Originally Posted by Bush Pusher

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The only reason I asked about sub trim was I noticed the tail servo tends to extend out slowly when just sitting still, But come to find out when I went to clean to servo the silver strip inside is worn through to black in the center so I have a servo coming to replace that one then I will test again.

Because of the gyro expecting motion, it's hard to infer anything about a servo's condition by it's action when standing still on the ground/table/floor.

Crashley77 and Stingrazor,

You posted some decent advice on how to mechanically set up heli's; however, none of that will effect Gyro drift.

There IS a "Calibration" procedure in the 130 User Manual Addendum that describes how to use Sub-Trim to eliminate Gyro drift. I'm too lazy to provide the link to the Manual Addendum, but if I remember correctly there is a link to the Addendum somewhere on HH's 130 webpage. Probably if you do a search for the term "Addendum" in this thread, you'll probably find a link to it here also.

At first I happily flew mine a few months without noticing any drift, probably because I only fly mine outside where there is almost always atleast some wind, and I'm usually too busy stick banging. However once I read about the Manual Addendum, I downloaded it, read it, performed the Calibration Procedure and discovered mine had significant AIL Gyro drift. After following the Calibration Procedure instructions, I saw an appropriate amount AIL Sub-Trim was able to eliminate the drift. Afterwards when I flew it again, I didn't notice any difference in flight performance, but like I said earlier, it is almost always windy where I fly, and even if it weren't windy, I'm probably too much of a stick banger to notice any drift during flight.

When I fist performed the Calibration Procedure, I think I remember reperforming the Calibration Procedure after the next LiPo change because at the time in other FBL heli threads many people where posting using Trim and/or Sub-Trim temporarily effects that flight only, because once a LiPo is disconnected and reconnected the Gyro's will reinitialize and whatever effect the Sub-Trim and/or Trim had before would be non-existent. If I remember correctly, after performing the Calibration Procedure the drift was eliminated even after unplugging and replugging the LiPo. However, I also remember reperforming the Calibration Procedure a month or so later and seeing the Gyro drift again. Since I don't notice ANY drift while flying either way, I just gave up worrying about the Calibration Procedure.

With smaller helis that I fly in my living room, I'm completely opposite, and normally do everything I can to make them fly a long as possible in one spot completely hands free. I even use a Bubble Level to verify my Take-off pad is plumb level with Earth's CoG.

Originally Posted by i812

Stingrazor,

You posted some decent advice on how to mechanically set up heli's; however, none of that will effect Gyro drift.

I think you probably meant someone else...? I only commented that servo behavior of a heli resting on a surface can be confusing because of the commands the FCB adds to any input.

@ stingrazor

I re-read the earlier posts, and technically you're sort of correct: my post was mainly intended for crashley77, but nevertheless from reading both of YOUR most recent posts, I still believe my post applies to you as well.

I'm not going to retype HH's Calibration Procedure and explain why it is different then they way you describe, other than state when their Calibration procedure is performed, during the inspection portion of the Procedure the heli IS stationary on the bench, AND no sticks are moved at all !!! That is essentially the verification portion of the Calibration procedure.

From reading your last two posts, it appears you kinda/sorta know what you're talking about, but it also appears you haven't read the Calibration Procedure, and therefore don't understand the "context" in which the Calibration Procedure applies. I believe if you read and perform the Calibration Procedure, you'll probably gain a bit more "wisdom" on how to inspect Gyro drift while on the Bench.

BTW, I edited my above post to include crashley's name

Also, I hope you know me well enough by now to know I'm not one of those that enjoys shoving people's faces in the "ground". My intent is not to be negative, but positive. In other words, I like seeing people smile, not frown. I live for smiles.

Its been a long time since I've seen negative intentions posted, so I'm fairly certain y'all enjoy others smiling also

For me all help is accepted with the same intent that it was delivered.

My 130X probably flies horrible, but I love it so I'm going to keep it. Drifting, isn't that something you do with the front wheels planted and the back end finding it's own path?

Not sure how to accomplish that, I'll give it a go when I get home tonight, first I have to find the wheels on my heli.

Originally Posted by i812

HH states 130 Gyro drift can be Sub-Trimmed out, but not to Trim it out. Because of that claim, I understood it to mean there must be a difference between the two Trim types, but never understood how they were really different other than different trim "step" increments.

After reading your above post, if I understand it properly, you claim on a CCPM heli:

Sub-Trim effects only one Servo's zero position

Trim effects atleast 2 Servo's zero positions
(EL channel causes all 3 Cyclic Servos to move, whereas AIL channel causes only 2 Servos to move oppositely)

By looking at my TX's display, I'm able to see how each channel's output signal changes as I move the sticks and switches and am certain the 130 doesn't require "mixed" signals from the transmitter (i.e. the "mixing" is pre-programmed and performed inside the RX). Therefore atleast in the 130's case, since the TX doesn't mix any signals, I don't understand how using Sub-Trim would be any different than using Trim other than knowing Sub-Trim allows fine increment adjustments; whereas Trim allows coarse increment adjustments (it's been a long time ago since I've looked at it, but if I remember correctly one of my TX's menus asks how many Sub-Trim step sizes do I want the Trim step size to be)

Yes, you are correct. In this case it doesn't matter. It is still important to know the difference though, because eventually you might run into a situation where it does matter, and you'll be better prepared to sort that out. Yes, the JR radios and many others let you set the trim size, in sub-trim units - which sets up a relationship that doesn't really exist.

Originally Posted by rotorist

Dang near took me 24hrs to think of away to explain it.
rotorist.

Yeah it's very hard to explain. I am a programmer, so I think of the radio in terms of a computer. It has input and output, and knowing how one is translated to the other is important. But, I can't explain it from any other perspective because for me, that is the simplest way. Input-output = sticks and channels.

Originally Posted by i812

Crashley77 and Stingrazor,

You posted some decent advice on how to mechanically set up heli's; however, none of that will effect Gyro drift.

Yes, because what's going on with gyro drift sometimes is the stick just isn't centered. You must make the gyro and the radio agree on where the center is, and we can't change what the gyro thinks, so we must change the center of the radio.

Originally Posted by jasmine2501

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Yes, because what's going on with gyro drift sometimes is the stick just isn't centered. You must make the gyro and the radio agree on where the center is, and we can't change what the gyro thinks, so we must change the center of the radio.

That might explain the Gyro drift I've experienced, even after performing the Sub-Trim calibration.

When I look at my TX's channel output display, even with all the sticks centered to "zero", and no stick movement, I'll see atleast one channel jitter around zero +/- 1 unit measurement. Maybe that channel is the Ail channel, and it is causing the Gyro(s) over time to slowly "peg" the Ail Servos?

If I ever purchase a new TX, then next time I'll pay attention to how stable the channel output signals are before purchasing it.

Are those mh main gears advertised much better? Survive crashes better?

Comments appreciated.

I like the Lynx. I have one with an autorotation hub.
The gear is thicker than stock,and I have not stripped it.
I have a heli eating tree that tested it well!
rotorist.

do mean like this that would be a great test

RC Helicopter Tree Trimming 101 (0 min 31 sec)

Holy cow poop, that just made me laugh That dude was using his 700 size heli to trim his shrubs!!!!!!!!!!! I can't believe that he looked like pretty much picking it up and going to try again.

Thanks for making me feel better about some of my flying

Nah, not that bad of a pilot.
I have a humongous pear and maple on the edge of my property.
Usually I get going at a pretty good speed and misjudge the distance between the heli and the leafy critters.
I have clipped the mains numerous times, resulting in stripped tail gears from the sudden stop of the rotor head, but never stripped the Lynx main gear.
Really peeves me when only one tooth is missing from a gear.
Heck, I just stripped a metal tail gear set last night. Tail first into mother earth. ( I heard her laughing in my dreams,LOL )
rotorist.

I had to fish my Mcpx out of a oak yesterday most of the time is a Quad I am pulling out of that same tree .
I did ask my neighbor to cut down his tree but for some reason he said no ?

Originally Posted by i812

@ stingrazor

I re-read the earlier posts, and technically you're sort of correct: my post was mainly intended for crashley77, but nevertheless from reading both of YOUR most recent posts, I still believe my post applies to you as well.

i812,

"You ate 12 of what?"

I was directing my post to Bush Pusher. I know he just got his 130X and is doing some work on it. I have discovered that allot of trim issues are due to poor setups. Not saying you are set-up poorly Bush Pusher. I just know you bought yours second hand like I did and sometimes they just are not setup the way we like them.

Most of the time, drift can be fixed with a proper mechanical setup. Calibration of the FBL is also crucial. However, this should be done after your mechanical setup, but before your test flight. It is a fairly simple process and can be taken directly from your 3X manual.

The FBL will adjust for some poor setup but we all know the saying "garbage in, garbage out".

Sorry I took so long on the response. I will not be at my computer very much over the next few days.

I just received an Xtreme Canopy on the mail. I first thought is was a piece of garbage. I went ahead and decaled it and gave it a test run. I lawn darted my 130 when the dang swash separated The canopy held up like a trooper! I don't think it looks as good as the stock, but it is tough. I will post a pic.