SZ4926 bogging- how to set up better

[RyanMccraeProductions]

Hi guys,

Ive got a 7HV ult, its running a single 6s with the 13t pinion and 14 deg pitch.
On full pitch pumps i can hear it bogging, obviously because its running 14 deg pitch.
I like the amount of pop/lack of pop with this set up, and rather than just lowering the pitch, which would loose some of that pop, can i work around it to get this feeling with no bog.

If i was to gear it up with a 14t pinion, and lower the pitch to 13 or 12.5, would i eliminate the bog? or would i be in the same situation still?

Thanks

[Lighty]

try and lower the overall pitch and use a an "S" curve in the pitch settings! works a treat!

[RyanMccraeProductions]

How much of an "S" curve would you recommend?
I had wondered if that would help in this situation.

[Lighty]

What TX are you using?

[RyanMccraeProductions]

Futaba 14SG

[Lighty]

Start with 100-70-50-30-0

Play around with it, see what feels best for you. This is off a 5 point curve radio 8FG. Sometimes I got to 65 and 35. for laughs.

hope this helps

[suthae]

a single 6s pack will not be able to handle 14 deg pitch, it's not your motor but is your pack that is giving up.

You need to drop your pitch to 11 Deg, run a 100% TC with a 14T pinion, and spend lots of flying learning collective management to not bog your head and blowout your tail.

I was running my 7hv on single 6s pack for more than year, clocked almost 2000 flights on it.

Below is a video of mine on this setup

compass 7hvU 6s 1200rpm 27 Dec Flight #3 Autorotation with crash. (4 min 20 sec)

[RyanMccraeProductions]

I did check the amp draw on the batteries a while ago and I was getting around 60 amp peaks. Which I thought would be fine for a 6s pack?

[Sebastian Zajonz]

Hello Ryan,

I think there is something wrong in your log. I've logged a flight with 6S 5000mAh 30C battery packs and I can reach without any issues way more than 200 Amp peaks. The average current is like 30 Amp.

For 6S you will always have some bog. Even with very high rated batteries.

Depends on your ESC it is a little more or less. For example some are faster or slower in response. You may can adjust P-Gain on your ESC a bit to get a more stable behavior.

Sebastian

[RyanMccraeProductions]

Thanks Sebastian,
Il have to redo the test, and check my gear is working ok. It is was with an eagle tree e-logger.

I am just using a Hobbywing 120HV, nothing fancy. Im not sure what P-gain is on a esc?
Is that something the higher end ones have?

So the battery is the weak point in the set up, do you also think going to the 14t and lowering pitch would be a better set up?

Cheers

[Sebastian Zajonz]

What head speed is your goal?

If you fly with like 1200 or 1300 RPM I would still keep the 14° and just work on my collective management. You can use the 14° for stops etc. but for climbing you normaly go down to 12°.

Its better to push the collective stick slowly.

[RyanMccraeProductions]

Im happy with 1200 or 1300, just what ever the motor bogs less with.

Thanks for the tips.

[quinn]

You would probably see an improvement with a 14 tooth but its gonna bog no matter what. 700 power systems just aren't designed to run on 6s. It will do it fine, but like mentioned before it takes good collective management. Personally, I leave mine at 14° pitch when I run 6s. It will bog really bad if I just nail the collective from a hover, but if you just ease into it, you can get it to move pretty quick. If you don't like the sound of it bogging, you can always govern it down to like 1100, but you will get better performance running at 100% and letting it bog.

[JeffPfeifer]

I've spent a lot of time experimenting with low headspeed with running half the cell count that you normally would run on the same size heli. From my experience all are easily boggable (dont think thats a word but oh well) so you have to use good collective/cyclic management. I have a 6hv that I have set up as a dedicated low headspeed heli and I run +- 15 degrees of pitch. Yes I can bog it badly on +- 15 degrees of pitch if I try to to a full pitch punch out, however I don't do that. But if you manage the collective and the energy of the disk well you can utilize the 15degrees of pitch in certain situations. For that heli I also run a 100% flat curve with no governor and gear the heli to get my target headspeed. Also on the low headspeed stuff I have found that lighter blades work better for me. They take less energy to roll/flip, and also recover headspeed quicker from a loaded condition. I know this thread is about the 7hv/Chronos, however most of this from my 6hv does apply to a larger heli. Here's a video of my 6hv:

https://www.youtube.com/watch?v=19JQANkSE98

[Rob43]

This prior edition of the 6HV was/is especially nice at the lower speeds.

I have a 7S4400 pack that I picked up for a bargain from a friend which I can use for lower speed work on these helis, but I've not tried it on the Chronos.

[RyanMccraeProductions]

Thanks for the tip on the blade weight, i'm just using the stock blades for now. But when i crash next, i might check out some lighter blades just for fun. Do you have any favourites ?

BTW thats some nice smooth flying.

[JeffPfeifer]

I'm running stock blades which are a little lighter less stable than some more dedicated FBL blades from other brands.

[RyanMccraeProductions]

Originally Posted by Lighty

Start with 100-70-50-30-0

Play around with it, see what feels best for you. This is off a 5 point curve radio 8FG. Sometimes I got to 65 and 35. for laughs.

hope this helps

I took it out today with that s curve, Felt much better to fly.

[Lighty]

nice one.