Originally Posted by SubManEric

A couple of reasons.

4. I reread this thread and conclude that "the collective we" do not agree on anything

Now thats funny

Personally, I found that the 11x7 gave better overall performance than the stock prop. Also, the larger, slower prop will give more thrust at lower throttle settings in spins, stall turns and other maneuvers.

I'm going to try the 6 pitch this morning, and see how it affects the performance. I may very well go back to the 11x7.

I'm not trying the 12x6 at this point because of ground clearance.

Originally Posted by SalamSyed

Just a thought... when we know that this plane is not meant for any 3D and is an all around sports aerobatic plane then why do most people switch from the stock prop and think the a 12x6 size is the way to go? That's a huge size prop for this size plane and in my opinion should only be be used if we want to get some post stall and high alpha performance. The stock prop should work fine if agree that it is a sport plane not a 3D plane.

I prefer the 12x6 for a couple of reasons, the most being that for landing on rough not super short grass I can land at a slower speed easier. I can also fly the plane slower for flying in a more park like setting and I can practice maneuvers at a slower speed or practice more in a single pass. It also helps when flying with slower aircraft since I am much closer to their speed if I enter the pattern.

For me I think the biggest miss per se is I would not really classify the Extra as a "Park" plane being Parkzone. I have since learned that there are many "Park" planes that are more geared to flying fields with a fairly large flying area with some tar or a hard surface to land on.

I've tried a few props on mine, all with the stock 220mah 25c 3 cell, mine tips the scales at 37oz flying weight
The stock 10.5X9 prop makes 42oz of thrust static, 32A draw. It is just barely enough to pull unlimited vertical, the plane accelerates relatively slow, but just seems to keep accelerating as far as the eye can see, the plane picks up speed in a dive very fast, but you need to keep on the throttle to maintain control, dropping below 1/2 with any control movement will bleed off speed pretty quickly.

The next prop I tried was the APC 12x6e prop, and MAN did it make a difference, measuring 62oz of static thrust, almost 50% more than the stock prop at an almost identical 33A draw. It will hover just a bit over 1/2 throttle, can take off in a couple feet, and climbs like a rocket. The prop is large, and even with larger 2.5" wheels, it only has about 1" ground clearance, and wil cut grass while taxiing with all 3 wheels planted. It also can be a very good air brake at low throttle, it slows the plane down much faster when throttle is reduced, and makes some moves like pulling vertical from a knife edge, and kind of a rough looking waterfall possible, you have a lot more control of the speed, both slow and fast, and while it may not be quite as fast as the stock prop, especially in a dive, it is pretty close in level flight, but has a huge advantage in acceleration and pullout.

My current and favorite setup is the BF-109 10.6X7.8 3 blade prop with a 2" white dubro spinner, it measures 58oz of thrust at 39A WOT(above stock ESC rating), close to the 12X6, but the steeper pitch gives it a faster top speed. It does not quite have the instant response and acceleration of the 12X6, it has a little softer and more forgiving feel, although it still has plenty for very fast pull outs from hovers, it seems to work best across a much wider range of speeds. It seems to have just as much, and maybe a bit more braking at closed throttle than either of the 2 bladed props. Slow flight seems to be more stable, hovers and harriers are a bit more stable than with the 12X6, and FAR easier than with the stock prop, there is more torque to overcome though, but it is consistent. It does seem to require a bit more correction for torque than the 2 bladed props at takeoff, and at slow speeds, but being it is the same length as the stock prop, ground clearance is not an issue, and with the bigger wheels, taxiing, takeoffs and landings from grass is easy. It also looks cooler IMO than the 2 bladers.

Interesting... I think I have a 109 stock prop laying around somewhere... I'll have to give it a try...

In my testing this morning, I preferred the APC 11x7E to the cut down (to 11") 12x6E APC. Just better overall performance. I have not tried the 12x6, but the 6 pitch felt to slow for this plane (albeit I am flying at 5000ft).

Originally Posted by Rodan

Interesting... I think I have a 109 stock prop laying around somewhere... I'll have to give it a try...

In my testing this morning, I preferred the APC 11x7E to the cut down (to 11") 12x6E APC. Just better overall performance. I have not tried the 12x6, but the 6 pitch felt to slow for this plane (albeit I am flying at 5000ft).

Yea, the 12X6 would accelerate the extra vertically faster than my corsair will acelerate horizontally, it had massive pullout, but you kinda hit a wall at about 60mph or so, it wouldn't go much faster even in a dive, but the BF-109 prop is different, it doesn't grab the air and launch the plane as hard as the 12X6, but is still much better than stock, if you drop the throttle, it will slow down smoother and a bit more than the 12X6. The APC prop just chanes speeds much more abruptly. The only real downside to the 109 prop is that torque is more apparent, the stock prop weighs 16.25g, the APC 23.75g, they both seem to have about the same feel as far as torque correction goes, the shallower pitch of the APC, but greater weight eems to equal out compared to the stock prop, the 3 blade weighs 24.25g, not including the MUCH thicker spinner on it now, and the extra weight is in the blades, not the hub like the APC prop, it takes a little more attention to the ailerons at slow speeds, but the extra weight also seems to make hovers and harriers a lot easier to do, and more stable, the plane will torque roll pretty easily with it, but has enough aileron that you can stop the roll, and slowly start to reverse it. I put a gyro in mine on the aileron channel, mostly to help with the wind, and it is turned down pretty low, but it also counteracts the torque of the prop pretty well once the plane gets on step, and during takeoffs. Now I can go from a hover, goose the throttle with elevator to put it horizontal, then hammer the throttle, and it takes off from nearly a dead stop without really dipping the left wing at all. Turn off the gyro, and it takes a good bit of aileron correction to do the same thing. Same deal with knife edges, almost 0 coupling at all, and with the 2 better props, it has enough power and tail authority to yaw around and either pull straight up, or reverse the knife edge, it is a little short on doing a full knife edge loop without taking it to a ridiculous altitude though.

Originally Posted by SubManEric

4. I reread this thread and conclude that "the collective we" do not agree on anything

Sorry, but I have to disagree.

Originally Posted by Flyextreme

Sorry, but I have to disagree.

Now that's funny!
McD

I had a problem that I'd like some opinions about.

I flew yesterday and everything was fine. I left the plane assembled overnight. I hooked up the battery today and every servo twitched. The motor even started and stopped randomly. This happened on multiple tries with several batteries. Sometimes the control surfaces responded to the transmitter, sometimes not during the twitching.

I flew another plane using the same transmitter and saw no signs of interference.

I took the EXTRA home and took off the prop, cowling and motor. I checked every connection from the receiver to the ESC and plugged another battery in. This time with the prop on the workbench. I like my fingers.

No twitching. Everything was rock solid. No obvious connection issues found, but who knows?

I use a 72 MHZ FUTABA transmitter and a Berg 4L receiver, which I think I eliminated as the source by flying another plane.

Any ideas? I am a little leery of flying the plane until I think I know the answer.

Thanks.

Eric

Could someone explain the prop sizes to me? My prop is beat up and chipped, so if there is a better prop out there that would be great.

Its written as diameter by pitch. The length of the prop by how far forward in inches it will travel in one revolution. If you liked stock, get another one of the same.

Originally Posted by lazor 22

Could someone explain the prop sizes to me? My prop is beat up and chipped, so if there is a better prop out there that would be great.

Read back a few pages....you should get info you need....

Originally Posted by lazor 22

Could someone explain the prop sizes to me? My prop is beat up and chipped, so if there is a better prop out there that would be great.

Read back a few pages....you should get some info you need....

Originally Posted by SubManEric

I had a problem that I'd like some opinions about.

I flew yesterday and everything was fine. I left the plane assembled overnight. I hooked up the battery today and every servo twitched. The motor even started and stopped randomly. This happened on multiple tries with several batteries. Sometimes the control surfaces responded to the transmitter, sometimes not during the twitching.

I flew another plane using the same transmitter and saw no signs of interference.

I took the EXTRA home and took off the prop, cowling and motor. I checked every connection from the receiver to the ESC and plugged another battery in. This time with the prop on the workbench. I like my fingers.

No twitching. Everything was rock solid. No obvious connection issues found, but who knows?

I use a 72 MHZ FUTABA transmitter and a Berg 4L receiver, which I think I eliminated as the source by flying another plane.

Any ideas? I am a little leery of flying the plane until I think I know the answer.

Thanks.

Eric

I almost 100% assure you it was a bad bind on the radio...well bind as in 72mhz bind.

Did you shut all down incl radio, restart all and see??just sounds like the 2 had some interference.

Originally Posted by jaskel

I almost 100% assure you it was a bad bind on the radio...well bind as in 72mhz bind.

Did you shut all down incl radio, restart all and see??just sounds like the 2 had some interference.

Jaskel - good thought. At this point I'm not sure if I turned the transmitter off. I know the receiver end was cycled because I switched batteries.

Thanks. I'll recheck a few more times before flying.