Weight limit

R

RTRyder

Merlin of Multirotors
I've finally found the weight limit of my Droidworx Hexa. As an experiment I paired 4 Turnigy 2S 5000 packs in series and then connected the 2 pairs in parallel to see if first the Hexa would fly with the extra weight and second if it did, for how long. The answer is while it does get off the ground, it takes at least 3/4 throttle just to maintain a low altitude hover, any thought of actually flying that way is out of the question, it's just too heavy and putting too much strain on the electronics.

Total weight of this setup is just a shade over 7 1/2 lbs and the normal flying weight with 2 batteries is right around 6 pounds, so it looks like the practical weight limit for a standard kit MK Hexa is 6 pounds to have sufficient power available. Ideally I'd like to get the Hexa back to the previous ready to fly weight of 5 1/2 pounds, so it's time to look for ways to reduce weight in the interest of increasing flight time and reducing stress on components.

Ken
 

D

DennyR

Active Member
Ken
I have been working towards finding the right motor combination for a heavy lift machine. My latest Flying Camera Mount design uses only four MK 3538's turning 14x4.7's cut down to 13" thus far I am not convinced that I need a hexa. at this payload. The model fly's far better when the motors are working quite hard. I get 10 mins from one 4100 lipo.

Denny
 

1

1001 Copters

Member
Hi rtryder,

it's an interseting information you give us, thanks :)
We are still testing he limits of the HEXASTAR-700 as Francklin have some trouble with the Bl-Ctrl (it seems that there is a current limit on it).
He received one of the "bad" FC 2.1: one that have the famous current limits defined on 3V insead of 3.3v.
For now we have lifted 3.3kg payload (battery + payload) for a total weight of 5.8kg.
While taking the frame by twoarms, there was absolutly no bending (it's an important arameter because when you will go down, the gravity will increase the weight due to acceleration)
 

R

RTRyder

Merlin of Multirotors
DennyR said:
Ken
I have been working towards finding the right motor combination for a heavy lift machine. My latest Flying Camera Mount design uses only four MK 3538's turning 14x4.7's cut down to 13" thus far I am not convinced that I need a hexa. at this payload. The model fly's far better when the motors are working quite hard. I get 10 mins from one 4100 lipo.

Denny
Click to expand...

I've been kicking around the idea of swapping the stock Roxxy 2827-35's out for a set of the MK3538, I'm just having a hard time justifying buying 6 of them at $90 something each! Then there's the potential reduction in flight time afterward although with more lift capability I can carry more battery and get that back to some degree. Its the whole cycle of spend/upgrade that gets me wondering if the benefits are worth it or can I live with what I've got, I don't plan to carry anything heavier than what I've already flown with and I can't fit any big DSLR's on the mount so I really don't have a need for a true heavy lifter.

The Hoverfly quad on the other hand has 4 RCtimer BC 2826-15 930KV motors on it and so far it kicks A** on 3S packs. I started running Turnigy 3S 2650mAh packs wired in parallel for even weight distribution and extended flight time and it easily gets 10 minutes not even coming close to low battery. Due to the cold I haven't tried to find out just how long it will fly in the current configuration, my fingers are getting pretty numb by 10 minutes, but I'd say easily 15 minutes. I also have a pair of 3S 5000 mAh packs and yesterday I strapped both of them on to see how it handled it and it flew fine, hover at barely over 1/2 throttle so it's not being strained by the extra weight and after 10 minutes in the air the packs read 57% charged when I connected them to the Hyperion Duo, looks like I'll get close to 20 minutes on that setup in warm weather.

The Droidworx has the good camera mount and I just swapped the lens on the GoPro, I'm really pleased with the result, so that's going to be my video platform and camera setup until something better and not uber expensive comes along though I think that's going to be way down the road. The Hoverfly has the old stock MK Hexa frame refit to quad configuration and carrying the old HiSight II mount. Due to Hoverfly still working out bugs in the firmware its not as stable a platform as the MK and the HiSight is not even close to being a sturdy, vibration free mount, so while it's OK for video with the GoPro, it's much better for the Canon SX 200 doing stills via CHDK. I did find a bit of a deal on the basic GoPro Hero HD so I grabbed another one for a spare/stock unit, now I have the older Hero with lens mod and the new one with stock wide angle so I can mount the spare on the Hoverfly if needed.

I think I've got the bases covered for the moment for both video and stills, now I'll just be fine tuning the two until I have a pressing need to upgrade which hopefully won't be for quite a while, the toy budget needs some time to recover.

Then again if I happen to find some extra $ lying around, I really would like to have one of Cedric's frames ;)

Ken
 
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D

DennyR

Active Member
On my latest FMC-3 I have started using the Pulso X2826/12 motors 5mm shaft running in 3 bearings. awesome power and so smooth. Vibration being the most common detriment to good video This design has some features to eliminate that problem. This is a floating design made from insulating foam plus balsa wood covered with fine glass cloth and epoxy resin. Note minimal prop overhang and rubber mounting of the arms
 


Droider

Droider

Drone Enthusiast
Flamin Harold... that looks very interesting.. Is it a mod on the one I have seen taking off the water?

What Video are you using there?

Dave
 


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