What's the deal with the rx?

[Jeeperfreek]

I bought a 4G3 used and was looking it over and have a couple quick questions. I have on order some new servos because there is a bad glitch in one and till then was going to try to put the rx back to original settings so I can do some of the same setup tips that are posted here. The adjustment pots on mine (or maybe all of them) have no detents? They just turn freely and dont stop? They don't seem to unscrew or tightin (which I don't think they should) but shouldn't they atleast stop left or right? What's the deal? Also, I think I have the tail motor issue everybody is having? It seems to surge at a steady throttle! It could be just me not knowing alot about these little guys and I haven't had it in the air yet because of the servos but if its on my bench blades turning to try to check the tracking the tail seems to sit steady but I can hear it change rpm? Could it just be me or is that the gyro starting to work even when not in flight? I can lock it down to my bench and get full throttle if i want but right now all it wants to do is shake like crazy. I can hear and see the front servo twitch after binding, stop, then looks like it starts back up after throttle is applied. Any clues?

[Dusty1000]

Hi, I would read what buildem336 says in this thread:

https://www.helifreak.com/showthread.php?t=116075

I have never got the tail perfect, but it's not bad. What I did was initialise heli, turn on dip switch 12, take off, land, turn one of the knobs on the TX, take off again, if better, turn knob more, if worse, turn knob other way, try other knob etc. Bit hit and miss but you can set it up while you fly the heli, landing to turn adjust the knobs of course. Then when you are happy, turn off dip 12 and your settings are saved.

The pots on the RX are supposed to keep turning, once you get past maximum, it goes straight to minimum etc. The 'mix' is like a proportional which adjusts the difference in power going to each motor. Mine is set in the 5.25 position but my 4G3 has original firmware in the 4 in 1 which was updated shortly after the heli was released. If yours is the updated version then as far as I know it should be in a different position. The way to tell if you have the updated version is if dip switch 10 works, then you do.

The best things I've done to this heli are set up the pitch mechanically then using dip 11, and fit wooden blades - it was a bit of a nightmare to fly out of the box but now it's delightful.

Dusty

[Jeeperfreek]

Thanks for the info! I'll give the dip's a shot when I get the new servos replaced. Damn Chineese new year!

[Michael211]

I read somewhere once that it's not a good idea to *lock* a heli down to a solid surface and then spool up the blades to high speed... it can cause the heli to tear itself apart.

When I tracked the blades on mine, I just held it in 1 hand by the tail boom firmly and spooled it up till I could see which blade tip was higher than the other. Not something I would normally recommend for anything larger than this, but I figure this little guy shouldn't be able to do much damage if it managed to whack my hand or arm (and like I said, I kept a very firm grip on the boom). :glasses2:

However being used you have no way of knowing what it's been thru already. It's likely the little guy has been crashed at least a time or two, and it may not have a perfectly straight mainshaft now as a result (which would result in severe vibrations!).

And yes, your tx knobs should have stops at full left and right (8pm and 4pm positions). You should not be able to turn them 360 degrees. Something's broken there I'd suspect. Also I just checked to be sure, and mine have a ratcheting feel to them as they turn.

I dunno what the deal is with your tail, but it could be the vibrations are giving the gyro grief and it's changing the tail motor rpm's as a result. If you hold the heli in your hand and spool it up does it still vibrate at 1/2 throttle and does the tail motor still change rpm's even when you are holding the heli perfectly still?

The little heli should not have vibrations when spooled up, and the tail motor should run a constant rpm if it's not trying to counteract the heli turning uncommanded.

I hope you got a really good deal on this little guy, he sounds like a basket case to me.

Thing is, these little birdies are hard enough to figure out when they're new.... used and not knowing what the previous owner put it thru, that's going to be a PITA to get it all sorted out.

- Michael

[Jeeperfreek]

I was afraid that the RX might be bad and I think you confermed it. If I were to get a new RX should I get the newer one for brushless? I'm not sure I want to get that deep into this little guy but latter down the road it might apeal to me! I have the 2601 TX so what RX would I need?

As far as locking it down I have some speaker carpet on the work bench to keep screws and stuff from falling to the floor and this thing actully just gets caught in the pile loops! Pretty handy realy but I never get to take off rpm.

[Michael211]

I'd work out those vibrations 1st, then if the tail motor still surges for no apparent reason you can start trying to figure that out. Vibrations can trick the gyro into thinking it needs to change the tail motor RPM's to counteract movement.

I'd think it better to go for the brushless components IF you have to start investing in replacement electric parts. If you have to buy new parts anyways, the cost difference between brushed and brushless just isn't that significant.

- Michael

[Jeeperfreek]

I know that the shake can trick the gyro but thats not the reson i think it needs to be replaced. It's because the pots on it don't have any detents or stops. When I replace the servo's i'll give it a better look but I think it will have to get replaced.

[watdazit]

My pots do not have a start and finish. I asked the supplier about this and he said they do just go around 360 deg and start again. I have a spare new Rx and they just go around and around.

[Dusty1000]

I think Michael211 thought Jeeperfreak was talking about the knobs on the TX, not the pots on the RX..

Any vibrations will likely be down to 1 of 3 things
Bent main shaft
bent feathering shaft
blades needing balanced

[Michael211]

Oh cwap! You're right Dusty... I don't know how that happened. I think I had a brain-fart.

Actually I even said tx knobs in my reply.

Yeah I have no idea if the rx pots have stops or not, I've not tried to turn them that far. They do have resistance when turning them though, they don't turn easily on mine.

Jeeper I kinda doubt your rx is the problem. Sorry for the confusion though!

- Michael

[Jeeperfreek]

Originally Posted by Dusty1000

I think Michael211 thought Jeeperfreak was talking about the knobs on the TX, not the pots on the RX..

Any vibrations will likely be down to 1 of 3 things
Bent main shaft
bent feathering shaft
blades needing balanced

Thanks for clearing that up guys! As long as everybody's RX's do the same thing then I'll take it out of the equation. Although since I'm doing the V2 upgrade anyway I'll recheck everything when the servo's get replaced. I know that the front one has to be glitching. I can see it twitch after it binds to the TX and then stop but its hard to see with the blades spining and shaking like they do.