swashplate leveling

[ovrundr]

Finally got the new s306g-hv servos and will be going through a complete reset and setup. I got the BLH1690A for HH and read through the manual and either this heli was setup wrong when I got it or I don't understand the manual.

in the manual it says to:

1. Disconnect the motor from the ESC by disconnecting any two wires between the motor and ESC
2. Disconnect all the linkages from the swashplate
3. Power on your transmitter
4. Enable idle up
5. Put the throttle stick to center position
6. Observe the left and right servo arms and adjust your subtrim so that they are level
7. Observe the elevator control arm (behind the motor) and adjust your subtrim so that it is level
8. Slide the swash leveling tool under the swashplate as shown in the photos
9. Place the swashplate flat on the tool
10. Adjust the linkages such that the swashplate remains flat when reattached
11. Once all linkages are attached, disconnect the battery from the ESC
12. Carefully slide the swashplate up and remove the swash leveling tool
13. Disengage idle up on your transmitter and power it off
14. Reconnect the motor wires to the ESC
15. Now go fly!

here my problem, in set 9-10. the way mine is setup the swahplate is a good 1/4" about the leveling tool with the linkage attached. Should I shorten the linkage to bring the swashplate down to the leveler?

Thanks
Rick

[KiloXray]

What manual are you getting that from?

[Rotarywing]

Somethings out of wack there, if your swash is 1/4" above your level tool your way into neg. pitch. You might want to go through the BX set up from the begining. It even sounds like somethings reversed somewhere.

[KiloXray]

Not to mention that you can't level your swash by just powering up the heli andputting your left stick at the center. I don't know what manual you are using, but none of the applicable manuals tell you to do that.

[ovrundr]

got the instructions from the HH level tool manual

http://www.horizonhobby.com/pdf/BLH1...structions.pdf

[Fooferdoggie]

that's for the flybar 450 3d. you need to go to menu g on the beastx to level the servos then use a ziptie to level it

[meowguy]

When the swash plate is level, the stick is at half, and the pitch of the blades is zero, the servo arms are at perfect right angles, the bottom of the swashplate must be 15mm above the top of the plastic side frames. The tool is 15mm thick and should slide right in that space. This is where you have to be. Otherwise as stated above everything will be out of whack. You have installed new servos, but you must have the geometry of the new servos, the same as the geometry of the old servos. That means the same distance of the ball from the center screw, and the same rotation of the arm on the spline shaft.

Once you have the correct height for the swash and the correct geometry, actually leveling the swash is pretty easy just using the AR72000BX in Step G. You can just do it by eye really. You will know the geometry is correct if your maximum physical pitch throw is the same value positive and negative in Step K.

Horizon will absolutely not tell you linkage lengths because every helicopter is different and they don't want the liability. I will not tell you linkage lengths for the same reasons. But the tool was made the way it was for this exact reason and it really works.

[KiloXray]

Originally Posted by meowguy

You will know the geometry is correct if your maximum physical pitch throw is the same value positive and negative in Step K.

Meowguy was mostly correct in his post, however the part I quoted is NOT correct. Sorry to call you out Meowguy, but there is so much BX setup misinformation out there, it really needs to be pointed out when it happens.

Step K is where you are telling BX what the + - pitch limits are. It is not a place that you can use to see if anything else was done right.

For example. you can have your geometry all whacked out and and see step K be at +12/-12, which would still be bad even though you have equal pitch. You could also have perfect geometry and step K could show +10/ -3, which would still be perfectly fine, even though the pitch value is not even close to equal.

The point is, the pitch "limits" in K are simply where you put them, and are not based off of the correctness of any geometry. To think of it another way, step K is basically the same as step E except it is for the main rotor, not the tail.

Hope that clears it up a bit, and didn't confuse anyone further.

[Nelsonisms]

I won't get into all the intricacies of how to set up the BeastX...I don't feel like typing a novel right now and all of that information is available on HeliFreak in many multiples of posts. I'll just say that the swashplate leveling tool the OP mentioned is applicable to the 450X. I've used it many times and it is useful on the 450X, so please don't think it was a waste of money.

First get all the servos set at 90 degrees in step G, then place that tool under the swashplate and adjust the rods so that it sits flat on top of the tool at midstick. It is designed to do exactly that, set the level of the swashplate as well as the height at midstick. Take note that there are cutouts for the screws in the bottom of the stock swashplate to sit down in. Once you do this and reattach the head you should notice that the washout arms are exactly 90 degrees to the shaft. Then attach the pitch links and adjust them for zero blade pitch while still at midstick.

I agree that the instructions that come with the unit are more specific to the 450 3D. You need to pay more attention to BeastX setup than those instructions. Certain things like disconnecting the motor while you work on the heli is good advice though.

[KiloXray]

Nelson, I think Fooferdoggie was saying the "instruction manual" that the OP was looking at is intended for the 4503D. I don't think he meant that the tool itself was for the 4503D. At least that is how I took it.

And he is right, those instructions are not correct for swash leveling with BX, but of course, I don't have to tell you that.

[Fooferdoggie]

right I meant the manual.

[Nelsonisms]

Originally Posted by Fooferdoggie

that's for the flybar 450 3d. you need to go to menu g on the beastx to level the servos then use a ziptie to level it

Originally Posted by KiloXray

Nelson, I think Fooferdoggie was saying the "instruction manual" that the OP was looking at is intended for the 4503D. I don't think he meant that the tool itself was for the 4503D. At least that is how I took it.

No worries. I read "need" in the same sentence as "zip-tie" and had a knee-jerk reaction. If that's not what was implied then I apologize. At least the OP should be crystal clear by now how to proceed.

[ovrundr]

thanks for all the info and making it clear. I "think" I have the idea now. I will be going through the BX setup tomorrow morning. I'll let you know how it goes.

Thanks
Rick

[meowguy]

Step K is where you are telling BX what the + - pitch limits are. It is not a place that you can use to see if anything else was done right.

KX, I respectfully differ with that statement. In the case of the original poster, he replaced his servos no doubt as part of a rebuild after a crash. No doubt he changed a lot of stuff. To simplify this lets say there are basically two sets of control rods on the swash plate. Rods from the servos to the swash, and from the swash to the blade holders. You could very easily adjust the rods from the swash to the blades to give a reading of zero pitch at half stick. But if the servo wheels for the rods below the swash plate are not the proper length, or the servos wheels not on the proper spline, you could have way more throw in one direction than the other. On my Trex 600n (a fb to fbl conversion where a lot of stuff was changed) I have had 22 degrees positive with 12 degrees negative and still had zero at center stick.

With the AR7200BX you could easily just choke down the positive and call it good. If you do that I can guarantee you will not get a blue light in Step. J.

I have never seen anyone on the web explain it this way, so I am asking you to think a little outside the box here. This came to me as an epiphany at 3:00am (the subconscious mind can work wonders on a problem) as I was struggling with why I could not get a blue light in Step J. I was not even close, being off by a degree and a half. Then I remembered what I had seen when in disgust I moved on to Step K, and for giggles, decided to see what my maximum throw could be. I then wondered what would happen if my pitch was symmetrical instead of off balance as I had witnessed. After some work on the rods and servos (with +17 and -17 that was adjusted down to +12 -12) that is when the proverbial (blue) light came on.

You can indeed use the AR7200BX to completely hide a bad setup and you can use it to help create a great setup. That's my thesis here.

[KiloXray]

Originally Posted by meowguy

To simplify this lets say there are basically two sets of control rods on the swash plate. Rods from the servos to the swash, and from the swash to the blade holders.

1) You could very easily adjust the rods from the swash to the blades to give a reading of zero pitch at half stick.

2) But if the servo wheels for the rods below the swash plate are not the proper length, or the servos wheels not on the proper spline, you could have way more throw in one direction than the other. On my Trex 600n (a fb to fbl conversion where a lot of stuff was changed) I have had 22 degrees positive with 12 degrees negative and still had zero at center stick.

3) With the AR7200BX you could easily just choke down the positive and call it good. If you do that I can guarantee you will not get a blue light in Step. J.

4) I have never seen anyone on the web explain it this way, so I am asking you to think a little outside the box here. This came to me as an epiphany at 3:00am (the subconscious mind can work wonders on a problem) as I was struggling with why I could not get a blue light in Step J. I was not even close, being off by a degree and a half. Then I remembered what I had seen when in disgust I moved on to Step K, and for giggles, decided to see what my maximum throw could be. I then wondered what would happen if my pitch was symmetrical instead of off balance as I had witnessed. After some work on the rods and servos (with +17 and -17 that was adjusted down to +12 -12) that is when the proverbial (blue) light came on.

5) You can indeed use the AR7200BX to completely hide a bad setup and you can use it to help create a great setup. That's my thesis here.

After reading this post over again, and the one in the other thread where you posted a similar explanation, I think I understand where you are going with this. I think you are basically trying to get at an alternative method for setting swash height not swash leveling. I'll bite. I'm gonna put some numbers in your post for reference so I can address all of the points. BTW, I don't take any offense to the fact that you disagree. I encourage discussion. I can, and could be wrong, and I encourage people to tell me when I am. So let's get started with my rebuttal and see where this goes!

1) This is a good starting point. I am glad we agree that, while doing this is possible, it is a bad idea and is incorrect.

2) I agree with you that the servo horns need to be the proper length (within reason) and that you need to have the horn mounted to the servo on the "proper spline" as you put it. To accomplish "being on the right spline", you simply need to have power on the servo and then put the horn on in the position that is closest to 90°. Then in step G, you select each servo and move it electronically the rest of the way until it is as perfectly to 90° as you can tell.

This is the foundation for your setup. From here you must set the swash height. This can be accomplished by either using the aluminum block tool that the OP was asking about, OR you can just measure 15mm to do it. I prefer the latter.

This is where we start to disagree though. As far as I know, the actual arm length should not affect affect whether or not you get more throw in one direction, provided you centered properly in step G. When you had +22°/-12° of maximum possible throw on your 600, you are right, that could be an indication of a swash that is at the wrong height or incorrect servo centering, but only because you should be able to get maximum throws bigger than 12°. Not all swashes need to be sitting at 15mm. This will vary by bird.

3) Here is where we really get far apart. I think this is wrong, and I think I can prove it to you. Yes, you can electronically dial out pitch throw that exceeds what you want your maxes to be. This what you are supposed to be doing in step K.

Out of curiosity and to test your theory, I fired up my 450 and went on down to step K. I wanted to see what my "maximum possible throw" was in pos and neg pitch. Below are the pictures of my "maxes". First thing you are going to notice is that both of them are much higher than 17°. This is due mostly to having slightly longer servo horns than the stockers. Remember earlier when I said "within reason". This is why. The length I am using is still inside the acceptable range and does not give me +-17°.

You will see that I have a maximum pitch of +27.4° and -22.4°. Now, according to your theory, if my "maxes" are not equal, then you "can guarantee you will not get a blue light in Step. J." Well, I beg to differ. On this bird, with this setup, I get a blue light that comes on at 5.8°.




An interesting thing to note is that on this particular bird, I am limited in positive pitch by simply not having any more throw on the servos. I am limited in negative pitch by physically hitting the swashplate against the head. The take away from that is that there are other factors that can limit max throw.

4) I can totally appreciate your theory but I think you are trying to find a round about way of finding the proper swash height. As stated earlier, this is done with the aluminum block or by measuring 15mm. If you are doing that correctly, and then building your links from the bottom up to get 0° in step G, you are pretty much a shoe in to get that blue light at 6°. By your method, you would have to get all the way to step K and then back track to G to fine tune for 0° pitch. There is a reason why these steps are in order. If you do them in order and properly, then it all works.

5) I sort of agree with you here. I think this can be clarified by saying that the BX can hide a "sloppy" setup. I think this is true in the sense that even of you don't have everything perfectly lined up down to a .1°, the BX will still be compensating in the air, and the bird will still fly perfectly fine. I think you can be off by the better part of a full degree before you start seeing strange flight characteristics, but that is just speculation on my part.

So there you have it. In summary,I stand by the idea that the entire point of step K is to electronically limit your maximum pitch throws, not to find swash height.

Your turn.

Cheers,
KX

[meowguy]

KX,
I think you have done a great job of explaining and interpreting my observations. Fortunately, enough information is provided with almost all helicopters to enable the mechanic to set the swash plate where it belongs during mechanical setup.

My 600 was an absolute nightmare to setup because the manufacturer did not provide complete instructions based on the main shaft length I was using. I could not get a blue light in J., the swash height was pretty much set for you by the linkages. I got longer swash balls, went in on the servo wheels, etc. Every post I read on the web said pitch rod length had nothing to do with getting the blue light, except for me it did. My numbers in step K were way off and after mechanically adjusting my pitch to even it out, the blue light came on. That is my story and I am sticking with it. (:-))

Thanks for your efforts on this.

Jim.

[ovrundr]

well all I can say is you guys are great. With just a couple threads here, I learn enough to diagnose the problem, swap out the servos and go through the setup. I tried it out in the back yard today (couldn't wait) and it is rock solid. Much better than before the crash.

Thanks again
Rick