Anybody running GY401 / 9257?

[CatchmyCorsair]

Fly in idle up and watch it lock in. Mine does the same in normal mode.

[Ecaf]

What he said. We need to get you a flat throttle curve. The change in RPM on the motor is affecting it also Im sure.

[Thunder Fighter]

Originally Posted by 9sec240

Yes, mine is setup on the bottom of the tail block.

I am curios if there is an issue with the gyro not being mounted on a flat surface. The tail block is peaked in the center which might affect how the gyro tape dampens the gyro. Are people running multiple layers or leveling the mounting surface?

I have used a piece of thin heavy duty double sided mounting tape onto the frame, put a thin sheet of plastic, similar to the canopy plastic on to this and then used the standard 401 gyro tape to mount the gyro onto the plastic.

This should allow me to remove the gyro and split the frames without replacing the gyro tape as well as giving a flat surface and I did trim the centre of the join just a little to flatten it out.

//Dennis.

[9sec240]

I do not fly in idle up yet. I am a fixed pitch convert too used to chopping the throttle. I can try a 0-INH-85-INH-85 curve and see what happens... or would you suggest a higher % throttle?

[vicrc]

If you do not fly idle up, try this

0-80-80-80-80

You can still shut the heli down but at just below mid stick your headspeed remains constant which will keep the gyro locked in, if the heli still wags reduce the gain.

You need to play with values for pitch curves, headspeed and gyro gain to get the proper lock on the gyro.

I don't fly normal mode as I have already made quite a few mistakes of not hitting idle up . So my normal mode is set at 0-40-40-40-40 just barely swinging the blades and heli wont even hover.

[9sec240]

Thanks so much for the advice. I will give that a try. Is the motor torque issue more of a big heli thing? I have a bunch of 450s that do not do this.

[rcmarty]

Might want to condiser using an idle up flight mode.
Throttle chopping can be a bad habbit. Keep in mind in an idle up situation with a 3d pitch curve , chopping the throttle will drive it into the ground (full neg shoud you be upright) , causing more damage potentially.
When i loose it, i fly it right to the ground (well try that is) and i hit the throttle hold when she's down. I've made some saves by not giving up, i had my raptor disappear in the taller grass (about 2') and pop back up on me. In reality if you've lost orientation or what ever , you don't have much to loose, do your best.

My throttle hold is my off switch.

Martin

[9sec240]

Wow.. now THAT made a difference. I started out with a 0 80 80 80 80 this was quite nice and the heli moved around smoothly..... then went to 0 100 100 100 100. WEEEEE HAAAAAA... That is MOVING. I have no expo set up on this heli so it is a bit twitchy at 100%. I went down to 85% and it felt sluggish now. LOL... I will probably land on 90% or so... I was running out of light and had to get busy rebuilding a buddies heli.

It seems that the tail a lot better now.

Thanks so much for your advice. I really enjoy learning.

[rcmarty]

A side note ..

What battery and pinion ?

a 6s with a 15T pinion at 90 or 100 % throttle is very likely overreving the head.

Martin

[9sec240]

Originally Posted by rcmarty

A side note ..

What battery and pinion ?

a 6s with a 15T pinion at 90 or 100 % throttle is very likely overreving the head.

Martin

That is exactly what I am running. Hyperion 6S 35C at 100% blasting pitch pumps in the front yard.


On that note, WHERE IS THE FAQ STICKY??? No "Protos for Dummies" thread?

I had a hard time finding what I thought was pretty basic info like collective and cyclic pitch ranges, info on the spring 09 bag, recommended throttle curves, etc..

I am not saying "YOU" specifically but somebody considered an "expert" on the Protos or even some "factory" support would be nice. The build manual is pretty slim when it comes to additional info.

[whisperdancer]

I'm also running the Protos with the 15T pinion, 100% throttle and the same batteries.
Is the head over it's limits? I don't know, but I assume the rpm values in the Protos manual chart are for 100% throttle, so it should be fine.
Last Saturday I flew the Protos with 35ºC (95ºF) and the MSH ESC was fine.
I have yet to measure the head speed with a hand tachometer, but it's not easy as a 500 heli at full headspeed is very strong.

[rcmarty]

i agree.
Clearly i'm not a protos expert , but i try to read all the threads and evaluate the information in them.
If i see a pattern i'm more likely to beleive what's being said.

Been following another thread https://www.helifreak.com/showthread.php?t=142643 and there running the 15t at 95 % pegging at 3000 rpm.
Yet a while ago it recall coraddo (manufacture of msh) saying that 3000 is too much and would cause vibe issues.

Maby that was with the older parts ... i know the alum mainshaft was a vibe problem.
I was having motor shut down problems, when reading further threads of the same issue corrado said to buy the 14T pinion and run a higher throttle setting.

Now i'm thinking that with the newer parts (spring 09 pack has a V3 of the tail grips, V3 tailbox , V2 flybar carrier) that the protos is more capable of a higher headspeed.

Martin

[HighFreq]

Running an higher throttle curve and gear it to reach desired headspeed is a common rule, expecially during summer.

Corrado

[whisperdancer]

But Corrado, is it safe for the mechanics to run the 15T pinion at 100% throttle?

[HighFreq]

We advice on using the head at no higher than 2800, it is up to user to observe what we reccomend or not. All i can say is that people that decided to run at 3000 we didn't have any bad feedback altough we do not encourage nor reccomend that headspeeds.

Corrado

[rcmarty]

Well good to know i haven't totally lost my mind yet.

I'm running the 14t on a jazz 55 gov mode at 90%. I have id1 at 75 right now but i'll put that to 80 i think.

Martin

[jmcneil86043]

Originally Posted by HighFreq

Lower plate is not square to main shaft, that means that you will have interaction between aileron and tail. Everytime the heli executes an aileron command there will be a fraction of the command that will go to the tail because the lower surface is at an angle to the main shaft.


Corrado

So, I made this mistake. For those wondering, the symptom I had was that the tail drifted. If I trimmed for one head speed, then changed flight mode to a higher head speed, it would drift again. If I trimmed at high speed and switched back to slower, I got opposite drift. Moving the gyro to below the tail boom fixed it right up. Thanks for this post, it saved me lots of headaches.