Bob Cat Copy Falcon 120 Jet
#5001
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Look into the wing through one of the holes in the root and see which way the shear web is installed. They should be vertical. Some of the early ones had webbing installed with the grain horizontal. It's pretty much a total rebuild of the wings if they are wrong.
There are a couple of sources for fuel tanks made specifically for the Falcon. Pretty much have to remove all the rear formers to get it in but they fit.
Some needed the motor platform reinforced, I didn't on mine.
They fly fairly well if balanced properly, a lot of fun.
I'm using a P-60 on the version I'm flying.
John
There are a couple of sources for fuel tanks made specifically for the Falcon. Pretty much have to remove all the rear formers to get it in but they fit.
Some needed the motor platform reinforced, I didn't on mine.
They fly fairly well if balanced properly, a lot of fun.
I'm using a P-60 on the version I'm flying.
John
#5002
My first Falcon 120 was 60 powered (a Wren 54 Mk3 rated 63N, 14 lb). That was perfectly adequate for a good performance and manoeuvrability.
I used the KISS principle: fixed gear, big battery well forward and no ballast, standard servos, single large glass fibre tank (made myself, 2.2 litre).
The only reinforcing I did was a little epoxy mixer with Kevlar fibres around the blind nuts that held the booms to the wings, and I changed to steel bolts.
I shortened the legs to reduce stress on the mountings.
The weight was about 6 kg, 13 pounds.
My first eventually hit a fence. My second one (still in box) will be similar.
I used the KISS principle: fixed gear, big battery well forward and no ballast, standard servos, single large glass fibre tank (made myself, 2.2 litre).
The only reinforcing I did was a little epoxy mixer with Kevlar fibres around the blind nuts that held the booms to the wings, and I changed to steel bolts.
I shortened the legs to reduce stress on the mountings.
The weight was about 6 kg, 13 pounds.
My first eventually hit a fence. My second one (still in box) will be similar.
#5003
Wow, long thread! I have a question. I have a chance to pick up a red falcon 120. It does not appear to be carbon fiber reinforced. I have no skills that would allow me to do “ mods” to the kit for turbine use. I have read several threads that say you can, in fact, fly these without the mods if you keep the power to a 60 size turbine, and don’t fly at full throttle for extended time, or when turning the jet at speed. What do you guys think? I’ve had a couple before, and they were a nice , small jet I could haul in my Durango and not have to pull my trailer....good off my local grass field...my other jets are bigger, and composite. I would appreciate any feed back...
I am on my 6th Falcon 1.20 and I love them. All have been the gen 1 or 2 (no carbon fibre) and I have found that at the minimum you will have to reinforce/re-glue the u/c mounts. I have photos of the process somewhere in this forum. My first Falcon had no mods done, was fitted with a Kingtech K80 and electric retracts. The second landing (not hard) resulted in the left hand main coming out of the wing, bearers and all. Inspection of the other side showed that the flour and water glue they used was about to let go as well. After fixing that problem and replacing the 22mm wing joining tube (original too short) it went on to have 70+ flights before I sold it to buy another.
Since number 2 and beyond I do the following with each new Falcon before flying.
1. Do the u/c bearer mod. (at the same time I change the angle of the bearers to allow fitting of trailing arm u/c legs,, note trailing ARM not trailing link,,, )
2. Measure the exact length of wing joiner tube required and replace the original.
3. Remove/reshape rear fuse formers to accept after market conformal fuel tank (2.6l)
4. If the wings are open bay structure I remove the covering and fully sheet them. (It is my personal choice to do so.)
5. Throw away all nylon wing/boom bolts and replace with steel.
6. I also fit the flaps upside down and surface hinge them to give added deflection.
You don't need to do most of these if you don't want but I suggest you re-glue the u/c bearers as a minimum.
Regards
Col
#5004
Junior Member
Falcon 120 on a 45N Turbine ?
I have a Falcon 120 with a Wren 80 on the back. It goes like stink and is a joy to fly. Problem is I want the engine ( and the heavy Electron retracts and brakes )for another plane .
I have a new Xicoy X45 that I am thinking of using on the Falcon. I will use some light cheapo HK retract units and some wire legs with no brakes to save weight . Fuel tank is currently a 2L pop bottle but will be substituted for a 1L bottle to save weight
Has anyone flown one of these on a 45N turbine ?
I have a new Xicoy X45 that I am thinking of using on the Falcon. I will use some light cheapo HK retract units and some wire legs with no brakes to save weight . Fuel tank is currently a 2L pop bottle but will be substituted for a 1L bottle to save weight
Has anyone flown one of these on a 45N turbine ?
#5005
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I have a Falcon 120 with a Wren 80 on the back. It goes like stink and is a joy to fly. Problem is I want the engine ( and the heavy Electron retracts and brakes )for another plane .
I have a new Xicoy X45 that I am thinking of using on the Falcon. I will use some light cheapo HK retract units and some wire legs with no brakes to save weight . Fuel tank is currently a 2L pop bottle but will be substituted for a 1L bottle to save weight
Has anyone flown one of these on a 45N turbine ?
I have a new Xicoy X45 that I am thinking of using on the Falcon. I will use some light cheapo HK retract units and some wire legs with no brakes to save weight . Fuel tank is currently a 2L pop bottle but will be substituted for a 1L bottle to save weight
Has anyone flown one of these on a 45N turbine ?
Have fun.
#5006
Junior Member
Thanks Terry...not in the US so no need for brakes :-))….I too can see no reason why not ..the X45 is really light and I think ,with the reduced weight, the package should be good....was just wondering if anyone actually flies one of these with a 45 ? ( reality as opposed to theory
#5007
Not an X-45 but a friend flew one with a Wren 44 Gold turbine.
Not a wonderful result, the Falcon 120 is a big, draggy aircraft & it had to fly at high throttle
settings to make headway & was a slow upwind, fast downwind model. While it was light
it would waft around & not fly jet like at all. At least take off & landing speeds were low.
He only flew it twice & bent the crappy standard wire undercarriage legs on the second landing.
At this point he lost interest in it, removed the gear & engine & gave it away.
Not a wonderful result, the Falcon 120 is a big, draggy aircraft & it had to fly at high throttle
settings to make headway & was a slow upwind, fast downwind model. While it was light
it would waft around & not fly jet like at all. At least take off & landing speeds were low.
He only flew it twice & bent the crappy standard wire undercarriage legs on the second landing.
At this point he lost interest in it, removed the gear & engine & gave it away.
#5008
Junior Member
Thanks Boomerang......food for thought !!
It is quite a "slippery" airframe with the Wren80 installed....fast and takes quite a bit of slowing down ..I tend to fly on about 1/2 throttle most of the time unless I want a bit of an adrenaline rush :-) ...but I too fear I may have to give it max beans all the time with just a 45 …..and I really don't want it wobbling about in the air and struggling like the old IC Ducted Fans used to.. ..so..perhaps this will be one idea I should shelve !
It is quite a "slippery" airframe with the Wren80 installed....fast and takes quite a bit of slowing down ..I tend to fly on about 1/2 throttle most of the time unless I want a bit of an adrenaline rush :-) ...but I too fear I may have to give it max beans all the time with just a 45 …..and I really don't want it wobbling about in the air and struggling like the old IC Ducted Fans used to.. ..so..perhaps this will be one idea I should shelve !
#5010
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Need info help with Falcon 120 plz....
Hi I recently acquired a falcon120 from an auction and have never worked on an R/C plane and was hoping you may be able to help me identify the parts and see what maybe missing or if it is worth messing with. I would appreciate any help you are willing to give, Thanks for your time in advance. Dell Howard (Dkat)
#5011
Hi I recently acquired a falcon120 from an auction and have never worked on an R/C plane and was hoping you may be able to help me identify the parts and see what maybe missing or if it is worth messing with. I would appreciate any help you are willing to give, Thanks for your time in advance. Dell Howard (Dkat)
Col
#5012
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You are right about the level of it....
I tried to list everything that had came with the model and am sending it to you. I wish I knew more but having to learn as I go and don't know if this is worth the time and expense to pursue...
I hope this attached so you can see it, if not let me know and I will redo......Thanks
I hope this attached so you can see it, if not let me know and I will redo......Thanks
#5013
I tried to list everything that had came with the model and am sending it to you. I wish I knew more but having to learn as I go and don't know if this is worth the time and expense to pursue...
I hope this attached so you can see it, if not let me know and I will redo......Thanks
I hope this attached so you can see it, if not let me know and I will redo......Thanks
The model itself though is not suitable for a learner pilot or builder.
Here are some of my 1.20s
#5014
HELP NEEDED
I built and flew one of these years ago on a Wren54 and it flew great. Until on day it met a fence.
I bought a new kit and put it in storage. Now I'm thinking of building it, I cannot find any note of reference to the amount of up elevator needed for trim.
Can anyone tell me please, how much up elevator is needed to trim it out?
I built and flew one of these years ago on a Wren54 and it flew great. Until on day it met a fence.
I bought a new kit and put it in storage. Now I'm thinking of building it, I cannot find any note of reference to the amount of up elevator needed for trim.
Can anyone tell me please, how much up elevator is needed to trim it out?
#5015
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I dont have any in my navycat and I dont remember putting any on the falcon I built either, are you thinking alister its a tail incidence issue? I would need to put mine together to double check but cant remember anything about this, my model trimming has always been if it has up elevator trimmed in then its bit nose heavy, I know my main battery is further back now than when I first flew it.
#5016
Thanks for the quick response Xairflyer,
The photos of my old model definately show the elevator set up from the flat bottom of the section by a large amount. But I can't measure it off the photos. And I can't find any written information in my notes.
If you lay a ruler along the flat bottom of the tail, how much gap would there be between the ruler and the TE of the elevator?
There must be some! surely?
I always thought that the flat bottom section was quite wrong aerodynamically, but it's convenient and kind of works. The model flew very well. It just looks wrong.
I'll build the new one with the kit tailplane, but may change it to a symmetrical section at some time.
I don't think it is a building error. I used all the kit parts and they fitted very well. I was hoping somebody more organised than myself would know. Or have one handy.
The photos of my old model definately show the elevator set up from the flat bottom of the section by a large amount. But I can't measure it off the photos. And I can't find any written information in my notes.
If you lay a ruler along the flat bottom of the tail, how much gap would there be between the ruler and the TE of the elevator?
There must be some! surely?
I always thought that the flat bottom section was quite wrong aerodynamically, but it's convenient and kind of works. The model flew very well. It just looks wrong.
I'll build the new one with the kit tailplane, but may change it to a symmetrical section at some time.
I don't think it is a building error. I used all the kit parts and they fitted very well. I was hoping somebody more organised than myself would know. Or have one handy.
#5017
My Feedback: (13)
If it is balanced properly you do not need any elevator trim, except with the flaps. The elevator is trimmed when a straight edge across the TOP surface of the elevator is flush. A bit of down thrust on the turbine as well, about 3-5 degrees. The usually accepted CG is about 13 in. from the leading edge at the fuse.
John
John
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alasdair (07-09-2020)
#5019
Thank you to you both.
My model is a Falcon, but I posted the question in the Tornado thread as well as I knew they were geometrically similar, but the Tornado is newer.
Your answers are precise and helpful.
Alasdair
My model is a Falcon, but I posted the question in the Tornado thread as well as I knew they were geometrically similar, but the Tornado is newer.
Your answers are precise and helpful.
Alasdair
#5020
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Thanks for the quick response Xairflyer,
The photos of my old model definately show the elevator set up from the flat bottom of the section by a large amount. But I can't measure it off the photos. And I can't find any written information in my notes.
If you lay a ruler along the flat bottom of the tail, how much gap would there be between the ruler and the TE of the elevator?
There must be some! surely?
I always thought that the flat bottom section was quite wrong aerodynamically, but it's convenient and kind of works. The model flew very well. It just looks wrong.
I'll build the new one with the kit tailplane, but may change it to a symmetrical section at some time.
I don't think it is a building error. I used all the kit parts and they fitted very well. I was hoping somebody more organised than myself would know. Or have one handy.
The photos of my old model definately show the elevator set up from the flat bottom of the section by a large amount. But I can't measure it off the photos. And I can't find any written information in my notes.
If you lay a ruler along the flat bottom of the tail, how much gap would there be between the ruler and the TE of the elevator?
There must be some! surely?
I always thought that the flat bottom section was quite wrong aerodynamically, but it's convenient and kind of works. The model flew very well. It just looks wrong.
I'll build the new one with the kit tailplane, but may change it to a symmetrical section at some time.
I don't think it is a building error. I used all the kit parts and they fitted very well. I was hoping somebody more organised than myself would know. Or have one handy.
#5021
I like mine a little nose heavy so mine has a little up trim. Just set it with the methods above and maiden it. I much prefer to be holding back stick while trimming on a maiden than pushing forward. My latest Falcon has about 1/8th inch of down elevator with full flap.
Col
Col
#5022
My Feedback: (10)
I've been off and on (mostly off) working on my Falcon 120. Honestly it needs to get finished so I'm putting it on the table for this winter. I no longer have a turbine for it as I put the JC Rabbit VT-90 (propane start) in my TopRC Cougar that hopefully I will maiden any day now. Open to new ideas for this powerplant. Probably want another JC or Kingtech though, not opposed to lightly used.
Questions for the experts as I've lost some of my notes over the years
-Throws for all surfaces even flaps?
-elevator throw when flaps are deployed?
-Where is the CG measured from and located?
I had the Hatch redone over the summer by a friend so its time to start glassing the wings and assembly prior to paint.
Questions for the experts as I've lost some of my notes over the years
-Throws for all surfaces even flaps?
-elevator throw when flaps are deployed?
-Where is the CG measured from and located?
I had the Hatch redone over the summer by a friend so its time to start glassing the wings and assembly prior to paint.
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dhamultun (02-07-2021)