Home › Forums › Free Flight › All Gas › AR, VIT Flight Adjustment
- This topic has 9 replies, 6 voices, and was last updated 15 years, 9 months ago by DAN BERRY.
06/04/2007 at 1:23 pm #40645
Could anyone advise me on the proper steps in adjusting a model with AR and VIT(F1P)? I’ve never flown such a model, but have one ready for testing. I’m a little nervous about it.06/04/2007 at 10:33 pm #44407AnonymousInactive
Some initial steps, (not sure if this is what you mean);
* Set your timer up so that A/R and engine stop both work together (they can be separated later as trim develops, so A/R helps transition).
* Set VIT to release about one second after engine stop (lengthen this delay as you use longer engine runs).
* For initial flights skip glide, and have the model DT down when the VIT pops.
* Get set up so that you will have a 2 to 2 1/2 sec engine run.
* Test glide as normal for an all-locked-down model, and aim for a nice bouncy looking glide.
Without some model details it’s tricky going further, but your power setting should have the rudder straight (or even a hint left), and the VIT giving about 3 to 4mm of movement at the trailing edge.
Make sure your systems work flawlessly before you fly, then start with a confident steep straight launch.
John06/04/2007 at 10:48 pm #44408
Thanks for the information. What I have is a dave Rounsaville F1P Excelsior with an F engine.06/04/2007 at 10:59 pm #44409JLorbieckiParticipant
Yup, pretty much what he said.
That is the cool part about VIT…Set up the glide just like you would with a standard model. test glide and keep the glide circle opened up to begin with. You do not want to use a lot of rudder because if the model speeds up in glide the rudder becomes more effective and can spin the model in.
You probably have 2 degrees of incidence in the wing. The stab will need to be at -1 degree or so. I know some people will actually test glide it with the stab in the power setting and they look for a very fast, nose down glide. I don’t like to do that. I just have it down the -1 degree and adjust from there.
Engine thrust should be probably at 0 to maybe a degree or two to the left. Some like to put 1-2 degrees of down in it, but we typically fly ours at 0 degrees.
I would recommend that the first flight be run at maybe 1 1/2 seconds max with the glide post released (or the glide arm). That way the model will DT instantly. That is the reason for the very short engine run- you don’t want to overstress the wing on a quick DT….John did a quick DT on his J model this weekend on a 3 second run and the model did three loops!
Also, as stated, you can fire the rudder off at the engine shut off but we have been doing it at the hit of the glide. You will need to play with that to find what you like. Also, the timing of the glide release can be modified as the engine runs increase. You may find that you want to trigger it later as the speed increases with increased motor run.
I think you will find that it is so much easier to trim because the power setting doesn’t screw with the glide setting…
Good luck!!06/04/2007 at 11:19 pm #44410gosParticipant
All good info. from John L.
Engine and autorudder pop at the same time with VIT a couple of seconds later, then DT in another couple of seconds so the model has slowed right down. I’ve seen wings fold (not mine) from DTing too early.
Be sure to check, check, check many times on the ground to make sure the same things happen every time and there are no ‘hang ups’.
Make sure the engine is at full song or only very slightly rich and make sure it shuts down on the ground too several times.
Hold the model verticaly on launch and push it away very positively for the initial 2 to 3 seconds motor run.
Good luck. Lets know how it goes. It’s a nice model, and I met Dave R once many years ago now.06/06/2007 at 3:47 am #44411AnonymousInactive
I am very new to timer function control surfaces. I just received my Astrostar kit and the VIT setup is very vague. Also there is no auto rudder indicated. What I’m looking for is a simple primer on how and why to set up a 3 function Texas F type timer for F1P. I’m not a junior with mentor to help at every step. If the juniors receive the same kit, they might be as puzzled as I am unless their Dad is there to help them. At this point I am frustrated beyound belief, I have a Cyclon engine which I understand, but coming from U/C many years ago, I don’t have a clue about the other functons!
Ron Patten ❓06/06/2007 at 12:23 pm #44412gosParticipant
It’s very hard to explain all the tricks that need to be done to make a power model fly well with or without moving surfaces.
I can understand your frustration Ron, and others that have not seen these models close up and all the work and little things that go into them.
I honestly feel you best shot it to get to a meet where FIC is being flown, as most if not all of these models have all the ‘doings’ on them.
Some F1J as well as open power models do as well.
Take a close look and plenty of pics. Aeromodellers love ‘showing off’ their models and would be only too willing to help out I’m sure.06/07/2007 at 3:17 am #44413
Thanks to all who replied. I think if I take it real slow everything will work out. Thanks again. 😆
06/08/2007 at 1:55 am #44414AnonymousInactive
Looks like I’m only going to watch this season, I won’t have this figured out by our NATS in August.
Ron06/08/2007 at 4:24 am #44415DAN BERRYParticipant
There are guys in Illinois. Find’em and they’ll show you whats up. Muncie has a few meets before the NATS. Or get to the NAts early. There is a junior comp on Sunday. There will be guys with knowledge. Most anyone will allow brain-picking.
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