Hoverfly Help with new problem on Hoverfly Pro gains

[jfro]

My x8 had been flying very nicely. Today, all hell broke loose after trying some new props on the bottom.

I fly it without camera (my light setup) and on futaba, set endpoints (gains) to high 20's to low 30's.
When I fly it with camera (heavy setup) the futaba endpoints are up around 80.

Today, experimented with 12x4.5 prop on bottom instead of 11x4.7 in my light mode (no camera).
It launched as expected. I flew maybe 3-4 flights of maybe 20 - 30 seconds each changing the gains each time Most gains were roughly 76 and on up to about 100 today with the bigger props. I might have tried a lower gain, but don't really remember. Didn't like it so switched back to 11x4.7's on bottom.

Battery wasn't even warm when I made the change.

After changing back to 11"props, I didn't have much control. It's trying to level itself pitching left - right and front and back. Have tried gains from 26 to 90. Higher numbers are more problematic, but nothing is even close to rising 4-6 ft and being level. It gets up a couple feet and goes all over the place. After each crappy landing (on very soft soil with longish grass), I check motors and landing gear for alignment.

I reset cables, checked tightness of props, changed battery, changed over to a different model (setup) on my radio that I was using until last week, etc etc.... All motors seem to be spinning properly and it sounds normal.

Finally, on about 8th attempt I took it up a little higher to see if it would level (which it didn't) and came down losing 2 props on bad landing, so i quit for the day.

I guess my big questions is how long does the HFP black board take to adjust after changing the gains?
Does changing the gains make other changes?
Does making large changes totally confuse the fc?


Thanks in advance for any advice on how the HFP board works and what I should try next.

 

[hoverben]

Hi Jim,

Just in case it becomes relevant, I am assuming you are flying a Y6 or X8. Please correct me if I'm wrong.

The HoverflyPRO shouldn't need "time to adjust." It should read the signal at the assigned gain and respond to it at that level regardless of previous gain. Two things that immediately come to mind:

1. Is there any chance that you are taking off with Auto-Level or Altitude Hold engaged?

2. If you are using bullet connectors on your motors/ESCs, check that they are all secured. We've seen some similar issues attributable to loose bullet connectors in the wiring harness.

 

[jfro]

First thing I checked was alt hold & autolevel.
No bullet connections. All soldered.

Xy8 config.

10 minutes between changing 12 back to 11" props. No changes on futaba other than endpoints for gains.

It has to be something I am overlooking, but I didn't change anything but props or land hard before this started. What can change in 10 minutes?

 

[jfro]

Problem solved.

Thanks Ben. You got me thinking when you said it sounded like it was trying to AH or auto level.

I went back to the radio (First thing when turning on radio, I have 4 switches I check first to make sure they are down as well as throttle.)

I checked them and they were down. I check on servo, and they showed middle position, which is my AH and AL. I switched to my other flying model and they were the same.
I then switched to my model I use on my sim, and the switches showed the correct positioning in servo mode.

I then switched back to my current flying model, and the switch was now showing correct. I changed to my old flying model and it also showed.

I then went back to current, changed the two broken props and it is now flying as it should.

Very strange on the radio bit as I didn't change models until I was 3-4 bad take offs after changing back to my old props.

Anyway, Ben thanks for giving me the "what to look for" which after ignoring your remarks because I'd checked the switches numerous times, after thinking about it, it got me to go check if the switches positions in servo mode.

Very appreciative.....

 

[Webheadfred]

Jim... Flew today. 5000mah and 3.7kg... 7 minutes 30 seconds with camera gimbal and maneuvering. You didn't like the bigger props on the bottom of the XY8?

 

[jfro]

Jim... Flew today. 5000mah and 3.7kg... 7 minutes 30 seconds with camera gimbal and maneuvering. You didn't like the bigger props on the bottom of the XY8?

That's 8.15 lbs which is just a touch over what I was flying today. I assume on your hex w/ avroto's 2814's.????

I ordered some 12x3.8 slow fly's for bottom props to try this weekend. The ones I tried today were 12x4.5. It felt like the motors were working alot harder and I didn't have camera or gimbal on it. I didn't like the sound as it sounded like they were laboring too hard. With battery, I was at 8lbs 1 oz. After going back to my 11x4.7's top and bottom, I was getting max 3m 48s to 4m 09s. Flew about 10 batteries after changing back. Most were in the 3:55 range. Easy flying....

If I don't figure this out soon, I may go the hex route as you did or if I sell some gear, I might build a quad with 375-400kv motors. Guys are talking 15-20 minute flight times. Maybe a quad to check and test out the sights and my xy8 for the beauty shots.

At 3:50 minutes, I certainly wouldn't have much margin of error if I lose orientation or am out 100 yards or even over water..... With camera and 2nd battery I'll be around 11 1/2 lbs, which it flies, but it lumbers a bit. Maybe the way I'm set up I'll get 5+ minutes max with 2 batteries....

Because I'm slow flying and doing very little climbing, I expected longer flying times. I'm perplexed at my short times.....

I'm going to try 12x4.7 top and bottom and then the 11x4.7 top and slow fly 12x3.8 on bottom. I'll keep my fingers crossed but don't really expect any great increase. I was expecting with camera and 2 batteries (around 11.5lbs total) just under 8 minutes based on other peeps experience.

 

[jfro]

What props did you fly today?

 

[Bartman]

jfro,

what setting are you using for timing on your ESC's? a good prop combination would be the APC SF's 12x3.8 on top and 12x4.7 on the bottom. my personal preference is the Xoar PJA line of props, specifically 12x5 on top and 12x7 on the bottom.

also, what motors and what's the cell count on your batteries?

bart

 

[jfro]

Avroto M2814-11S, 5000 mAh 4s (2-turnig 30-40C and 4- GensAce 40C)....
Turnigy 30amp.
Timing was what Hoverfly suggested. I had to call them.`

brake off
battery type nimh/nicd
cutoff mode Reduce Power
cutoff threshold high
startup mode ...normal

timing mediium

 

[Bartman]

Avroto M2814-11S, 5000 mAh 4s (2-turnig 30-40C and 4- GensAce 40C)....
Turnigy 30amp.
Timing was what Hoverfly suggested. I had to call them.`

brake off
battery type nimh/nicd
cutoff mode Reduce Power
cutoff threshold high
startup mode ...normal

timing mediium

you're flying one battery at a time at a total weight just over 8 pounds? what are you using for the threshold to stop flying? time? voltage?

 

[jfro]

you're flying one battery at a time at a total weight just over 8 pounds? what are you using for the threshold to stop flying? time? voltage?

I took my voltage beeper off and am now using time. I bring it back by 3:30-3:40 and hover till it sort of won't stay up at 50-60% throttle and I land.
With 2 batteries, gimbal, and camera (gh2), it's just a tad heavy till I maybe get some 12" props that I like.

 

[Webheadfred]

Hey Jim, sorry I was playing poker when you replied... I'm flying the APC 12x38 SF's. they seem to be doing pretty good.


You know... Looking back at your ESC configuration, I'm pretty sure I have my voltage threshold set to low, not high. I looked through my HFP manual and found nothing about threshold. My thinking here was that I wanted as much voltage for as long as I can get it. With a high threshold, the ESC, in my opinion, will start to reduce power to the motors at a higher voltage cut-off. With a lower threshold, the ESC will continue to supply as much power to the motor, longer; until it hits that lower threshold. With the soft cut-off and NiMh setting, these serve to do the same as well. The thinking is, of course, that you don't want the power to just stop, you want the most gradual decrease available to allow you to set her down.

I may be completely wrong here but I'm sure I have my threshold set to low.

 

[Bartman]

that makes a lot of sense Fred along with the fact that he'd be damaging the batteries if he were really flying them to the point that he was noticeably losing power.

with two 5000mah, 4S packs and total weight of 11.5 pounds, temps less than about 92 F, I can comfortably get up to about 8 minutes of flying with my XY8 and Tiger/Avroto motors. the 30A ESC's will be a limiting item with the set-up, i've switched over to 40A as a standard for those motors, but he shouldn't be having a problem at the weight he's at. in upstate NY the temps haven't been very hot yet so the ESC settings may be the culprit as 3.5min flight times are really low.

bart

 

[Webheadfred]

I don't recommend my treatment of batteries on anyone. I kinda do the same. Fly for a timed amount, maneuvering and whatnot, and then bring it in and practice low level hovering until I have to increase throttle a good amount to keep it in the air. I then set it down. I'm getting easily a good 7 minutes with about an extra minute to screw around with at low altitude. This all on one 5000 mah battery. Jfro is losing something somewhere. He's on basically the same setup, weight, motors, etc.

Let me see... 8 motors = 33% more power than 6. Add the 15% loss of efficiency, then maybe 5 minutes wouldn't be out of line. He's getting almost 4 so maybe the ESC setting could be the difference. Just a guess...

 

[Bartman]

I don't recommend my treatment of batteries on anyone. I kinda do the same. Fly for a timed amount, maneuvering and whatnot, and then bring it in and practice low level hovering until I have to increase throttle a good amount to keep it in the air. I then set it down. I'm getting easily a good 7 minutes with about an extra minute to screw around with at low altitude. This all on one 5000 mah battery. Jfro is losing something somewhere. He's on basically the same setup, weight, motors, etc.

Let me see... 8 motors = 33% more power than 6. Add the 15% loss of efficiency, then maybe 5 minutes wouldn't be out of line. He's getting almost 4 so maybe the ESC setting could be the difference. Just a guess...

FWIW, SleepyC is flying a 6S powered XY8 I built for him with my EOSc camera mount, with two 6S 6000mah packs he's flown just under 19 minutes using a Sony NEX. With two 6000mah 4S packs on my older heli I can do 8 1/2 minutes pretty comfortably and have pushed it to 9 1/2 at 11.5 pounds.

 

[JZSlenker]

Old batteries? Props not on the correct direction?

We have 10 lb X-8 with two 4200 4S batteries averaging about 9.5 minutes using 12" top and 13" bottom props .

 

[jfro]

This is making me want to pull my hair out.... You guys are saying the same thing I found when researching (lots and lots of reading) before starting my build.
I was expecting 7-8.5 minutes loaded at 11- 11.5 lbs with 2x 5000mAh 4s 30-40c batteries. I almost get that 8.1 lbs.

I started with bullet connectors on my esc's and motors and an 8awg stranded copper wire home made harness with 16 gauge off the harness to the esc's power lines.
I then changed to a silicone 8awg harness, shortened up the 16mm cables, and took off the bullets and soldered the connections. Didn't make any difference.

It flies very nicely. It just bad on flight times. My first flight with my brushless gimbal was beyond the quality I was hoping to start with. With some luck, my new brushless gimbal will be ready to go this weekend.

I'm going to try some more prop combo's this weekend, and if things don't improve, I guess it's unsolder the 40+ friggin connections, put bullets back on them (more weight) start testing motors and esc's. I have 1 extra esc and motor. I don't think it's motors because the sound when flying is very steady. During my setup on the gains, I could almost close my eyes and judge by sound.

I just went out & flew easy and slow. Some wind, but I stayed below my 2nd story and tree line.
3:39, end of line, 50% throttle on hoover, at the end, it was about 60-70% on throttle to attempt to keep hoover as it gently landed. Yesterday with same settings, only using the variable (webhedfreds) variable throttle curve, I was getting 3:50 to 4:09. I pretty much lost 20+ seconds.

Battery start was 16.77v all cells equal. finish 13.54v all cells equal.
That is 4.19 and 3.39 per cell on start/finish.
That means I used .81v per cell and had .39v left if looking to go down to 3v / cell.

That theoretically means, if it were linear and I understand it's not, that I had about 48% more power to keep the xy8 up if I wanted to go right to 3v per cell. That would equate to another .48x 3:39(219 sec) = 105 seconds, added to my 219 seconds, for 324 seconds, or 5 min and 24 seconds
So being conservative, maybe using 50% of that left over juice, maybe I'd get 22% or almost 55 seconds more time if I changed the esc setting.

I've read many say use the 80% rule and your batteries will last longer and safer... 80% of 16.77 is 3.35/ cell and I finsihed at 3.39 which is pretty close.

So, it seems to me my flight times are crap, esp. since I'm only a little over 8lbs right now. Maybe I'll get lucky with the 12" props this weekend.

Thanks for taking the time to try to help me out. Really appreciate it.....

 

[Bartman]

jfro,

if you're using standard Turnigy Plush ESC's they should be set up like this

1. Brake--OFF
2. Battery Type -- Ni-xx
3. Cut Off type -- Cut Off
4. Cut Off Voltage -- Low
5. Start Mode -- Normal
6. Timing Mode -- Middle
7. Music/Li-Po -- all blank
Governor Mode -- OFF

As Fred said, you are likely being power limited at your ESC's. For the weights you're flying, any prop should get you better flight times than what you're getting. At 8 pounds I'd use 11" props, maybe even tens. 12's will be too much prop and the heli will be very floaty.

Check your ESC's. Double check the timing as LOW will kill flight times also.

Bart

 

[jfro]

Old batteries? Props not on the correct direction?

We have 10 lb X-8 with two 4200 4S batteries averaging about 9.5 minutes using 12" top and 13" bottom props .

Batteries are new. Props are correct. It flies like butter.....

my Avrottos are 770kv and I thought 12" was the max size they could comfortably turn. You are the 2nd person who has mentioned using 13" on their x8 with Avrotto's or similar sized 770 kv motors.

I tried some 13x6.5's, but the motors were hot and I wasn't anywhere near hoover at 50% throttle. I'm pretty sure I tried them without my camera so was either at 8.1 or 9.35 lbs. I don't remember if I tried with 1 or 2 batteries. I just remember I didn't try for very long as I felt the motors were working way too hard....

Now, that being said, I'm confused about if I should be putting the larger prop on top or bottom.... I've read both so I'm confused.
I'm also guessing the 6.5 was a bit much.

This weekend, I'll have a 12x3.8 set to test. I can then test top and bottom at 12, or 12 and 11 or 12 and 13. Maybe something will click.

I'm getting the idea I should change my ESC setting at least to medium if not low. I agree with Bart, the 30amp

At the end of your flight, what your voltage readings?

JZSlenker, your 10 lbs w/ camera seems pretty light. If I went to 2-4000 4s batts, it would get me down to 11 1/4 lbs. I have one extra plate that I made to further dampen my camera gimbal, so I'm not sure what else I could lose. If I put 40 bullet connector on, I'm going to go up another couple ounces....

Oh well, it's something I've done and maybe eventually I'll figure it out.

Thanks again.

 

[Bartman]

jfro,

are your ESC's set up the way I posted? 13" props are too much for those motors at that weight. the larger diameter or high pitch goes on the bottom.

i'm about to drive up there and fix it myself! lol