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Aug 15, 2019, 11:51 PM
Quadaholic
--Oz--'s Avatar
Quote:
Originally Posted by Ian444
What standards/setup do you use for IR testing? I'm interested because everyone probably does it different, and there could be something for me to learn. In the past I have used an average current draw that the battery would deliver over the duration of the flight in the quad that the battery is being used in. Then compare no-load to loaded voltage, at a couple of points during the discharge curve.

I have a bunch of batteries that need IR testing right now and a bit of free time, hence the interest.
Most of my chargers do IR, but the cheep Turnigy 50W accucel v2 50W chargers ($4.99 on sale, lol, they work great, I have 14 of them) give a bogus reading on the most positive cell (stupid error not reading the battery balance connector and reading though the main positive lead and connector), adding much more IR to the most positive cell, = bogus).

My iCharger 306b and GT1000 charger seems to report semi close IR readings, but the Wayne Giles IR meter seems to be the "factory standard" for testing IR on LiPo's. I picked one up for a song and that's what I use (Wayne Gilges).

FYI, IR has a huge variance with battery temperature. Cheap cells when pushed, heat up, and lower there IR, but overall they are self destructing themself and overall they last less life cycles. I personally think the Turnigy Graphene are the best cells on the planet (lowest IR and most life cycles), but I could be wrong.


EDIT, here is the link: https://www.rcgroups.com/forums/show...0#post41744189
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Aug 16, 2019, 09:58 AM
Registered User
Thread OP
Quote:
Originally Posted by Yamaford
Here is my um Progress?? lol enjoy my failure. I haven't practiced as much as I should but I do feel im improving every session.

https://www.youtube.com/watch?v=NiQx...ature=youtu.be
Looking good!. You could do with some end plugs to stop filling your frame up with mud and grass
It's nice when you can feel the improvement between almost every session. The rate definitely slows down, the better you get, and you have to work harder for it.

I get a kick out of the continous improvement in flying ability, probably the main reason which keeps the interest going. Can feel myself being slowly bitten by the 3Dheli bug, now the inverted practice is starting to pay off. Keen to get myself one soon and experience this new dimension IRL.
Aug 17, 2019, 07:13 PM
Registered User
Quote:
Originally Posted by gc_ober
frame #43:

280mm tubular frame with 2206-2122kv motors and GF 6042 props is built and flown.

Results:

1) 850mah 4S battery provides more than minimum session time.
2) Accel is OK at 13.2 G; although could be better.
3) Quad at its motor limit in step response to 1300d/s.
4) Extreme yaw jump due to a combination of lightweight and high inertial moment. This jump impacts even normal flying.
5) 280mm is fun to fly in a big field!

Next action:

Change motors to higher kv: 2206-2522kv.
Reduce max RP rates to 1200d/s.
Use motor tilts (already done and this reduces yaw jump significantly)
Results of this action:

I liked the 2206-2522kv motors over the 2122kv. The throttle response immediately felt better and the Z-accel peak was improved: 14.2G for the 850mah and 15.5G for the 1100mah.

I ran both 1200 d/s and 1300d/s with ff 2.0 features on recommended first settings. With current PIDs I see D noise that gets into the motors. With FF 2.0 applied I don't see a need to use so much D now just to control gyro overshoot with the max step response: There is some PID retuning to do here before even tweaking FF2.0 knobs. I think 1300 d/s can tune out OK.

The 280mm needs a 1100mah battery, not a 850mah with the 2206-2522kv motors: Just too much motor demand with the 6" props.

I tried running without motor tilts thinking a slightly heavier 1100mah over an 850 could tame yaw jump a bit. This is better and no longer an issue for most of my yawing flying around, but a snap yaw even to 650d/s can still jump it up a lot. I will evaluate some more without tilts -- this would simplify some things for me.

Lastly, I stuck this 43' high in a big tree. I lost orientation coming at me and it moves so fast. It spent several days there but finally got it out. Only ruined the battery. I need to stop flying while standing under trees.

EDIT: Will use 7.5^ motor tilts on both 280mm and 260mm. All quads jump with snap yaws. But I don't like the amount of yaw jump, such as rapidly turning into a funnel, with my larger quads. Motor tilt is a very useful technique when needed.
Last edited by gc_ober; Aug 19, 2019 at 12:47 PM.
Aug 18, 2019, 05:44 PM
Registered User
Well, I bought cheapest arrow (<$4 with tip and fletching) - pulltruded fiberglass tube 8 mm OD, wall thickness ~0.7mm fiberglass and ~0.2 mm coating.
Feels springy in a hand (maybe too much). I will use it in my H frame tubular build and see how it holds.
Aug 20, 2019, 09:36 AM
Quadaholic
--Oz--'s Avatar

Ot


I did some Cox 049 motors in my days, rc planes, u-control combat and a few cars. I figured out how to mod the reed valve motor to go from ~18Krpm to 25Krpm 20+ years ago. In a forum they had a contest to guess how long a stock 049 reed valve motor will run on 32oz of fuel. With that info, I tried to calculate efficiency of the 2 stroke motor, LOL 5%. If anyone can look at my calc's to see if I screwed up, tia.

Quote:
Originally Posted by gc_ober
Results of this action: I liked the 2206-2522kv motors over the 2122kv. The throttle response immediately felt better and the Z-accel peak was improved: 14.2G for the 850mah and 15.5G for the 1100mah.

The 280mm needs a 1100mah battery, not a 850mah with the 2206-2522kv motors: Just too much motor demand with the 6" props.
Awesome!
What 6" props?
Aug 20, 2019, 12:10 PM
Registered User
Quote:
Originally Posted by --Oz--
What 6" props?
GF6042.

The quad feels very quick.
Aug 20, 2019, 02:55 PM
Quadaholic
--Oz--'s Avatar
Quote:
Originally Posted by gc_ober
GF6042.

The quad feels very quick.
Looks great, the G's are off the charts and has a proper transport home
My three old dogs are jammed in a backpack full of other stuff, but they come out to play often, so they are happy.
Aug 20, 2019, 04:17 PM
Registered User
Quote:
Originally Posted by --Oz--
Looks great, the G's are off the charts and has a proper transport home
My three old dogs are jammed in a backpack full of other stuff, but they come out to play often, so they are happy.
I second that - this quad looks sexy!
Aug 20, 2019, 04:30 PM
Registered User
Quote:
Originally Posted by joelucid
I second that - this quad looks sexy!
Thanks.

I really like yr FF 2.0. I can back off of the relatively high D needed only to suppress the step overshoot. Not sure how to balance the FF term gain vs FF boost. I have turned the boost down as I see gyro leading setpoint on the way up. I'll wait for yr update before going further.
Aug 20, 2019, 10:22 PM
Quadaholic
--Oz--'s Avatar
Almost done with the external discharger, I would like a big heatsink, but will wait to find something cheep, lol, and it works fine as is. I was easy cycling 10 4s-1300 new batteries ($9ea), 17 minutes to charge them at 3A each, and 22 minutes to discharge to storage levels. Cycling has never been so easy and quick.
Aug 21, 2019, 06:37 AM
Registered User
Quote:
Originally Posted by --Oz--
Looks great, the G's are off the charts and has a proper transport home
pizza boxes
Aug 21, 2019, 09:06 AM
Registered User
Quote:
Originally Posted by gc_ober
pizza boxes
I also use pizza boxes.
Aug 22, 2019, 09:29 AM
Registered User

Gauging motor tilt


I'm not sure how many use motor tilt. But for those interested, here are my methods of gauging motor tilt as my builds have variable adjustment for motor tilt.
Last edited by gc_ober; Aug 22, 2019 at 10:07 AM.
Aug 22, 2019, 09:33 AM
FPV Addict
Yamaford's Avatar
Quote:
Originally Posted by gc_ober
I'm not sure how many use motor tilt. But for those interested, here are my methods of gauging motor tilt as my builds have variable adjustment for motor tilt.
Pretty handy!
Aug 23, 2019, 06:23 AM
Registered User

Stretched X 280mm


I built another stretched X quad using 8/6 mm tubes. The one I already have is a 300 mm one, the new one is a bit smaller with 280 mm. It can be built by cutting a single 0.5 m tube in half, and with each motor mount adding 15 mm it adds up to 280 mm. I kept the aspect ratio of 5/4. The CAD file is attached and the carbon parts can be ordered without any commision rate here: https://armattanproductions.com/page...oduct_grid/799


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