First Build

[ronp]

Phil I did have the corona digital metal gear servo with a .7 speed, now it's a tower pro 90. I have another servo on order. If this servo is causing all the issues I'll just wait for the new servo because this is getting crazy.
When I move the rudder stick left the slider goes right and visa versa. Man I had it on my kitchen table and knocked into the TX causing the throttle stick up and man those frickin' blades hurt when they hit an arm. My bicep is black and blue. It sheared off the bolt holding the gear onto the shaft.
I need to go over the head again after that mishap.
Let me ask you when you set the pitch on the main blades I know motor unplugged and throttle at 1/2 stick. Do you set the pitch in idle up mode or regular mode?

[akphill]

Ouch Ronp I would just Waite until you get the new servo that sg 90 servo is not really up to the task of running your tail rotor

Sounds like your servo is moving in the right direction

I always unplug my motor when I am working on cyclics as I did similar to what you did
only I threw my pitch gauge into my forehead and that really smarted I'll tell you

I would check your main shaft and your feathering shaft after your misshape it doesn't take much to bend them I set my pitch up in rate mode separate from idle up mode

[ronp]

Yeah thanks Phil the motor will be unplugged in the future, don't realize how much power and force that these helis have.
I am definitely going to wait for the new servo before I continue. Wasted to much time with this inferior servo.

[shakey]

Hey Ron, I have tried the T pro 90's once before and they were nothing but a headache for me. That's why I went to the EXI digital. If your running the T pro's, that might be your problem. I am running the EXI digital for the tail on one of mine and a Spektrum on the other, they both hold smooth. I hope the new servo you are getting works good for you. Can't wait to here you say it's up and away.

I really can't help you much because I am not familiar with the Futaba radio at all. I am sure there are many differences from the DX radio.

Glad to hear your alright also. That could have been bad. Heard many horror stories about props.

Good luck!

[ronp]

Thanks Shakey. I had ordered a small micro servo with a .9 speed, digital and only weighs 7.5 grams. I am still waiting for my larger servo but I figured what the heck while I'm waiting, I snipped the small connector it came with and soldered a JST connector and plugged it in.
I was told that the servo was too small and it wouldn't have enough power to operate the rear but after I hooked it up I think it's working. I switched the gyro back to digital mode and tried to bring it up but the battery I have just isn't cutting it.
I had a 2200 Mah but it got sliced when I had the accident. I am trying with a 20c 1100 battery but when I get to 3/4 throttle it cuts out. I have a new battery on the way so until then I'm going to try my other 1100 battery on a full charge and see what happens. Too windy today.
Question to the group. What is the minimum torque you guys use in a servo? I know I have been told to keep the cyclic servos to around 9G but I have never seen anything mentioned regarding the servo torque..

[Gabe]

I would never go below 9G. That's the bare minimum for sport flying. If you're doing 3D don't take any chances and bump it up to the equivalent of the the DS420's.

[akent]

Ron, you are probably overamping those 1100ma batteries. They will probably start to puff if you fly them much. Those are too small for a 450!

The tail on a 450 needs power and speed. Like Gabe said, they should not be too small.

If you run a servo that is not designed to be a tail servo (or can't handle the stress) they will burn up. IMHO, the TP90's belong in a trash can.

Just my 2c.
Kent

[ronp]

Thanks guys like I said I have the new servo as well as battery on the way but they are on that slow boat from China...LOL
I don't think it'll get up with that 1100 battery anyway and if the servo fries well it's not that much of a loss, it was cheap.
Do you guys look for a certain minimum torque in a servo for either cyclic or tail?

[Raygun]

Get a servo with the same torque rating as the one Gabe recommended otherwise the one you have will strip, that tiny servo is probably working because it is over volt-ed right now when it fails you will crash.. Ray

Another thought it could short and feed back into the receiver not worth the chance!!!

[ronp]

Will do Ray

[ronp]

Well with a lot of assistance from Sol regarding the pitch curve I finally got the heli up and hovered a short time. Unfortunately the rudder servo went
belly up. Am waiting for my new ones that were sipped from H.K. yesterday.
Would someone explain how to set up the gyro gain and what it does....thanks ron
Also does anyone have a way of getting stripped hex screws out of the frame. There are at least 6-8 screws that the hex just rotates in the head of the screw.

[Doozer]

For gain set up watch this video:

video.helifreak.com/?subpath=finless/jr/g770&filename=gain101.wmv

As far as your screws go... you can grab a pair of pliers and try to spin the head, or drill them out. If you have small vice grips see if you can get them to latch on, then spin the grip. One thing is for sure, the kit you have has some soft metal screws if that many are stripped. I went through this with the Guru-Z screws. I'd back out what you have remaining and go to Ace and grab new screws.

[ronp]

Thanks Dooz. I watched the entire video and he goes into how to set up the radio and what % gain you get based on your settings depending on what radio you have. I have a Futaba so what I see on the radio is what I have.
Now what he doesn't explain is what gain is and what it does to the servo when you change or set the gain. What happens when I increase or lower the gain? What affect does it have on the gyro performance?

[Gabe]

"Gain", in layman's terms, is the sensitivity of the gyro. A higher gain setting means that the gyro will correct more for smaller and smaller movements. This can be a negative thing as too much gain and the rudder servo is overcorrecting constantly and you will get huge amounts of tail way making the bird uncontrollable.

The optimal setting for your gain in typically the most gain without experiencing any tail wag. So start small, with just enough to keep the bird from spinning like a top. Then, slowly increase the gain until there is no drifting or the tail or wag.

If you get wag, turn it down a smidge. It's really a trial and error process. A good gyro and rudder servo will have a decent range of no wag and no tail drift. Whereas the cheaper electronics will experience some wag and drift at all settings. This is why I typically spend the extra money here. Drift and wag are two things I can't stand when working on 3D or even sport flying.

[ronp]

Thanks Gabe now that explains what gain is. Sometime those Finless videos tell you everything but what the main topic is. Now that clears things up and it only took 30 seconds...thanks... ron