Dustin's Blade 450 3D Update

[Derek]

Having owned a blade for some time I did know that vibrations cause havock with those gyros, but I'm sure I mentioned this weeks ago.

Take the main rotor blades off, leave flybar paddles on. You can hold heli down while you spin it up above half stick. You can feel for vibrations at this point. Might be paddles that are not balanced, or it Could be a simple case of more padding under gyro. I had 3 of those gyro pads under mine..

Is the tail spinning fast enough for the gyro to do it's work correctly, belt slipping at higher throttle!!

My thinking is this...if there were excessive or nuisance vibrations, the tail would be all over the place...but you are right about these basic gyro's being sensitive to vibrations. Many paths of researching has shown that people are not fond of this particular gyro because it's overly sensitive to vibration. Dustin did buy an Align GP780 gyro, same as what is on my Trex 500, and he shipped it to me yesterday.

I do have 3 layers of 3M double sided sticky foam tape under the gyro....just like my helicopters.

However, this is interesting here...Tony...You suggested to take the main blades off, leave the flybar paddles on and test the helicopter for vibrations. Now...I know that the flybar paddles are balanced and the flybar is centered in the head. I set all that up during the rebuild. So...since it is QUITE cold outside, lol, I figured I'd just spin the helicopter up on my kitchen floor. It's not a super large kitchen but for this simple test, I figured there'd be plenty of room. Ok...turn on tx...plug in helicopter...do the usual pre-flight check....swash moves correctly...tail direction correction is working correctly....move the rudder stick and the tail blades move correctly. Ok....take off Throttle Hold....spin it up and I get absolutely NOTHING from the tail. At this point, I'm even more stumped. Ok, possibly a bad tail servo (suppose to be brand new...I bought it from my LHS)??? I disconnect the tail servo from the gyro and plug it into the AUX1 port on the rx. Move the cyclic stick and I get nothing from the servo. Hmm! I plug the AUX1 servo back into AUX1 and the cyclic works just fine. I plug the tail servo into the aileron port on the rx...move the stick...nothing from the tail servo. I plug the aileron servo back into the rx and move the stick....the cyclic moves just fine.

So boys and girls....what does this tell us??? It sounds to me like a simple problem of a bad servo.

What do you guys think?

[Tony]

Yep, buy a new servo Derek, or firstly try an old servo you may have lying around and do the same tests. If ok then you can get the proper one. Get the shop to test it, that's bad news buying a faulty new servo mind...I have a little servo tester from china I use, just connect the servos to it, put a load on them by holding the horn and making sure they are fighting against the load...

[Derek]

I just spoke with Tony, via Skype, and he suggested that I try another servo, any servo, in the tail. This way, if the suggested "test" servo does work, then that should tell me that the gyro is fine and the "questionable" tail servo is, in fact, faulty.

Here is a math lesson/fact for you all today....

1 Good Helicopter + 1 Bad servo = Not A Good Situation
1 Good helicopter + 4 Good Servos = Awesome stories, pics, and videos, lol

Class dismissed!

I just got home from my usual 12 hour work shift...time for a shower and bed. I'll test the tail servos this afternoon.

[DamhDearg]

Sounds like progress Derek.

[Tony]

Haha, like it.. We must have wrote those together D

[Derek]

Dustin sent out a GP790 gyro to me on Thursday. It showed up yesterday. Very nice! I'm just waiting on a new tail servo to get here now.

[Tony]

Are you fitting both servo and gyro together? You won't know what the actual fault was then if they cure problem..!!!!

[Derek]

oh no....I'll start with the new servo, when it gets here. Hopefully the problem with solely with the tail servo. If a new tail servo fixes the troubles, Dustin has asked that I add the GP790 gyro instead of the G210 Eflight gyro.

[Tony]

That's good, was hoping you would do that...lol

[Derek]

Ok, I just came in from the garage. I was testing the tail servo that I bought for the 450 3D. This was a NEW eflight tail servo that usually comes with the RTF. I connected the tail servo to the rx on one of my planes. Connected it to the GEAR channel and flipped the GEAR switch....nothing. Connected the servo to the rudder channel on the rx.....nothing. It just sits there and looks at me.

I grabbed one of my spare Hitec servos...not suitable for a "tail servo" but it's a functional servo. I connected the Hitec servo to the tail gyro of the helicopter and it immediately began to hum. I moved the rudder stick and the servo does move. Oddly enough, when I plugged the servo directly into the RUDDER channel on the helicopter rx, I get no movement on the servo at all. Is this normal?

While trying to proceed, I think I'm just going to buy a new servo that is NOT an Eflight servo. Dustin has the DS415m servo's on the cyclic. What would be a suitable digital tail servo? I can't use my Trex 450 as a reference because I have the DS520 servo on it for the tail.

[Tony]

Derek, you have the patience of a saint mate...lol..

I do recall having the tail servo plugged directly into the rudder channel of RX and it worked fine. If you recall a while ago on RCH I was going to attempt a flight without a gyro at all..

Have you tried removing the cyclic servos from the RX to see if tail servo works?

If it was my heli I'd be replacing ALL the electronics with Known working parts, ESC, RX, gyro and servo with a fully charged battery. Then if it works ok I'd put the old ones back in one at a time till it fails..

And if working parts doesn't fix it I'd throw it in the bin.... Haha, no seriously, I would double check the wiring, then I'd probably remove the cyclic servos from the RX and see if the tail servo worked then...

I'm just thinking of things I would do so if there daft ideas just ignore me...haha

[Derek]

I've been doing some thinking about this whole thing and now, I have quite the puzzle in my head.

After the last test, it's confirmed that the Eflight servo that i bought is dead. Ok, moving on. I took one my functional servos and plugged it into the gyro and it immediately began to hum. I moved the rudder stick to the left and right and the servo moves very well. Out of curiosity, I plugged the servo directly into the RUDD channel on the AR6115e rx and the servo didn't work. I plugged the servo back into the tail gyro, with the gyro and signal wire plugged into the rx, and the servo moves with rudder stick input. What's the deal with this? It almost seems like we may have a faulty rx, too. I say that because it doesn't make sense to me that the servo will work when it's plugged into the gyro but the servo won't work when it's plugged directly into the rx.

[Lee]

The servo should work if plugged into the RX alone.
If the RX is damaged, then why does it function when the gyro is plugged in, that is the question
Don't you have another RX to just try it with?

[Derek]

That's what I thought, too, Lee! The servo "should" definitely work when it's plugged directly into the rx. I do have a 6 channel OrangeRx DSM2/DSMX rx that I can try.

[Tony]

It sounds like the RX isn't giving the servo any voltage, but the gyro is... I do recall some strange wiring setup for that gyro...

And the reason the servo works from the gyro is the gyro only needs the negative and data signal...

How have you got it wired up Derek, RX to gyro to servo, there was a Y wire on mine...

Lee has beat me to it suggesting another RX...

[Derek]

The gyro has three leads from it. One is a brown, red, orange female servo wire that is connected to the Rudder port on the Rx. There is a single Yellow wire that is connected to the Gear channel. Then there is a brown, red, orange servo female servo wire that the tail servo connects to.

I just tested the rx again and now my Hitec servo is working from the rx directly. Perhaps I connected the servo to the rx backwards earlier. I suppose that's possible. So, to test that theory again, and turned everything off and then turned it all back on. Plugged the Hitec servo into the rx directly again and the servo is working. So...I'm going to say that the rx is good because the Hitec servo works when it's plugged into the gyro and when it's plugged into the rx directly.

I was on the Align website. They have a DS426m servo that is meant for the tail. Since Dustin has the DS415m servos on the cyclic, I'm going to order a DS426m servo for the tail.

[Tony]

sounds like a plan Derek. everything else seems to be OK now... i recall Paul saying he had some DS76 servos maybe he has a working one to sell ya cheap for the tail. its the DS76T you need

[Derek]

I dont know if I want to put another eflight servo on this helicopter. The tail servo that I bought for the helicopter was a $17.99 eflight servo and now its not working at all. Even with that servo plugged into one of my planes, it's not working. I think I'm just gonna order an Align DS426m servo. That way Dustin will have all Align metal gear servos. The DS426m servo is a tail servo that replaced the DS425m servos.

[pvolcko]

Sold the DS76T already to KevG along with 3 cyclics.

Make sure you get a refund on that DOA servo, Derek!

[Derek]

I'll see if I can get a refund on that servo. I bought it over a month ago and no longer have the receipt.