I needed some small, simple handheld fpv monitor for the cheap price. Found on Banggood RX5808 receiver with 5" display, but all the cases I found are ugly and not so handy. So got an inspiration to design my own version. And here it is! Feel free to download and print it yourself :) Total price is under $30 and your time.
I've done a test with tiny whoop's 260mAh lipo battery. It lasts for half an hour. So with over 3000mAh Li-Ion you can get an operation time almost for 6 hours!
Here is the BOM list:
Banggood: RX5808 5.8G 48CH FPV Receiver with 480*320 5 Inch HD Display Snow Screen Monitor DIY $25
Banggood: 3 Pins Toggle Switch AC 125V 6A 2 Position SPDT $1.32
For SMA connector you can use the one that came with the monitor set. It's RP-SMA if it suits you. Otherway get some SMA pigtail connector. Google :)
And at last, you need one M3 bolt, at least 10mm long.
See the assembly video: https://www.youtube.com/watch?v=Yvh2YlkTi1U
Tape the PCB to the display with double-sided tape. Put flat cable under it.
Get a broken brushless motor and rip two magnets from it. Grind them with the sandpaper for a better connection.
Solder black and red wires to each magnet. Glue the black wired magnet to the bottom of the Li-Ion holder.
Solder black wire to the GND pad of the PCB.
Solder red wire with the magnet to the toggle switch's centre pin. Solder another red wire to one of the side pin of the toggle switch. Solder another end of the red wire to PCB's VBAT pad.
If you want to keep RP-SMA connector, just keep it. Or change to SMA version. Mount it to the cover. The 8mm socket wrench helps a lot :)
Cut an empty side of the button panel to make it shorter. Do not cut over the traces. Put its plug and wire through the hole on the bottom of the mount and place the panel. Slide the panel lock behind the button panel.
Keep one nut on the toggle switch and put inside the switch hole on the side of the case. Adjust with the nut how far switch's toggle will come outside with your preference. Hot glue it to the place.
Slide the Li-Ion holder to the case.
Arrange the wires behind the display and slide it to the case.
Insert 18650 Li-Ion battery negative side on the bottom. Connect "red" magnet to the positive side. Check to see if the monitor works.
Put on the cover. There is an angled lock on the left side of the cover. You have to slide the cover in a 45-degree angle from top left to bottom right.
Screw the M3 bolt and it's done!
Add some 5.8G antenna :)
2 perimeters are enough for all parts.
Infill in the case at least 20%.
Infill in the cover at least 40%.
3 solid top and bottom layers.
You can use PLA, but it's not a good option for use outside. A better choice is PETG or ABS (if you like it).
Supports are needed only in the cover's SMA and bolt hollow.
Remember to rotate the cover upside down in the slicer :)