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Bob Cat Copy Falcon 120 Jet

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Bob Cat Copy Falcon 120 Jet

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Old 12-29-2016, 06:52 AM
  #4926  
sweetpea01
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Thanks Ed. I'm still thinking I'll try the direct link but not sure exactly how'll I'll make it work
Old 12-30-2016, 03:51 PM
  #4927  
sweetpea01
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Got a few things done this week.

1a. Got the nose wheel steering is figured out. It's going to look like the video below. Since the glue was crap holding in the braces I tore the whole front thing out and will attach the servo to the front of it. I used a temp servo for the time being to set it up. I'll post a video once I clean things up a bit.
https://www.youtube.com/watch?v=iE505LhvYrI

1.a I'm also going to Carbon Fiber glass the wheel mounts and create storage areas for my airtanks so they are upfront. Probably some Battery and weight holders (so I can change the CG easier)


2. I found 4 JR8611A's I had left over from other builds. So now I only need 3 servos (1 being nose steering)

3. I ordered my engine mount and ordered a centerline A4 tank that will be used for smoke (after a few flights)

4. I tore out the blind nuts in the booms and the wings and put 1/4x20 in. Then I cut and Hysol'd bolts into the wings. I use nylon wing nuts on them as attachment points in the fuse. Been doing that on 42% gassers for years and they never come loose and are easy to put on and change out on yearly maint.

5. I put a wood dowl in the boom hole on the wing. I want my bolts more flush and it will be easier to glass this way.

Last edited by sweetpea01; 12-30-2016 at 03:53 PM.
Old 01-10-2017, 12:23 PM
  #4928  
sweetpea01
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Weather here has been horrendous! It's been 60, flooding rain, then zero, then snow, then zero, now wind and rain and going to upper 50's.

I finished creating my direct link to the nose gear but I don't like it. It will create a tiller bar that is longer than I want (otherwise the linkage hits the wood gear mount) which will require a really large cutout for the nose gear and I was going to do a gear door similar to the BVM Bobcat for ease of use. So I'm probably going with the wire pull-pull setup.

I installed my Turnigy lights in the wing just to see how it will look. They are really a night/dusk light system so I might pull that out and do something brighter before I glass things up. I'm still waiting on my small wingtube and some hardware to show up. I got my 5degree engine mount though. I sanded the wing dowl down and that is now flush.

Just hasn't been a good couple of weeks for me in the shop. This weekend though I will be at it.
Old 07-24-2017, 12:40 PM
  #4929  
Dpienaar
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Default Kt p80

Originally Posted by Dr Honda
For the new guys, just coming into the Falcon group... Todd at DreamWorks sells my motor mounts now.


Here are the 0 degree mounts. (what I use)

http://dreamworksrc.com/catalog/falc...ee-p-2405.html

Here are the 5 Degree mounts that most of the guys here use.

http://dreamworksrc.com/catalog/falc...ee-p-2406.html



Click image for larger version

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Hallo what diferance does the 5dg down do vs the 0dg DW only have the 5dg mounts in atock
Old 07-24-2017, 12:41 PM
  #4930  
Dpienaar
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Default Kt p80

Originally Posted by Dr Honda
For the new guys, just coming into the Falcon group... Todd at DreamWorks sells my motor mounts now.


Here are the 0 degree mounts. (what I use)

http://dreamworksrc.com/catalog/falc...ee-p-2405.html

Here are the 5 Degree mounts that most of the guys here use.

http://dreamworksrc.com/catalog/falc...ee-p-2406.html



Click image for larger version

Name:	PB281135.jpg
Views:	118
Size:	7.0 KB
ID:	2225477
Hallo what diferance does the 5dg down do vs the 0dg DW only have the 5dg mounts in atock
Old 07-24-2017, 02:16 PM
  #4931  
edwarda10pilot
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Originally Posted by Dpienaar
Hallo what diferance does the 5dg down do vs the 0dg DW only have the 5dg mounts in atock
If you do not put the 5* of down thrust, you will have to re-trim the plane every time you make a change in throttle setting. A number of us have spent a lot of time making changes to the thrust of the engine to find the setting that requires NO TRIM changes with different throttle settings. That thrust setting is 5* of down thrust.

Ed
Old 07-25-2017, 04:06 AM
  #4932  
Dr Honda
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Originally Posted by edwarda10pilot
If you do not put the 5* of down thrust, you will have to re-trim the plane every time you make a change in throttle setting. A number of us have spent a lot of time making changes to the thrust of the engine to find the setting that requires NO TRIM changes with different throttle settings. That thrust setting is 5* of down thrust.

Ed
Not true. I fly mine with zero mounts, and there isn't any real change in trim. But mine is heavy... so that may make a difference.
Old 07-25-2017, 06:32 AM
  #4933  
why_fly_high
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Originally Posted by Dr Honda
Not true. I fly mine with zero mounts, and there isn't any real change in trim. But mine is heavy... so that may make a difference.
If you always fly at one power setting you can trim for that power setting. With mine and a 100 I cruise at 1/4, sometimes buzz around at half, and sometimes I do full throttle high speed passes. I can tell you from my experience that 5 degrees is just about right to avoid trim changes with power changes.
Old 07-30-2017, 09:41 PM
  #4934  
Dieselman1220
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If you don't have a 5 degree mount I have found that a wheel collar under the the front mounting straps works about perfect.
Old 11-23-2017, 01:13 PM
  #4935  
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Hi
Does anyone know if there should be down thrust on the turbine or should it be mounted parallel ie no down thrust.
thanks
Old 11-23-2017, 03:10 PM
  #4936  
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Originally Posted by charlie turbine
Hi
Does anyone know if there should be down thrust on the turbine or should it be mounted parallel ie no down thrust.
thanks
Anywhere between 0 and 5 degrees has been used. My current Falcon 1.20 (no 4) has 3 degrees of down thrust (jet pipe end down) and flies well.

regards

Col
Old 11-24-2017, 05:58 AM
  #4937  
joeflyer
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If you read the threads you'll see that most use 5 degrees of downthrust. The real answer is that it depends on your engine and how fast you want to fly. Without some downthrust the plane wants to go up at higher speeds. The faster you go the more it raises. If you don't want to be re-trimming your plane at higher speeds then put in some downthrust.

I've had two of these and have flown them with several different engines. If you're using a 10# engine then it probably doesn't matter much. For 14 - 17# of thrust 5 degrees works fine. If you've got 18# or more go with 6 degrees.
Old 01-31-2018, 04:10 PM
  #4938  
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Default He!p

I know this old but hope some are around.

I have a new in box falcon 120. I want to go electric pusher for noise reasons. I however am finding the motor prop selection hard.

Can anyone help?
Old 01-31-2018, 05:39 PM
  #4939  
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I think the size of motor you will need for the weight of this airframe will preclude it being used as an electric pusher because of the prop size/diameter needed for the motor vs the ground clearance with the standard length undercarriage, on take off this clearance decreases quite considerably.

Mike
Old 01-31-2018, 08:17 PM
  #4940  
hobbyaire
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I experimented with an 11 x 12 APC glow prop (they don't/didn't make that one as an e-prop) .. it was satisfactory .. it indeed did work .. not all that fast, but gave a cool turbine like sound, rather than a prop sound.
I had about a 2000 watt, 240kv motor on 10S ..
.. however, I didn't stay with that .. went on to turbines
Old 01-31-2018, 10:08 PM
  #4941  
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3000 watt is where I I think it needs. I just cannot figure out what motor go for
Old 02-02-2018, 06:54 AM
  #4942  
BaldEagel
 
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If I remember correctly someone makes three bladed pusher props, that may be your best bet.

Mike
Old 02-02-2018, 11:52 AM
  #4943  
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Originally Posted by BaldEagel
If I remember correctly someone makes three bladed pusher props, that may be your best bet.

Mike
Prop availability is wider than you think, direction can be reversed remember.

Any three blade prop is on the shopping list, just remember to put the 'curvy side' to the front!

Last edited by Boomerang1; 02-02-2018 at 11:55 AM.
Old 02-02-2018, 12:45 PM
  #4944  
Larrythelathe
 
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I was more asking what motor. I would do ic if electric is undoable but must be possible if you can do it with iIC
Old 02-02-2018, 01:28 PM
  #4945  
BaldEagel
 
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Need for remembrance, this airframe was designed in the first instance for an IC engine, go to page one.

Mike
Old 02-02-2018, 01:46 PM
  #4946  
Larrythelathe
 
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Yup agreed I have a noise sensitive site local. Also one I can fly jets turbines. Local one would be god hence the electric option.

What pitch was used for a three blade 1.20" glow engine? I assume /30cc petrol would be the same?
Old 02-03-2018, 05:06 AM
  #4947  
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Default Fan conversion

I have seen here in FL a Falcon fly w a 5" fan successfully. Good speed etc. I have a new in box Turbax unit w neu motor and speed control for sale. $350 (all nib)
Dave
Old 02-04-2018, 02:02 PM
  #4948  
Larrythelathe
 
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Sorry if I went that way it would be a jetfan 120mm

One thing you guys may be able to help with. My wood work has been pulled from the front as it was a bit loose. Its left a run of resin. How did you all remove this? I have built up new former to allow for the steering servo. How did they intend the builder to do this?

Also how did you do the hatch and canopy?
Old 01-11-2019, 01:35 PM
  #4949  
i3dm
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guys,
whats the recommended CG fir the falcon 120 jet?
Old 01-11-2019, 02:25 PM
  #4950  
john491
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C G is 12-3/4" to 13" aft leading edge of the wing at the root. Just about the leading edge of the belly hatch,
John


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