Maidened Horizon's Micro P-40......huge disapointment

[mattman0182]

I got her about 35 feet in the air, and started to make a slow left turn as I had flattened her out. So it was in the air about 8 seconds when I lost power. No control surfaces would respond.

She fell and hit a patch of thick, soft grass with the left wing and did a half turn landing right side up. There was no visible damage.

I thought there was no way the battery could be dead after less than a minute. But I charged it full again to see if that is why I had lost the plane.

I held the plane in my hand to test it with the new fully charged battery. I hit the throttle up and down... the receiver made noises but NO response from the motor.

I checked to make sure the Prop was on properly, which it was. I pushed it in a little anyway.

I tried the same thing, I throttled to full while holding the plane. It was strange....
The motor slowly spooled up to full speed. Then, while my DX6i was sitting on the table at full throttle, the motor was cutting on and off. From full throttle to nothing. At that point I shut her off and put her back in the box.

I will be calling horizon tomorrow. I don't want to take the plane apart if there is a chance they will fix it for me. There is really nothing else I can do.

Also, as I was removing the landing gear (the way as instructed), the whole plastic gear mount came off the wing. On the other wing, the magnetic part that affixes the plastic gear cover came off.

I have not even gotten a real flight in and the plane is already falling apart. Guess I will see what Horizon can do for me. If nothing ill just resort to those "cheap" brands from now on. Not even sure I want the P-40 now. :/ It looks great, that's about the only good thing about it.

[JetPlaneFlyer]

Sounds like a old/tired battery causing voltage to sag, or possibly the battery not fully charged.

[TM4197]

I had a Ultra Champ which did the same exact thing. I had plenty of batteries, so I was able to determine it was not battery issues. I could throttle the motor up, but as I walked away 20+ feet from the plane, the motor would not run. It was determined later the antenna had disconnected from the circuit board. Company sent me a new one, we now have about 100 hours on it. She still purrs.

[mattman0182]

I sent her back to them so ill find out if they will cover it or not. Was just frustrating because it was the first flight attempt lol. I didnt do anything to break it. Seems like my Champ and my pals um Corsair are much better built planes.

[mattman0182]

Well, Horizon took care of me for Free!! I am not home, but the plane arrived already today. Ill post my findings as soon as I can get home and test it out.

[JetPlaneFlyer]

Originally Posted by TM4197

I could throttle the motor up, but as I walked away 20+ feet from the plane, the motor would not run. It was determined later the antenna had disconnected from the circuit board. Company sent me a new one, we now have about 100 hours on it. She still purrs.

Guess that's why the advise is to always do a range check on any new model, and why range check function is built into most Tx's. I'd kind of assumed that mattman0182 had done a pre flight range check, but I guess assuming anything is dangerous!

[hayofstacks]

Good deal matt. Let us know how it turns out. I'm glad horizon stands behind their products.

[mattman0182]

Originally Posted by JetPlaneFlyer

Guess that's why the advise is to always do a range check on any new model, and why range check function is built into most Tx's. I'd kind of assumed that mattman0182 had done a pre flight range check, but I guess assuming anything is dangerous!

Oh I did A LOT of pre-flight checking. I had the D/R set up at 70. The control surfaces were all working fine.

I understand your point about a range check, but the plane was way too close to me to be out of range for any aircraft.

When I get back home to check her out, ill take every precaution possible. I will also spend a lot of time making sure the Tx is properly set up.

[rcers]

Originally Posted by mattman0182

I had the D/R set up at 70.

That is a BIG no-no. That likely won't leave you with enough control and just when you are getting the stick moved it will really start to move quickly.

I have only ever flown with more than 50% and that is for very specialized use.

Normal is 20-30%.

Originally Posted by mattman0182

I understand your point about a range check, but the plane was way too close to me to be out of range for any aircraft.

Not if there is something wrong. Range check can tell you if things appear to be working right.

A plane can be out of range at 30 feet if the RX is broken.

Originally Posted by mattman0182

When I get back home to check her out, ill take every precaution possible. I will also spend a lot of time making sure the Tx is properly set up.

Good idea - time on the ground looking helps. But you need to fix the extreme Expo - that is not helping you. Less throw is fine - extreme expo rates not.

Mike

[sbstnp]

Originally Posted by rcers

That is a BIG no-no. That likely won't leave you with enough control and just when you are getting the stick moved it will really start to move quickly.

I have only ever flown with more than 50% and that is for very specialized use.

Normal is 20-30%.

Care to explain this part again? You say that 70% D/R is no-no, that you only fly with over 50% and then only 20-30%?

I assume you are talking about expo but you somehow you forgot to specify.

D/R set at 70% is good for a not very fast warbird.

[rcers]

Exponential takes away the linear movement of the servo. So when you program the values in the radio you program for "less" control sensitivity around the stick center.

The issue with very large expo rates is you move the stick an almost nothing happens, move more, but only a tiny bit more control surface diflection, then you move a bit more and again a very small result. Once you get to around 70 percent of the input all of a sudden the surface starts moving VERY rapidly and will likely cause an over-control as the servo now has to do 70% of its movement in 30% of the stick movement. That is VERY drastic.

When you use smaller values like 20-30% you get that small movement right around center but it starts moving more quickly at a lower stick movement. This is better. There are a few airplanes where values of 50% or so will make a very large surface with very large throws manageable to fly. The other use is a very fast model where you need most of the control to be super soft as anything else will cause the model to depart controlled flight - unless you are going slower.

It is hard to explain but Expo is not supposed to be a cure for too much control throw. If you want less control authority, you should limit that mechanically or it does not hurt to limit the servo movement a bit either (again you want mechanical advantage so you don't want to tell a servo to only move 30% of its max throw as they are much less efficient doing that).

Make sense?

[JetPlaneFlyer]

I use 70% expo on some of my 3D models. 70% and more is actually recommended in the manual for some of the big names in 3D aerobatic models like Extreme Flight Sebart etc.

Thing is that you only use that last 30% of the stick travel for 'stick banging' type manoeuvres. For normal flying you don't ever move the sticks anywhere near the zone where movement starts ramping steeply up.

But expo is a personal thing.

[rcers]

Originally Posted by JetPlaneFlyer

But expo is a personal thing.

Very true. I am not a 3D guy - but most of those guys seem pegged around 50%.

But agree.

What I also know is there is a special reason once you get above 50%. JMHO.

Mike

[mattman0182]

The P-40 manual said the "low" D/R rating would be at 70 percent. That is why I set it up that way.

I had no idea what expo settings I should have in there.

Since I am a huge historic aviation fan, I would be trying to do some semi-scale flying.

I love to do tricks and things, but nothing outrageous. I prefer it to look realistic.

And although this is a UM plane, the less twitchy the better.

[JetPlaneFlyer]

Originally Posted by rcers

What I also know is there is a special reason once you get above 50%. JMHO.

Mike

Just to make the controls a bit less twitchy around centre. If you have 45 deg of throw and huge surfaces (80 deg throw on elevator!) then you need heaps of expo to calm it down.

As a random example here's the set up instructions copied direct from a Sebart Sback 30e build manual:

Control throws
Please, follow the recommended linkage setups:

For the AILERON we recommend the following throws:
Low rate: 20° up / 20° down Expo: 40%
3D rate: 45° up / 45° down Expo: 80%

For the ELEVATOR we recommend the following throws:
Low rate: 20° up / 20° down Expo: 25%
3D rate: 60° up / 60° down Expo: 80%

For the RUDDER we recommend the following throws:
Low rate: 30° left / 30° right Expo: 30%
3D rate: 50° left / 50° right Expo: 60%
Note: the Expo is (+) for JR systems, and (–) for Futaba systems.

[rcers]

Yes Jet - I know what expo is for. See my post above.

Guys - I get there are a few planes with the need for more EXPO - that is a RARE exception however. Almost all of those planes are 3D. I have also used up to 65% on EDF jets too.

I also flew for 15 years before ANY radio even had expo. It is a great tool but not a must have to fly. (Most planes)

This plane IMHO is not that. I have flown the UM P40 - it is a tame airplane - no need for 70% expo.

Again - I stand by my remarks for pilot unfamiliar with expo very large extremes causes some very abrupt surface changes as you approach full stick movement. On 3D that is great - on rookies learning how to fly it is strange and honestly detrimental.

Rookies are not flying Sback's and other 3D planes or Jets.

Just sayin'

Mike

[JetPlaneFlyer]

Sorry, I wasn't advocating use of 70%+ expo on something like a UM P40. If the P40 were mine I'd probably program in no more than 35% but I'm sure it will be perfectly flyable with no exponential at all.

[mattman0182]

I am thinking of leaving expo alone and having dual rates at 70

[rcers]

Originally Posted by mattman0182

I am thinking of leaving expo alone and having dual rates at 70

My opinion - that is a mistake - it may actually make the plane harder for you to fly.

Up to you.

Mike

[mattman0182]

Arent the factory dual rate settings 100 percent and expo 0?

What would you set it up as? Your opinion is better than mine al day and every day when it come to this stuff lol.

[rcers]

I would try 20-30% expo - as indicated above.