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Andy7:
19 Aug 2019 09:14:20
Good for you!  ~~
DarkButterfly:
18 Aug 2019 19:13:57
Had another negative encounter, it's been a few years since the last one, just an uneducated ******, going on about drones being illegal yada yada yada.    :-/
Still that didn't spoil my flying time, had an absolute blast  ~~
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30 Jul 2019 15:26:34
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29 Jul 2019 20:14:10
DB that just means you have shed loads of props in the first place ;-)
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29 Jul 2019 18:53:33
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Printing 3d Forum

Quads at Holming Beam on Dartmoor

Started by Col_M, Monday,September 23, 2013, 01:07:33

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Col_M

Monday,September 23, 2013, 01:07:33 Last Edit: Monday,September 23, 2013, 01:14:45 by Col_M
Me and my bro decided to do some flying around Holming Beam on Dartmoor. This was the first time I';ve got out with 8" props, the quad behaves much better but it is a lot slower than the 10" ones. I may have to try 9" ones which will hopefully be a good compromise.

TBS Discovery : DRQ-250 : Q450 : Blade mQX

JerryCampbell

What was it that you didn';t like about the 10" props.
I';m happy with the 10" but I heard that 9" is great also.
I would like to know the difference.
Let us know if you try them.
Jerry

Col_M

Monday,September 23, 2013, 07:12:35 #2 Last Edit: Monday,September 23, 2013, 11:25:11 by Col_M
Hi Jerry, the issue with the 10" props was that they caused some fluttering when yawing which no amount of PID tuning fixed and they caught the wind a lot causing the controller to work really hard making the quad to buffet around a fair bit.

Another thing I noticed, out on the moor the video interference was so much less than when flying in a city park. I got out to 350m with not even a sniff of signal break up using Gav';s skews.
TBS Discovery : DRQ-250 : Q450 : Blade mQX

flybywire

I concur with the signal thing.  The ';green'; outside my house is un-fly-able due to 5.8 RF interference.  I use 10" props on my 450, seems ok.
Did you hear the ';Bitten'; booming by any chance whilst on the moor COl_M? 

Andy
Blog: http://ajwillis303.wix.com/stuff
The spiritual home of fpv large
Keep it emax, capiche?
Hardware? sure, I got hardware!

Col_M

Took me a second to work out what you meant, I thought you meant the A4 Pacific loco Bittern and was upset I missed it. I didn';t hear any bittern booming when I was there, I probably wouldn';t have known what it was if I did unfortunately, however I have now educated myself with the help of YouTube.

I have a theory that the big props are an issue because I';m using unflashed ESCs as like you say the props themselves shouldn';t really cause all that much of a problem on a 450.
TBS Discovery : DRQ-250 : Q450 : Blade mQX

KeithW

Quote from: flybywire on Tuesday,September 24, 2013, 11:16:27
I concur with the signal thing.  The ';green'; outside my house is un-fly-able due to 5.8 RF interference.  I use 10" props on my 450, seems ok.
Did you hear the ';Bitten'; booming by any chance whilst on the moor COl_M? 

Andy
Re 5.8 Ghz  do you get any decodable video  I notice near me on a bad roundabout they have fitted cameras with antennas that look very short,will find out the freq.Shades of things to come maybe or here already.
Keith

flybywire

Wednesday,September 25, 2013, 12:10:41 #6 Last Edit: Wednesday,September 25, 2013, 12:14:05 by flybywire
Years ago, (as a young lad) when attempting to enter the hedonistic world of photography, I was given some good advice by our local ';pro';.  He told me to ';standardize'; my procedures, i.e use the same combo of paper/film developer every time, to get consistent results. 

What does that have to do with multi-rotors I hear you ask?  Well, just in that, I try to apply that same logic to motors/props.
I read a lot about folk using different sizes of props, and asking what to use on a certain setup, I also know there are scientific charts based on electro-mechanical theory that should give you the optimum prop size for a given size of motor Kv/frame/payload combo.  I have come to prop size through trial and error, and have now stuck to it.  If any new folk want to try this combo they';re welcome to try.
My trusty 450 uses 900 Kv motors, and has 10" props.  My slightly larger CX4 uses 11" props, but similar size motors I bet the CX4 would fly just as well on the 10"ers though.  I';m currently building a 550 hex, and have taken delivery of 6 of HK';s finest carbon 10x5';s, so I think in future I';ll only buy 10" props for these quads, which will simplify things somewhat.
As I say, it works for me, but I guess a lot of folk will say otherwise, or that every multi is different etc. 
One thing I have noticed though, which does have plenty of science behind it, is that all objects have a ';natural'; resonant frequency that they resonate at, so various sizes of props will produce vibes at different rpm ranges, which may have a slight bearing on different frames etc, and yes I mean fully balanced props as well.  Just watch a heli spool up; it will hit a rev range whereby it shakes a little, even when blades are true, if it were off the ground at this point it would be unfly-able.
https://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=39774.  Unbeatable price, that';s why it';s now saying stock level -2!   Must have had the last 6, sorry!  :whistling:
Blog: http://ajwillis303.wix.com/stuff
The spiritual home of fpv large
Keep it emax, capiche?
Hardware? sure, I got hardware!

JAB1a

Nice video Colin, I believe I have been telling/suggesting/hinting at you since we met that you should be using 9" props  :rolleyes: , for the Kv of your motors 8" is just not going to cope well  :banghead:. might I suggest again you should try 9x4.5 props...if you go for 9x4.7 then you will have the same effect in Yaw as you did with the 10" I think  ~~

Col_M

Monday,September 30, 2013, 15:07:29 #8 Last Edit: Monday,September 30, 2013, 15:11:42 by Col_M
I';m not ignoring you  ;) well I probably technically am! :tongue: but I';ve only just got around to flying again after moving back to the UK and I got the 8" props a while back so thought I might as well try them. I also have 9x5 carbon props for my new quad so I';ll see how they work on the 450.

Where do you get 9x4.5 props from? they';re not that common, most of them are either for DJI';s fitment or three bladed. The 9x4.7 seem to be everywhere though.
TBS Discovery : DRQ-250 : Q450 : Blade mQX

KeithW

Quote from: flybywire on Wednesday,September 25, 2013, 12:10:41
Years ago, (as a young lad) when attempting to enter the hedonistic world of photography, I was given some good advice by our local ';pro';.  He told me to ';standardize'; my procedures, i.e use the same combo of paper/film developer every time, to get consistent results. 


My trusty 450 uses 900 Kv motors, and has 10" props.  My slightly larger CX4 uses 11" props, but similar size motors I bet the CX4 would fly just as well on the 10"ers though.  quote ]  What is the 450 weight ready to fly no payload    what payload do you carry.Thanks

flybywire

Hi Keith
My 450 weigh';s in at 1.4kg including gimbal & gopro, so you can add 1kg on for the 4cell lipo.
The CX4 is 1.8 kg with gimbal & gopro.  I use the same lipo on both.
Hope this helps!
Andy
Blog: http://ajwillis303.wix.com/stuff
The spiritual home of fpv large
Keep it emax, capiche?
Hardware? sure, I got hardware!

JAB1a

Haha sorry was not having a go, just could not believe what I was reading lol

The 9x4.5 props are much more ridged than the 9x4.7';s and don';t get wobbly/knocked off smooth rotation by the wind, they cost about £1.95 a pair, they almost always need balancing but the performance and the locked in feeling while flying is perfect. Many places sell them... the 4.7';s are as floppy as 10" props

http://www.ebay.co.uk/itm/Counter-Rotating-Props-9-x-4-5-Pair-CCW-CW-Multicopter-Various-Colours-Large-H-/261278014967?pt=UK_ToysGames_RadioControlled_JN&var=&hash=item3cd5621df7

bit more pricey than where I got them last but that';s ebay for ya ;)


Quote from: Col_M on Monday,September 30, 2013, 15:07:29
I';m not ignoring you  ;) well I probably technically am! :tongue: but I';ve only just got around to flying again after moving back to the UK and I got the 8" props a while back so thought I might as well try them. I also have 9x5 carbon props for my new quad so I';ll see how they work on the 450.

Where do you get 9x4.5 props from? they';re not that common, most of them are either for DJI';s fitment or three bladed. The 9x4.7 seem to be everywhere though.

Col_M

No worries  ;D I did work out one possible reason why it was quite sluggish, I had the throttle travel adjustment dialed down so I';ve increased that, when I can next get a flight in at the weekend I';ll test it out and see if it feel any better.
TBS Discovery : DRQ-250 : Q450 : Blade mQX