I redesigned the dozer 190 to a smaller dozer 160. This 160 class multirotor can only be equiped with 3 inch props and is compatible with 1306 and 1104 motors. It is not exactly the same quad as the dozer 230 or 190. This time the frame is has a real X shape. It also has the clean and dirty sections, but it made from vibration absorption soft silicone
Currently this build is equiped with gemfan 3030 props. They are easy to find, cheap and deliver the beste performance/efficiency in combination with my roboterking 1306-4200kv motors and a 3cell lipo. These 1306-4200kv are really hard to find. Most 1306 motors are 3100kv. 4000kv become more and more available. But these 4200kv are really hard to find.
Flight time for tis fpv race quad is limited to 3min. The goal was to keep the AUW less then 300 grams. But with my current 700tvl board cam this is almost impossible. Performance is good. I still got a 3on1 thrust to weight ratio.
I redesigned the dozer 230 to a smaller dozer 190. This sub 200 class multirotor can only be equiped with 4 inch props, but is compatible with 1806 motors. It is exactly the same quad as the dozer 230. It has the clean and dirty sections.
Currently this build is equiped with these 4045 bullnose props. They are very strong and cheap. Best fit to maximize performance are HQprop 4040 tri blade props. But these props are expensive and break much easier on impact (crash).
The dozer 230 is ready. Compared to my dozer 260 (see blog below) this frame is much lighter. Total AUW for the dozer 230 with a 3 cell 1000mah is 450. That is 150 less then the dozer 260 and I still have the same flight time. Equiped with the gemfan 5030 props this build has a 3,2 on 1 thrust to weight ratio. I future I'll 5040 tri blade props. This will provide me a 4 on 1 thrust to weight ratio.
The dozer 230 is build the same way as the dozer 260. (see blog below) Difference is size and the bottomplate is complete carbon or glassfiber. This means that this frame also has a clean and dirty setcion. The center plate (clean section) is isolated from the rest of the frame by rubbers. This centerplate holds the flightcontroller, fpv cam and RC receiver.
I have designed a new smaller (230mm) frame that is still compatible with 5 inch props. Less weight. But I can't use my multiwii 328p flightcontroller. This new multirotor frame is only compatible with 36mm flightcontrollers. I'll use a NanoWii FC on thuis build. Currently this quadcopter frame is CNC cut from 3mm thick G10 glass fiber material. Weight of bottom plate equales 78 grams.
The HQProp 4040 and Diatone 4045 cause the motor to overheat after just a few seconds on max power. These 2 props and all other 4 inch triblades and 5 inch props I used in previous benchmarks are not usable on this motor.
The RC brushless motor test bench (version 1) is ready.
The RPM sensor is made with an infrared LED and an infrared phototransistor (TCRT5000L). The IR LED constantly emits an IR light that is invisible to the eye. the phototransistor acts as a switch that is toggled by IR light. Every time a prop blade is between IR led and IR phototransistor the IR phototransistor switches off. In most RPM tutorials this on/off switching is counted during some time. e.g. 100 times a switch off during 250ms equals to 12000 rpm for a 2 bladed prop. But this means you'll only have an RPM readout every 250ms this would slow down my benchmarking.
To calculate the RPM I use the time difference between the switches, or the time difference between the blades. This gives me a RPM readout every turn of the prop. e.g. 4 miliseconds time difference between the blades equals to 7500 rpm for a 2 bladed prop.
Now I have all sensor data for this project. And I can start benchmarking my motors and props. The current PC application is a bit limited. It just start/stops a benchmark cycle and it captures all data. The data can be saved to a file or copied to clipboard. At the moment there is no fancy graph. But this can be done with any spreadsheet application because the saved benchmark file is a tab delimited csv file that can be imported in almost all spreadsheet applications.
My RC brushless motor test bench project is almost finished. I hooked up an ACS 712 30 ampere current sensor. This sensor will read out the current consumption of the motor and send it to the arduino board. I also made a basic voltage divider in order to read out the battery voltage with the arduino board.
I currently have programmed the arduino board to read voltage, current and thrust. With a very basic command set and human readable output it is possible to control the arduino (test bench) completely by hand with arduino IDE serial monitor feature.
But I also created a small PC application that makes it easier to control to board and run a pre programmed benchmark sequence. With this small program it is possible to save or copy the incoming data. This application is created with the processing IDE and is java based. So it should run on every java compatible platform (operating system)
The ACS 712 sensor is a cheap one from ebay. In order to get it to
work well you should add a capacitor on the ACS 712 FILTER pin. To achieve this you will need some soldering skills. Without the capacitor this sensor is useless in this application. I used a 10nf cap.
I would like to downsize the Dozer 260 (class 250) to a Dozer 210/200 (class 200). These class 200 multirotors are mostly equipped with 4 inch props and AUW < 400 grams. To achieve this I need to build a smaller frame and reduce the weight on all parts (electronics, battery, motors, esc). To find the best drive (motor/prop) combination I'll build a fully automated and computer-controlled motor test bench. This should allow me to measure thrust/efficiency for a lot of motor and prop combinations fast and accurate.
I'll use an arduino board to control the ESC and to read all sensor values. The arduino will then send all data to the PC via a usb or bleutooth connection.
The weight sensor measures the thrust generated by the motor and prop. I'll also hook up a RPM meter based on an IR emitting and IR receiving LED. This will provide the rotation speed of the motor/prop. And last I'll also add a current sensor to measure the motor/prop power consumption. All this data will be read by the arduino board and send to my PC.
Step1: Attach the front and rear arms to the bottom plate.
you will need 4 x M3 x 30mm screws. Step2:
Mount the nylon spacers on the frame. The front spacers are 40mm long and mounted on the M3 screws from step 1. The center spacers are also 40mm long and attached to the bottom plate with M3 x 6 mm screws. The rear spacers are 20mm long.
Because I could not find 40mm nylon spacers I used 2 x 20mm.
Mount your motors and esc to the frame. Connect all power cables and fix them to the bottom plate. Make sure they come out at the rear part of the quad between the rear nylon spacers. This version does have a powerdistribution board (PDB), but that is planned in the next version of this frame.
Mount your FPV camera, flight controller and rc reciever on the clean section board. To mount the flight controller I used 6mm nylon spacers. The RC receiver is fixed with tape. I use is a board cam that I mounted on to the board with a 3dprinted part. This can be attached to the clean section board with two 6mm M3 screws (drill extra holes in clean section plate) or just glue it to the clean section board with some epoxy.
Then mount the clean section plate on to the frame with 6 anti vibrating rubbers.
Mount the top battery plate on to the frame. Use four 6mm M3 screws and add two 20mm nylon spacers. Make sure when mounting the battery top plate that the cables connected to the flight controller on the clean section do not touch the top battery plate. Else the antivibration effect will be lost.
Step6: Last step is the top vtx plate. Before mounting the plate to the frame first attach your video transmitter, on screen display module, and vtx antenna to this plate.
On my multirotor I used an Immersion 5.8ghz 25mw video transmitter in combination with a Immersion spironet antenna. And an HK E-OSD module. I just used some tape to attache everything to the plate. I also isolated the open copper parts from the vtx antenna.
Then mount the top vtx plate to the frame with four 6mm M3 screws. The vtx power cable comes out at the back and can be connected to the battery. The video cable goes down and can be connected to the camera.
4 x M3 x 30mm screw + nut
12 x M3 x 6mm screw
2 x M3 x 6mm screw + nut OR epoxy glue (depending on how you prefer to mount the fpv camera case)
Minimal tools you need to build this frame:
- 30cm measuring stick.
- hand saw (for cutting metal)
- screwdriver to fasten the M3 nuts
- handrill with 3mm and 7mm drill (for drilling metal)
- 1.5mm carbon fiber sheets to cut out the different plates.
- 15mm square aluminum tube to cut out the different arms.
- copper wire & lipo battery plugs
I'm using this sony 700TVL CCD board camera . This camera has no case and needs someting like a case in order to be mounted in the quad copter. Therefore I designed a very basic open case that holds the fpv cam. 3D printed with ABS or PLA it will weigh about 5 grams.
This case is designed for the 32mm board cam standard. Most 32mm board cams should fit in this case. 38mm board cams will not fit in this case nor in the frame.
I glued this case to the clean section plate with epoxy. You can use the 2 holes at the bottem to screw it to the plate with two 6mm M3 screws. But then you will have to drill two more holes in the clean section plate (these are currently not present on the current design)