I just finished a Hobbico Nextar Trainer. The weights and balance is perfect but the first two flights were squirrely. Iwant to de-tune it. I bought a guage to measure the distances of the throws and am trying to decrease the throws but not having success. I have experimented with both the holes on the servo arms , the rod end adjustments and the horns on the elevators and rudder. I can't seem to get them to have significantly less throw and I also can't get the ailerons to have different throws for up and down. Instructions call for different upward and downward deflections on ailerons
thanks

Are you using dual servos for the ailerons? If you go to the inner most hole on the servo and the outer most hole on the control horn that will give you the least amount of throw. You may have to go with a smaller servo arm.

See the attached diagrams

For the control horns on the control surfaces.You get less throw as you move the pushrod further way from the control surface, more throw as you get in closer.

For the servo arms. You get more throw as you moveaway from thethe center of the servo horn, less throw as you move the pushrod towards the center of the servo horn.

For aileron differntial, you need to set up you aileron servo as is shown in the diagram below

Ken

I knew you would come thru Ken. A picture is worth, well a couple of words anyways

If you have a computer radio, you can also "de-tune" the throws by turning down the travel at the transmitter.

For any genaric trainer computer radio or not. Always start out with the pushrods for the elevator and ailerons two servos or one on the inside holes at the servos and furthest hole out on the controls surfaces. If you have a computer radio you can fine tune from here.

On the rudder use the middle hole at the servo and the furthest out at the rudder. However for the nosewheel you want the nosewheel pushrod on the inside hold at the servo and furthest out at the nosewheel. This will give you less nosewheel travel than the rudder and definately what you want.

Excessive throws is at the top of the list of the new airplanes I check. Number two is CG to far aft for any number of reasons and excusses.

Indeed RCKens picture is the way to mechanically apply aileron differential. You can also do this with a two aileron servo set up. Another way is electronically depending on the radio you may or may not have.

What differental is, allows the upward moving aileron to move further than the downward moving aileron. This in turn minimises the higher drag (adverse yaw) of the downward moving one and the airplane will track nice around a turn instead of wallowing around with the nose wanting to point away from the turn.

John

Thanks
You folks are awesome. Quick informative responses with pictures to boot. Got home late last night and had to go to the workshop to try these adjustments. Too bad I had to work today and cannot try it out. Am off all day tomorrow so wish me luck[img]C:\Documents and Settings\iherling\Desktop[/img]

I do not know if this picture will post, but I just built this safety bench for my runway on my farm. (the house in the background is my neighbor, not me). I was flying an Avistar 3 yrs ago and had only been flying for 1 season and doing fair. I just started up again this spring and crashed the avistar after 2 flights so went back to the trainer.

i guess basic members cannot post photos

Thanks to CGretired, I was able to go back and enter pix
thanks

Any member in good standing can post photo's.

Once you place an original post in a thread, or reply/comment to a post and save it to the thread, you can go in and edit the post. You will see a link at the bottom of the edit screen to add items - pictures.

Try it. Edit your post and look at the bottom. You will see "Upload More Files?" Click on the link and add a photo or two or three.. don't forget to click ok OK when done each screen.

CGr.

Looking forward to your pictures. Having a starting bench and runway outside your door, How sweet it is

John

Edit: Ah Ha I see it now beautiful, man all you lack now is a grill! I,ll supply all the glow fuel, brickets and the burgers[8D]

If anyone ever has the opportunity to be in Maryland, just send me a post.  Love to open my field to anyone who wants for fly.  It is interesting that I invite people all of the time and the only ones who ever show up are two of my buddies who fly sailplanes and gliders
What a shame, aye!

Great picture. How long does that grass stay green in the Summer?

Nice setup! I live in Frederick, MD (about 60 miles away from Freeland). I was just in Parkton over the weekend at the RCMB field for an IMAC class. Does the neighbor in the picture ever complain about the planes?

Brad

OK, everybody over to Iherling house. John is bringing the grill and burgers. I got the Big Orange. Nothing like a good RCU party.[8D][8D][8D][8D]

neighbor never complains.  they actually enjoy watching me crash and of course sailplanes are silent.  grass does turn browner in summer, but then again it actually makes take off easier cause the grass is less lush.  I would love to have a party and lots of tents and spot a pots.
BKdavy pls touch base and we can fly.  I once belonged to RCMB but no longer fly with them
They are very close to me
[email protected].