This is a long term work in progress.  

I've always wanted a home/backyard flyer in the 3inch variety that was like the betafpv hx11lr frame, but better. HX115 LR Toothpick Drone – BETAFPV Hobby

This one was unique in the sense of a 1S bus style chassis design for the frame.   Given a lot of 1S stuff is toothpick this was a bit different.  It suffered from issues of course, namely those crappy frame screws that weren't standard.  It was also tricky to fit anything digital (especially early walksnail nano cams) into it.   Like the Armattan Odonata (also bus style frame but smaller prop size) this frame had analog in mind when designed.

What I'm interested in is a frame of similar style but really low profile with the battery mounted on top.   I've done a lot of toothpick stuff and feel that the traditional battery at the bottom mount design hinders performance, especially coming out of a dive, this is like the textbook of challenges on (digital) 1S.

So I thought, instead of stacking the aio and vtx, put them side by side and go for a really low mount.  In the end I achieved on a 3d printed prototype at 8mm internal clearance.  Measured from lower deck to top deck.  Just enough to fit a 1/2S AIO and a walksnail/hdzero aio shaped vtx.

I am using the NanoLongrange project STL files as the basis of the draft model.  I hacked together a shitty model in tinkercad.   Eventually I want this in CF for the top and bottom frame plates.  Then TPU print for camera mount and TPU print for rear antenna array / GPS.


The design has the digital vtx up front and the aio fc at the rear.  Either way, you will need a long vtx antenna or a long mipi camera cable if you choose to swap this orientation around.   Bit of a pain and a limitation.  The goal is to get the battery on top but low and close to the thrust line.  I'm hoping the fickle nature of 1S flight will appreciate this design element and return the favour with improved performance, especially in the handling dept.

The motor wires also need to take bit of a long walk, under the digital vtx and to the rear aio.  Everything to do with wires in this build is increased.   With the 8mm clearance I can get them under the vtx and over the fc without putting pressure on anything, too much.


Components on this build.

• HM 1202.5 11500kV motors
  
• WS 1S vtx(v2), nano camera, ultra short mipi cable(lite kit)
  
• Betafpv 12A 1S digital only AIO (V3 with Aterytek MCU)
  

The 3d print wasn't too hard to remix from the original STL, not everything is accurate nor centered.  If this prototype 3d print shows promise then I will redo the design from the ground up.  Applying everything I have learnt from the mistakes on this version. 


This 3d print version took on a life of its own.  I designed the top deck to snap into the camera housing to help hold it down.  There are no standoffs.  The two AIOs have eight plastic screws holding them in.  The camera and motors are all mounted with plastic screws.  This keeps the weight to 59g dry which (for a 3d print) I'm happy with.  Regular 2mm silicon whoop gummies are used with an extra silicon rubber placed on top.  This fits the 8mm clearance profile well.  The vtx usb port and the fc usb port don't touch the top plate with the 8mm clearance.

The vtx antenna is not in the final position, this will change.  I've mounted it on the arm for now to get it in the air.


The battery pad is made out of TPU and glued on.  It's not the best but better than the hard surface of the PLA.   I've also done this for screw head clearance.  Again, not final, it raises the battery profile for one thing and I question needing the extra screws under the battery footprint all together.

Here's the end goal, battery position check. 


Without the TPU battery pad the props are dead middle of the battery.  I'm keen to see what this does.

A quick test this evening and it does fly.  Will need to tune and maiden properly tomorrow morning.

Ultimately this is a test for something that will eventually be CF.  So I'm drawing inspiration from the NBD savage bee frame as well: NewBeeDrone SavageBee V1.8 Frame 65mm/3inch - Buzz Fpv  I like the lattice like design.   Having built a toothpick with it have found it rather strong and very light.

Will post video tomorrow if I don't break it!

Very nice and very interesting. Looking forward to see how the 3D print flies even though you plan to eventually replace with CF.
For the VTX, if you plan to mount it in front, would you get more rigidity out of the frame by mounting it square instead of diamond orientation? This would allow for a stronger bottom plate instead of having two corners poking out.
Also @skywander posted a file for the HX115LR bottom plate, which he modified for cutting if you wanted to work off that. Maybe the camera mount can still be a CF blend print that mounts onto the bottom plate, never liked assembling those plate mounts.

As for flight performance I have a HX115LR 2S build with both top and bottom mount battery, I don't notice a lot of difference between the two in flight, but I prefer bottom mount as the battery gives some buffer in crashes for the fragile frame and also gives it a better chance to take off after a crash. 2S pack is a little heavier, but plenty of power to pull out of dives, it will be interesting to see your findings with the 1S.

Having access to a 3d printer is surely a boon to diy mockup/trial stuff for sure! WS hd cam/viewing on this model!

fwiw if it helps, like mstc said, check here for kinda similar. looks like it was downloaded a few times but I've never heard any feedback so maybe it sux?...

(29-Jan-2024, 01:30 PM)ph2t Wrote: Ultimately this is a test for something that will eventually be CF. 

How hard is to take a 3D print over to Carbon Fibre?  Are there minimum run sizes for it?

I've thought about building my own frame a couple of times in the last year.  I have specific wants from a frame and haven't found anything so far that meets the criteria.  But at the same time I have no clue how to go about it.  For the sake of discussion I am looking to build one piece frames, so no separate arms, probably more akin to the Twig(let) frames I currently fly.  What is the design process for doing it?  AutoCAD to make the models and then send to a manufacturer?

Sorry, loads of questions.  When you get to that point in your process, I will be interested in any info you throw up regarding it.

(29-Jan-2024, 07:29 PM)skywanderer Wrote: Having access to a 3d printer is surely a boon to diy mockup/trial stuff for sure! WS hd cam/viewing on this model!

fwiw if it helps, like mstc said, check here for kinda similar. looks like it was downloaded a few times but I've never heard any feedback so maybe it sux?...

Ha ha, I didn't see you post any feedback either? Did you ever put yours together, how does it fly?

Hahaha, mine's is getting side tracked...



...so nope, not yet.

why are that long arms in the back popular? it seems to me an H-quad design would offer only benefits; more stiffness and rigidity on a lower weight

(29-Jan-2024, 09:56 PM)hugnosed_bat Wrote: why are that long arms in the back popular? it seems to me an H-quad design would offer only benefits; more stiffness and rigidity on a lower weight

Those are not arms, but legs... Vitruvian  ... designed by the master engineer of flight himself

aah leonardo, but it looks like a banksy with that smile in the middle xD

(29-Jan-2024, 11:18 PM)hugnosed_bat Wrote: aah leonardo, but it looks like a banksy with that smile in the middle xD

Ok, just wire me the $1 million and I will send over the framed original  

(29-Jan-2024, 02:34 PM)mstc Wrote: Very nice and very interesting. Looking forward to see how the 3D print flies even though you plan to eventually replace with CF.
For the VTX, if you plan to mount it in front, would you get more rigidity out of the frame by mounting it square instead of diamond orientation? This would allow for a stronger bottom plate instead of having two corners poking out.
Also @skywander posted a file for the HX115LR bottom plate, which he modified for cutting if you wanted to work off that. Maybe the camera mount can still be a CF blend print that mounts onto the bottom plate, never liked assembling those plate mounts.

As for flight performance I have a HX115LR 2S build with both top and bottom mount battery, I don't notice a lot of difference between the two in flight, but I prefer bottom mount as the battery gives some buffer in crashes for the fragile frame and also gives it a better chance to take off after a crash. 2S pack is a little heavier, but plenty of power to pull out of dives, it will be interesting to see your findings with the 1S.

I thought of the square orientation, but the space and layout became an issue. With multiple connectors (mipi, jst, solder pads) I just couldn't get a layout I was happy with. Also I want the two diamond aio areas to be inline with a true X layout once I try that. I'm using deadcat due to the remix of the nanolongrange being that layout. You're right about the rigity given the shape.

That 2S HX setup prolly has plenty of guts to not worry about the (small) difference battery location makes. I reckon on 1S this is a thing though. This is my gut feeling, no science, lol.

Thanks for the link to Sky's post on the HX frame, I knew I had seen that somewhere, just couldn't place it.

(29-Jan-2024, 07:29 PM)skywanderer Wrote: Having access to a 3d printer is surely a boon to diy mockup/trial stuff for sure! WS hd cam/viewing on this model!

fwiw if it helps, like mstc said, check here for kinda similar. looks like it was downloaded a few times but I've never heard any feedback so maybe it sux?...

Thank you Sky, good to see someone else understands where I'm coming from in regard to the uniqueness of this frame.

(29-Jan-2024, 09:05 PM)Pathfinder075 Wrote: How hard is to take a 3D print over to Carbon Fibre?  Are there minimum run sizes for it?

I've thought about building my own frame a couple of times in the last year.  I have specific wants from a frame and haven't found anything so far that meets the criteria.  But at the same time I have no clue how to go about it.  For the sake of discussion I am looking to build one piece frames, so no separate arms, probably more akin to the Twig(let) frames I currently fly.  What is the design process for doing it?  AutoCAD to make the models and then send to a manufacturer?

Sorry, loads of questions.  When you get to that point in your process, I will be interested in any info you throw up regarding it.

I think you could find a CF cutter vendor on aliexpress pretty easily. Also as Sky mentioned in his HX thread, cncdrones/madness will do it for you for very small runs, even one offs.

I use tinkercad because it's easy. I also looked at the free version of fusion 360 and freeCAD but there is a learning curve that is less intuitive than tinkercad. It is hard to design complex shapes in tinkercad though. I just import the STL from the thingyverse and start hacking it apart, lol. Once done I would export it to STL again and then see what the CF cutter vendor says. This 3d print design isn't final, I would modify base plate thickness to suit CF (ie: 2 or 3mm, not the 4mm it is currently set to due to it being plastic).

All things considered, it flys pretty well.


It is heavier than my other 1s toothpick builds and is not running any bl32 esc so I'm happy with the performance for now.  Even the vtx antenna placement was surprisingly good.

Sweet flight. that flies much like I like my own flights, but you can tell it is slightly heavier. But heavier isn't all bad. I think the main dowside is the flight time. Still for 1S that is still pretty nice.