My GPS Racer is less and less fun project. For last few weeks it acts as sensor platform for my attempts to bring rangefinders and terrain following modes back to INAV. This time in a way that will work.
Two weeks ago it was carrying HC-SR04 sonar (crappy device). Week ago it was carrying US-100 (much better device). This week it is carrying both US-100 sonar and VL53L0X lidar!
DigitalEntity apparently had too much spare time and he finally wrote (ported) a driver for VL53L0X and starting from version 1.8 (probably) INAV will be able to use this cheap lidar.
Yes, VL53L0X is cheap and that means it's not state-of-the art device. First of all, it has limited range. 2m is all it can do in a room. No idea how it will behave in sunlight. Hard to guess, but I'm afraid that 1m will be all it will able to do in real life conditions… But we will see in a next few days.
Next week passed and Depron Airboat is almost ready. Almost, since it still needs some finishing and I'm missing a BEC. Turned out that total power usage of one 9g servo and FrSky X4R receiver is slightly too high to just use single LM7805. 350mA during servo movement means more that 2W of heat ((12-5) * 0.35) over single LM7805. Too much, so I will have to scavenge old models for still functional step-down converter.
One of my first DIY RC projects was a Depron Airboat I've build almost exactly 2 years ago. 12x6x2 inch hull, motor, servo, rudder and ESC. And honestly, I loved it. It was a great fun playing with it. Too bad, it did not survived very long. It broke in a middle of a lake and I decided my live is worth more. All I have left is a video
This season I started to build another Depron airboat. Slightly bigger, heavier and with more power. And partially 3D printed. Hull will be made from Depron, but propulsion and steering system will be (is) printable.
After few hours of printing time, propulsion and steering is done. What is left is to make a hull. 18x8x2 inches made from 6mm Depron. I might cover bottom with glass fiber and impregnate with polyurethane wood glue diluted with alcohol.
New thing will be a reversible ESC. I've already configured and tested FVT Littlebee 20A to act as reversible ESC and it seem to be working like expected. I only wonder how effective rudder will be when on reverse. Not much I effective probably…
And yes, STL files will be available when this is proven to be working. Everything for the community 🙂
It's not a secret, that me, and QuadMeUp, are not only about quadcopters. From time to time I like to do something completely different.
When I was a child (10-12 or something like that) I loved to build boats. Simple crude design: styrofoam or bark, simple sail or DC motor and tinwire propeller. No RC link. Just let it sail in "somewhere there".
When I got a 3D printer and learned that servos can be converted to continuous rotation simply by replacing potentiometer with a pair of resistors, the idea to build paddle wheel boat powered by servos was almost obvious.
So, here it is!
Hull can be 3D printed, STL files are available on Thingiverse
Wheels are powered by 2 TowerPro 9g servos converted to continuous rotation
RC link by cheapest FrSky compatible D8 receiver
2S LiPo gives enough "juice" and with power usage of about 300mA it can sail for hours
While SkyZone SKY-01 are pretty good FPV goggles, they are not very comfortable. Instead big faceplate, they only have rubber eyecups. This approach works, but well…
Like always, there is a solution: 3D printed faceplate for SkyZone SKY-01. Thingieverse has at least few different designs, but I’ve chose the one from the link above. They fit right and do not have fan adapter which I do not use.
For last few months I’ve been happily 3D printing PLA on glass. Prints were repeatable, initial adhesion was just fine, ready print was easy to remove after glass cooled down. But I wouldn’t be me if I did not wanted to try something new. So I tried “the ideal 3D printing surface” BuiltTak.
My initial impressions were very positive. Nice mate surface a little similar to fine grain sanding paper. I was a little afraid that adhesion will be even too good and it will be hard to remove the print. But hey, they had to think of it, right? After all, BuildTak is quite expensive after all. Continue reading Review: BuildTak Printing Surface
Elastic filaments opened brand new areas for 3D printing. We are finally able to print something that bends, compresses and stretches. While TPE (ThermoPlastic Elastomer) filaments like NinjaFlex or FlexiSmart are still about 4 times more expensive than plain old PLA, they are not so expensive not to give them a try.
Unfortunately, due to the fact that they are elastic even before melted and extruded, they require special printing conditions. During my experiments with FlexiSmart I've came down to following conclusions:
Because TPE is elastic, flow through the nozzle has to be as smooth as possible. If not, it will coil inside extruder
Bowden extruder system greatly increases chance of failure. Friction of bowden, while small enough for ABS or PLA, is too big for TPE. Filament will coil. Direct extruder gives less chance of failure
One has to pay big attention to the distance between extruder nozzle and bed. Usually it has to be a litter bigger that for PLA or ABS. In all the cases when I was switching from PLA to TPE, I had to raise nozzle a little. If not, TPE coiled. TPE has better initial adhesion than PLA, so rising a nozzle does not have side effects
Filament retraction is a huge NO NO. Disable retraction since it will increase the chance of coiling significantly
With no retraction it is a good idea to enable Combing. Nozzle, instead of taking the shortest route to travel, dripping TPE everywhere, will move above already printed layer. This greatly improves print quality
Top printing speed is 30mm/s, but I recommend slower speeds. I have best results when printing at 15mm/s. On 25mm/s quality is still acceptable, but degradation starts to be visible
I had best results of TPE printing on glass with 220deg nozzle temperature and 60deg bed temperature
Not everything can be printed with elastic filament. Any thin vertical structure will come deformed. After all, it will move during printing due to a friction with extruder nozzle
While I was printing with FlexiSmart, almost all points from the above list will be true for other TPE (NinjaFlex). Temperatures might be slightly different, but general rules applies.
It’s still middle of winter here in northern hemisphere, but I’m slowly preparing for next flying season. One of my goals is to push my DIY HC-12 Telelemetry System to a next level. In both range and quality. For quality I’m planning small hardware LTM decoder with LCD. For range, I want to reach at least 1.5km with 9600bps FU3 mode and 2.5km with 1200bps FU4 mode.