how much thrust?

Alibas

Member
this is probably a common question so apologies for that. but i want to try some eclipson planes but im not sure my current motor can provide enough thrust. what kind of numbers are necessary for something like the EGW-80 at about 800grams? 800 grams of thrust or somewhere closer to 1000g-1200g?
 

JasonK

Participation Award Recipient
it is more complicated then just 'how much thrust' as you could have a very high thrust setup, that has a very low pitch speed, and wouldn't be able to get the craft going fast enough to fly, you could also have a motor/prop with a very high pitch speed, but low thrust, which would have a different issue.

What is the recommended motor/prop for the planes in question?
What is your motor/prop?
 

JasonK

Participation Award Recipient
here is what eclipson recommends motor wise:

MOTOR
KV- 1200 to 2400
MAX POWER - 100 to 300 watts
MAX DIAMETER - 28mm
VOLTAGE - 11,1V (3S)


Proposed - Sunnysky x2212 kv1250


and farther down it said you can just use a FT power pack B.
 

Merv

Site Moderator
Staff member
It depends on how you want to fly. Here are some guidelines that may help. It’s the total flying weight of the plane that you need, including motor and battery. Use the all up weight of the plane in the air.

• 50 to 70 watts per pound is the minimum level of power, good for park flyers and lightly loaded slow flyers.
•70 to 90 watts per pound is perfect for trainers and slow-flying aircraft.
•90 to 110 watts per pound is good for fast-flying scale models and some sport aerobatic aircraft.
•110 to 130 watts per pound is what you want for advanced aerobatics and high-speed aircraft.
•130 to 150 watts per pound is needed for lightly loaded 3D models and ducted fans.
•150 to 210+ watts per pound gives unlimited performance for any 3D model.
 

Alibas

Member
it is more complicated then just 'how much thrust' as you could have a very high thrust setup, that has a very low pitch speed, and wouldn't be able to get the craft going fast enough to fly, you could also have a motor/prop with a very high pitch speed, but low thrust, which would have a different issue.

What is the recommended motor/prop for the planes in question?
What is your motor/prop?
the motors i have are 2300kv EMAX RS2205. which does 450w and 1000g thrust with a standard 5" drone propeller and im planning on using something like a 7x4 propeller. the recommended powerpack B 2212 1050kv motor which i cant seem to find the specs of but it has an advertised "over 1kg of thrust" and the motor overall has the same advertised features of the smaller EMAX. so from i can gather the 2205 with a faster spinning lower pitch prop should be sufficient right?
 

JasonK

Participation Award Recipient
your probably not going to want to put that big of a prop on that 2300kv EMAX RS2205 unless you run a lower cell count battery then you do with the 5", it will load the motor quite a bit more then a 5".
 

Alibas

Member
your probably not going to want to put that big of a prop on that 2300kv EMAX RS2205 unless you run a lower cell count battery then you do with the 5", it will load the motor quite a bit more then a 5".
yes i would limit the output to a suitable level. the propeller used for the test on the spec sheet are 5045. i'm more of a drone guy so thats what i have. the motor is basically the same as the powerpack f with a 6x3 dualblade, so my intuition tells me a 5045 triblade should be enough for the task, the thing is my intuition is often wrong. compared to the recommended motor, both have similar thrust levels, one at high pitch lower rpm and one at low pitch high rpm. so the lower pitch option would be slower correct?
 

JasonK

Participation Award Recipient
your pitch speed is your pitch * kv * voltage, so for the same battery, a prop with 1/2 the pitch, but running at 2x the kv will have the same final pitch speed.