Hey,
I changed the frame of my quadcopter and due to that the weight increased to nearly 3 kgs. During this I changed the motors and battery from 3S to 4S. Now, by the motor datasheet the copter should have enough lift to take off but with max throttle it just sits on the ground. Is there a possibility that APM itself limits the max current?
From the GC I saw that the max current was 40 Amps with max throttle from the remote. However from the motor datasheet it seems that with 12" props it should consume up to 60 Amps ( 4 motors) and lift ca 5 kg?
Has anyone encountered a similar problem or point me in some direction of what to check?
APM 2.7 with power module
4S Turnigy 10000 mAh
Afro 30 A ESC
Motors: RC Timer 5010 530 kV
http://rctimer.com/product-914.html
Props: 12" 4.5
I have checked all the parameters I could find in the mission planner and recalibrated the ESCs and reinstalled firmware for APM.
Thanks in advance!
Replies
Yes, 3 kgs is the actual payload and I recalibrated the radio as well. Under 60 Amps I meant in total, which means 15 Amps per ESC.
I will try bigger propellers and higher pitch first, hopefully it will get it flying but most likely I will have to buy new motors. But seen from the calculations it should lift off even with the current 1245 propellers?
Tonis,
From the motor specs you mention, there is no way your quadcopter lifts the intended payload with a 4S LiPo battery, which is what you said you have.
So, either you are actually using a 5 or 6 cell battery and in that case most likely you have a problem with the 30A esc that are protecting itself from overdraft and burning out, or you really have a 4 cell battery that it is not capable to provide the needed power.
Wait,
Bigger propeller definitely, but keep the pitch at 5.
I also agree with James, you do not have enough power to fly safely. If you want to lift a 5kg allout weight, then you need to have at least 6 of those 5010 Motors.
APM sets your "MAX THROTTLE" at ~90%, leaving the last bit for stability output. Do not try to change this, it is very necessary.
I'm working on the specifications for a 5kg and 9kg Hex copters and I will post the info when complete.
eCalc is a good guide too
With those 5010 disk motors it is better to use 15" props. 12x45 is just too small for that payload.
You've got a 30 amp esc but you want to pull 60 amps? Your esc is probably limiting current to stop its self burning out!
Those calculations don't seem right, here I tested you setup on ecalc:
The setup doesn't have enough power to fly safely!
Tonis, The 4.5 inch pitch on the 12 inch prop may be too much for your motor battery combination. You could test the prop, motor, esc and battery by themselves with a scales to see how much thrust the motor is generating.
The RC Timer motor data shows that a 12 inch prop with a pitch of 3.8 inches would provide the maximum lift of 5KG. Though you may want to check several props with different pitches and diameters.
I checked with ecalc to see if there was a 12 inch prop that would provide enough lift. Ecalc indicates that a 12 inch prop with 6 inches of pitch will do the job. Kind of the opposite of what I was expecting. Worth testing though. :-)
Ecalc indicates that with 12in x 6in props and the 4s1p battery that each motor will be drawing 8 amps in hover. As a plus this is will only require 74% of the throttle.
From the motor specs actual lift capability for a safety flying using 1238 prop and 5S battery should go around 1.820 x 4 / 2 that is assuming you have 4 motors installed so it will lift 3.64Kg.
Unless it is a typo Tonis wrote 4S battery so it will have maximum around 2.74Kg pull.
Over increasing the propellers pitch will definitively drain more power and produce motor heating to the point that could burn something.
Hi
the near 3 kg are your actual payload right?
did you recalibrated radio?