Not sure then, maybe i'[ve been unlucky, but my p-51 went after around 25-30 flights, my 4-site in 14 flights (i was counting after the P-51) and since then, i haven't brought any others.

Originally Posted by Bowerz

Like i said earlier on, i would rather pay slightly more to not have to keep replacing motors. the fact is these micro brushed motors burn out way too quickly for my liking. However if they have changed the makeup of these motors and fixed that issue, i'll be all happy!

I'm sure they are the same motors because on average, you should get at least 100 flights easily on them, so overall, you were not lucky! And the way I (and likely HH too) see it, people who buy those airplanes fall mostly into two categories:

1- People who don't have much experience, buy those small airplanes, and crash them badly before the original motor die.

2- People who have lots of experience, who will get 400+ flights out of those, before something new come out, or/and they get bored of them. They won't mind changing 3 or 4 motors on them during that time, at the cost of $5 each (solo/bravo) for a total of $120 (still cheaper than brushless).

The biggest problem is truly when you don't get those 100 flights (again, average!) out of a motor. Cannot complaint, I've been lucky so far. My worst one lasted 72 flights, but I have a few that lasted 200+ flights. I always have one ready with the right pinion and long wires on it, so it fit any of my UMs. And I remove the front lip on the motor mount of my 4-Sites, Extra, etc so I can pull the motor from the front instead of the back. This allow me to change a motor in about 5 minutes, so I can even swap one during a flying session if I want.

Originally Posted by RealGambler

I'm sure they are the same motors because on average, you should get at least 100 flights easily on them, so overall, you were not lucky! And the way I (and likely HH too) see it, people who buy those airplanes fall mostly into two categories:

1- People who don't have much experience, buy those small airplanes, and crash them badly before the original motor die.

2- People who have lots of experience, who will get 400+ flights out of those, before something new come out, or/and they get bored of them. They won't mind changing 3 or 4 motors on them during that time, at the cost of $5 each (solo/bravo) for a total of $120 (still cheaper than brushless).

The biggest problem is truly when you don't get those 100 flights (again, average!) out of a motor. Cannot complaint, I've been lucky so far. My worst one lasted 72 flights, but I have a few that lasted 200+ flights. I always have one ready with the right pinion and long wires on it, so it fit any of my UMs. And I remove the front lip on the motor mount of my 4-Sites, Extra, etc so I can pull the motor from the front instead of the back. This allow me to change a motor in about 5 minutes, so I can even swap one during a flying session if I want.

Good tip on the mount mod. Going to try that on my polecat

What is the best replacement brushed motor for these ?

Originally Posted by brushless55

What is the best replacement brushed motor for these ?

I have had good luck with Solo pro motors
These motors are about the same power but seem to last longer and are more consistent power wise. The stock PZ motors are not as robust and vary a lot in performance.

Don't throw out the old motor before removing the gear and connector. You need to replace the connector and the gear on the SX motor with the parts from the stock motor.
I buy 4-6 at a time and always have 2 on the shelf.

All three of my micros have this motor and with a 5043 prop and Hyperion 240 mah flat packs I'm pretty happy with performance and flight times.

The slow roll in the video looks great - does the AS3X system take care of that for you? I.e., no need to fiddle the rudder and elevator yourself to maintain altitude during the roll? I almost feels like cheating, but should make you feel like a great pilot!

There seem to be several favors of AS3X receivers out there - please forgive me if someone already answered this, but I I am wondering if this specific receiver will go into brushless mode like the AR6400 and allow us to add a brushless ESC?

Originally Posted by jdwolters

There seem to be several favors of AS3X receivers out there - please forgive me if someone already answered this, but I I am wondering if this specific receiver will go into brushless mode like the AR6400 and allow us to add a brushless ESC?

The only official answer we got so far from Seth Arnold is: "The ASK and Spitfire use a similar board to the AR6400L" That's not really conclusive.

But the good news is: There's an official picture of the receiver in the ASK-21 that clearly show the usual 3 pins connector for the motor connection! (And funilly, there's no motor in that airplane!.) So odds are that the brushless hardware is in place in the new receivers as well.

Originally Posted by jdwolters

The slow roll in the video looks great - does the AS3X system take care of that for you? I.e., no need to fiddle the rudder and elevator yourself to maintain altitude during the roll? I almost feels like cheating, but should make you feel like a great pilot!

There seem to be several favors of AS3X receivers out there - please forgive me if someone already answered this, but I I am wondering if this specific receiver will go into brushless mode like the AR6400 and allow us to add a brushless ESC?

No, the as3x softens movements rather than eliminate them, you will still have to use rudder and maybe elevator, but it will be far less than without the system and with alot less coupling.

Originally Posted by JRuggiero

Being too lazy to research propeller efficiency relative to number of blades, and the UMX Spit's 4-blade prop, I offer this. The first of the full-size Spits (and Hawker Hurricane) were equipped with two-blade fixed-pitch props. The next generation had three-blade props. The Mark XI Spit had four-bladers; some Griffon-engined Spits had five-blade props, as did the Hawker Sea Fury.

Prototypes of the B-29 had three-blade props, but production versions had four-bladers. Likewise the early C-130 had three-bladers, while later versions had four-bladers. Newer C-130s have six-blade props. The Grumman C-2 has eight-blade propellers.

It would seem to me that, as power is increased, it is more practical to add more blades to the propeller to convert that power it into thrust, rather than increase the diameter. A smaller propeller disk allows shorter landing gear and closer placement of two engines per wing on a four-engine airplane.

How that translates to model airplanes, particularly very small ones, I don't know. Has anybody done tests?

Jim R.

Jim,

Propeller theory at large & small scales has been well-established for many years. A single-blade prop is the most efficient, regardless of scale. However, single-blade props are impractical in all but a few cases. A notable exception is C/L racing - where single-blade props are the norm, precisely because they are the most efficient. With our RC planes, a correctly-sized two-blade prop will provide better performance than a correctly-sized three or four-blade prop of similar design. Scale appearance & clearance issues are the reasons for using multi-blade props on our models. The tradeoff is efficiency. With glow & gas-powered planes, one can usually choose a more powerful engine of similar dimensions to offset a lower-efficiency scale prop. With electrics, that is not always an easy thing to do.

There are two primary reasons for using more than two blades on full-scale props:

1) When a two-blade prop of sufficient diameter to fully-absorb the engine's torque would present ground-clearance issues (or in the case of multi-engined craft, fuselage clearance or nacelle placement issues).

2) When a two-blade prop of sufficient diameter would have a prohibitively high tip-speed at typical throttle & pitch settings. You don't want the tips to go supersonic for any period of time, as it dramatically reduces efficiency & can damage the blades. Preferably never, but it happens on some planes during the takeoff run. The sharp snapping sound heard from planes such as Cessna 180s & Beavers on takeoff is not the engine's exhaust note. Rather, it is the sound of propeller tips going supersonic.

Joel

Originally Posted by turboparker

Jim,
The sharp snapping sound heard from planes such as Cessna 180s & Beavers on takeoff is not the engine's exhaust note. Rather, it is the sound of propeller tips going supersonic.

Joel

Wow, that's very interesting. I never knew what that sound was. I always assumed it was the motor "popping" as it was warming up to an efficient running temp.

You learn something every day. Thanks!

Mac

Originally Posted by MaladroitFL

Wow, that's very interesting. I never knew what that sound was. I always assumed it was the motor "popping" as it was warming up to an efficient running temp.

You learn something every day. Thanks!

Mac

which is the same reason a bullwhip snaps, the tip has gone supersonic

Wrong thread....

turboparker,

Multi-blade propellers: I hadn't thought about the supersonic prop tip problem. Now I recall that the Republic XF84-H "Thunderscreech" suffered from that problem in a very big way.

I recall the time when free-flight modelers used single-blade props with counterbalance. This trend lasted longer on rubber-power Wakefield and similar competition models than it did on glow-powered models, where counterbalancing never seemed to work well, leading to engine bearing and mount failure. There was also the question of asymmetric thrust around the rotating axis.

From my own experience, I accidentally broke a blade on a rubber-powered indoor model. I flew the airplane anyway, and, despite the unbalanced shaking, the climb was much more vigorous. I didn't try any further tests on a one-blader.

Jim R.

Originally Posted by JRuggiero

turboparker,

Multi-blade propellers: I hadn't thought about the supersonic prop tip problem. Now I recall that the Republic XF84-H "Thunderscreech" suffered from that problem in a very big way.

I recall the time when free-flight modelers used single-blade props with counterbalance. This trend lasted longer on rubber-power Wakefield and similar competition models than it did on glow-powered models, where counterbalancing never seemed to work well, leading to engine bearing and mount failure. There was also the question of asymmetric thrust around the rotating axis.

From my own experience, I accidentally broke a blade on a rubber-powered indoor model. I flew the airplane anyway, and, despite the unbalanced shaking, the climb was much more vigorous. I didn't try any further tests on a one-blader.

Jim R.

The master of one-bladed aircraft...

1 blade propeller. Will it work on Nitroplanes Hawk 3D? (9 min 3 sec)

1 Single Rotor Blade helicopter experiment, Horizon Hobby Blade 400. (7 min 43 sec)

I called it. I'm sure we'll see a ultra micro icon a-5. Haha just came to mind randomly. Also I'm hearing tons of complaints of the brushed motors. There is no issu with them!!! They're cheaper, can last a long time, don't need super powerful batteries, and Ive never had any issues. When I was into airhogs I had a sharpshooter for about a year and a half until it got attacked by a dog, and even with their low quality I never had an issue with any of the motors. My mcp s has over 300 flights on the stock brushed motor. No issue here. It's just e-flute makes model that everybody wants that have brushless and barge more from hem. I think e-flits should make their umx's to have the option of a brushed motors to make them cheaper. Just my honest opinion on brushed motors.