Beginners - ARF's - Adjustments

[Ollie]

The proliferation of ARF's is bringing many beginners into the hobby/sport. I have heard many on this forum express concern about how easily these beginners can be discouraged and drop out. A stumbling block sometimes associated with buying an ARF is an appliance mentality that doesn't realize the importance and affect of proper adjustment as a prerequisite to success.

One of the attractions that fuels the ARF trend is the building time it saves and the skill development it avoids in pursiut of instant gratification. It encourages people to try to teach themselves to fly. However there are a couple of catch 22's. It is much easier to learn to fly on a well adjusted plane than on a poorly adjusted plane and the beginner can't develop adjustment skills till he can fly. The other catch 22 is that it takes patience and skill to properly adjust a model. Skill development is what the ARF buyer has, in many cases, avoided and patience is often not one of the beginning ARF buyer's strong suits.

A solution to some of these problems is to hook beginners up to clubs where the knowledge is and where willing mentors are to be found. Often, for a school age beginner, transportation to a club flying site is a stumbling block.
The local hobby shop can help the beginner make the connection but more and more beginners get their ARF by mail order. I don't know of any mail order outlets that are trying to fulfill this vital link. I don't know of any ARF suppliers that adequately emphasize the importance to beginners of getting flight and adjustment instruction.

[Hostage-46]

Well put Ollie,

I was given an ARF kit as a gift and figured it would be a very easy proposition. Open the box, and a few evenings later it's off to the field.

While my build time was obviously reduced, this experience reminded how much effort it takes to properly trim a sailplane.

And that process can never be taken away as there are so many variables between local conditions and personal preferences.

[ICTHRMLS]

Seems to me the ones that would benefit the most should get involved... the AMA. I know there is a tremendous knock on this organization in some circles but wouldn't it be easy for them to approach the manufacturers/mail order houses with a paper listing of sanctioned clubs by speciality (sailplane, heli, jet, etc.)? This could be included with each order/kit and would be more useful than a lot of the printed material you get with your order.

Why it might even boost membership.... imagine that :p

[jrgospod]

Good points Ollie,


I think the AMA should have a beginners first year discount program and a students (deep discount) plan. A little amount from a lot of people is better than none at all. I have a friend that built a gas plane two years ago but has never flown it. The local club cost $50+ and the AMA is another $50+. He has books to buy and school supplies. I have been trying to get him hooked up with an instructor at a local hobby store for help. Cost does count for new flyers.

[jrgospod]

Good points Ollie,


I think the AMA should have a beginners discount program and a students (deep discount) plan. A little amount from a lot of people is better than none at all. I have a friend that built a gas plane 2-3 years ago but has never flown it. The local club cost $50+ and the AMA is another $50+.

The clubs should have foam trainers for the new people to learn on and wave the first year dues to get them started. My friend has books to buy and school supplies. I have been trying to get him hooked up with an instructor at a local hobby store for help but the AMA cost may still be a problem. Cost does count for new flyers.
John

[wingsnapper]

Ollie,
You hit the nail on the head with the comment that proper adjustment is difficult. I have been modeling for a number of years now and still find difficulty in getting my birds in rig. I am beginning to believe that the intial build of the plane is only about 75% of the work.
While I am on the subject, I have a question for you. I have a 2M Lil Bird that I think should produce tighter turns at a given bank angle. The CG is within specks, but upon hand tosses, one click of down makes a very linear shallow dive while one click of up kinda makes the nose stay up too much. It never takes on that long "float" you like to see. Further, the plane yaws well with rudder, but still doesn't turn as well as the one I had before. In other words, when I watch the video of Dave Thornberg turning so tightly with such little bank angle I start to think.... Why doen't mine do what his does? Besides the obvious level of skill, I really think something is just a bit out of whack. Any thoughts?
"... A properly trimmed sailplane shouldn't need much elevator input in a turn..." - Mr. Thornberg.
JS

[Ollie]

JS,

CG specificatioins are no more than a useful place to begin flight testing and adjustment. The forward limit is determined by the control power in the elevator. When that control power becomes insufficient for the most extreme maneuver in pitch, then the CG is at the forward limit. The aft limit is more about the pilot's flying style, reflexes, etc. The aft limit is usually just forward of the neutral point where the plane has no tendency to recover from a pitch disturbance.

I have a flying buddy that flies almost every week. He typically takes about a year before he has a new plane adjusted to his liking. He is a lot more meticulous and thorough than I am.

I had a Paragon and when I got through adjusting it to my taste, I had removed 3/16 of incidence from the wing and moved the CG back about an inch from the location shown on the plans. With the tow hook an inch behind the place shown on the plans, I had no trouble launching it. It flew great for me but was too squirrely for the guy that I sold it to.

Back to your specific situation. You should try moving the CG aft in small increments and retrimming the stab neutral until the plane handles more to your liking in the turns. You may find that as you do so it takes more concentration to fly smoothly and to keep the speed constant. You may also notice that the plane becomes more sensitive to gusts and signals lift more clearly. You will have to find the compromise between conflicting objectives that suits you best.

The best information about CG flight testing and its effects is by Dr. Mark Drela. See:
http://www.polecataero.com/
Go to Articles in the menu and click on the article about CG by Dr. Drela.

[aeajr]

You aer talking about ARFs. What about RTFs.

I started flying 5 months ago. I have no interest in build models, so I went the R-T-F route. I think this is such a great way to get started.

I thought I would share my experience so others might benefit.

I am a first timer. However I am also one of these guys that goes into intense
research when I get interested in something. After several months of research,
talking to people, flyers and non, I bought an Aerobird. It is a super value
and very easy to fly.

HobbyZone AEROBIRD THREE CHANNEL ELECTRIC PARKFLYER

Very inexpensive and rugged for a three channel starter - $130-$160
The plane comes complete and fully assembled. Charge the flight battery, put
on the wing, put the batteries in the transmitter and up you go! Even the
batteries for the transmitter are included.

New flyers like me are going to crash, especially if you are teaching yourself
to fly. You don't want something that will be costly to fix. The plane is
very rugged, but there is a full line of parts available at reasonable cost.
You can replace the whole main fuselage for $49 including the motor and all
the flight electronics. A wing is $15 and the tail is $9. So, if you crash
badly you can get everything for under $75 and you are back in the with a
three channel plane.

If you are interested I have written up a tips sheet on how to fix the
Aerobird.

Here is a review of the Aerobird
http://www1.wildhobbies.com/news/default.asp?cmd=view&articleid=853
On these pages you will find Videos of the Aerobird in flight
http://www.parkflyers.com/html/aerobird_video.html
http://www.modelflight.com.au/model_flight_videos.htm

With 100+ flights on the Aerobird, I fly in 15 MPH winds and fly with great
confidence. Personally I am amazed that the plane still flies, but it flies
great! I love it and have recommended it to many friends who fly them now as
well. They all learned very quickly!


From Electric Park Flyer to Glider


THE GREAT PLANES SPRIT SELECT 2 METER

The Spirit Select is completely assembled with all the electronics installed.
It includes a 72 MHZ single stick radio. This is very easy to use and is very
similar in look and fell similar to the Aerobird's radio so I picked it right
up and flew. It is branded Hobbico, but it is really a Hitec radio.

Here is a link to the site where I purchased it for $139 complete!
http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXVK55**&P=7

Here is a link to the ARF version where you can find links to two product
reviews. If you want to do some building, the ARF is the route, but for an
extra $40, I got the radio and the plane ready to fly. For me that was
perfect.
http://www.greatplanes.com/airplanes/gpma1045.html
Video
http://www.greatplanes.com/gallery/gpma16.mov

The plane has spoilers built in the wings, but you don't have to enable them.
The Select model does not come with the spoilers enabled but the instructions
tell you how to do it. I will do that soon.

I started flying the Spirit in Mid July and have about 50 flights on it. I spent the first 20-30 flights focusing on launching and landing practice. However, this plane has a reputation of being a great thermalling plane. I have had flights of 15-20 mintues and had the plane so high it was a dot in the sky. Now I am learning more about thermal hunting from the experience guys in teh club. I would definitely recommend it.

Will I ever build a model? Sure, and maybe soon. I did build an ARF Electrajet, which is a molded foam parkflyer.

That was a learnig experience but I am glad I started RTF. Got me in the air fast which is what I wanted. Now I am hooked!

[why2cay]

I am new to RC sailplanes. I have been following this thread and quite a few others on different sites regarding the ARF. I received my first sailplne last Xmas (a Windstar Arf) and have constantly upgraded it thanks to the tips and suggestions all you great folks. The difference in its perfromance the past 2months is 200%. I have taken almost 5 oz of weight out of my plane. The biggest weight saving idea was to put in gold - n - rod pushrods and get rid of the dowel and theaded rod. This alone saved 2.5 oz. I had a club expert help me balance the plane for maximum flight and took another 3 oz's of weight out (mainly from the nose...the CG suggested by the instuctions is a very liberal one). I did make the wing a one piece with fiberglassed joint as this was stressed to me as a weak point when I first searched the internet about ARF sailplanes.. One of my biggest points about this post is join a club, join a website or newsgroup and ask these people for their opinion ( believe me they do have one). These planes can be made to fly well. I now enjoy flying mine.They may never be contest winners but they got me hooked.


steve

[Ollie]

Wing Snapper,

On rereading your post, I see that I did not address one of your concerns.

If one click of up or down trim produces too much of a trim change, it may be that you have more elevator throw than you need. Try moving the clevice out farther on the elevator control horn or in farther on the servo or, if you have it, go to low rate to reduce the elevator trim sensitivity. Do a test flight that uses full elevator throw for your most extreme maneuver to see if you still have enough.