How to calculate MTOM (maximum take off mass)

[andrewrob]

Hi all
Just wondering what the process is for this? I tried using ecalc but keep getting errors so I must be doing something wrong.
Need to put the figure in our operations manual for the BNUC-S

Thanks

 

[jes1111]

Post a screen grab of your eCalc and I'll try to help identify any errors.

 

[andrewrob]

Sorry, completely forgot to reply to you! I've attached a screenshot of the ecalc.
Specs of the multirotor are:
Droidworx AD6 frame
All up weight including everything is 5700g
6x APC ACE 13" 6.5 props
6x Torxpower 3536 heavy lift motors (700kv)
2x 4s 5800mah batteries in parallel

Let me know if you need anymore information.
Thanks

View attachment 6722

 

[Blacksails]

When did you do your ground school? The name Andrew rings a bell.

Anyway, if your running two 5800 mah lipos in parallel then you've got 11600mah. So change that.

Your motor specs are all out. The torxpower 3536 is a tiger motor clone with slight changes. I use them too. Select tiger motor MT2814-11 in ecalc and that will get you as close as damn it.

Hope that helps you out. Might have missed something but can't run ecalc on my phone....

 

[jes1111]

View attachment 6723The Torxpower motors are similar to the Tigers I've selected on the attached. On this basis your MTOM would be 7059g (5700 + 1359) - the mass at which eCalc calculates that you'd need 70% throttle to hover (the safe limit in order to retain headroom for control). However, I'd say that the figure would be better generated from a real-world test with your rig - what maximum weight leaves you able to fly with full control over the aircraft in all conditions (wind, etc.)

With respect, I hope there's someone else working with you who understands the technical stuff better - BNUC-S is supposed to certify the technical and flight capabilities of the individual/team

 

[andrewrob]

Thanks for that. I'm just the camera man, both of us are new to all this in general, we're normally ok with most things but the MTOM confused me a bit. Made worse by me keying the wrong things into ecalc!

Thanks again for both of your help

 

[Blacksails]

Are you Doms camera man? If so I'm Alex. Sat next to him on the ground school.

Change the motor cooling to good. Your still over the motors limit at full throttle though.

 

[andrewrob]

Yes I am! Small world.