f450 battery mount - bottom plate

[3d wana be]

Battery also on the bottom on mine.

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Thanks for saying hello

How does it fly with the naza off to one side?

Could you please post a pic or two of how you mounted the lipo on the belly?

I will start building it again 2moz

 

[PeterLester]

IMHO - With the Naza mounted off to one side I would expect that it will not spin 180 degrees on the frame center and there might be other issues.
The Kalman equations in the IMU are based on having a common center point for the 9 to 12 dof which assumes the IMU, i.e., controller is located at the center of gravity of the airframe.
The x,y and z adjustments in the NAZA software are only a finer adjustment from the center of gravity specific to GPS antenna positioning.

Also unless magnetic north and true north are exactly the same for your flying location(s) the GPS antenna might also need adjustment according to the angle of declination.

 

[3d wana be]

IMHO - With the Naza mounted off to one side I would expect that it will not spin 180 degrees on the frame center and there might be other issues.
The Kalman equations in the IMU are based on having a common center point for the 9 to 12 dof which assumes the IMU, i.e., controller is located at the center of gravity of the airframe.
The x,y and z adjustments in the NAZA software are only a finer adjustment from the center of gravity specific to GPS antenna positioning.

Also unless magnetic north and true north are exactly the same for your flying location(s) the GPS antenna might also need adjustment according to the angle of declination.

So i got the job done by adding a small plate to the landing gear to mount the battery. Also, i moved thegps directly over the naza.

I now have bloody toilet bowl effect. any one know much about it?

Peter, did you change gain settings after the change?

I have recalibrated the gps and also changed the gps co-ordinates in the naza assistant

any ideas? anyone?

 

[skipper1]

Your Naza needs to be in the center of your bottom plate and pointed in the correct direction, this is very important.

 

[Benchmark]

I have no problems at all with my Naza controller to the side. Even the picture on DJI official website has it installed to one side too. As long as you give the correct XYZ valua then you are good to go.
As regards the battery on the bottom, the bottom plade had to be drilled to attach the velcro band which wraps round the battery.

 

[PeterLester]

I don't have the toilet bowl nor the coriolis effect with mine with naza in center of airframe which is also @ center of gravity and F550 trimmed to stay at one 3d gps location with rc xmitter laying on the ground!

 

[3d wana be]

the answer has blown me away

yes its mounted dead centre and pointing straight ahead.

Reading another forum on here, people suggest to turn the naza about 10 degrees clockwise as we are in Aus and its something to do with the naza

This didnt work for me. I read another thread and another Aussie bloke turned it about 30 degres clockwise

What a difference ! It has never flown so good before

its strange how it would fly well and as soon as i moved the battery mount position, it changed everything.

My GPS hold is fairly accurate now, i would reccomend other aussies try this

 

[skipper1]

Congratulations, frustration can run high when messing around with these things.

 

[Fireeater]

Hi all

Doing a tear down and rebuild on my dji f450 this week. Wondering how every one who has mounted the battery on the bottom plate has done so?

Is there any benefit in your opinion, of doing so besides a better looking quad?

Thanks

I purchased another bottom plate and secured it to the original bottom plate using: (x8)Metric Aluminum Female Threaded Hex Standoff 4.5mm Hex, 37mm Length M2.5 Screw Sizes and (x8)Metric 18-8 Ss Cup Point Set Screw M2.5 Size, 10mm Long, .45mm Pitch from MCmaster.com (Awesome Site!!!). This gives me a 53mm x 37 mm opening to slide the battery into. You will still have to secure the battery with a velcro strap but this idea protects it from belly flops and has a clean look.

 

[skipper1]

Great idea, can you post a bunch of pictures for the rest of us?

 

[Fireeater]

I am away from the quad until mid next week. I'll post some pics then.

 

[Fireeater]

Here is the pics of my build using additional an additional frame plate for a battery mount. I hope this will help you on your battery mounting ideas. Off the subject but can someone might help me with a decision. The current setup is using a 3s battery and APC 10x4.7 props weighing AUW 1650 grams. My flight times are around 8 minutes and 70% throttle to hover. Can I increase the props to Graupner 11x5 to gain more lift and longer flight times? Ecalc shows my motor amps above manufacturer recomendations with 11' props. I see others running 11" proprellers but are they ruining their motors?





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[PeterLester]

The build looks excellent as do the photos. I assume you have software that can rotate your GoPro videos 180 degrees so they can be viewed rightside up. If you want to reduce the overall weight to gain more airtime, hexagonal nylon standoffs are also available as an option to the aluminum and you can cut identical top and bottom plates out of carbon fiber plate.
The foam rubber golf balls may be light but they also create airflow drag. I would just use a short piece of heat shrink for the tips.

IMHO.... While there might be a small safety factor built in to the motor data, the longevity of the motors likely will be compromised. More specifically the enamel insulation on the copper windings of the motor will break down primarily due to heat especially closer to to motor terminals. That will lead to an electrical short and one or more failed motors. Also excessive heat will permanently reduce some of the magnetic strength of the motor magnets requiring more throttle to achieve the same flight performance as previously.

 

[Fireeater]

Thanks for the comments on the mutlirotor. This is my first quadrotor and I have had as much fun modifying the DJI450 as flying it. The GoPro has a setting in the options to reverse veiw which is nice for this set up. Also thanks for the advise on reducing weight. I will make those changes with my spring project using as DJI550 using the same stacking concept. Since this is my first mulirotor. This robust setup is more suited to my periodic ground checks and other mishaps. I noticed on Ecalc that the box that became red was "max. current". So my thought is that as long as I don't give it full throttle, I should not damage the motor. Is that a plausable idea?

 

[helloman1976]

Hi all

Doing a tear down and rebuild on my dji f450 this week. Wondering how every one who has mounted the battery on the bottom plate has done so?

Is there any benefit in your opinion, of doing so besides a better looking quad?

Thanks

Order some legs, they make a WORLD of difference and are completely necessary in my opinion. I had thought that the legs would negatively effect the flight characteristics of my hexa but I was wrong, it's the opposite. The legs allowed me to added 2 batteries underneath and put my Go Pro knock off camera under there as well. The weight underneath the Hexa made it much, much more stable and much more fun to fly. I use velcro battery straps and I can swap out 2 battery packs in less than 2 minutes and be back up and flying on a fresh set. I highly recommend it if you like the idea and I think it looks mean that way, people say mine looks like a flying spider
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[PeterLester]

Re: The red box indicating max current in ecalc provides the maximum safe current value for the motor. Momentarily exceeding 80% throttle likely is not a serious issue if you motors are still running cool. However you still have the option to upgrade the motors to some degree to more powerful ones and still use the same 30 amp ESCs. Just remember that the starting current for each motor is typically 150% of the running current which makes the ESC the weakest link in the chain and you don't want any of them failing in flight. Also keep in mind that the larger props require a larger spinning radius which can cause a collision with the other Multicopter blades especially with short arms on a Hexacopter or Octocopter. And some of the prop air flow can be impeded by the central part of the airframe. There are two ways to extend the motor arms, machined aluminum extenders that bolt on to the existing DJI arms or replacement carbon fiber tubes and saddles designed to bolt directly to the DJI center plates.

 

[Fireeater]

I measured and the 11" props have clean path; close but clean. Changing motors is a option but I thinking if I'm going to spend more money on the 450; it would problably be more financially responsible to just upgrade to the 550. I do have some Turnigy Park 480 1020k motors. I might have screwed up the 480 motors though cutting the wires short and adding bullet connectors to them. I tried to fixed mistake by soldering a new wire onto the existing but the motor winding seems to be acting as a heat sink.

 

[waterhouse75]

Using these legs to get some space under our 550 and the batwing to move the gopro out front. Ordered another batwing to move the battery back to balance. Should accomplish what you're looking for.

http://www.irisaerial.com/products.html

I just got my Batwing this week. I'll have to check, but I don't think the batwing + case + camera mount + camera comes close to the weight of any of my batteries.

Anyway, I flew today all day like this:

http://www.flickr.com/photos/jabella/8339861529/in/set-72157632346584361

Battery has velcro on bottom, and a single strap. Seemed great.

 

[Wangta]

Benchmark - what size battery is that? How did you mount it in that orientation? It doesn't seem like it's possible with velcro straps?

Battery also on the bottom on mine.

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[lachieminge1811]

Inherent mechanical stability of an aircraft is improved by means of wing dihedral and/or lowering the center of gravity, e.g, lowering the battery. A battery on top reduces inherent mechanical stability making the IMU work harder to compensate. Battery on the bottom also needs landing gear to prevent battery from a puncture on hard landings. Ideally the center of gravity should be in the middle of the IMU which is inside the Naza controller.

The thing is, if you mount your battery underneath your quad, it will act as a pendulum and when coming out of a turn, have a slight wobble when levelling out. If it is mounted on top, the weight pushes the force into the quad.