(23-Jun-2020, 12:31 PM)kaitylynn Wrote: Hey Harry,

With a 9+ minute flight time, you could make 5km out and back.  If you have GPS and a tested RTH setup, you could fly till the video failed and then just initiate a Return To Home command.  You can just wait till the video returns to assume control again.  GPS offers some cool features.

Hi Kaity, 

Wow. That is very interesting about the RTH setup. If I had this setup on my original GEPRC Phantom,  I might not have lost it.   

Now, I have got to get a GPS setup. In fact, that would even be good on some of the smaller builds.   

I will be ordering one (or more) MATEK GPS & COMPASS MODULE M8Q-5883   unit(s). This is the one that you use, correct?

This will be my first GPS install and setup; suggestions and guidance is much appreciated. Thanks

Thanks for the insight. 

One thing to be careful of with GPS Rescue Mode in Betaflight is that it's quite basic and I'm not sure I would put my full trust in it for automated flight.

I know people have had successes with it but other people have also had failures. If the GPS co-ordinates don't register correctly before take-off (not just not locked in, but incorrect co-ordinates as we've already seen) then if GPS Rescue Mode gets invoked, your quad is going to fly off somewhere of it's own accord never to be seen again. Likewise, if satellites drop below the minimum while in mid-flight then instead of coming home, you quad will just drop to the ground instead. These are just a few things to be aware of. I don't think I would rely on GPS Rescue Mode in Betaflight unless it was an absolute emergency, and then I would be crossing all my fingers and praying that it actually worked properly and that my quad made it back home safely.

By contrast, the GPS functionality in iNav is streets ahead and I believe it has some features to try and help mitigate some of the above, so of you are planning on doing medium to long range stuff then I would strongly suggest that you consider switching over to using iNav instead of Betaflight on those particular quads. I believe Kaity is using iNav on her long range quads.

I have two models of GPS that I am using for all of my builds at this point. Both are Matek, the M8Q-5883 (2 of these) is for my INAV builds and the SAM-M8Q (1 of these) for my BF build. As the price is practically the same, I will likely just use the M8Q-5883's going forward. Having the compass is nice and it can be disabled if not needed.

I tried to use the cheaper options, but they tended to break in crashes for me so in the end did not save any money. I have yet to break a Matek in such a way I could not repair it.

Most of the new GPS modules are small and light enough to be installed on Micro's (3" and under), so why not!? At the very least, you have a GPS fix you can use as a reference should your craft find an unexpected resting place.

Hi Snow, as you suggest, I will definitely be cautious and test. One of the things that I like is the little "arrow" that points back to home. The other, more important, thing is being able to activate a feature to have the quad start flying back home when video goes out of range and come back until the video is re-acquired and I can regain control. This would be nice. It always scares me when the video goes out. 

At this point, I am not looking for automation, just the ability to get the quad back where I can control it.

I will look into iNav. It might be interesting.

I think that I will go with the Matek M8Q-5883 units.

Hi Kaity, you like the Matek gear; it works good and holds up well. That works for me. I want it to work.

Thanks to both of you.  I really appreciate your guidance and assistance.

Harry

UPDATE:     Phantom-X flies good and sustains crashes extremely well. This little guy is tough. No problems with the arm extensions, they are solid as a rock. It is still in the original configuration with the Flywoo NIN 1103 7650kv motors and Gemfan 3018 props.  Fly times are between 6:30 and 7:00 minutes with GNB 2 x 1s 650 mAh battery pack and over 9:30 minutes with GNB 3s 1100 mAh battery (AUW = 162 grams). I am still collecting baseline data; I want to run a few more packs through before swapping out the motors. It is performing pretty much as expected, Phantom-X is durable like a tank, and things are easy to swap out. The videos all look the same as the one already posted, so I will only post new videos if there is something special to show or take note of.

My second build,  Phantom-i , and third build,  Phantom-3A , are in the "Tiny Whoop & Micro Quad" section.

2020-07-19

Modification:  New FPV Cycle 1303 5000kv motors (w 2mm prop shaft).

The new dry weight is 97 grams; the AUW is about 128 grams with my standard 2 x 1s 650 mAh GNB battery pack which includes the adapter cable. This weight is about 6 grams heavier than with the 1103 motors. 

Just a note: about a week ago, I removed the extra support brackets at the end of the extended arms to save some weight. It still survives crashes with no damage. Using the two motor mount bolt holes to attach the arms appears to be sufficiently strong. 

Now, lets see how it flies.

Good morning Harry, just a question on prop selection...do you find the 2 blade props to be louder than their 3 blade cousins?

(19-Jul-2020, 05:03 PM)kaitylynn Wrote: Good morning Harry, just a question on prop selection...do you find the 2 blade props to be louder than their 3 blade cousins?

Hi Kaity,

I will have to get back to you on that one.    So far I have only been running bi-blade props, regardless of size. Thing is, once these birds get airborne, I can't hear them at all unless I do a real close "fly by" and then just barely. At one point, I did put some 4 inch HQProp bi-blades on the Phantom-X (yeah, 1103 motors) and they were quieter than any prop that I have run on anything. I know this was a little questionable, but it flew really well, I couldn't hear it at all, but it did shorten fly time on my 2 x 1s 650 mAh GNB pack to 6:30 minutes. On the other hand, it got 9:30 minutes on the 3s 1100 GNB battery with the 4 inch props. /// Who knew you could run 4 inch props on 1103 motors...and the motors were cool to touch after the flight; NOT Hot at all     ///

My very first EMAX Tinyhawk Freestyle came with the Evan Rush 3 blade props, but I quickly swapped them out for HQProp T65mm 2.5 inch bi-blade props and have basically been running them and their 3 inch version ever since. I have also used the Gemfan 3018 bi-blades alternately on the Phantom-X and other 3 inch builds. 

My baseline testing is about finished and I have collected the data. Now, I will try some tri-blades and compare them. Presently, I have the following tri-blade props: Avan Mini, Azure, and Gemfan.    

So, I will let you know the results 

I have been flying mostly three blade since starting in to this hobby. Even on my JYU Hornet, 5" tri-blade props replaced the bi-blades pretty quickly. It was not until I started into the larger quads, 250mm to 300mm that I started to experiment with them. They definitely have a different sound to them when I hear them.

That is wild, 4" props on 1103 motors. Do you have ESC amp draw in your telemetry? I would watch the draw closely as that is a lot of demand on that small a motor, but it really does not seem a stretch that it worked. Those little motors can generate some power!

(22-Jul-2020, 01:43 AM)kaitylynn Wrote: I have been flying mostly three blade since starting in to this hobby.  Even on my JYU Hornet, 5" tri-blade props replaced the bi-blades pretty quickly.  It was not until I started into the larger quads, 250mm to 300mm that I started to experiment with them.  They definitely have a different sound to them when I hear them.

That is wild, 4" props on 1103 motors.  Do you have ESC amp draw in your telemetry?  I would watch the draw closely as that is a lot of demand on that small a motor, but it really does not seem a stretch that it worked.  Those little motors can generate some power!

Hi Kaity,

Part of the reason that I switched to bi-blade props is that all of my research at that point indicated that bi-blade props are more efficient than tri-blade props. For some reason, I thought the quad might be a little "slower"; nothing I can prove, just what I thought   ; been using bi-blades ever since. On the other hand, I have several different tri-blades that I want to try and compare since I now have quite a bit of data.

Also, I just ordered a decibel meter so I can compare sound levels. I will likely do some hover tests in the house with different types of props and compare the sound levels; then I will have some data for you.

Once my quads are launched, I can't even hear them. On the other hand, we were at the soccer field one day and this guy was flying a 5 inch and it sounded like a huge chain saw. It was so loud, you could hear it in the next subdivision. I don't know the difference, but I was surprised when the 4 inch props I tried were quiet.

You know, there is an option for amp draw, but I don't think it works correctly without being calibrated because the readings are WAY different for every one of my quads that have it. So...don't really know. Most of the videos that I have watched for battery calibration don't really work for 1s batteries; especially 2 1s batteries wired in series to make a 2s "pack". Yeah, nobody seems to have a "rule of thumb" method to adjust the settings based on the reading in the OSD vs what the mAh of the battery is listed at. But when I figure it out, I will share my methodology with anyone who wants to know. 

I only flew a couple of packs with the 4 inch props on the 1103 motors since it cut the fly time down to about 6 and half minutes on my standard 2 x 1s 650 mAh battery packs (my baseline power pack). I did check the motors after each flight and they were not even warm. Since they were slightly less efficient, I switched back to 3 inch props. 

The 1303 5000kv motors that are currently on Phantom-X have 2mm prop shafts. Yeah, they make 3 inch props with 2mm center hole just for this motor (and the Flywoo Robo RB 1202.5 5800kv motors that also have 2mm shafts). So, I will have to drill out a set of tri-blades and a set of the 4 inchers to use with these motors. Yeah, then I get to mount them with 2mm bolts.

When my decibel meter arrives, sound testing begins 

Hi Kaity,                                                                         { 2020-07-23 }

I received the decibel meter and the first sound tests have been completed. These are all "hover" flights with altitudes from about 3 feet to 8 feet within about 4-8 feet of the decibel meter. Flying LOS indoors with these quads and looking at the decibel meter was very interesting, but I managed it. Given that the sound levels vary with increases and decreases in throttle and the precise distance from the meter. The readings that I am showing are my best observance for hover (steady as I could manage) at about 4 feet elevation.  

Ambient sound level in the house was about 50-60 decibels. 

The the 2.5 inch props on the Phantom-i and the 3 inch on the Phantom-3A had very similar sound levels.
The Bi-Blade 2.5 and 3 inch props were registering in the mid 70's  (about 73 to 76).
The Tri-Blade 2.5 and 3 inch props were in the mid 60's (about 64 to 69).

The Avan Rush (2.5 in Tri-blade) and the Avan Mini (3 in Tri-blade) showed consistently lower readings around 65-66.
The HQProp (2.5 in Tri-blade) and the Azure (3 in Tri-blade) were slightly higher at around 68-69.

The Phantom-X with 1303 motors registered the least variation between the different props.
The Gemfan 3018 Bi-blades were in the mid 60's with a slight bias at 68.
The HQProp TT3x2.5x3 Tri-blades were in the mid 60's with a slight bias at 66.
The Gemfan 4024-1.5 Bi-blades had a very tight range around 65-66.

The Gemfan 4024 Bi-blade props and the Avan (both 2.5 and 3 inch) Tri-blade props were comparable and had the lowest sound levels.

Interestingly, the 4 inch Bi-blades are about the same as the smaller Tri-blade props, however, the 4 inch props tended to have less variance during throttle changes.  Even more interesting is that the 4 inch props sounded quieter to the ear; maybe due to a difference in the tone or audible "pitch". I currently do not have any 4 inch Tri-blade props. 

My assessment for this testing is that the Tri-blade props tend to be about 8 to 10 decibels quieter than the equivalent Bi-blade props and is close the ambient sound volume outside our front door which is about 66 to 70 decibels (of course the pitch is different and the ear makes that distinction). Even though the sound increases with increases in RPM, overall it is pretty close to normal outdoor volume levels; at very much distance the ambient sound overpowers the sound of the quad.

////////////////////////////  NOTE  ///////////////////////////////////////////

I am leaving the 4 inch props on the Phantom-X 
This will provide baseline and comparison data for the Katana-LR4.

////////////////////////////////////////////////////////////////////////////////

  

Upon flying the Phantom-X with the 1303 motors, I notice that there is now some video distortion that wasn't there before.  

In an effort to resolve this, I have swapped the 470 uf 25v capacitor for a 1000 uf 35v unit.  Hopefully, this will remove the new distortion.

By distortion, do you mean static or jello?

Hi Kaity, I would call it static; jagged dark splotches sort of come in from the right side; sort of like someone is "chipping" away at the video, but it comes and goes. It is definitely not jello; this video doesn't "wiggle", it kind of gets chipped out; but it is sporadic. Most of the video is sort of Ok, but then it chips out at times.  This didn't happen until I installed the 1303 motors so I figure that they generate more "noise". I have increased the capacitor, but have not gotten a successful flight. Last time I took it out, the VTX antenna disconnected (OK, it was my fault), so NO video...so couldn't fly. Will try next time.

Did you check out my Katana-LR4 flight video?

I did! Super smooth and an efficient build

Did the antenna get pulled off in a tumble?