New FT Explorer

[quorneng]

Andt.T.
My concern is that the motor should not get hot with a 9x6 on a 3s, particularly if it is in the open stuck on the front of a plane.
The fact that it did and is now not as free running means something is wrong with it, possibly a magnet has come loose or a crash bent the motor shaft.
The size of a 3s battery or the ESC will not cause a motor to run hot. You are using a 9x6 'e' prop not a 9x6 prop for IC engines? IC props are less efficient so require more power from the motor.
I fear that motor is now scrap.

As an aside the weight of a plane always matters.
Its weight determines its flying speed and thus the power required to fly and also the speed it 'contacts' the ground! The kinetic energy of an impact is proportional to mass and its velocity squared so extra speed makes a big difference in any impact.
Eventually too much weight makes a plane virtually unflyable.
Is a 3300 mAh 3s the recommended size?

 

[luvmy40]

Double check your mounting point. Make sure there is nothing contacting the motor housing or the rear portion of the shaft If you forget to cut the packing tape out of the center hole on the firewall and the motor shaft protrudes out the rear that is enough to over heat your motor. Any drag at all can cause problems.

 

[Andy.T.]

Andt.T.
My concern is that the motor should not get hot with a 9x6 on a 3s, particularly if it is in the open stuck on the front of a plane.
The fact that it did and is now not as free running means something is wrong with it, possibly a magnet has come loose or a crash bent the motor shaft.
The size of a 3s battery or the ESC will not cause a motor to run hot. You are using a 9x6 'e' prop not a 9x6 prop for IC engines? IC props are less efficient so require more power from the motor.
I fear that motor is now scrap.

As an aside the weight of a plane always matters.
Its weight determines its flying speed and thus the power required to fly and also the speed it 'contacts' the ground! The kinetic energy of an impact is proportional to mass and its velocity squared so extra speed makes a big difference in any impact.
Eventually too much weight makes a plane virtually unflyable.
Is a 3300 mAh 3s the recommended size?

Really good points about weight, force delivered in a hard impact, etc. I suppose when my first wing folded and the plane fell pretty straight down for a good 100ft +, the nose probably didn't absorb all that force. Perhaps the motor was damaged from that.

I actually didn't realize there were differences in propellers. I thought one 9x6 was more or less equivalent to another. Some of the props I've gotten are Master Airscrew brand, and some are light grey nylon things I got cheap on Amazon. I've done a fair amount of digging yesterday and this morning and so far can't seem to find much in the way of indications of E vs IC. I don't really get how one would tell them apart. Any clues?
I found a neat calculator online for setting up an RC plane electrical system, but alas, it didn't have the Flash Hobby motors I have.

 

[Andy.T.]

Andt.T.
My concern is that the motor should not get hot with a 9x6 on a 3s, particularly if it is in the open stuck on the front of a plane.
The fact that it did and is now not as free running means something is wrong with it, possibly a magnet has come loose or a crash bent the motor shaft.
The size of a 3s battery or the ESC will not cause a motor to run hot. You are using a 9x6 'e' prop not a 9x6 prop for IC engines? IC props are less efficient so require more power from the motor.
I fear that motor is now scrap.

As an aside the weight of a plane always matters.
Its weight determines its flying speed and thus the power required to fly and also the speed it 'contacts' the ground! The kinetic energy of an impact is proportional to mass and its velocity squared so extra speed makes a big difference in any impact.
Eventually too much weight makes a plane virtually unflyable.
Is a 3300 mAh 3s the recommended size?

3S I think is the recommended for the Explorer. 3300mah is on the bigger end, but it has sounded like I'm not the only one who's speed build kit Explorer came out pretty heavy compared to the supposed expected weight.

I've been obsessively trying to figure out this prop thing. Figured I might as well show a picture of the props If have. I probably don't need to explain them to anyone but myself as I'm sure this was all basic stuff, but I will since I have time. Top down:
-9x6E that might have burned out the 2836 1500Kv on my Explorer
-a cheap set of what I thought were going to be 10x4.5's, which they are, but they are flimsy and am guessing are for quads
-Master Airscrew 10x4.5's. I was excited about these, but now I notice these are multi rotors as well. Would these not do well on an airplane?
-MAs 10x6, GE
-11x5 APC
-not pictured, set of nylon "CW 9x4.5 airplane propellers" is how they're labeled, that look pretty comparable in shapeto the 9x6 that was on my Explorer

Maybe this is another basic question I should know, but it doesn't matter which way the motor turns, as long as it is the correct direction for the propeller as it is facing the correct way, right?

 

[quorneng]

Andy.T.
According to the Flash Hobby web site your motor has a maximum power output of 368W. On a 3s that would running about 30A from the battery. There is no mention as to whether this figure is a continuous rating or just a short period 'burst' figure.
To be honest as far as selecting a prop what you need is a Watt meter. This will tell you in real time how many Watts the motor is taking. If it is taking more than 368W or getting unduly hot then you know the prop is over loading the motor so stop before anything gets damaged!
When you run up to full power do make sure the plane is secure and that you are always behind the prop. A prop with 368W behind it can give you a hospital emergency injury.

I always check any motor/prop/battery combination on the bench with a Watt meter (for both Watts and Amps) before I even consider fitting it to a plane. Unless you do this it is just trial and error guesswork which can get expensive, indeed costing rather more than the Watt meter.

 

[Andy.T.]

Andy.T.
According to the Flash Hobby web site your motor has a maximum power output of 368W. On a 3s that would running about 30A from the battery. There is no mention as to whether this figure is a continuous rating or just a short period 'burst' figure.
To be honest as far as selecting a prop what you need is a Watt meter. This will tell you in real time how many Watts the motor is taking. If it is taking more than 368W or getting unduly hot then you know the prop is over loading the motor so stop before anything gets damaged!
When you run up to full power do make sure the plane is secure and that you are always behind the prop. A prop with 368W behind it can give you a hospital emergency injury.

I always check any motor/prop/battery combination on the bench with a Watt meter (for both Watts and Amps) before I even consider fitting it to a plane. Unless you do this it is just trial and error guesswork which can get expensive, indeed costing rather more than the Watt meter.

Funny that you mention that I was just doing exactly that, testing w/ a watt meter on the bench. Er, garage floor. I guess I should move a couple planes so I can use the bench and not bend over.
The 9x6 prop was definitely overloading the motor. That was drawing consistently over 30amps. I switched to the 9x4.5 that arrived this afternoon and looked very similar in shape, material, and brand to the 9x6. T he 9x4.5 provided more thrust and less power draw. With my 3300mah 3S mostly fully charged, it was running about 12v even and 24-28amps. With an extra 20% thrust to boot (was pushing against a scale).
Which leads me back to my ponderings of before new motors and props arrived from the Wells Fargo Wagon, er I mean Amazon delivery truck. Is there a different type, style, material of prop that could be a correct choice where my original wasn't?

 

[quorneng]

Andy.T.
There is always a bit pot luck on exactly how close to the claimed maximum that a motor or ESC can safely go for an extended period. Manufacturers are known to 'guild the lily' a bit for marketing purposes.
The rule of thumb suggests keeping below 80% of the claimed maximum gives some head room for both motors and ESCs.
Of course if you can build 'light' it helps as the power to fly is directly proportional the the plan's weight.

Now if you can get it so light that the plane can fly using just 10% of the maximum for the motor, ESC and battery a) nothing gets hot and b) you can fly for a long time!