The making of the Diabolo S #18 : a factory insight

[wblombard]

So this weekend I installed the Pyro 850-50 and my new Speedx blades. I had to modify the frame slots a bit in order to get the motor meshing correct. Pitch has not been changed as of yet and still on 13 Degrees...not for long though.

Yesterday was testing day..I was hoping that the 850-50 motor would have kept RPM more constant but I'm still loosing 200 RPM during the dive.

First flight was just a tester and taking it easy to make sure everything is ok. The 3rd flight is where it all started. I just had to join the 300Km/h club and so I gave the DS everything it had in her.

After looking at the data contained in the GPS Logger 2 I came to the following conclusions. The dive max height was 300m high (not sure why the google map plot below shows different but this is utilizing the raw data from the GPS logger. Max speed reached was 303,56km/h at a height of 26.1m above ground.

from the raw data I hit 298km/h at a height of 51,4m and speed continued for climb up to 303,56 and slightly reduced to 300.65km/h at a height of 18m...the thing that surprised me the most was that I was within the 303 and 278km/h range for more than 2 seconds. Below is a graph that I tried to plot to show the speed in my fastest run starting with the dive and the other graph shows the speed over the two seconds.

Upon the pass the by standers including Darry Tarr were making noises like a bunch of cow boys...I think we all realized upon that pass that this was by far my fastest pass yet with the diabolo S...I must admit I was shaking like no other and could hardly take a picture of the speed displayed on my TX...A friend actually had to take the picture...shaking to much. I went out on a limb on that flight as the pass was quite low...18m was the lowest point.

I was pretty stocked with the out come and very happy with the result. The next steps are to increase the pitch. RPM was at 2650 at 84% TC.

Looking forward to hear what you guys think!

[Mercuriell]

Great stuff William ! I think your plot of speed over 2S tells the story, GPS speed depends on the accuracy of fixing the position and then calculating time interval between the points. A variation of over 8% in 2 seconds isnt likely in real terms. I would use those figures to calculate a mean which I would lay money on would be pretty close to real speed, in this case it would be ~285km/hr. Still a great achievement!

Have you tried the IRCHA/ FAI protocol of a flat segment before speed measurement?

[snowman1638]

what tail blade do you use? I think 86mm to 92 mm will be good enough for speed run

[wblombard]

Originally Posted by Mercuriell

Great stuff William ! I think your plot of speed over 2S tells the story, GPS speed depends on the accuracy of fixing the position and then calculating time interval between the points. A variation of over 8% in 2 seconds isnt likely in real terms. I would use those figures to calculate a mean which I would lay money on would be pretty close to real speed, in this case it would be ~285km/hr. Still a great achievement!

Have you tried the IRCHA/ FAI protocol of a flat segment before speed measurement?

Thank you John! I'm not to familiar with the FAI protocol, however I was trying to do a graph vs height and speed as well but damn I just could not get it right. I know that a pass should be over a 200m stretch therefore I should actually do a speed run over 2.5 - 3s to get a more accurate reading.

I do try to keep the heli level during the pass and its pretty much level to be honest. I'll try to get a video up of a flight next time. Will send it to you as I did in the past, maybe you can up load it again. Must say the sound that the DS makes at full speed is quite something. There is so much room for error and honestly upon the stall turn (dont have the guts to do a cuban 8) its sooo hard to see...Memory is all I go on, but yesterday I almost lost her....

A comment was made yesterday about my BLS451 servos...I just hope that can handle the forces at that speed because any glitch could be catastrophic!!

[wblombard]

Originally Posted by snowman1638

what tail blade do you use? I think 86mm to 92 mm will be good enough for speed run

Rails 95mm

[wblombard]

Originally Posted by Mercuriell

That's what I find interesting about the variation of GPS speed over 2 secs you charted. There's no way with your flying style that they could vary so much!

I too am having doubts about my 451s, I think they are on the edge of the envelope in the DS and I wondered if some of my nose up,pitching tendency wasn't the elevator servos being overcome! I see some 172s in my near future!

The smaller tail blades would be ok for speed runs but the tail would feel soft in other flight so I Think 95s are a good compromise!

I'd be pleased to put up,your vid on the HF server, you could send it to me by a Dropbox link maybe ...

Thanks John! Once a have another video i will sure send it to you. The BLS 451's have really been around a long time and proven them selves over the years. DT has a serious dolphin effect on his DS...we trying to sort that out with the head gain.

Attached is the excel file (sorry cant attache the file..will email it to you)...maybe you would like to review the raw data from the GPS as well. I'm quite certain, value for money the GPS unit is accurate enough, however not for speed events but for a general consensus and feel good effect. Its nice to know what the approximate speed is the heli is traveling.

A lot more practice to take place but hoping to take part in one of the speed events in the future

[crash at 42]

Must say the sound that the DS makes at full speed is quite something. There is so much room for error and honestly upon the stall turn (dont have the guts to do a cuban 8) its sooo hard to see...Memory is all I go on,

+1 it becomes a black sliver

[TommyBear]

Opportunity beckons for me to add another limited edition matching #18 to the fleet.

[helicraze]

Seems a lot end up on the shelf not flying

[Raptorapture]

Originally Posted by TommyBear

Opportunity beckons for me to add another limited edition matching #18 to the fleet.

My thoughts exactly, or were they to grab it before you? Maybe we could do a number swap...

[wblombard]

Very nice

[JRAY]

Originally Posted by TommyBear

Opportunity beckons for me to add another limited edition matching #18 to the fleet.

Nice! Quite the score to have both of those number 18's.

[helicraze]

That heli isnt being sold

[TommyBear]

It's a shame that Klaus H changed his mind and decided to keep it now.

[craigdieselmac]

Its a hard knocks life for a high end RC Heli collector..

[TommyBear]

My backup battery has finally arrived.

[craigdieselmac]

Sweet.. I use a 900mah version of the same battery. I modified and used the standard ESC mount to mount it at an angle below my Kosmik ESC so it sits above my main packs.. I even made a harness for it to plug inline with the slave of the Kosmik and that battery is always charged.

[TommyBear]

Originally Posted by craigdieselmac

Sweet.. I use a 900mah version of the same battery. I modified and used the standard ESC mount to mount it at an angle below my Kosmik ESC so it sits above my main packs.. I even made a harness for it to plug inline with the slave of the Kosmik and that battery is always charged.

Great idea.

Can you share the wiring schematics and pics please.

[craigdieselmac]

I can.. I thought I had them on here somewhere.. I'll get them tonight and try to get the pics uploaded. I made an adapter from 2 female JR style servo plugs.. Do a rough schematic tonight.

[craigdieselmac]

I hav a pic on RR.. Here is a link
http://m.rc.runryder.com/helicopter/t759915p7/