Wiring a “spare” rx?

[Dan B.]

I’ve looked around but haven’t found any reference to this. I had the idea that I could wire up a nice, powerful UBEC and power up a spare receiver (unbound) to basically use as a junction box for fans and lights. I can’t think of any reason why this wouldn’t work, and it would allow a really tidy and versatile way to add stuff without taxing the ESC’s built in BEC. Also (mainly) to save room and the weight of another dedicated battery.
Any thoughts?

 

[King blitz]

I’ve looked around but haven’t found any reference to this. I had the idea that I could wire up a nice, powerful UBEC and power up a spare receiver (unbound) to basically use as a junction box for fans and lights. I can’t think of any reason why this wouldn’t work, and it would allow a really tidy and versatile way to add stuff without taxing the ESC’s built in BEC. Also (mainly) to save room and the weight of another dedicated battery.
Any thoughts?

I would like to see how you do this .I might try the same if it works out.

I would like to see how you do this .I might try the same if it works out.

Plz when you start this be detailed.so my little brain can grasp it all

 

[HZRDOS]

Splice off the pos and neg connection from the ESC to receiver and plug into the extra receiver? Not connecting the third control wire it should just get the needed voltage off the ESC and power it?

 

[Dan B.]

Unless someone chimes in to alert me of something I’m missing (which is entirely possible/probable) I’m going to give it a try. I’m finishing up that street/speed build finally, and was waffling over how to set up fans and lights with batteries or a UBEC, and I don’t want to wire the UBEC into my rx because I want my servo there, and removed from fans and lights.

Splice off the pos and neg connection from the ESC to receiver and plug into the extra receiver? Not connecting the third control wire it should just get the needed voltage off the ESC and power it?

No. The ESC would not be connected to the extra rx, nor would the servo. It would just be powering accessories. But yes, the UBEC that would power it would be powered from the ESC battery inputs.

 

[gotnitro]

LED's hardly pull anything power wise and if your build is for speed runs, you really don't need fans.

 

[Dan B.]

LED's hardly pull anything power wise and if your build is for speed runs, you really don't need fans.

This build won’t be a dedicated speed runner now that the second build will be coming up. It will be mostly a hairy, overpriced street basher that will see an occasional speed run up to about 100mph or so. So fans will be a must. And I’ve got three big ones, they’ll be pulling almost 5 amps between them (plus almost another 2 amps for the 4 big front lights and 6-row rear lights) so I didn’t want them on the main rx, even with a 20amp UBEC powering it. I don’t want the ESC’s BEC doing anything but turning and burning.

 

[gotnitro]

Give it a go then!

 

[ArrmaFreek2022]

I’ve looked around but haven’t found any reference to this. I had the idea that I could wire up a nice, powerful UBEC and power up a spare receiver (unbound) to basically use as a junction box for fans and lights. I can’t think of any reason why this wouldn’t work, and it would allow a really tidy and versatile way to add stuff without taxing the ESC’s built in BEC. Also (mainly) to save room and the weight of another dedicated battery.
Any thoughts?

I was thinking about doing something like this but didn't find much on it either. It would work, my idea was to have a second transmitter to turn on fans lights and accessories. For now Just went with a battery and a switch connected directly. What about one of these really cheap china ESCs, small like a BEC then adding a small receiver?

 

[Dan B.]

I was thinking about doing something like this but didn't find much on it either. It would work, my idea was to have a second transmitter to turn on fans lights and accessories. For now Just went with a battery and a switch connected directly. What about one of these really cheap china ESCs, small like a BEC then adding a small receiver?

I think that would work, but I wouldn’t want a separate radio anyway. I’ll have switches under the lid for lights and fans, so wouldn’t have a use for another ESC, I already have a HW UBEC I’ll be using to power it up.

 

[LibertyMKiii]

From the BEC you could do a 2 or 3 way splitter instead of using the RX ports. This may or may not be cleaner or smaller, but just throwing ideas out.

 

[Senton_Prime]

From the BEC you could do a 2 or 3 way splitter instead of using the RX ports. This may or may not be cleaner or smaller, but just throwing ideas out.

View attachment 286105

This guy.. +1
I was just about to msg, before you go cutting..

 

[King blitz]

LED's hardly pull anything power wise and if your build is for speed runs, you really don't need fans.

Thats good to know.i was planning on getting new fans but I probably still will cause I like the sounds and the looks and I'm sure it won't hurt

 

[Dan B.]

From the BEC you could do a 2 or 3 way splitter instead of using the RX ports. This may or may not be cleaner or smaller, but just throwing ideas out.

View attachment 286105

The HW UBEC has two power leads (to maximize amps through the Futaba plugs) to plug into the rx, or I would do just that. Plus, I think everything including the UBEC will fit into a spare receiver box that I have.
I was hoping to just find a Futaba style “junction box” similar to a rx that I could power up, but if they exist I haven’t found one after hours of obsessive googling.
I’ll be using a RadioLink R6F non-gyro receiver and snip off the antenna lead, plug in the two power leads, and have 4 slots left for fans and lights.

 

[Senton_Prime]

The HW UBEC has two power leads (to maximize amps through the Futaba plugs) to plug into the rx, or I would do just that. Plus, I think everything including the UBEC will fit into a spare receiver box that I have.
I was hoping to just find a Futaba style “junction box” similar to a rx that I could power up, but if they exist I haven’t found one after hours of obsessive googling.
I’ll be using a RadioLink R6F non-gyro receiver and snip off the antenna lead, plug in the two power leads, and have 4 slots left for fans and lights.

How is this coming along..

 

[Dan B.]

I won’t get the receiver until the middle of next week. I was going to use one of my old receivers but they’re all 6.0 volt and I want to run it on 8.4 to max out the fans. I should have everything soldered by then (ESC leads, cap pack, UBEC, telemetry cable, fan leads, etc.) if work leaves me alone.

 

[Rottster]

Why not just use a dupont pin header? They're about 6 bucks on Amazon.

 

[Dan B.]

Why not just use a dupont pin header? They're about 6 bucks on Amazon.

By the time I built it it would be quite a bit bigger and not nearly as robust, right? That’s my take, I have no experience with them. Could you be specific, I’m interested in the approach?

 

[Budha]

I’ve looked around but haven’t found any reference to this. I had the idea that I could wire up a nice, powerful UBEC and power up a spare receiver (unbound) to basically use as a junction box for fans and lights. I can’t think of any reason why this wouldn’t work, and it would allow a really tidy and versatile way to add stuff without taxing the ESC’s built in BEC. Also (mainly) to save room and the weight of another dedicated battery.
Any thoughts?

Would you run the 2nd circuit off a separate smaller secondary battery or try and run it in line from your main battery?

 

[dk10438]

Dan
Why don’t u use a futaba sbus hub?

 

[chilly81]

Would something like this be helpful at all? It's RX controlled switch, but when it's on, it pulls power from that side JST connection, not from the RX. There are other simple ones that pull from the RX - like a simple on/off control for fans or lights. But this offers the ability to tie in another power source without setting up another RX. Not sure if it would be useful in your situation. I ended up getting one by accident thinking you could use it as a standard switch too - but no, it's only switching that aux power source in.

switch