xtra 330

My Feedback: (19)

Hi Don,

Been flying for many years andhave always worked "around" a problem I always encounter. On my most recent ship 3W Yak, I have 2 servos per stab half. Each stab has its own Matchbox going into a Duralite Powerbox. My problem is this:

No matter how I set my radio up, I always have mismatched throws on 3D rates on my elevators. The way I go about setting up my servos is this....and please correct me if I am wrong, which I probably am.
1) Obtain 2 servos that are relativley close at neutral for each stab half.
2) Set the ATV to 140% on the transmitter
3) Sub trims are at 0, slight mismatch will be fixed with the Matchboxs
4) Set up Dual rate thows on transmitter
5) Plug in one servo per stab half and check neutral(elevators at zero incedence), and max throws
6) Adjust accordingly with the Matchbox
7) Plug in other servo on each stab and adjust throws with the Matchbox

Now at this point one would think if this is done, the servo travel through out its range would be equal with the other stabs servo. But this is not the case, My pattern rates are set perfect on all flight modes......but when I go to 3D mode, max throws are off by as much as 4 -5 degrees.

Is this normal or am I doing something wrong, something tells me I should be using the Trace Rate function on my transmitter(10x).....which I have never done, but makes perfect sense. I am just not too sure about its use along with ATV function. Should I leave the ATV function at 100% and adjust the Trace Rate for the elevators at 140%?

Any help would be appreciated.

Thanks, Joe

Don Szczur

My Feedback: (1)

Joe, Just got back from the NATS, so here is my response. Try different arms on each servo to better match the centers without having to dial in the centering electronically. You can also get two sided arms and switch (180 degree) to better match. The arm grooves are slightly differnent so you can better match neutral that way. Even better, H9 makes a really nice adjustable spline servo 3D arm which works very well. Go with ATV's close to 100 percent, and use a longer arm (3D) if not already using. Assume you are using JR servos (8411 or 8611 types).

Don

xtra 330

My Feedback: (19)

OK, Thnaks for the reply, but I am kind of confused. I have always been under the impression to set ATV up to 130-140 to get best resolution out of the servo. I have heard horro stories about people having problems in flight due to lower ATV settings. Just curious is to why you recomend 100% ?

My other question is about Trace Rate function. Is this why you recomend 100% on ATV...so you can adjust for higher throws with the Trace Rate Function, allowing the servos to travel the same through out its entire range of movement?

I am currently using 2EA 8611a on each stab at 140% ATV....Trace Rate setting is at factory setting 100%( if it matters)...I am using 1 1/4" SWB servo arms with the linkage set at the 2nd most outer hole on the arm.

I am just really curious about this Trace Rate function...everyone who I speek with has never utilized it, and would like to know its capabiliteis and function with our planes?

Thanks Don, and congrats on your finish at the NATS!

Joe

xtra 330

My Feedback: (19)

another question...do you think you might be able to make it to the Triple Tree IMAC contest in August? It's setting up to be a very good turnout in the Unlimited Class..and would be some good practice for the masters!?

It would be nice to have someone of your caliber to help and give out pointers to the up and coming.

xtra 330

My Feedback: (19)

Hi Don, any comment on the Trace Rate function?

Don Szczur

My Feedback: (1)

Joe,

Trace rate puts the throw through on the whole function. For example both elevators or ailerons without having to go into the ATV function to adjust them separately.

My trace rates are all set to 100% right now.

Here is my setup:
No duralite powerbox. Just one Rx (JR R2000). Two Duralite 4000 packs with regulators, plugged in to the same Rx through two separate switches.

I use two leads going back to the elevators. One on the right (elev), and one on the left (aux 3), I checked my ATV and the elev is 120 and the aux 3 is 130 up and down.

So I'm not using matchboxes, since I just have one elevator servo in each stab half.

However I will probably use matchboxes on the elevators if I go with two servos per stab half on the new extra that I'm building. With regard to Triple Tree, I'll brief you on my situation, and then make you a proposition.

I am still building a plane, I have to learn the two known sequences, I have to get all the equipment for the new plane, I have to finish off the new plane, I am CD'ing a pattern contest on 23-24 Sept, I am hosting a pattern clinic on the 12th of August, My wife informed me that we are going to her father's 80th birthday over labor day weekend, I have to trim the new plane out, I have to fly the new plane for at least 3 weeks to get familiar with it if I want to be competitive for the Masters. I have to fiinish picking freestyle music, I have to start to practice a freestyle routine, I have to fly through a minimum of 16 different unknown sequences to practice for unknowns in order to finish in the top 15. I have to pracitice 16 more unknowns to finish in the top 10, I have to practice 32 more unknowns and perfect the freestyle in order to make the finals. One minor detail, I have to do all the above between the hours of roughtly 7PM (9PM if I fly) and 2 a.m each evening since I'm scheduled to be working full time.

If you assemble a small squad and meet me here this weekend, we work 14 hours on Saturday, 12 hours on Sunday and I take Monday off and we all work 18 hours on Monday we should have the plane for the most part done. Then if you could bring someone who is reallly good with music match and can surf the internet for songs while we work on finishing off the plane... if you can make all this happen then I'll come to the Triple Tree IMAC contest and do whatever you tell me to do there.

xtra 330

My Feedback: (19)

sorry for bothering you, I'll let you get back to work. just thought you might want to come down and fly at a contest. Thanks for answering my question about Trace Rate Funtion.

Don Szczur

My Feedback: (1)

Joe,

No bothering at all. I would love to make the IMAC contest, it just looks as though I'll be tied up in the near-term.

Best of luck there!

Don