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Posted by DingoII | Nov 01, 2020 @ 12:40 PM | 6,170 Views
The rules for organizing a man-on-man contest require that (citation from F5J sporting code): the composition of Groups should minimize the situation where any competitor flies against another many times.

On our air fields it is likely the most frequent question - why do I have to fly 4 times against a pilot X? And adding, that the pilot X always gets 1000 while the other guys I do not meet with at all.

While I am convinced that the flying order (a term from the F5J rules) has a very little influence on the total score board, any improvement in the flying order matrix could make more people happy and therefore the contest more enjoable.

I spent some time over this issue and here is the outcome:
- problem and solution description in the pdf file
- excel (with macros) for calculation in the zip file

I would appreciate any comment/discussion.

Thanks, Jan
Posted by DingoII | Oct 31, 2020 @ 09:50 AM | 7,744 Views
Sometimes I need to refer back to my builds and comments on them. So this post is only for making the thread location easier.

Mig-15 EDF 69 mm: https://www.rcgroups.com/forums/show...out-1-10-scale

FJ-1 Fury EDF 30 mm: https://www.rcgroups.com/forums/show...Christmas-Fury

Su-25: Frogfoot EDF 50 mm: https://www.rcgroups.com/forums/show...27181-Frogfoot

E-Slite: https://www.rcgroups.com/forums/show...081-E-Slite-V2

Arado 96: https://www.rcgroups.com/forums/show...%28Avia-C-2%29
Posted by DingoII | Aug 13, 2017 @ 03:50 AM | 3,861 Views
I have been fascinated by the EDF for some time. I came across the EDF just few months ago when I "impulsively" added the DuraFly Vampire to my shopping cart at the Hobbyking site.

I did some bits of the EDF theory (please see it attached) during my holiday (cannot just swim and drink a do nothing else ;-) ) and then also measured the Vampire performance:

Flying at full throttle (interleaved with gliding) gave 4.5 minute of powered fligth. Recharged 2610 mAh into 4S-2650. This gives about 33 A, or 520 W of input power.

Max. speed measured by GPS telemetry was about 100 km/hr (scattered between 93 and 113 km/h in several passes). The landing speed was about 27 to 32 km/hr.

Then I devised a simple U-tube differential pressure gauge. It is just a piece of tubing taped to a vertical scale. The ends of tube are then introduced into the location od interest (please see the pictures). The pressure difference across the impeller measured at full throttle was about 180 mm of water column, without the access hatch is was just about 60 mm.

Well, all this data fall within the expected range of values, and although I would not expect them to be 100% accurate, seem to confirm that the theory works.

Thanks, Jan