TMotor 9.5x4.5 Prop

I

Iketh

Member
Can someone explain to me how the exact same prop at the exact same RPM can give vastly different thrust on 2 different motors? Specifically TMotor's 9.5x4.5 listed with their mn2212 motors. I can't give a link because this is my first post on this forum.

Basically, it's saying 4260rpm is 293g thrust on one motor, but 4400rpm is 176g on the other.... I don't understand
 
Iketh said:
TMotor'
Click to expand...
What KV?

This looks pretty straight forward @ 3S

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great, now if you would, also show the 14.8v chart to see what I'm talking about... same props, different thrusts at the same rpms
 
the chart on tmotor's page would make it easier... they have a 920kv and 780kv mn2212, both using same props in the charts
 
Has the throttle range been set on the esc's from the Tx.
With Quad plugged in & props off.
I think it's throttle stick up
Turn on tx
Wait a second then throttle down.
Then try calibrating the esc if your not using Dshot.
 
Last edited:
mozquito1 said:
Has the throttle range been set on the esc's from the Tx.
With Quad plugged in & props off.
I think it's throttle stick up
Turn on tx
Wait a second then throttle down.
Then try calibrating the esc if your not using Dshot.
Click to expand...
:) Are you sure you are in the right thread?
 
Jackson said:
:) Are you sure you are in the right thread?
Click to expand...
Well he's getting 2 different outcomes on 2 different motors with the same prop.
Yes he might have calibrated the esc's but if it's a new quad then it may need doing.
Google, setting stick throttle range.
One of the esc's may have a different value. Than the other. Pretty basic.
 
And if it's not that then do the KV match.
Why only 2 motors. What about 3+4.
What are ther outputs. Do they match 1 or 2.. Then maybe a faulty esc.
Do you have the blheli configuration app on chrome. In the setting is also sliders for min & max throttle.
Mine are 1020 min & 1980max
 
You didn't say on paper, I thought it was a real problem like you had a test bench set up or your quad was dodgy.
Considering you did not show us this paper. Why did you just not ask the manufacturer. Wasting time.
 
You are looking at different voltages and amp draws. Do you think that a 40hp, 4 cylinder engine can pull as well as a 200hp, 8 cylinder engine at the same RPM?
 
if there are identical props attached to each crankshaft and the 4 cyl can reach the same RPMs, yes
 
got a response from tmotor...

here's the question I sent:

Hello,

I have a question about this motor and prop combination. So I can better make a decision which motor to buy, can you please explain why your propeller (9.5x4.5 that is listed in the data sheets for both motors MN2212-920 and MN2212-780) can give different thrust at the same RPMs? For example, referring to your data sheets, 4260rpm is 293g thrust for the 780, but 4400rpm is 176g for the 920. Can you please explain how this is possible?

Thank you,

Keith


and the response:

Sorry , after check with engineer , the testing data for MN2212 both KV were wrong .

We will re-test it , and update the correct information .

Sorry to make you any inconvenient .

------------------

CiCi Chen

Sales Manager
 
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