Servers by jDrones

Nimbus Tricopter VTOL


(Greg Covey) #123

Hi Gordon,

Thanks, that would be awesome!


(Gordon Ottershaw) #124

Good looking plane! Please post a picture of the balancing stand.


(Graham D) #125

I asked this on the Foxtech FB page as one seems to get a quick response there: "I have installed the PG20 in my Nimbus v1 and it has the A and B plug, I can use 2 batteries but sometimes I want to use 1 battery. If I use 2 batteries then the PG20 is set up to switch from battery A to battery B on transition.

However, if I use only 1 battery connected to plug A then will the PG20 recognize that there is no battery B and thus will not switch and just fly the whole flight on battery A?"

and got this response: “… with one battery connect only, the PG20 can’t work.”

That doesn’t seem like well designed software.

I have confirmed that with only one battery connected to A it will hover fine, just don’t know what it will do when transitioning, will it continue just using the one battery or switch off completely?


(Greg Covey) #126

Graham,

Can’t you just switch to FBWA on the ground and see if you still have power?


(Graham D) #127

Not sure, as FBWA would cause a transition event but don’t know if there’s a something that prevents a transition on the ground. I suppose I can do it without props just in case :slight_smile:


(Gordon Ottershaw) #128

Checked with the folks at Foxtech. They say they will have samples of this ‘new’ packaging from their vendor in a week.


(Gordon Ottershaw) #129

NIMBUS-2000-06-21.zip (344 Bytes)
This is the file that was on the SD card. Next I’ll try to copy the running config from the x9d to the SD CARD.


(Greg Covey) #130

Hi Gordon,

Thanks for the file and packaging information. Assuming the shipping cost isn’t too bad, it would be a nice way to store the Nimbus VTOL if they sell the packaging separately.

Cheers!


(Greg Covey) #131

Gordon,

The file you posted seems to be some strange .bin log file but it is only 390 bytes. It doesn’t load in Mission Planner and posts this error below. I even tried viewing it with NotePad++ just to see if it was a .param file renamed but it seems to be some small binary file.

“Log Browse will not function correctly without FMT messages in your log.”

P.S. I just noticed above that you refered to the X9D SD card. We want the Pixhawk .param file which is stored on the Pixhawk SD card according to FoxTech. Alternatively, you can connect with Mission Planner and save the parameters to a disk file from the Full Parameter List screen under the Config/Tuning section.


(Graham D) #132

Greg, I think that .bin file is the Taranis X9D model file.


(Gordon Ottershaw) #133

Uh-oh, my newbie is showing. I’ll try again this weekend.


(Greg Covey) #134

No bothers…we appreciate the favor!


(Gordon Ottershaw) #135

My searches for how to backup or download the pixhawk firmware or configuration have not provided useful results. Could you direct me to a really good guide. Perhaps my search terms are just wrong.


(Gordon Ottershaw) #136

Hi Greg…I think I’ve got it this time.Nimbus_Parameter_List.zip (5.4 KB)


(Greg Covey) #137

Hi Gordon,

You got it…thanks! There is some information in the Mission Planner Wiki on obtaining the Full Parameter List here and then saving it to a file.

Here are some of the “wind resistance” settings that I see from your V2 parameter list.

Q_VFWD_ALT,0
Q_VFWD_GAIN,0.05
Q_WVANE_GAIN,0
Q_WVANE_MINROLL,3

Q_A_ANG_PIT_P,6
Q_A_ANG_RLL_P,4.5
Q_A_ANG_YAW_P,3
Q_A_ANGLE_BOOST,1


(Michael De Leon) #138

Hello guys. Im really impress on your developments here.

We still had issue with our vtail servos. Left side burn out again. Im not sure if it was binding. Did anybody experience this.

Will try out flying it again.

Btw the flightmodes set up by foxtech is qloiter, auto and cruise only. Transition works at 14ms.


(Gordon Ottershaw) #139

A question about the center(s) of gravity. The thought occurred that this bird has 2 different centers of gravity. It has a tri-copter CG. It also has a Nimbus airplane CG.

Starting from what I think I know…the Nimbus airplane CG is 100 mm AFT of the wing’s leading edge. No problem, I can shoehorn both batteries in, strap on the nosecone and it balances perfectly with the motors tilted up for vertical take-off.

However, as soon as the motors tilt forward the plane is nose-heavy due to the motors’ mass shifting about 40 mm to the front.

What is the tri-copter mode’s calculated CG? Can that CG be altered to minimize the nose dive that happens during transition to plane mode?


(Graham D) #140

Gordon, the important CG is that for fixed wing so this should be measured and adjusted while the motors are in the forward position. The flight controller will compensate for the change in CG while in the hover mode and it only moves a cm or so, so doesn’t have much effect. Also it is only for about 5 or less percent of the whole flight so should not have any adverse effects like motors getting too hot. It’s just not practical nor necessary to dynamically adjust the CG in flight.

Michael, our tail servos’ were buzzing so I flexed our tail surfaces a lot off the plane until they loosened up the foam hinge. No problems since then. But that is a worry as it’s potentially catastrophic if it happens in flight and is not noticed.

Greg, I see Foxtech is selling a 16Ah Li-Ion battery for the Nimbus, it is a healthy 1500gr (53oz) though (https://www.foxtechfpv.com/foxtech-6s-16000mah-li-ion-battery.html). I get worried when things start getting so heavy.


(Greg Covey) #141

Hi Graham,

I had not seen the new pack, thanks. I am still hoping for Foxtech to sell their new packaging. I like that they keep expanding more support options.

On the new battery subject, it seems that the Foxtech 6s 16AH Li-ion pack can easily hover the Nimbus VTOL without using the dual battery swapping board. My graph above shows about 30amps to hover without payload. I can’t see adding a 2.5kg payload reaching up to 48amps hover current. We need to understand why your graph shows 58amps. I see that your weight was 4.2kg (9.25lb) which exactly matches mine so I assume that you had no payload at the time?

Perhaps others can post their current graphs or even a .bin file and we can graph it for consensus.

Lastly, I still prefer the Multistar packs since they are less expensive and I do not need to cover 400-1000 hectares. Cheers!

FoxTech 6s 16AH Li-ion Battery - $249
3C discharge = 16 x 3 = 48amps
1500g

Multistar 6s 12AH Lipo Pack - $111.
10C discharge = 12 x 10 = 120amps
1610g

Multistar 6s 10AH Lipo Pack - $119
12C discharge = 10 x 12 = 120amps
1320g


(Wasim Akram) #142

Hi Greg/Graham,

Here’s another pack worth considering: Multistar 6S 16Ah 10C LiHV (High Capacity Lipo) pack, which weighs about 1745g. I use one of them. IMHO I would only bet on a continuous current discharge rate of 2C to ensure minimal sag (a 10C continuous discharge could prove catastrophic). Still it should be able to handle a hover current of let’s say 30-40A for 30s without any problem. However, it’s a discontinued product, but with some luck, you might find a few on eBay (I am one of the lucky ones in this respect). Hobbyking currently sells a 12C version (i.e. Multistar 6S 16Ah 12C LiHV) but this one weighs about 2015g, which may be a bit too much for Nimbus?