Just 3 months after the release of their first popular 250mm RTF racer, walkera now offers a new version/revision model, the runner 250 advance including now some flight assistance via a GPS/Glonass module. The “Advance” version introduces also some changes versus the original design.
This article is still under construction and I will add asap some important/missing elements. I wanted to share with you my first impressions/conclusions but please notice, there is a lot to add. Expect something converging I hope before 1 week.
+ 1 x Walkera Runner 250 advance (with a 3S 2200mAh, 25C LiPo using a XT60 connector)
+ 1 x Devo 7 transmitter (using 8xAAA batteries not included)
+ 1 X Transportation bag
+ 1 x Anti-sliding rubber band
+ 1 x Charger+power unit
+ 1 x Trainer port cable
+ 1 x Allen keys
+ 1 x Instruction manual (English)
+ 1 x CDrom
Now the new edition comes with a transportation bag
The total weight with the transporation bag is under 2Kg, really easy to carry in any conditions and/or for long walk distances. A Nice initiative
Externally, the runner 250 advance (RA) introduces a visible change vs the former one: a huge front plastic bumper protecting the 800TVL/HD cam module
Now, on each arms you can find also some latteral LEDs indicating to other pilots in which direction the RA will turns. A nice feature for FPV racing
Here is a direct comparaison with the former edition
A large plastic bumper is now protecting the FPV camera lens
As you can guess, part of the video is hidden now with the new guard
Espacially when inclinaison is positive where the video is hidden latterally and on the top part
Really strange bumper design ….
Versus the former edition, now the battery is blocked in more or less in the central position in order to
1) Center the COG
2) Avoid damages, especially for the camera module in case of hard frontal crash where the LiPo would be catapulted front
To reduce even more slicing effects, a rubber band is provided to be installed below the LiPo
On the front left part, a buzzer is now installed. In practice not so loud when engaged (TX off for example)
Now compared to the first edition, the two status LEDs are no more synchronized each other. The left one is more indicating the GPS status while the right one more the arming/calibration status.
For example the left LEDs reports how many satellites (GPS + Glonass I guess) is currently received
The right LEDs indicates more the arming status and the different calibration status
The GPS module is in plastic, be sure, it will break as soon as the RA will flip on back in case of crash…
The module is also announced to receive the russian satellites. In practice, I didn’t notice any real improvement versus pure GPS module. No HDOP informations unfortuantly are displayed on the OSD.
When the number of stallites is 0, the GPS assisted mode is automatically turned into manual mode.
Now RA clear reference is appearing on arms
notice the presence of rubber feet, a minor improvement for the RA
629g in total
versus the 596g of the runner first edition
Unfortunatly, the thickness of all plates remain the same: less than 1mm for all the three horizontal plates
Just around 1mm for the battery plate when this one must also carry more than 200g of the LiPo !!!
As for the Runner 250, this is Achille’s heel of this machine. Think to stock spare ones and/or to double the bottom one by gluing an extra one and/or to add some vertical standoff to transmits parts of the forces to the upper structure parts
Only arms are 3mm
More, frame elements are still not in 100% carbon. !!!!!
Still some 2814 brushless motors but not announced to 2500Kv versus 2100Kv for the first edition
Some new 6 inch props are now included: lighter without being more fragile
versus the former model
Still the same 15A ESC
A 2200mAh capacity model with XT60 connector and rated 25C. The battery as for the runner original.
5.8G 8CH Video receiver
The TX5816 is the (non-CE) version emitting more than 200mW. The Walkera module is a 8CH model working on the rare “B” band and the default channel is B8 = 5733MHz
Now the OSD module display much more informations coming form the GPS module
As you can see, you have a lot of informations now very useful. I noticed two potential problems:
For some video receiver, the last bottom part of the screen is not displayed so impossible to read/record GPS coordinates
It’s working, in fact, you need to be sure that your receiver is in PAL mode
2) As you can see in the FPV video demo, time to time, the GPS coordinates “jump” to another location probably linked with a bad reception.
I would expect such outliers would be filtered.
The same FC, multiwii based (8bits MCU). I noticed when I plugged it the first time on my W8.1 machine with a microUSD cable (not provided), the FTDI drivers bricked the serial controller
I had to reinstall manually some old drivers. The main visible difference with the former edition are the lables written nearby each port.
The multiwii version I used to connect the RA is the V2.4: https://code.google.com/p/multiwii/
To install manual FT232RL driver (for W8++)
The Devo7 reprensents the standard entry model from Walkera
A large model easy to grab but a little bit heavy IMHO especially with the 8xAA batteries inside. More, this remote eats fast batteries.
Personnally, I plugged a 1900mah LiFe battery inside.
On the left top part of the radio, you will find a one 3-way switch, one 2 way, one pot while on the right part, two 3-way and one 2-way. For the basic version with the 800TVL cam, the more important switches are the right one. The MIX select the flight mode: MIX0 is the GPS assisted flight mode holding the quad in position when throttle is fixed to 50%, MIX1 is the manual flight mode and MIX2 actives RTH. The D/R button is in practice not configured by default in multiwii (whatever DR0 or DR1, A,E,R are between 1100 and 1900). The last switch FMD selects between “horizon”(FMD0) and “accro” mode (FMD2)
For left switches, the GEAR permits to turn on or off the HD camera recording (not available for the 800TVL FPV cam).
The throttle hold switch is out of the box not configured as for the original Runner 250!!!! really what’a pity.
In the list of “Walkera don’t take any feedback into account”, by default the fail safe status of the throttle is still fixed to “Hold” !!
It means, at least in manual mode, your RA will fly away (see unboxing video for demo). You absolutly need to fix this error.
Luckely, you can retake control of the quad after a connexion lost. The trick to push a bit up and down the throttle stick then to re-arm the quadcopter.
There is a trainer port DSC where you can plug the jack cable to your favorite simulator
Here is a video the stability in GPS hold (MIX0 position)
I will test asap more the RTH mode (MIX2). For this mode, the RA first climbs to 15m of altitude
I am a little bit worry about RTH efficiency since for some FPV flights, I observed some micro-periods where GPS indicated some crazy values whom can alterate the RTH process.
Other important questions I will try to answer asap:
1) Is RTH engaged when 2.4G control link is lost ?
2) Can we take-off and/or land in GPS mode ?
EDIT 10/11/15: Answers:
1) No RTH is not engaged with the radio connexion is lost, at least when throttle fail safe is set. Maybe the “hold” default setting activates RTH when the connexion is lost
2) Yes we can take off in GPS mode
I also performed some RTH testings. After climbing to 15m, the quadcopter takes a while to aim the ground target. All the descend process can take up to 1-2min.
Now, after the acceleros and gyroscopes calibration, in order to have a precize and accurate GPS + compass localization, you must perform also a third compass calibration. The two first ones remain unchanged:
1) For accelerometers:
2) For gyroscopes:
3) and finally for the compass
It’s important to correctly do this step and also to ensure the battery is well installed to fix the Center Of Gravity. If not, you may expect some “toilet bowl” effects
+ Transporation bag
+ Efficient 800 TVL FPV cam
+ Powerful 5.8G VTX (>= 300mW)
+ Very stable cruiser machine
+ Good radio range
+ Turns lights
+ Just 32g more heavier than the former edition
+ 2500Kv motors
+ Buzzer (but not extremely loud)
– Throttle Failsafe, D/R, throld hold not programmed on the radio
– Not 100% carbon elements
– Thin and fragile battery plate
– Front bumper blocking part of the visual scene
– No RTH when the transmission is lost (if FS is set to -100)
– Flip of the Death in accro mode with low throttle value
– 5.8G CL antenna too short, not efficient and partially blocked by the surrounding structure
– None genuine FT232RL serial interface for the FC
– Some outliers GPS/OSD values can occurs
– Don’t offer impressive vertical acceleration
– 8bits FC with multiwii 2.4
RCgroups thread: http://www.rcgroups.com/forums/showthread.php?t=2518702#post32918168
This quadcopter have been courtesy provided by Banggood in order to make a fair and not biased review. I would like to thanks them for this attitude.
Spare parts: https://www.banggood.com/buy/runner-250-advance.html
EDIT 10/16/15: The Advance version with a CC3D (32 bits FC) is now announced:
Probably a better choice, since you can probably install CF. The GPS management will be improved