with switching BECs it won't really work well. Normally on a twin you disable one of the ESC's BEC, but here you should disable both for a separate BEC.
The amperage of the ESC has no effect on the amperage and voltage of a BEC. They are two completely separate things, so a 100 amp ESC still might not supply enough power.

No I mean that the bigger ESCs also have bigger becs from what I have seen, but yeah it still might not be sufficient

 

[Battery800]

Here’s my little diagram. It sucks because I’ve never made one of these before lol.
Red is positive, black is negative and gray is signal (it should be yellow irl I think, but I didn’t have anything yellow).
Also, note that both red wires coming from the ESCs are cut short.
View attachment 204250

Here's a better diagram:
View attachment 204251

Alright, now it’s not so confusing, thanks! Now the only thing I think I need to know is how much current the stuff will pull so how big of a BEC to get

 

[Battery800]

I was looking at the one you linked, why does it have two 3 pin plugs?

 

[Ketchup]

I was looking at the one you linked, why does it have two 3 pin plugs?

This is a quote from the product description:
"Additionally, this unit features dual output leads which not only provides power redundancy, it also spreads the current load over two sets of leads to ensure you are not putting too many Amps through one lead".
It is a 20 amp BEC, so it would provide a lot of amperage if needed.
Like I said though, the one I linked may not be the best for your uses, or even any good. I only did a small BEC search a few days back and that's how I found it.

 

[Battery800]

This is a quote from the product description:
"Additionally, this unit features dual output leads which not only provides power redundancy, it also spreads the current load over two sets of leads to ensure you are not putting too many Amps through one lead".
It is a 20 amp BEC, so it would provide a lot of amperage if needed.
Like I said though, the one I linked may not be the best for your uses, or even any good. I only did a small BEC search a few days back and that's how I found it.

At this point I’m only imagining and finding the right parts, but before that I have to understand how to make a big build, as the biggest plane I have made is about the size of a mustang, not exactly huge

 

[Ketchup]

At this point I’m only imagining and finding the right parts, but before that I have to understand how to make a big build, as the biggest plane I have made is about the size of a mustang, not exactly huge

I think we're in the same boat here lol. I'm not building the biggest thing in the world, but I do plan on building something relatively large and complicated before next summer.

 

[The Hangar]

But one scaled up about 150% is a possibility

It’s really not necessary to use high voltage servos for most applications, you use them if you need lots of torque as well as super fast movement. I have servos in my 85cc yak that aren’t HV and they put out over 30 pounds of torque in .16 seconds.

 

[The Hangar]

It’s really not necessary to use high voltage servos for most applications, you use them if you need lots of torque as well as super fast movement. I have servos in my 85cc yak that aren’t HV and they put out over 30 pounds of torque in .16 seconds.

Savox had a good collection of servos and you should be able to find something that will work. If you’re building a monster sized plane then you’ll need something bigger than those emax 20g ones.

 

[CappyAmeric]

In this project that I am imagining that may or may not come to a flite fest Ohio near you in the future, I will probably use two sunnysky 2814 motors that will draw about 80 amps each so 2 100 amp ESCs to be safe. Then, I am planning to use 4-5 20g servos depending on whether I go for a rudder or not, and 2 13 gram servos for the flaps. With this setup, I’m wondering if two included becs will double the bec capacity or not change it, and if that will be enough considering that they are 100 amp ESCs after all...

You should not need an 80 amp ESC for a SunnySky x2814. Their specs call for half that: 40 amps. https://sunnyskyusa.com/products/sunnysky-x2814-brushless-motors.

 

[Bricks]

You could for go all the BEC stuff and use a 2 cell Life battery for receiver power.

 

[Battery800]

You never use multiple BECs at once. At least with switching BECs it won't really work well. Normally on a twin you disable one of the ESC's BEC, but here you should disable both for a separate BEC.
The amperage of the ESC has no effect on the amperage and voltage of a BEC. They are two completely separate things, so a 100 amp ESC still might not supply enough power.

What about in a glider where there is no motor? Can I just use a bec?

 

[Battery800]

You should not need an 80 amp ESC for a SunnySky x2814. Their specs call for half that: 40 amps. https://sunnyskyusa.com/products/sunnysky-x2814-brushless-motors.

For the v3 (blue) 2814 1400kv

Don’t know if this accounts for spikes and such

 

[CappyAmeric]

For the v3 (blue) 2814 1400kv View attachment 204256
Don’t know if this accounts for spikes and such

The v3 lists 80 amp ESCs. I would not go higher.

 

[Battery800]

The v3 lists 80 amp ESCs. I would not go higher.

Ok then

 

[Ketchup]

What about in a glider where there is no motor? Can I just use a bec?

You could do that or you could just use a receiver pack like Bricks said.

 

[Battery800]

You could do that or you could just use a receiver pack like Bricks said.

How do I connect that?

 

[Ketchup]

How do I connect that?

Not exactly sure really since I have never used one. I think that you would just plug it straight into the receiver though.