A Better Receiver Box

[Jamr]

Happy Friday everyone.
I am hoping to get some input from all the really inventive RC people out there.
I am trying to make the ultimate receiver box for people that have the room for it.
I like to separate the power requirements of my extra electronics (Lights, sounds) on my cars from the receiver and to the battery directly so they do not suck the power off of the receiver.
I also like to put a fuse holder and buck voltage converter on that fused battery line so that I do not have to run a resistor at every LED I use. Since batteries come in all different voltages I use a BVC to convert that voltage to a straight 6vdc or 3vdc. It just makes it easier when adding on other electronics later.

Bottom line; I have lots of electronic components I have to shove into the receiver box.
This is just the converter and a channel relay switch along with the receiver and a winch controller. I will also have to add a lighting box with the blinkers and such which I will have to put in a different box.

With this F450 I have a lot of room, so I am designing a receiver box that can hold all of this.
With my other cars, room was tight so I had to design extension boxes that extended the volume of the original box while still retaining the so called waterproofness of the box.

These work but are a pain to design due to the area I have to work with.
This new box is without constraints since I have so much room in this truck.

I had already switched out the receiver and the box to this but there just isn't enough room in that box so I have do make my own.

I looked on the various 3d print sites and could not find a decent waterproof one so I am designing one myself but I would like to get some input on what others might want in a receiver box.
Here is what I have so far.

It is about 55mm wide and 32mm tall and 33.5mm deep
Got a lot of ideas for water resistance like foam or a rubber band on the lid, beveled outer edge for water resistance, drip holes where the screws are, and a foam wall for the wire door.
I am also unsure of the antenna placement spot. Maybe all four sides and you break off the ones you don't want?
Also does anyone know of the exact ID and OD standard for an antenna tube? Is there a standard? I like the idea of having a antenna tube next to the receiver box that keeps the antenna out of harms way. Also placement of the antenna. Is it better to have the antenna high above the electronics? Maybe a holder on the lid if you have the vertical room?
Anybody else have any extra needs for a receiver box I am not thinking of?
Thanks for the ideas.

 

[Jerold]

Yeah, I totally see what your getting at. All of my boxes are jammed packed and I put on the cover to make it look nice.

The double stack box you made is pretty cool. One thing you can do is use water proof panel mount connectors. Then plug in your wires to the outside of the box. This could make your box completely water tight. The issue is the connectors take up space. Of course you would need to tidy (shorten) up your wires them so they don't get stuffed in the box.

You can buy pin headers.

They connect and they JST just fine. However, they have no polarity and only have friction on the pins to keep them in place. They will probably fall off if you bash. But they would be easy to embedded into a custom box and seal it up with some hot glue.
https://a.co/d/9ASRUH7

I don't know that you will find one design that fits every application. However, I have swapped out boxes before but the relocation was much better. On my Limitless I moved it to the top rail, then use the servo mount and a piece of ABS for the antennas. It's a spaghetti maze inside.

The BEC is either a buck converter (switching regulator) or a Low Drop Out regulator (LDO). You might be able to find a cheap switchers on Amazon/eBay, but they don't last long.

Good switching regulators can be 90+% efficient. However, you have to size them right, do some work and good ones aren't cheap. The cheap ones are probably more like 70-80% efficient in reality. The LDOs are horrible because the current = current out. So 1A @6V draws 1A at 32V. Basically our drawing 32W to get 6W, which would be like 18% efficient.

The Amazon special uses an LM2956S. The schematic for it is in the datasheet. They aren't terribly robust. It looks like it's about 82% efficiency at 6V, best case
https://www.ti.com/lit/ds/symlink/lm2596.pdf

They literally copied the reference design and considering you get 6 for $10, it probably costs them $0.50-$0.75 per board. Nothing wrong with the design, but it's not manufactured for longevity and you will probably need all 6 of them. I would just pay the $10-30 for a good one and call it a day.

Discrete LEDs will need a resistor to limit the current or if it's a packaged product it "might" have the resistor in there. You can get LED drivers (constant current) that don't require resistors. What resistor & LEDs are you referring to?

 

[Jamr]

Yeah, I totally see what your getting at. All of my boxes are jammed packed and I put on the cover to make it look nice.

The double stack box you made is pretty cool. One thing you can do is use water proof panel mount connectors. Then plug in your wires to the outside of the box. This could make your box completely water tight. The issue is the connectors take up space. Of course you would need to tidy (shorten) up your wires them so they don't get stuffed in the box.

You can buy pin headers.
View attachment 171127

They connect and they JST just fine. However, they have no polarity and only have friction on the pins to keep them in place. They will probably fall off if you bash. But they would be easy to embedded into a custom box and seal it up with some hot glue.
https://a.co/d/9ASRUH7

I don't know that you will find one design that fits every application. However, I have swapped out boxes before but the relocation was much better. On my Limitless I moved it to the top rail, then use the servo mount and a piece of ABS for the antennas. It's a spaghetti maze inside.
View attachment 171118

The BEC is either a buck converter (switching regulator) or a Low Drop Out regulator (LDO). You might be able to find a cheap switchers on Amazon/eBay, but they don't last long.

Good switching regulators can be 90+% efficient. However, you have to size them right, do some work and good ones aren't cheap. The cheap ones are probably more like 70-80% efficient in reality. The LDOs are horrible because the current = current out. So 1A @6V draws 1A at 32V. Basically our drawing 32W to get 6W, which would be like 18% efficient.

The Amazon special uses an LM2956S. The schematic for it is in the datasheet. They aren't terribly robust. It looks like it's about 82% efficiency at 6V, best case
https://www.ti.com/lit/ds/symlink/lm2596.pdf

View attachment 171126
They literally copied the reference design and considering you get 6 for $10, it probably costs them $0.50-$0.75 per board. Nothing wrong with the design, but it's not manufactured for longevity and you will probably need all 6 of them. I would just pay the $10-30 for a good one and call it a day.

Discrete LEDs will need a resistor to limit the current or if it's a packaged product it "might" have the resistor in there. You can get LED drivers (constant current) that don't require resistors. What resistor & LEDs are you referring to?

Those connectors are a great idea. I am not sure about the wire management and the connector staying on as you said. Cool idea though! Thanks.

Good to know about those buck converters. I will keep it in mind. They say their effiency is up to 92%. Who knows.

I use varying LED's in my cars. Some have attached resistors some do not. I want to be able to pick and choose my LED's when I need them meaning I will need a voltage I can change per application.

Love your application with that box. It looks stock!
Here is an update:
First prototype made.

This hole is for any of the water that comes into the screw opening to escape.

Couple things I want to change.

1. Bigger Wire Wall Opening.
2. Drop screw heads flush with top of cover??
3. Add a antenna pole mount.

Anybody else have any other tips?
Thanks for the input.

 

[Jerold]

Good to know about those buck converters. I will keep it in mind. They say their effiency is up to 92%. Who knows.

Yes, they are 92% when you put in 20V and get 20V out. Look at the graph in the other post.

The box looks great! That's a good printer, looks very smooth.

This hole is for any of the water that comes into the screw opening to escape.

How deep are you going to run this? I would think the water would get down into the threads? If you use stainless steel screws they won't rust and it should be fine.

Making something 100% waterproof submersible is a bit difficult. However, splash proof should be pretty doable. Have you thought about having a "pressure chamber" to route the wires. You could even put some antenna mount there. For the lid to make it air tight, you might try a rubber seal. Here is one example, but McMaster has all kinds of stuff.
https://www.mcmaster.com/products/g...water-resistant-neoprene-o-ring-cord-stock-6/

You would probably need at least 6 screws, 2x for head seal crossing/corner?

 

[Jamr]

Yes, they are 92% when you put in 20V and get 20V out. Look at the graph in the other post.

The box looks great! That's a good printer, looks very smooth.

How deep are you going to run this? I would think the water would get down into the threads? If you use stainless steel screws they won't rust and it should be fine.

Making something 100% waterproof submersible is a bit difficult. However, splash proof should be pretty doable. Have you thought about having a "pressure chamber" to route the wires. You could even put some antenna mount there. For the lid to make it air tight, you might try a rubber seal. Here is one example, but McMaster has all kinds of stuff.
https://www.mcmaster.com/products/g...water-resistant-neoprene-o-ring-cord-stock-6/

You would probably need at least 6 screws, 2x for head seal crossing/corner?
View attachment 171183

This is great.
I was not going to run the threaded screw hole all the way through the box and out the bottom but now I am thinking it may be best just in case water does get down into the threading of the screw.
Yes, I am using stainless steel screws.
Yes I assumed that waterproof is pretty much a pipe dream. Especially with wires penetrating the box so I am pushing for splash proof. Although I will try to submerge a prototype box with nothing in it once I get one completed to see if there is any water penetration.
The chamber idea is great although it will take some supports on the printng side to complete. I think I can try that tonight or tomorrow.

 

[Jamr]

OK I thinned the walls by a couple of mm which means I will have to redesign the lid which is no problem as I had to add the extension with the new air chamber cover anyway.
I added the chamber on the box and moved screw tubes out to meet new size of the interior walls so now the interior gained 2mm both ways.
I'll post a pic when it is done printing.
@Jerold Thanks for the input and the cool drawing. It was great!

 

[Jamr]

Update;
Latest update on prototype with low resolution print to save filament.
With Air Chamber

With drainage screw holes on bottom.

With antenna mount at bottom.
This looks terrible as it is the support that is removed.

New lid with air chamber roof.

I need to make the antenna tube support taller.

 

[Jamr]

Update;
Latest prototype.