FBL Gyro AR7200BX Setup Problem

[Heliman450]

Hi all, I was working on my Blade 450X setting up the AR7200BX and have failed to resolve a longstanding problem.

The first time I checked it out (it was bought RTF), I discovered that the pitch settings were somewhat strange in that 50% stick didn't give a zero degree value. I tried various things but failed to get it better than -1.5. My solution, albeit a temporary one, was to reset the 50% to zero degrees but in so doing lost 1.5 degrees of the -11.0 degrees set in the gyro as the minimum and gained 1.5 degrees on the maximum (originally +11.0).

As I was only using the positive range during my exercises, it didn't matter to me. However, I wanted to return to the issue in due course and that's why I'm seeking some advice. So the problem................

When I select Menu Point G to set the centre points for the servo arms the servos go to the central position to await any fine adjustment. All looks level and the levelling tool confirms it. Stepping through to select each servo arm in turn produces the correct Status LED indications. However, when exiting the final servo and returning to the reference position the three servo arms jump upwards (the swashplate follows this too when the links are connected). I checked with my digital pitch gauge in position and as each servo is selected, zero degrees are maintained. The pitch measurement drops to -2.0 degrees when returning to the reference position. During this process the collective stick remains at zero input.

I went through the setup twice and checked through once without disconnecting the servo arms/links. At the moment, I'm of the opinion that it's an internal problem with the gyro, maybe firmware? I can continue with my temporary fix but longer term want to get to the bottom of the problem. It now shows -7.5/+0.3/+13.0

Any input will be gratefully received.

 

[D.O.G.]

You need to go into letter "I" to get your swash plate to move in the right direction. In the Transmitter you need to get into reverse servos settings and that will get your servos to move in the right direction. Left,right,forward and backward. Need to get all that set first before you go to "J" setting for your 6 degree with the blue light. Make sure you get close to the blue light. Need a level and stable platform to set your heli on. I hope this helps a little bit.

 

[Heliman450]

You need to go into letter "I" to get your swash plate to move in the right direction. In the Transmitter you need to get into reverse servos settings and that will get your servos to move in the right direction. Left,right,forward and backward. Need to get all that set first before you go to "J" setting for your 6 degree with the blue light. Make sure you get close to the blue light. Need a level and stable platform to set your heli on. I hope this helps a little bit.

Hi D.O.G., thanks for the quick response. See the picture below, which is my workshop setup for ensuring that the helis remain level during maintenance. they are clamped to the table so that it makes it easier for me to work.

I've been through the whole setup twice. The servos are all working in the correct direction and have never needed changing. Swashplate up = negative pitch and down = positive pitch. Are you saying that I need to make changes there anyway?

 

[murankar]

well if your talking about the align 500/550 then it should be leading edge control. If your swash goes down for positive an up for negative then your grip arms are reversed. I would bet money on it.

The blade 450X I am almost positive [also] that it is leading edge control. make sure you have leading edge control first then go through the setup stuff.

 

[Heliman450]

well if your talking about the align 500/550 then it should be leading edge control. If your swash goes down for positive an up for negative then your grip arms are reversed. I would bet money on it.

The blade 450X I am almost positive [also] that it is leading edge control. make sure you have leading edge control first then go through the setup stuff.

Thanks murankar, no I'm talking about the 450X, which is trailing edge control so my swashplate direction is correct. The picture is an old one to show D.O.G. my arrangement for ensuring that the heli remains still and perfectly level, hence, the four spirit levels. It isn't that I don't know what I'm doing mechanically, it's a search for any quirks associated with the gyro. Instructions aren't always that good and maybe I've missed something there.

I could do a reset of all settings and go through it again. What do you think of that?

Cheers,
Phil

 

[D.O.G.]

I would go through the set up again but this time have the you tube video playing in the back ground. Just an opinion. Nice stand you have their.

 

[Heliman450]

I would go through the set up again but this time have the you tube video playing in the back ground. Just an opinion. Nice stand you have their.

Cheers D.O.G. I don't think the video I watched helps as it only shows how to step through the setup options. What I'm after is the combination of the mechanical and the electronics. I've already put together a maintenance procedure, which I'm working on finalising now.

I'll go through again after doing a factory reset. I've kept a record of my standard settings i.e. servo frequencies etc. so no problem there.

Thanks again for the feedback.

 

[trainrider06]

I think the Blade swash goes in reverse of what an Align swash does, you may simply need to adjust your swash up or down by your links. Turn all 3 the same amount up or down and see if that changes your readings....

 

[Heliman450]

I think the Blade swash goes in reverse of what an Align swash does, you may simply need to adjust your swash up or down by your links. Turn all 3 the same amount up or down and see if that changes your readings....

Hi Rodney, the swashplate direction isn't the problem, it's going in the correct direction. The problem is that the swashplate moves slightly resulting in a negative 50% stick value. I've tried various tweaks with the servo arms' positions and can get a small improvement, but not much.

My go-by at the moment is to lose some travel on the negative side and gain some on the positive. Currently, this about two degrees. I can get zero at 50% stick or leave well alone and achieve zero degrees at 63% stick.

I've been waiting on some feedback from the guys before touching it again. Scheduled for tomorrow is a factory reset and complete run through of all settings.

Anything else that comes to you will be much appreciated.

 

[murankar]

If you have not done so I would do a hard factory reset. Clear out any data in that thing. There could conflicting settings. When I had my beastx clone I had to do that to get full swash travel back. Then go through the setup.

 

[trainrider06]

Hi Rodney, the swashplate direction isn't the problem, it's going in the correct direction. The problem is that the swashplate moves slightly resulting in a negative 50% stick value. I've tried various tweaks with the servo arms' positions and can get a small improvement, but not much.

My go-by at the moment is to lose some travel on the negative side and gain some on the positive. Currently, this about two degrees. I can get zero at 50% stick or leave well alone and achieve zero degrees at 63% stick.

I've been waiting on some feedback from the guys before touching it again. Scheduled for tomorrow is a factory reset and complete run through of all settings.

Anything else that comes to you will be much appreciated.

Yeah I was agreeing with you, the Blade swash moves different than say an Align does.
What I was saying about the swash links was sometimes you'll get more pitch on way or the other because the swash isn't centered, and to center it you go up or down X amount of turns equally on all 3 cyclic links up or down....but it sounds like what murankar was saying that there is some conflict within the BeastX...

 

[Heliman450]

Hi guys, thanks to all for looking in and making suggestions. I'll keep all in mind as I go through the reset and new setup.

Let you know how it goes. If it turns out to result in a fix, then all I can say is that the problem has existed ever since I bought the heli, so the guy(s) who built it didn't notice or didn't want to spend the time fixing it. Maybe it's a Friday afternoon product

 

[murankar]

Chances are they did not fly hard enough to notice.

Also to agree with and earlier post but yes if you have unequal travel between positive and negative then the swash is not centered on the main shaft while at mid stick. Mechanical setup is important with that beastx.

 

[Heliman450]

Hi guys, I eventually managed to solve the problem. Here goes with a summary..............

1. I carried out the "Factory Reset" and it made no difference whatsoever! Actually, it didn't reset any of the non-default (factory) settings. Servo frequencies remained as per the previous selections.

2. I tried four different combinations of ideas for possible solutions until finding the correct one. The best I got was within 1.5 degrees (plus and minus).

3. The wording in the original AR7200BX User Guide is rubbish. No wonder they messed up the original RTF setup. Consequently, my version of the procedure was also lacking.

4. In Menu Point G after setting up the servo arms to the central position the swashplate jumps up slightly. I think this is to release the swashplate levelling tool. If one sets the pushrod lengths to allow the levelling tool to move slightly during the process this results in the best (course) setting for the swashplate. Pushrod lengths are: Aileron 53.17mm, Elevator 48.16mm, Pitch (Aux 1) 41.98mm and the two top pushrods to the blades 45.08mm. These measurements were taken after achieving -11.0/0.0/+11.0.

5. Here I was inspired by Rodney's contribution. When switching into Menu Point J, the blades are moved in line with the helicopter and the pitch gauge should be reading zero. I checked both blades and the pitch was equal at -1.5 degrees. All three servo arms were perfectly lined up. The solution was to shorten all three pushrods by the same amount (1.5 turns - each half turn gives approximately 0.5 degrees of pitch change). This is equivalent to lowering the swashplate.

For a trailing edge configuration the swashplate moves down to increase the pitch value. Of course, one has to make a judgement as to whether the change can be achieved using the top pushrods or a combination of both sets of pushrods. Conversely, if the pitch value was positive, then the pushrods needed to be lengthened.

6. It's my view that the lifting of the swashplate at the end of Menu Point G is the cause of the negative pitch value (swashplate up, degrees down).

The adjustments in item 5 were done before moving the cyclic stick to achieve the positive 6 degrees to "teach" the cyclic pitch geometry. The problem came about because the original User Guide says to go back to Menu Point G. Don't do this, correct the problem as I've described in item 5. Result, a perfect -11/0.0/+11.0

 

[trainrider06]

Good deal Phil, glad you got her righted! Usually the manual will give you the length the servo link rods should be when beginning setup, these should get one close to if not 0 centered on the shaft with the swash.

 

[Heliman450]

Good deal Phil, glad you got her righted! Usually the manual will give you the length the servo link rods should be when beginning setup, these should get one close to if not 0 centered on the shaft with the swash.

Hi Rodney, the reason I found this Forum was because the customer support from Horizon Hobby didn't/couldn't answer my query. The RTF manual doesn't show how to assemble my Blade 450X. There are no details in it and I asked them for information on the start dimensions for the pushrods and how the mechanical setup works in conjunction with the AR7200BX. Their response was "Look in the internet, there are many sites that show you how to assemble a helicopter". I think they should do some surfing themselves as they built it and included the -2.7 degrees into the RTF heli originally.

As you can imagine, I was somewhat less than impressed and will never buy another Horizon product. When my use of the Blade is over I'll stop buying spares for it and simply leave it to gather dust or possible give it a spectacular meeting with the ground! At least I could strip it of the electronics for use elsewhere if I resist that temptation.

Thanks for your input to my problem, it freed up my thinking to just go for it!

Cheers and thanks to all the guys who contributed, too.

 

[trainrider06]

I have heard good and bad about Horizon, mostly good, and that their support was pretty good.
I hate to hear that you had a bad experience with them, because you sound like a good guy.
But you got her right now, and have gained another bit of info for future builds!
That's a good thing!

 

[Heliman450]

Nice one Rodney, I too, always look for the positive in a situation. I fully understand that businesses and the employees find themselves stretched. I'm sure when the product concerned is within a year of purchase they always give priority to those customers. Can't really blame them for that. Pushrod lengths...............? I'm sure they could have at least told me that or given me an assembly guide.

Bye for now!

 

[trainrider06]

Yes they failed right there.....did I say push rod? LOL cars bikes helis, all mechanical things float around in my head....
Servo links? Maybe Servo push rods I guess is a name for them too....I forget what they are usually called....myself I like dog bone links.....
There is nothing in the manual about the link size at all, I just pulled it up and sure enough nothing.
Really not much but how to set radio and BeastX up, and an exploded view of parts....Thats not much help.
You should take measurements of the links now that you have it settled. for future reference....

 

[Heliman450]

Check out thread #14, where I've shared it with the RC-Help.com community and anyone else clever enough to connect with our family and take part!