General Hand launch mix
- Thread starter Billfitt
- Start date
RandyDSok
Well-Known Member
I'm sorry to tell you... you won't get a direct answer to your question. Most pilots will have different aircraft, radios and more importantly.. flying conditions as well as flying styles than what you will develop over time.
You may be able to program out different aspects of flight like how the rudder responds in a roll done with ailerons etc... but on take off the time frame is so short and the conditions will vary enough that you can't just simply program in how much elevator you will need in the first 10-15 seconds of flight... you will just have to learn to make those adjustments on a as needed basis.
Let's begin with the conditions... primarily the wind. With a micro airplane, you will want to have almost no wind just to be able to fly period. Larger aircraft can handle more wind but even then, a 4 foot aircraft you probably don't want to fly in more than 10-15 mph winds. Flying a micro will require much lower wind speeds and I suspect even something like a 5 mph wind will be a challenge. On the other hand, having a higher wind speed will help in the take off portion since you'd get more wind over the wings at the start.
At the RC club I used to be a member of... only a few ever even had aircraft that required hand launching but there were some. Still, each pilot had their own different style that they used during take off. Most would even get another experienced pilot to do the hand launch portion while they just controlled the airplane with the radio they used. The launcher and pilot would typically start off with a quick conversation of how they want it launched ... ie how much of an angle up or level with the ground etc.
Of the pilots that were doing their own launching an controlling... each aircraft would make them take off the airplane differently depending on the qualities that the model had... there was no one set of rules that could be programmed into the radio to handle it. The pilot themselves controlled how much elevator was needed depending on that days flight conditions. Different days required more or less controls depending on wind conditions. Just things like was the wind steady or gusty... or did it even exist made a lot of difference in how the pilot would fly the aircraft.
How much elevator you need at take off will vary on the conditions that day you fly it. You will have to just learn what your specific aircraft needs "on the fly" and as conditions change dynamically. Now you even have an idea of how the saying "on the fly" even got it's own start.
About electric motors in general. They are not meant to be ran at full throttle. Do not run yours over 75-80% for any ANY length of time or you risk burning it out. I typically kept my top end at the 65-75% range at most and if I was trying to have a longer flight... 55-65% was usually the best you can do to get a longer flight.
So when launching... set your throttle around the 75-80% range right before take-off and expect to pull it down a little later... but your elevator and ailerons/rudder are what you will give the most focus too until you reach stable flight. How much of those controls you will need will vary based on the conditions of the day as well as the flight characteristics of your specific model. Even two identical models will differ slightly in some aspects.
To shorten and reword slightly if you are doing your own hand launching... On take off... set your throttle, place your fingers on the controls for your elevator/ailerons on the radio... estimate the amount of elevator you will need that day based on the conditions ( mostly the wind )... run a few steps and launch at which point place the hand you launched with on the throttle... just release the elevator as needed so it returns to zero when the aircraft "tells" you to do it. Adjust the other controls as needed for conditions like the gusts etc.
You may be able to program out different aspects of flight like how the rudder responds in a roll done with ailerons etc... but on take off the time frame is so short and the conditions will vary enough that you can't just simply program in how much elevator you will need in the first 10-15 seconds of flight... you will just have to learn to make those adjustments on a as needed basis.
Let's begin with the conditions... primarily the wind. With a micro airplane, you will want to have almost no wind just to be able to fly period. Larger aircraft can handle more wind but even then, a 4 foot aircraft you probably don't want to fly in more than 10-15 mph winds. Flying a micro will require much lower wind speeds and I suspect even something like a 5 mph wind will be a challenge. On the other hand, having a higher wind speed will help in the take off portion since you'd get more wind over the wings at the start.
At the RC club I used to be a member of... only a few ever even had aircraft that required hand launching but there were some. Still, each pilot had their own different style that they used during take off. Most would even get another experienced pilot to do the hand launch portion while they just controlled the airplane with the radio they used. The launcher and pilot would typically start off with a quick conversation of how they want it launched ... ie how much of an angle up or level with the ground etc.
Of the pilots that were doing their own launching an controlling... each aircraft would make them take off the airplane differently depending on the qualities that the model had... there was no one set of rules that could be programmed into the radio to handle it. The pilot themselves controlled how much elevator was needed depending on that days flight conditions. Different days required more or less controls depending on wind conditions. Just things like was the wind steady or gusty... or did it even exist made a lot of difference in how the pilot would fly the aircraft.
How much elevator you need at take off will vary on the conditions that day you fly it. You will have to just learn what your specific aircraft needs "on the fly" and as conditions change dynamically. Now you even have an idea of how the saying "on the fly" even got it's own start.
About electric motors in general. They are not meant to be ran at full throttle. Do not run yours over 75-80% for any ANY length of time or you risk burning it out. I typically kept my top end at the 65-75% range at most and if I was trying to have a longer flight... 55-65% was usually the best you can do to get a longer flight.
So when launching... set your throttle around the 75-80% range right before take-off and expect to pull it down a little later... but your elevator and ailerons/rudder are what you will give the most focus too until you reach stable flight. How much of those controls you will need will vary based on the conditions of the day as well as the flight characteristics of your specific model. Even two identical models will differ slightly in some aspects.
To shorten and reword slightly if you are doing your own hand launching... On take off... set your throttle, place your fingers on the controls for your elevator/ailerons on the radio... estimate the amount of elevator you will need that day based on the conditions ( mostly the wind )... run a few steps and launch at which point place the hand you launched with on the throttle... just release the elevator as needed so it returns to zero when the aircraft "tells" you to do it. Adjust the other controls as needed for conditions like the gusts etc.
Thank you for your reply and insight.
I thought I had seen a horizon plane that they had hand launch mode to help make it easier, but I can’t find which one now. I was trying to duplicate that feature.
where I fly the grass is on the higher side and it makes take off and landings harder with such small wheels on a umx model. The plane toppled over on landing because the wheels got caught in the grass. I’m hoping belly landings will be a little more gentle. I went to 3 in wheels to hopefully improve the landing and takeoffs better on my apprentice 1.5.
I am limited in my dexterity and have hit the throttle cut switch as I was hurrying to to get my hand down to get on the right stick. I have for some reason had the plane nose in the ground on launch on 2 other occasion.
the mix is on a switch so once it’s in the air I can go to normal flight controls. The amount of elevator applied is incremental to a max of 30%. I guess it will be a little trial and error to fine tune.
I am hopefully be out at the field tomorrow and I can see how it works.
thanks again
bill
I thought I had seen a horizon plane that they had hand launch mode to help make it easier, but I can’t find which one now. I was trying to duplicate that feature.
where I fly the grass is on the higher side and it makes take off and landings harder with such small wheels on a umx model. The plane toppled over on landing because the wheels got caught in the grass. I’m hoping belly landings will be a little more gentle. I went to 3 in wheels to hopefully improve the landing and takeoffs better on my apprentice 1.5.
I am limited in my dexterity and have hit the throttle cut switch as I was hurrying to to get my hand down to get on the right stick. I have for some reason had the plane nose in the ground on launch on 2 other occasion.
the mix is on a switch so once it’s in the air I can go to normal flight controls. The amount of elevator applied is incremental to a max of 30%. I guess it will be a little trial and error to fine tune.
I am hopefully be out at the field tomorrow and I can see how it works.
thanks again
bill
RandyDSok
Well-Known Member
Well... small planes and grass were never best of friends... and a micro ... let's just say may even have trouble on a putting green... lol.
Micro's are going to be twitchier than a larger aircraft of the same type of setup. In addition, a prop at the front will be better for hand launching because it is putting air directly over the wing which gives it added lift. With a ducted fan, it's only the forward momentum that provides air over the wing so it won't have as much lift during take off.
Micro's are going to be twitchier than a larger aircraft of the same type of setup. In addition, a prop at the front will be better for hand launching because it is putting air directly over the wing which gives it added lift. With a ducted fan, it's only the forward momentum that provides air over the wing so it won't have as much lift during take off.
I did get to fly the a-10 today. It was kinda windy 7-10 mph. Some of the planes were being tossed around a bit.
I had some help with launching the plane from an experienced pilot on both modes. I had the controls and he hand launched the plane in the air. I grant you my fumbling was no help. The first try with normal launch mode the plane nearly hit the ground but I was able to to get it into the air and fly some. I did pass the receiver to another pilot to trim it out and give it a try. We joked afterwards that if the plane had a prop we would have had grass clipping flying in the air.
The second launch we tried the launch mode. The plane stayed about 4 ft off the ground and I did stumbled some to get it into normal mode it continued to fly well. The plane was pretty fast for such small fans and didn’t need to go past 1/2 throttle for comfortable flight. It handled the wind surprisingly well and really it helped to slow it down on landings.
the belly landing went well and skidded on the grass pretty easily. The launch mix may not be the perfect solution it worked today as I hoped. I went home with no repairs needed so I’m happy
I had some help with launching the plane from an experienced pilot on both modes. I had the controls and he hand launched the plane in the air. I grant you my fumbling was no help. The first try with normal launch mode the plane nearly hit the ground but I was able to to get it into the air and fly some. I did pass the receiver to another pilot to trim it out and give it a try. We joked afterwards that if the plane had a prop we would have had grass clipping flying in the air.
The second launch we tried the launch mode. The plane stayed about 4 ft off the ground and I did stumbled some to get it into normal mode it continued to fly well. The plane was pretty fast for such small fans and didn’t need to go past 1/2 throttle for comfortable flight. It handled the wind surprisingly well and really it helped to slow it down on landings.
the belly landing went well and skidded on the grass pretty easily. The launch mix may not be the perfect solution it worked today as I hoped. I went home with no repairs needed so I’m happy
RandyDSok
Well-Known Member
I forgot to make a suggestion if you haven't done it already that is... Get a neck strap or a tray to hold your radio. Most radios come with them ( unless those have been dropped in sales now ) and better more comfortable ones are not expensive. A radio tray strap can provide more stability but they also are harder to get out of your way when you aren't using them. Of course if two pilots are going to be flying, then both are a bit cumbersome when switching pilots.