Well like the title says .... Just bought a 450 with the famous..or not so famous (im finding out) Aligns 3gx. I have been into larger helis but always had a few 450 with flybar. I have never had a flybarless head so bought this unit from someone and was new to him and never been flown. Now Im finding out why it did'nt fly. So i proceed to finish install and had a lot of trouble getting throttle to arm. Come to find out the 3gx unit was bad and so I bought another one used. The throttle armed on this one just fine. Installed the "new to me 3gx" by Tonys awesome videos (by the way those are some of the most informative videos I've viewed.. great job Tony) after viewing all 5 I set the heli like he suggested. (First time was set up according to Aligns directions with the "new to me 3gx") When I took it out for the first flight before using Tonys set up It spooled up to half throttle and the head starts twitching like its got a mind of its own....to the point it looked and acted like it could flip over. So i stopped and decided to do some more looking on line. Thats when I found Tonys videos. So tried it the second time and almost exact same thing... head starts acting very strange like it wants to roll over. Now i know first I thought of was it the Alerion was reversed. So I checked several time and what i notice is when you move the heli to the left for instance, the head will move opposite direction but not very far and then move right back. In fact you really have to look hard to even see which way it moves. But I determined that when Heli tilts left, head moves right ever so slightly then back the other way. Soooo.. after reading some more threads about the 3gx Im starting to think i should just get rid of it but because of the money I have in it I would sure like to keep trying a few more times before giving up and going to a Micro Beast. Also I did upgrade to 5.0 version... somewhere I read that I should try and go back to version 2.1 ? Is there anyone out there actually flying with a 3gx with version 5.0 ? Im not to picky about the set up as long as the dang thing doesn't flip over. Thanks for any help guys !
450 Just bought a 450 with the 3GX...
- Thread starter 7379df
- Start date
trainrider06
Active Member
Hi 7379df! Welcome to RCH! Well unfortunately, or I guess fortunately Tony is the 3gX guru, unfortunately you probably have a 50/50 chance of that thing working good for ya sad to say. Myself I have never even tried to mess with those (your a brave man and I salute you for trying!) the good thing is the AR7200BX is getting cheaper and cheaper, and that controller works very well as you may know. So if Tony cannot get that sorted, you'll probably need to get ya a BeastX. But you'll know 99% that you'll have a smooth heli to fly!
murankar
Staff member
Those 3gx gyros are a pain in the <insert your favorite body part here> to get working. Good news is some people actually got those things working just fine. Those people are few and far between.
I could make some suggestions but I think you should know what works for you by now. I would just get another gyro of your choosing.
If its all shaking or "hunting" then turn the gain down. Sounds like a gain issue. If that does not fix it I would not try and tune it, i would just get another gyro. If your dead set on trying to get the 3GX to work then your going to be doing a lot of tuning flights to dial out any negative issues. What version of the 3GX firmware are you using? From what I have been reading on here V3 is the route to go. With V3 you will need to get the heli in the air quickly, meaning before it hits full head speed. V3 hates being on the ground. If you go with V5 then you may have a tail issue that's going to haunt you. It may never tune out. Just know that you may not win the battle with that gyro.
I could make some suggestions but I think you should know what works for you by now. I would just get another gyro of your choosing.
If its all shaking or "hunting" then turn the gain down. Sounds like a gain issue. If that does not fix it I would not try and tune it, i would just get another gyro. If your dead set on trying to get the 3GX to work then your going to be doing a lot of tuning flights to dial out any negative issues. What version of the 3GX firmware are you using? From what I have been reading on here V3 is the route to go. With V3 you will need to get the heli in the air quickly, meaning before it hits full head speed. V3 hates being on the ground. If you go with V5 then you may have a tail issue that's going to haunt you. It may never tune out. Just know that you may not win the battle with that gyro.
Smoggie
Well-Known Member
I used 3GX when I first started with helis. They are not easy to setup and the software is not at all helpful, but in most cases once you get to know them they perform ok, not great but ok. I had most luck with V4.0 software, I had my helis flying pretty well on V4 with no real issues. V5.0 was alright for smaller helis (so probably ok for your 450) but not good on the bigger stuff (gain range was too low).
Your gyro compensation sounds to be correct, you do only get a small 'twitch' opposite to the direction of movement, that's normal. The 3GX does have a reputation for being prone to tipping over on spoolup and spooldown. Best bet is to get up to headspeed as quick as possible and get swiftly into the air.
Your gyro compensation sounds to be correct, you do only get a small 'twitch' opposite to the direction of movement, that's normal. The 3GX does have a reputation for being prone to tipping over on spoolup and spooldown. Best bet is to get up to headspeed as quick as possible and get swiftly into the air.
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Tony
Staff member
If you are dead set on getting the 3GX to work, then yes, go back down to 2.1. It's the most stable version out there. Once on that version, just follow my videos. Make sure to adjust the pots on the gyro so they read 105 in the program so you are about mid on the cyclic gains. If that doesn't work for you, then I'm afraid you have one of the gyros that is a pain to tune. It can be done, but it's more trouble than it's worth. especially since you can get others so cheap now.
If you are looking to upgrade, then just let us know and we will help you out. I have a full series on setting up the AR7200BX and the Ikon gyros, so if you go with those, the videos are already there to help you get it setup.
Welcome to RCH!
If you are looking to upgrade, then just let us know and we will help you out. I have a full series on setting up the AR7200BX and the Ikon gyros, so if you go with those, the videos are already there to help you get it setup.
Welcome to RCH!
Derek
Well-Known Member
Hi 7....i'd just like to add my opinion. I have 5 helicopters. 4 have the Ikon and my Trex 450 has the 3gx. You were saying that your 450 seemed like it wanted to flip over. That is likely because it had v3.0 firmware and that version was notorious for tipping helicopters over on spool ups. I have v5.0 on my 3gx. I've had v5.0 on it for well over a year and I love it. It's super solid and it just works.
As for Tony's 3gx videos....definitely follow them. I have followed them many times and they've always rewarded me.
As for Tony's 3gx videos....definitely follow them. I have followed them many times and they've always rewarded me.
Admiral
Well-Known Member
Hi 7379DF, I had three helicopters setup with 3GX systems two 450s and a 500 all of them flew OK using Version 5, however I had a couple of crashes with the 450s that may or may not have been pilot error which damaged my confidence in the 3GX.
Since changing to two AR7200BX and a K-Bar I have had no unexplained crashes and doing much better. I can't say for sure that I had issues with the 3GX but I don't seem to have any issues now.
Since changing to two AR7200BX and a K-Bar I have had no unexplained crashes and doing much better. I can't say for sure that I had issues with the 3GX but I don't seem to have any issues now.
So I turned down the pots today on the 3gx all the way to the left on both(CCW). Decided to try it again and still doing the same thing... I take the throttle up slow... 1/4 throttle and no jumping of swash.. very solid .. then on up to just almost half way ..when it starts to get light on the skids and just out of the blue the swash will jump left or right and when it does it seems to stay tilted in that direction. I am currently running the version 5.0 I want to take it on up but i just cant get myself to do it. Got that gut feeling something bad gonna happen...lol. Is there any settings in the program that i could try and turn down just to tame it a little. I might try and get a video if i can find time. That would help alot. Thanks guys.
Tony
Staff member
Download 2.1 and downgrade the gyro. You will need to uninstall the program from your computer and install the new program (2.1), then connect the gyro and "update" the firmware to 2.1. Then, go through all of the setup again. This should get it a little more stable.
Here is the link to the page where you can download the software.
Rc-Help - 3GX How-To
Here is the link to the page where you can download the software.
Rc-Help - 3GX How-To
Smoggie
Well-Known Member
The swash stays tilted because the heli is on the ground and because it's sitting on the ground it cant respond to input as the gyros expect it to. The answer is to get the heli in the air where it is free to respond to input.
BTW, probably not related but what throttle and pitch curves are you running?
BTW, probably not related but what throttle and pitch curves are you running?
I double checked and all throttle and pitch curves are linear. I will go back to the 2.1 and give that a shot...if I have no luck with that I think I'll go ahead and get the micro beast.
- - - Updated - - -
By the way...Aligns web sight only goes down to version 3.0. Where could i find 2.1 ? Thanks !
- - - Updated - - -
By the way...Aligns web sight only goes down to version 3.0. Where could i find 2.1 ? Thanks !
Smoggie
Well-Known Member
Personally I found v4 to be fine, it never gave me any real issues once I got my head around how to set the thing up, and V5 was also ok for smaller helis but needed the gain pots turning all the way up.
If you are using a 'normal mode' linear throttle curve (0,50,100%) then that will give you very poor results and may explain some of your problems. As you will know on a collective pitch heli the general idea is that the rotor RPM stays constant and you control the lift by changing collective pitch. A 'normal mode' linear throttle curve means that RPM is constantly changing which to put it bluntly makes the heli 'fly like crap'.
My advice would be to use an 'idle up' flat line curve and use throttle hold to start and stop. Though if you really want to use the collective stick as a start/stop you would be much better using a throttle curve that ramps quickly up to speed, something like: 0,75,75,75,75%.. The idea that by the time the collective stick gets past 25% travel you are up to full headspeed. If doing it that way you then want a pitch curve that has only a couple of degrees or so of negative pitch so that the heli isn't sitting spinning with lots of negative trying to push it into the ground.
If you are using a 'normal mode' linear throttle curve (0,50,100%) then that will give you very poor results and may explain some of your problems. As you will know on a collective pitch heli the general idea is that the rotor RPM stays constant and you control the lift by changing collective pitch. A 'normal mode' linear throttle curve means that RPM is constantly changing which to put it bluntly makes the heli 'fly like crap'.
My advice would be to use an 'idle up' flat line curve and use throttle hold to start and stop. Though if you really want to use the collective stick as a start/stop you would be much better using a throttle curve that ramps quickly up to speed, something like: 0,75,75,75,75%.. The idea that by the time the collective stick gets past 25% travel you are up to full headspeed. If doing it that way you then want a pitch curve that has only a couple of degrees or so of negative pitch so that the heli isn't sitting spinning with lots of negative trying to push it into the ground.
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