TTGO T-Beam LORA with buttons and USB by idleshands

Last crawled date: 3 years, 4 months ago

The case by thekwijibo has a few nice features missing from the other models on thingiverse... access to the buttons/USB, a case that allows for "tilted table operation", and it aligned properly with my asymmetrical antenna board.
However, it didn't quite work for my needs, largely because I had a 1-inch screen instead of the 1.3" OLED. This turned out to be something of a blessing, since it also turned out that my preassembled screens weren't mounted squarely, so even if the hole was the correct size, it wouldn't have lined up correctly with my screen.
I ordered my boards (915Mhz) from the "official" aliexpress listing: https://www.aliexpress.com/item/4001220665769.html?spm=a2g0s.9042311.0.0.38664c4dkrE54I
My additions:
1 inch screen insert.stl
This is an insert that snugly fits around the actual screen part of the preassembled 1-inch screen that I received as part of my T-Beam order from aliexpress, since it clips around the screen itself (and not around the circuit board), it allows for a lot of slop in terms of how squarely the assemblers put it together
Since it wraps directly around the screen and "floats" over the opening in the case, it allows some very wide tolerances in screen placement
You may need to play with scaling on this one depending on printer tolerance and/or filament... for one of my filaments it printed so perfectly that it actually "clips on" to the screen, but for another filament it was loose enough that I had to hold it in place while putting it into the case

GPS antenna holder.stl
This provides an alternate position for the GPS antenna... stock it's mounted directly beside the LoRa antenna and winds up directly below the case lid... my understanding is that even RF transparent materials can cause reception issues if they are too close (within 3-4mm) to the antenna... so this antenna holder moves the GPS antenna a little further away from the lid, as well as away from the other antenna and a bit further from the circuit board. I'm not an expert by any means, so I'll be testing this to see if it actually improves GPS reception at all, but it made sense to me
The GPS holder should be added after the PCB is already in the case, if you attempt to add it all at once, it's very difficult to get into the case opening. Once the PCB (and everything below it) is seated as desired, then you can wiggle the GPS holder into place with the arm that runs along the top of the battery holder skewed slightly, so that it will go around the antenna pin, and then slide it back so it's flush against the PCB, and the antenna pin should help hold it in place (see image 3 and notice how the right-most pin is over the top of the "notch" in the GPA antenna holder). There isn't anything permanently attaching the GPS antenna holder and the PCB by default, they sort of just clip/rest together, since there's not a lot of places it can go once the lid is in place .
The screw hole in the GPS antenna holder was originally meant to allow mounting to the PCB, but it turns out the case opening is too small to comfortably allow this, so you should think of it as a visual indicator for orienting the part against the board, rather than as a hole for mounting. If you got creative, you could probably use fishing line or something similar to tie the two together through this hole after assembly.
The GPS antenna holder was designed against my board, and the little notch is supposed to "clip" underneath the nearest pin of the antenna... if the pins of your antenna don't allow for this, you'll likely need to trim that arm back so it doesn't run into the pins, and if the antenna holder winds up moving too much without this, you may want to find an alternative way to secure the antenna holder (hot glue?), or just leave the GPS antenna in the stock position on top of the battery holder. Lots of people use this configuration without issue.
Also note... I saw another case which had a GPS antenna holder, but it mounted the GPS sideways... the metal dot on the GPS antenna is supposed to point a the sky, so make sure however you mount the GPS antenna, it's oriented so that the dot is in the "up" position most of the time when you're using it... it can certainly work in other orientations, but if you want the best performance, point it at the sky.

USB Insert - 1.Xmm.stl
This is just a simple insert that goes around the USB plug and covers the surrounding hole to make it look cleaner and possible keep out debris... due to possible differences between boards, it's designed to hook around the board/port, and "float" over the opening in the case
Because of differences in USB cables... you may have problems with certain cables not plugging in all the way with this insert
Designed in 3 different thicknesses (between the "face" of the USB port and the inside of the case), to hopefully account for different USB ports and mounting distances... for my boards, the 1.8mm size was the right fit

Buttons_0.6mm_nozzle.stl
This is a simple remix of the buttons thekwijibo made, because his design was too fine to work with the 6mm nozzle I have in my printer. This design should also print fine on smaller nozzles

Buttons_0.6mm_nozzle_short.stl
Same as above, but I also shortened the buttons down, so they sit flush with the case. These buttons are much harder to find just by touch (if you have this need, you could remix the buttons with some texture on top to help with this), but they are plenty easy to press even though they are flush with the case.
The original button height makes the buttons easier to press (especially if you're wearing gloves, or trying to operate blindly), but the buttons also stand so proud that you can press them just by setting the radio down on the "bottom" of the case.

The rest of the files included are unchanged from the original design. I beleive "Case.stl" and "096_Body.stl" are largely the same, with just a difference in screen size. For my radios, I printed "Case.stl", since that matched the naming convention of "Lid.stl", all the images you see of my radios in this design are using the "Case.stl" model.
General note, when printing PETG, I've noticed vertical holes seem to "shrink" more than PLA (in this model, it can play a factor in the button and antenna holes, which I have not modified at all from thekwijibo's original model). I suspect this is due to PETG being higher temp and also slightly more elastic than PLA, so when it's printing around a hole, it's basically stretching a molten rubber band around the edge, which winds up pulling itself in further... I believe lowering the temp or slowing the speed might help with this, but I haven't messed with it enough to really say for sure.