[bbbair]

Hey Kevin;

Retracts are a very personal thing (IMHO) and I don’t REALLY have a problem with them…

BUT!

In this circumstance – they add a lot of weight to a new airplane and it does concern me… That having been said the weight IS at or around the point of balance…

Transforming my Harvard into a ‘Yale’ is an interesting option… but … the retracts ARE installed so they will stay put … for the time being.

Just now I am looking for ways to install the ~2 pounds (~1 Kilo) of weight required to balance the plane. This design does NOT afford me the luxury of a long nose in which I can add the required ballast. So I must try to SQUEEZE the ballast into a tight area around the engine. (oh joy…)

Such are the trials of a committed modeller!

[CF105]

I hear ya, Rob! Matter of personal choice.

Dead weight sucks!

[bbbair]

Sometimes you have to take a few steps back before you can go forward- such is the case on this AC.

I finished building the AT6 a couple of weeks ago and then started the systems testing (a very important thing to do) and I found that the elevators were not working smoothly and the Ailerons were also ‘Jumpy’. Not good!

This plane has been under construction for 2 years now and I do not want to loose it on it’s maiden roll out!

So I tore out the Elevator control rods (RED) that were binding and I’m in the process of replacing them with ¼ scale (black) push rods. Trust me – it was MUCH easier installing the push rods before the plane was covered!

I have had to use the Black push rod sheath to bore through the formers and run the new push rods – a time consuming and frustrating experience if ever there was one!

That having been said – it is easier to re-do them now rather that pick up 10,000 pieces of broken Airplane when the thing fails on take off!

I’ll be looking at poor electrical connections on the Ailerons as well as binding on the Control Arms – but that is pretty simple compared to the push rods…

OK So the Spring of 2017 will be the maiden date.

It’s a good thing I have lots of other planes to fly!

[CF105]

Glad you discovered the issues now!

Don't know what you're using for servos, but I had some rotten luck with certain Hitec digital HV ones I bought just this year. Was a shock - I've had nothing but good results from their servos in the past.

[bbbair]

OK Guys I Just succeeded in Balancing my Harvard…

That may not seem like such a big deal but I have been attempting to do this simple thing for SEVERAL WEEKS now… and I was not having a lot of luck doing it.

It took just over 6.5 POUNDS of weight in the nose to balance the Harvard! This did not make sense or make me happy! So I started to look at the plane and asked all sorts of questions about my building methods and more than one curse was directed at the designers. But everything checked out and the plane was still not balancing!

So I started to look at the plans once AGAIN and I noted that the CG was between 4 & 5” from the Leading Edge of the Wing – which is where I marked the point on the inside of the Fuse.

But Something caught my eye today… I had marked the inside of the Fuse 4-5” from the Leading Edge of the Wing Saddle… NOT THE WING!

The Harvard (AT6) has a large Wheel ‘Bubble’ on the wing that IS IN FRONT OF THE LEADING EDGE OF THE WING! I had measured the CG from the wrong point of reference!

Once I corrected the initial start point, the CG moved Aft almost 2 inches and the plane balanced up with a MERE 894 grams (~2 pounds) of ballast which is a far cry from the 6.5 pounds that I first measured!

The plane is advertised to weigh in at 15 pounds… but I added the retractable landing gear so my overall weigh has come in at 16 pounds 6 ounces. (I think that is acceptable… )

Just now I’m going to call this a victory – but if anyone else comes across another Mid West AT6 Kit – I am going to recommend that you do some serious weight control on the tail section!

[Trumpetman]

Good catch! Can you imagine how nose heavy that thing would have been.... I'll bet you wouldn't have even been able to get the nose to rotate on takeoff

[bbbair]

Originally Posted by Trumpetman

Good catch! Can you imagine how nose heavy that thing would have been.... I'll bet you wouldn't have even been able to get the nose to rotate on takeoff

Thank you and 'YES' you are right - it would have been a mess.

IF I had been able to get off the ground it would have been a nightmare to control and a SAFE landing would have been out of the question...

That is why we check EVERYTHING! and if it doesn't make sense... CHECK AGAIN!

[87801]

I love the construction in this one

[bbbair]

Hi guys;

I have been having some problems with my servos in the Harvard – I have solved my issues, but in the process I’m feeling rather stupid – but the hobby is all about learning so I guess that I’ll get over it.

The Ailerons and Elevators worked hesitantly and not in a uniform manner - certainly not the way that would allow safe operation of a RC Aircraft. While all the rest of the servos worked flawlessly. (there are seven servos and each servo has it's own channel to control it)

NORMALLY I use two receiver packs in my giant planes – but I have noticed that the average charge after a day of flying was only 400 ma on a 2300 ma battery pack. So I reasoned that a second battery and the ‘Battery Share’ device was not needed. So I left the second battery out this time (besides there isn’t much room in the nose of the Harvard) – What a Mistake!

After a lot of head scratching, charging batteries and changing of servos etc, I dropped in a second receiver battery in parallel and the problem disappeared! It would seem the issue was current demand of the servos vs current capacity of the battery.

Now I have to install another battery as well as the switch and then re-balance… not a really big deal but – frustrating none the less.

Not AS frustrating as loosing a plane but still frustrating.


Happy Landings

[Orion1971]

Gorgeous build. Ive just started the same kit so paying close attention to everything youve suggested. I have a separate set of plans for mine that details building flaps into it so Ill be making that modification as well. Cant wait to see how your maiden goes.