Bob Cat Copy Falcon 120 Jet
01-26-2009, 12:46 PM
#2301
RE: Bob Cat Copy Falcon 120 Jet
Ed
With the risk of being shot at I will try to answer your question, from 15deg up to about 40degs of flap you will get increased lift as well as increased drag, therefore not much difference on thrust level required from a normal landing, just needs to be set up to float in on a fairly long approach, from approx 45degs to 90degs drag will increase dramatically over the lift that will be produced by dropping the flaps, which will slow the approach and increase the rate of decent, therefore an increase in thrust is required to keep the wing flying and the airflow as smooth as possible over the wing at the higher angle of attack needed to keep flying, at this sort of angle of attack the wing is pushing a cushion of air in front of it and the flaps to a certain extent are holding it there, in an ideal situation if you have the facility in your Tx to put the ailerons up whilst the flaps are down you get the best of both worlds, lots of drag to slow you down, and a reduction in lift by the ailerons acting as spoilers, but adding washout to the wing to help prevent low speed stalling, I have been using up ailerons on everything I fly for years due to a small flying patch and steep approach's needed, Oh yes up ailerons also reduce wing rock in a harrier if you are into 3D flying.
Who will be first to fire the gun. LOL [sm=tongue_smile.gif]
Mike
With the risk of being shot at I will try to answer your question, from 15deg up to about 40degs of flap you will get increased lift as well as increased drag, therefore not much difference on thrust level required from a normal landing, just needs to be set up to float in on a fairly long approach, from approx 45degs to 90degs drag will increase dramatically over the lift that will be produced by dropping the flaps, which will slow the approach and increase the rate of decent, therefore an increase in thrust is required to keep the wing flying and the airflow as smooth as possible over the wing at the higher angle of attack needed to keep flying, at this sort of angle of attack the wing is pushing a cushion of air in front of it and the flaps to a certain extent are holding it there, in an ideal situation if you have the facility in your Tx to put the ailerons up whilst the flaps are down you get the best of both worlds, lots of drag to slow you down, and a reduction in lift by the ailerons acting as spoilers, but adding washout to the wing to help prevent low speed stalling, I have been using up ailerons on everything I fly for years due to a small flying patch and steep approach's needed, Oh yes up ailerons also reduce wing rock in a harrier if you are into 3D flying.
Who will be first to fire the gun. LOL [sm=tongue_smile.gif]
Mike
01-26-2009, 12:49 PM
#2302
RE: Bob Cat Copy Falcon 120 Jet
ORIGINAL: Vettdriver
Mine slows down pretty well at 45deg. which is the most throw I can get.
But I'm going to cut them off and rework them to get more just because I can.
Mine slows down pretty well at 45deg. which is the most throw I can get.
But I'm going to cut them off and rework them to get more just because I can.
If you are going to cut them off, just swap them over to the other wing and turn them upsidedown you then have a straight edge at the TE of the wing to put in Robart pin hinges, you wont need the 125deg's you can then get, but it makes it an easy job.
Mike
01-26-2009, 02:17 PM
#2303
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RE: Bob Cat Copy Falcon 120 Jet
ORIGINAL: Crazy4Flight
Jeff,
If you are mixing rudder to an AUX channel for your steering add expo at least 50% to reduce sensitivity.
bob
ORIGINAL: jramirez
Joe,
You were right about the back angle to the nose gear issue. I finished up my Falcon and did some range test and ground runs but found the steering way too sensitive with the angle placed forward. I did this so the gear hinge would not hit the retract well and crack it. I saw how you raised yours to fit the retract better, but I had already installed mine and did not want to break the well apart trying to get it out. I almost cartwheeled the plane just running it up to speed due to the wandering effect the angle forward created. I am going to turn it around and try again. I also had a fuel leak with a pinhole in the line which fill my fuselage with full while taxiing around. I used alot of the old stuff from my first Falcon and had a small piece of fuel tubing that got kinked in the first crash that I had not noticed. Oh well, back to the drawing board.
Jeff
ORIGINAL: joeflyer
Jeff,
Not sure if I understand your issue. Perhaps a picture would help. If you're referring to the scissor hinge on the strut; it doesn't make any difference if it faces forward or aft. You will have much better ground control if your nose wheel is angled back somewhat.
Joe
Jeff,
Not sure if I understand your issue. Perhaps a picture would help. If you're referring to the scissor hinge on the strut; it doesn't make any difference if it faces forward or aft. You will have much better ground control if your nose wheel is angled back somewhat.
Joe
Joe,
You were right about the back angle to the nose gear issue. I finished up my Falcon and did some range test and ground runs but found the steering way too sensitive with the angle placed forward. I did this so the gear hinge would not hit the retract well and crack it. I saw how you raised yours to fit the retract better, but I had already installed mine and did not want to break the well apart trying to get it out. I almost cartwheeled the plane just running it up to speed due to the wandering effect the angle forward created. I am going to turn it around and try again. I also had a fuel leak with a pinhole in the line which fill my fuselage with full while taxiing around. I used alot of the old stuff from my first Falcon and had a small piece of fuel tubing that got kinked in the first crash that I had not noticed. Oh well, back to the drawing board.
Jeff
If you are mixing rudder to an AUX channel for your steering add expo at least 50% to reduce sensitivity.
bob
I did add 50% expo but was having an issue with the steering not tracking where I intended it to go. In other words, I would be going straight, then the gear leg would lean slightly and cause it to drift pretty severely, then correction would overcorrect and it would veer severely the other direction. The pull pull seems tight but the slop in the gear strut combined with the reverse direction the angle of the strut is facing seems to both be working to cause this.
Anyone have any input on this problem?
Jeff
01-26-2009, 04:53 PM
#2304
RE: Bob Cat Copy Falcon 120 Jet
Jeff
If you have the leg pointing forwards you will get odd steering traints the leg should be pointing backwards to achive the correct Ackerman angle, this is the lean back you have on your king pins on the front of your car to get self centering on your steering. Look up Ackerman angle in the dictionary it will explain it better than I have.
Mike
If you have the leg pointing forwards you will get odd steering traints the leg should be pointing backwards to achive the correct Ackerman angle, this is the lean back you have on your king pins on the front of your car to get self centering on your steering. Look up Ackerman angle in the dictionary it will explain it better than I have.
Mike
01-26-2009, 05:27 PM
#2305
My Feedback: (48)
RE: Bob Cat Copy Falcon 120 Jet
Jeff,
I'm not sure what Ackerman said but if you can bend the strut back about 20 degrees or so near the top of the wheel it will give it a self centering or caster effect. Your tracking and steering will be greatly improved.
See picture. Yes, I know that the strut coil is facing forward. See post #2208.
Ed,
I use about 45 degrees for full flaps. The plane can slow down to almost walking speed when landing.
Joe
I'm not sure what Ackerman said but if you can bend the strut back about 20 degrees or so near the top of the wheel it will give it a self centering or caster effect. Your tracking and steering will be greatly improved.
See picture. Yes, I know that the strut coil is facing forward. See post #2208.
Ed,
I use about 45 degrees for full flaps. The plane can slow down to almost walking speed when landing.
Joe
01-26-2009, 06:03 PM
#2306
RE: Bob Cat Copy Falcon 120 Jet
ORIGINAL: BaldEagel
Jeff
If you have the leg pointing forwards you will get odd steering traints the leg should be pointing backwards to achive the correct Ackerman angle, this is the lean back you have on your king pins on the front of your car to get self centering on your steering. Look up Ackerman angle in the dictionary it will explain it better than I have.
Mike
Jeff
If you have the leg pointing forwards you will get odd steering traints the leg should be pointing backwards to achive the correct Ackerman angle, this is the lean back you have on your king pins on the front of your car to get self centering on your steering. Look up Ackerman angle in the dictionary it will explain it better than I have.
Mike
01-26-2009, 06:59 PM
#2307
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RE: Bob Cat Copy Falcon 120 Jet
ORIGINAL: joeflyer
Ed,
I use about 45 degrees for full flaps. The plane can slow down to almost walking speed when landing.
Joe
Ed,
I use about 45 degrees for full flaps. The plane can slow down to almost walking speed when landing.
Joe
Thanks again gyz.
Ed
01-26-2009, 07:41 PM
#2308
RE: Bob Cat Copy Falcon 120 Jet
Of course you are all correct its castor angle and not Ackerman, you will have to forgive an old man his lack of memory, my excuse is its my birthday today and I started a little early.
"Rudolf Ackerman discovered and defined this principle early in the 19th century. Since then Ackerman Steering has had a huge impact on many different vehicles.
Ackerman Steering is used on all sizes of vehicles from full size down to scale models, no matter if it is 2wd or 4wd.
Some refer to Ackerman as the degree of toe-in or toe-out a wheel or tire has. Ackerman does have a relationship with the amount of toe-in or toe-out on your rc vehicle.
But, Ackerman Steering deals with the angle of inside tire and outside tire in a corner or curve relative to the degree of toe-in or toe-out. Will that is about as clear as mud. Let see if we can clear it all up.
I will throw myself on my sword the next time I get it out to clean it, appoligies to anyone I may have confused including myself. hic [:-]
Mike
"Rudolf Ackerman discovered and defined this principle early in the 19th century. Since then Ackerman Steering has had a huge impact on many different vehicles.
Ackerman Steering is used on all sizes of vehicles from full size down to scale models, no matter if it is 2wd or 4wd.
Some refer to Ackerman as the degree of toe-in or toe-out a wheel or tire has. Ackerman does have a relationship with the amount of toe-in or toe-out on your rc vehicle.
But, Ackerman Steering deals with the angle of inside tire and outside tire in a corner or curve relative to the degree of toe-in or toe-out. Will that is about as clear as mud. Let see if we can clear it all up.
I will throw myself on my sword the next time I get it out to clean it, appoligies to anyone I may have confused including myself. hic [:-]
Mike
01-26-2009, 08:05 PM
#2310
RE: Bob Cat Copy Falcon 120 Jet
ORIGINAL: BaldEagel
Of course you are all correct its castor angle and not Ackerman, you will have to forgive an old man his lack of memory, my excuse is its my birthday today and I started a little early.
"Rudolf Ackerman discovered and defined this principle early in the 19th century. Since then Ackerman Steering has had a huge impact on many different vehicles.
Ackerman Steering is used on all sizes of vehicles from full size down to scale models, no matter if it is 2wd or 4wd.
Some refer to Ackerman as the degree of toe-in or toe-out a wheel or tire has. Ackerman does have a relationship with the amount of toe-in or toe-out on your rc vehicle.
But, Ackerman Steering deals with the angle of inside tire and outside tire in a corner or curve relative to the degree of toe-in or toe-out. Will that is about as clear as mud. Let see if we can clear it all up.
I will throw myself on my sword the next time I get it out to clean it, appoligies to anyone I may have confused including myself. hic [:-]
Mike
Of course you are all correct its castor angle and not Ackerman, you will have to forgive an old man his lack of memory, my excuse is its my birthday today and I started a little early.
"Rudolf Ackerman discovered and defined this principle early in the 19th century. Since then Ackerman Steering has had a huge impact on many different vehicles.
Ackerman Steering is used on all sizes of vehicles from full size down to scale models, no matter if it is 2wd or 4wd.
Some refer to Ackerman as the degree of toe-in or toe-out a wheel or tire has. Ackerman does have a relationship with the amount of toe-in or toe-out on your rc vehicle.
But, Ackerman Steering deals with the angle of inside tire and outside tire in a corner or curve relative to the degree of toe-in or toe-out. Will that is about as clear as mud. Let see if we can clear it all up.
I will throw myself on my sword the next time I get it out to clean it, appoligies to anyone I may have confused including myself. hic [:-]
Mike
01-26-2009, 08:09 PM
#2311
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RE: Bob Cat Copy Falcon 120 Jet
ORIGINAL: BaldEagel
Of course you are all correct its castor angle and not Ackerman, you will have to forgive an old man his lack of memory, my excuse is its my birthday today and I started a little early.
"Rudolf Ackerman discovered and defined this principle early in the 19th century. Since then Ackerman Steering has had a huge impact on many different vehicles.
Ackerman Steering is used on all sizes of vehicles from full size down to scale models, no matter if it is 2wd or 4wd.
Some refer to Ackerman as the degree of toe-in or toe-out a wheel or tire has. Ackerman does have a relationship with the amount of toe-in or toe-out on your rc vehicle.
But, Ackerman Steering deals with the angle of inside tire and outside tire in a corner or curve relative to the degree of toe-in or toe-out. Will that is about as clear as mud. Let see if we can clear it all up.
I will throw myself on my sword the next time I get it out to clean it, appoligies to anyone I may have confused including myself. hic [:-]
Mike
Of course you are all correct its castor angle and not Ackerman, you will have to forgive an old man his lack of memory, my excuse is its my birthday today and I started a little early.
"Rudolf Ackerman discovered and defined this principle early in the 19th century. Since then Ackerman Steering has had a huge impact on many different vehicles.
Ackerman Steering is used on all sizes of vehicles from full size down to scale models, no matter if it is 2wd or 4wd.
Some refer to Ackerman as the degree of toe-in or toe-out a wheel or tire has. Ackerman does have a relationship with the amount of toe-in or toe-out on your rc vehicle.
But, Ackerman Steering deals with the angle of inside tire and outside tire in a corner or curve relative to the degree of toe-in or toe-out. Will that is about as clear as mud. Let see if we can clear it all up.
I will throw myself on my sword the next time I get it out to clean it, appoligies to anyone I may have confused including myself. hic [:-]
Mike
Whatever the principle it's called that is causing this effect, it sure is profound. I almost cartwheeled the Falcon just taxiing it around. I wasn't even up to half lift off speed when it became uncontrolable. Very scary indeed. I will turn this nose gear around and report back on further testing. Once again thanks for the input.
Jeff
01-26-2009, 09:37 PM
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RE: Bob Cat Copy Falcon 120 Jet
Jeff,
Not sure why your having the issue you are. Mine is set up on a Y-harness from the rudders with nothing more than 50% expo.
However, If you are over controlling the nosewheel and you can't dial it down digitally you can always go with a smaller servo horn for your steering to reduce the throw.
Not sure why your having the issue you are. Mine is set up on a Y-harness from the rudders with nothing more than 50% expo.
However, If you are over controlling the nosewheel and you can't dial it down digitally you can always go with a smaller servo horn for your steering to reduce the throw.
01-26-2009, 10:21 PM
#2313
My Feedback: (48)
RE: Bob Cat Copy Falcon 120 Jet
Jeff,
I'm inclined to agree with Vett. It will definitely help to have your nose wheel castered back, however from what you described it sounds like you have way too much steering throw. Depending on the jet, a lot of guys use dual rates; high rate for taxiing out and a low rate that is just enough to keep it on the runway. Try an experiment with your steering rate dialed down and see if that doesn't help.
Joe
I'm inclined to agree with Vett. It will definitely help to have your nose wheel castered back, however from what you described it sounds like you have way too much steering throw. Depending on the jet, a lot of guys use dual rates; high rate for taxiing out and a low rate that is just enough to keep it on the runway. Try an experiment with your steering rate dialed down and see if that doesn't help.
Joe
01-27-2009, 07:42 AM
#2314
RE: Bob Cat Copy Falcon 120 Jet
ORIGINAL: rjbob
Happy birthday, Mike!
Happy birthday, Mike!
Mike
01-27-2009, 07:47 AM
#2315
RE: Bob Cat Copy Falcon 120 Jet
ORIGINAL: jramirez
Well Mike,
Whatever the principle it's called that is causing this effect, it sure is profound. I almost cartwheeled the Falcon just taxiing it around. I wasn't even up to half lift off speed when it became uncontrolable. Very scary indeed. I will turn this nose gear around and report back on further testing. Once again thanks for the input.
Jeff
Well Mike,
Whatever the principle it's called that is causing this effect, it sure is profound. I almost cartwheeled the Falcon just taxiing it around. I wasn't even up to half lift off speed when it became uncontrolable. Very scary indeed. I will turn this nose gear around and report back on further testing. Once again thanks for the input.
Jeff
As the last few posts, try it on the ground without the turbine running, just push the airframe along with the rudder/nosewheel deflected and see how much it moves to one side, with a three wheel UC its supprising little movement that is needed on the nose wheel to get a large amount of movement from the fus. Let us know how you get on.
Mike
01-28-2009, 08:07 AM
#2316
RE: Bob Cat Copy Falcon 120 Jet
Just a quick pic to show the wheel well covers I am making to cover over all the reinforcement I doing to the wings, still have to line the wheel well.
Mike
Mike
01-28-2009, 08:20 PM
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RE: Bob Cat Copy Falcon 120 Jet
Hey Guys,
I turned the nose wheel around and it made all the difference in the world. The forward angle made the steering too sensitive. I think with the strut angled back it has inherent self centering and makes it more stable. The Falcon is done and should be flying this weekend. Once again thanks for all the input with this problem.
Jeff
I turned the nose wheel around and it made all the difference in the world. The forward angle made the steering too sensitive. I think with the strut angled back it has inherent self centering and makes it more stable. The Falcon is done and should be flying this weekend. Once again thanks for all the input with this problem.
Jeff
01-29-2009, 09:25 AM
#2318
RE: Bob Cat Copy Falcon 120 Jet
Jeff
Glad it worked out in the end.
A few more pics of the wheel wells, for you guys i the UK they are the basin that a Sainsburys Steak and Kidney pudding comes in, an added bonus is that epoxy does not stick very well to it, so I use them to mix my epoxy in and then just flex the sides and it all falls off.
Just need to tidy up the hinge points for the flaps and the hole cut for access to the wing bolts and then start on the other wing, been a long job as I have been fiddling with the Rookie as well.
Mike
Glad it worked out in the end.
A few more pics of the wheel wells, for you guys i the UK they are the basin that a Sainsburys Steak and Kidney pudding comes in, an added bonus is that epoxy does not stick very well to it, so I use them to mix my epoxy in and then just flex the sides and it all falls off.
Just need to tidy up the hinge points for the flaps and the hole cut for access to the wing bolts and then start on the other wing, been a long job as I have been fiddling with the Rookie as well.
Mike
01-30-2009, 07:37 AM
#2319
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RE: Bob Cat Copy Falcon 120 Jet
Well I finally got a video of a flight, and landings do not get any smother than this one... BTW I don't fly anymore than half throttle except in vertical climbs so you can see the power potential of the T-750. This is a great turbine combo if you have the discipline to use throttle management. http://www.youtube.com/watch?v=blqFiqgGB7A
01-30-2009, 07:58 AM
#2321
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RE: Bob Cat Copy Falcon 120 Jet
I uses a 9303 2.4 radio and I found this mix on RCU which I believe is used with BVM KingCat, I used the settings verbatim and all I had to do was add about 5mm of down elevator.
Ok, here we go. I am going to start with setting up a brand new model.
1) Enter System Menu (hold "ENT" and turn readio on). You should know how to set up the Model Name and Type Select.
2) Under "DeviceSel", select "Flight Mode" and then selct "Flap SW".
3) I have the following switches activated: Gear - Act, Flap - Sys., Aux2 - Inh, Aux3 - Act (brakes), Aux4 - Act (smoke and I have it using the "BUTN" switch.
4) Hit "List"
4) Now go to "Wing Type"
5) Wing type is set to "Normal"
6) Go to Dual - Aile and select "AUX2". This automaticall sets up Aux2 as your opposite aileron.
7) Now, hit "ENT"
8) Set up your "Flap Sys" to your desired settings. Adjust both your flaps and elevators to the desired throws.
9) Now, the only mix you have to do: Go to mix 1 or 2 (multi-point mixes), and set up a "Flap to FPRN" mix. The diagram on the right will show your flap and aileron (or flaperon) settings. The horizontal line is ailerons and the vertical line is flap position. As you adjust your flap switch, you will see the vertical line move across the diagram. Here are my settings for this mix:
Point 0 -60
Point 1 INH
Point 2 INH
Point 3 0
Point 4 0
Point 5 0
Point 6 0
The -60 above shows how much aileron I have for my crow.
Ok, here we go. I am going to start with setting up a brand new model.
1) Enter System Menu (hold "ENT" and turn readio on). You should know how to set up the Model Name and Type Select.
2) Under "DeviceSel", select "Flight Mode" and then selct "Flap SW".
3) I have the following switches activated: Gear - Act, Flap - Sys., Aux2 - Inh, Aux3 - Act (brakes), Aux4 - Act (smoke and I have it using the "BUTN" switch.
4) Hit "List"
4) Now go to "Wing Type"
5) Wing type is set to "Normal"
6) Go to Dual - Aile and select "AUX2". This automaticall sets up Aux2 as your opposite aileron.
7) Now, hit "ENT"
8) Set up your "Flap Sys" to your desired settings. Adjust both your flaps and elevators to the desired throws.
9) Now, the only mix you have to do: Go to mix 1 or 2 (multi-point mixes), and set up a "Flap to FPRN" mix. The diagram on the right will show your flap and aileron (or flaperon) settings. The horizontal line is ailerons and the vertical line is flap position. As you adjust your flap switch, you will see the vertical line move across the diagram. Here are my settings for this mix:
Point 0 -60
Point 1 INH
Point 2 INH
Point 3 0
Point 4 0
Point 5 0
Point 6 0
The -60 above shows how much aileron I have for my crow.
01-30-2009, 08:40 AM
#2322
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RE: Bob Cat Copy Falcon 120 Jet
Here is another flight of the Falcon 120, love the low flybys and verticals... http://www.youtube.com/watch?v=AdBrdxaUXNQ
01-30-2009, 09:29 AM
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RE: Bob Cat Copy Falcon 120 Jet
ORIGINAL: BirdofpraY
Here is another flight of the Falcon 120, love the low flybys and verticals... http://www.youtube.com/watch?v=AdBrdxaUXNQ
Here is another flight of the Falcon 120, love the low flybys and verticals... http://www.youtube.com/watch?v=AdBrdxaUXNQ
Don't feel you have to let the peanut gallery influence your flybys!
Jeff
01-30-2009, 09:39 AM
#2324
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RE: Bob Cat Copy Falcon 120 Jet
The Peanut gallery are good friends and they always push for the extra excitemant. Oh and the guy that said lower is partial owner of this jet... lol... I used his Elan retracts and struts and some servos from his X-Elan. In all for a low cost jet with lay around parts and and a few mods this is a great jet and plan to build another one later on and will do something alittle diffrent to support full throttle flights in the next version.