500 Derek's Trex 500 hover test

Derek

Well-Known Member
Ok, so I had one of the new parts for my 500 come in today. This is it:

500PRO Main Gear Case Set H50003A

The thought was that maybe the unit wasn't centered correctly/evenly. I replaced the stock Case Set with the new Case set and took the 500 outside. Spooled it up and............nope...still has the slight wag/hunt. Once again...I'm at a loss.

The next new part to try is this:
Tail Drive Gear Assembly H50043

Here's hoping!!!
 

Tony

Staff member
I know this has been answered, but what is your head speed? Voltage*KV/gear ratio? Have you tried setting this thing to 100% throttle and trying it?
 

Derek

Well-Known Member
I know this has been answered, but what is your head speed? Voltage*KV/gear ratio? Have you tried setting this thing to 100% throttle and trying it?

I don't really know what the head speed was. I don't know how to measure that. My throttle curve has been 0,45,75,75,75 in normal mode....85,85,85,85,85 in Idle 1......95,95,95,95,95 in Idle 2. I did try the heli at 100% throttle and got the same results at all throttle percentages. That's what lead the heli pro to believe that something is "out of round".

You asked about the voltage KV/gear ratio. I'm not sure what you are asking here, but I'll try this...the 6S 3000mAh lipo was fully charged. The charger actually has been showing a bit over 3100mAh when it stops. The motor is a 1600kv and the gear is the stock main gear with 162 teeth and a 13 tooth pinion.

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If it has to much mechanical gain it can cause the tail to wag . try moving the ball on the servo closer to the servo

Unfortunately, Jesse, the ball link is at the inner most hole, already. What a bummer!!!
 

Tony

Staff member
Here is your head speed at full voltage of 4.2vPC

100% = 3235
95% = 3073
85% = 2749
75% = 2426

This is just an estimate at 100% efficiency.
 

Derek

Well-Known Member
WOW! Those are some big numbers. They are probably pretty average, as far as 500's go, but I've never known what the head speed was and never thought the head speed was that high. Thanks Tony!
 

Tony

Staff member
As stated, that is at 100% efficiency. To find a number closer to actual, multiply those numbers by .85

That will lower it down. And also, remember this is with a full battery fresh off the charger. As the voltage drops, the motor is going to slow down.
 

Derek

Well-Known Member
As stated, that is at 100% efficiency. To find a number closer to actual, multiply those numbers by .85

That will lower it down. And also, remember this is with a full battery fresh off the charger. As the voltage drops, the motor is going to slow down.

I can't imagine that I own anything that is 100% efficient, lol, so we'll go with those numbers multiplied by .85. :)

That being said....I, although very much less experienced than many people on this forum, fully believe that the issue with the tail is not a head speed issue. I believe this because, although I was very much less confident in my skills last year, I was able to hover the 500 with a very solid tail. This tail wagging (hunting) all started after we put the metal head on the heli. I'm planning on taking the metal head off my 500 and putting the stock head back on to see what happens. I'm kinda 50/50 on what kind of results that I want to see. I'm 50% wanting the issues to be gone after putting the stock head back on because then the issue will be resolved. However, I am 50% not wanting the issues to be resolved after putting the stock head back on because I really don't want the metal head to be the culprit. I will work on that this weekend. I could be doing it right now but I'm in the middle of two other planes (my Albatross has some pieces with glue drying and I'm putting the electronics on my twin boom plane).

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Well ... I hope the issue is spotted !!! I am losing sleep over it ......

I hope to find the issue real soon. I really do! I was really hoping to be flying this 500 before IRCHA 2013, next month. Don't lose any sleep over it, Westy! I imagine it's just "the nature of the beast" and will be tamed eventually. I've gotten past the frustration and I've just realized that it just needs work.
 

Tony

Staff member
Have you bound this back up to your DX6i with teh old Rx yet? If not, try it. This very well could be a Tx issue. I would do that first before replacing the head.
 

Derek

Well-Known Member
Yep....did that when I went to see the heli pro. I told him that you suggested it. He doubted the idea but did say that it was possible. We did bind the 500 to the DX6i and still got a wag. Bummer.
 

Tony

Staff member
I doubted it as well, hell I'm doubting just about everything right now lmao. But like the issue with the forum, it's going to end up being one little issue that is very easily over looked and you wouldn't think was the problem.

Tail blades turning and facing the correct way

belt turned the correct way

Gear mesh set correctly

Gyro setup correctly

Linkage set correctly

No binding in the tail

That is what I would start out with, and it's what we have been over. I'm at a loss on this one.
 

Derek

Well-Known Member
lol....at this point, i'm just about willing to turn my tail rotor blades around backwards, reverse the tail belt, tilt the main gear, run the gyro in rate mode, make each linkage 1mm different from the others, and over-tighten everything on the tail.....then see what happens, lol
 

Tony

Staff member
well, you would find the issue with everythign that you are goign to have to replace after the massive crash lmao.
 

Tony

Staff member
stupid question. Is the servo tight on the tail boom? If you grab the tail blades, do you see any play in anything as you are trying to twist them?
 

Derek

Well-Known Member
well, you would find the issue with everythign that you are goign to have to replace after the massive crash lmao.

Yes...there would be some VERY obvious "issues" if the heli was setup this way, lol

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stupid question. Is the servo tight on the tail boom? If you grab the tail blades, do you see any play in anything as you are trying to twist them?

...just as you've told me before, there are no stupid questions....and yes...the servo is tight on the tail boom.....and no, there is no play

I just can't believe this, lol.
 

Derek

Well-Known Member
I have no delay set. The way that I understand it is that a 500 does not delay. I didn't have any delay set last year and it hovered just fine.
 

Tony

Staff member
Yeah, I never run delay. However, you can try dialing in just a bit of delay and see if it helps.
 

Graham Lawrie

Well-Known Member
I havent read all of this thread, no time, so i may be repeating a question. What ESC is on it? I had "nodding dog" on mine as I had not set up the TX to low and high speed on the ESC when I programmed it:) It is like night and day now that it is correct, man do those blades turn at speed now:)
 
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