Jump to content

F3J/F5J flap deployment setup.


DaveH

Recommended Posts

3 minutes ago, satinet said:

If don't have proportional control over your landing brakes you will never get accurate results. 

Tosh ..........    tosh.thumb.jpg.2de00d6fcf9cdb80138367710c5fa825.jpg

Link to comment
Share on other sites

Whatever you say Mr Satinet.

If your model is quite good (and no brakes), it will sink at 0.35m/sec and fly about 6m/sec. So with 20 seconds to go you will need to be 7m up and 120m away.

Any increase / decrease in wind speed will change where you land. Any extra lift or sink along that 120m will change where you land.

Hence brakes are needed. Brakes simply increase the drag - by a lot.

You either want it to sink a lot, float slow or fly fast.#

The brakes are the “sink a lot” function. Thermal mode is “float slow” and speed mode is “go fast”

Brakes = DRAG...... SINK.

If you want to go fast, that means fly fast efficiently.

If you want to fly slow – that means hang about, which does not mean add a lot of drag.

If you want to come down faster you add down elevator. Due to being set at max brake, it comes down faster, but does NOT increase forward speed. The ground covered is probably less.

So yes, the landing is infinitely variable, but by using the most efficient method.

 

Landing.thumb.jpg.78c8b306639cbdaf15c1aec6b949f52b.jpg

 

 

Link to comment
Share on other sites

Trying to follow this...

What is the point marked ‘Default’ on your graph please?

You seem to be 20.8 metres high with 20 seconds to go, not 7 as you proposed.

Link to comment
Share on other sites

My landing phase is always "with 20sec to go"........... So look very carefully.

This flight / Landing was posted in public on 16th Dec. At ground level it was 10 to 15mph wind.

Above ground level (80m) it was faster than my "normal" glide speed (18mph) so we can say 20mph.

I came into land on brake and speed mode, not "normal mode"

The model was a Graphite, posted here recently under New Planes. The whole point of this project was to fly where most people would stay home ! (and do big daft aerobatics)

Yes it really was on time and on the spot.

 

WindLand.thumb.jpg.f071687598b3cd0996b6413e17d595bb.jpg

Link to comment
Share on other sites

17 minutes ago, AnthonyB said:

Whatever you say Mr Satinet.

If your model is quite good (and no brakes), it will sink at 0.35m/sec and fly about 6m/sec. So with 20 seconds to go you will need to be 7m up and 120m away.

Any increase / decrease in wind speed will change where you land. Any extra lift or sink along that 120m will change where you land.

Hence brakes are needed. Brakes simply increase the drag - by a lot.

You either want it to sink a lot, float slow or fly fast.#

The brakes are the “sink a lot” function. Thermal mode is “float slow” and speed mode is “go fast”

Brakes = DRAG...... SINK.

If you want to go fast, that means fly fast efficiently.

If you want to fly slow – that means hang about, which does not mean add a lot of drag.

If you want to come down faster you add down elevator. Due to being set at max brake, it comes down faster, but does NOT increase forward speed. The ground covered is probably less.

So yes, the landing is infinitely variable, but by using the most efficient method.

 

Landing.thumb.jpg.78c8b306639cbdaf15c1aec6b949f52b.jpg

 

 

I do say and everyone who's flown f3j, f5j, f3f, f3b, f3k etc etc. Is thinking the same thing.

It takes a special kind of arrogance to put a post up somewhere like barcs giving everyone a lecture about how lift and drag work.

 

  • Like 1
Link to comment
Share on other sites

6 minutes ago, mikef said:

Trying to follow this...

What is the point marked ‘Default’ on your graph please?

You seem to be 20.8 metres high with 20 seconds to go, not 7 as you proposed.

I don't have a clue about "default."

My landings always start with 20sec to go. I always try to be at 20m at that point. That is with decent air brakes.

Link to comment
Share on other sites

4 minutes ago, satinet said:

I do say and everyone who's flown f3j, f5j, f3f, f3b, f3k etc etc. Is thinking the same thing.

It takes a special kind of arrogance to put a post up somewhere like barcs giving everyone a lecture about how lift and drag work.

 

It is not a "lecture" and nor was it "arrogance" to point out the blindingly obvious.

BRAKES = DRAG and everyone should know - No lecture, No arrogance.

Brakes (drag) makes you come down. If you want to penetrate an increasing wind, you don't want drag. If you want to hang in the air (and not come down) you use your most efficient way of doing it.

If you have a better way, then you use it.

Please, being rude does not make your method any better.

 

Link to comment
Share on other sites

4 minutes ago, mikef said:

This seems to show a vertical component of about 4m/s on impact - an artefact of the measuring system perhaps?

The vertical component is 1.04m/sec. This was a very blustery day, with the pressure at ground level changing, hence it looks like I landed underground. A sink rate of 4m/sec is reasonable under braking. I added the markers to show the landing regime. The touch down was perfect, so I would say the model was flared (as we all do) just before the ground.

Took another look at landing..............

 

MoreLand.thumb.jpg.01291a5ad3c482429c0e75ab36b74e22.jpg

Link to comment
Share on other sites

OK I took zero for the ground.     ( <- This original comment deleted 1 hour after post - reason, noticed that the response to my '4m/s question' was answered with a different graph, not the original 4m/s impact one)

I see your point about using the most efficient way to handle 'speed', 'loiter' and 'descend quickly' but it's the disjointed nature of the transitions that puts me off.  I can understand that you might prefer it that way.

I have always used proportional 'brakes' but it took me a while to learn to use them proportionally.  I used to move the stick in an 'all or nothing' way and often miss putting my floaty little F3K models exactly where I wanted them - not a big problem as you can move to meet the model for rapid relaunching in F3K

I have started F5J now and found I had to learn proportional braking to get my spot landings right - for me, I couldn't seem to manage the energy of the more massive lumbering glider accurately in a 'bang bang brakes' way - you can't move the spot to meet the model!

  • Like 1
Link to comment
Share on other sites

The graphite has a vented spinner and vented bulkhead and not as much vent space for the incoming air to leave.

I would estimate while travelling at 18mph it will make the model seem lower, when it stops it will seem to rise (all in a fraction of a second.

Link to comment
Share on other sites

42 minutes ago, AnthonyB said:

The touch down was perfect, so I would say the model was flared (as we all do) just before the ground.

I dont fly F3J or F5J (yet) - but my understanding is that for the landing you want to "hit the spot" - literally - nose down, into the ground - which is why F3J planes have a droopy nose

Someone even invented a special mix for it - "KAPOW" mix

https://www.rcgroups.com/forums/showthread.php?2796638-KAPOW-mixing

Happy Landings !

Phil.

Link to comment
Share on other sites

26 minutes ago, mikef said:

OK I took zero for the ground.

I see your point about using the most efficient way to handle 'speed', 'loiter' and 'descend quickly' but it's the disjointed nature of the transitions that puts me off.  I can understand that you might prefer it that way.

I have always used proportional 'brakes' but it took me a while to learn to use them proportionally.  I used to move the stick in an 'all or nothing' way and often miss putting my floaty little F3K models exactly where I wanted them - not a big problem as you can move to meet the model for rapid relaunching in F3K

I have started F5J now and found I had to learn proportional braking to get my spot landings right - for me, I couldn't seem to manage the energy of the more massive lumbering glider accurately in a 'bang bang brakes' way - you can't move the spot to meet the model!

My brakes have developed over 25 years, whilst doing F3F, F3B, E-400, E-Slot, ALES and F5J ......... The best is with flaps and ailerons.

I have not done F3K which will cause a problem - full span aileron.

There is no "transition" when it is set up well, it can be spectacular if not. Don't forget this is also used on an Ava 4M which is spoiler only and yet is fine. When in brake on a full house F5J, the flaps are well down and the ailerons well up and so in "braking" mode you really need the rudder - so it is mixed (only here) with aileron. Your (mode 2) right hand has all the control and the left hand is pressing the sprung brake switch. You cannot really operate the rudder or throttle if you are just a 5 fingered human. You can reach the mode switch (just below) and you can also reach the sub-mode switch on the side.  Those are (really) the only switches on the TX.  All of my Tx are exactly the same.

 

ProSwitc.thumb.JPG.42dbf8173f7773f5de814d098bfbaf30.JPG

  • Sad 1
Link to comment
Share on other sites

4 minutes ago, Phil.Taylor said:

I dont fly F3J or F5J (yet) - but my understanding is that for the landing you want to "hit the spot" - literally - nose down, into the ground - which is why F3J planes have a droopy nose

Someone even invented a special mix for it - "KAPOW" mix

https://www.rcgroups.com/forums/showthread.php?2796638-KAPOW-mixing

Happy Landings !

Phil.

Yes Phil, be my guest. (I fly every possible day - all year round)

 

MudNose.thumb.jpg.a7254a2f89796dd7bf7db8565dbdd726.jpg

Link to comment
Share on other sites

@Anthony - why have you got such an aversion to using CROW proportionally - like most of us do?

We like to have the proportional control over descent rate - yours is on/off - whats the advantage?

Phil.

Link to comment
Share on other sites

2 minutes ago, Phil.Taylor said:

@Anthony - why have you got such an aversion to using CROW proportionally - like most of us do?

We like to have the proportional control over descent rate - yours is on/off - whats the advantage?

Phil.

Becaus I am too stupid to be able to use it.

That was not sarcastic or smart or anything - just the truth. I just can't do it.

BUT David, the OP has seen me land a few times whilst demonstrating - bang on.

I will listen to anybody and reason with them - I always want to learn.

Here (also) is my newer Tx - same as 20 years ago. Again - if I had more switches, I would probably hit the wrong one.

 

ProfSwit.thumb.JPG.4210cd4ad23bf04fc8a7b5c71c847b0c.JPG

 

  • Like 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.