FxRES April 2022 2m F3L/F5-RES Monthly Duration Challenge

[martynk]

FxRES Monthly Postal Rules

This is a “for fun” challenge for UK based pilots. Anyone may enter with:

1. a bungee-launched F3L (F3-RES) specification glider using the reduced length Hi-Start. The reduced length Hi-Start bungee has a maximum of 10m of 6/4mm surgical tubing and 50m of static line (minimum 30lb breaking strain). Lighter/smaller/shorter bungee rubber may be used.

OR

2. an Electric motor launched F5-RES specification glider fitted with an Altitude Limiter set to 60m and a maximum motor run time of 20 seconds.

Object: Fly your F3L or F5-RES glider for as long as possible from a flat field. Each monthly challenge will commence on the 1st day of the Calendar month and  the person who's time is unbeaten at the end of the Calendar Month 'wins' and a new challenge will start. The annual challenge league will end on the 31st December of each year. A new annual challenge league will then commence on the 1st of January.

Rules:

Models must comply with the Model Specification rules for F3L (F3-RES) or F5-RES as appropriate.

You may self-time your own flights

Flight times begin when the tow-line falls from the tow-hook (for F3L/F3-RES) or in the case of a F5-RES glider when the motor stops.

The model must land in the launch field or (if there is no field boundary) within 150m of the launch position for times to count. There is no landing bonus.

If you are using a bungee launch (for this event or any other), then the launch line MUST be secured using a corkscrew dog tether or similar bungee stake to minimise the risk of injury caused by a loose stake.

Scores must be submitted on the relevant monthly postal event posting on the FxRES forum at www.barcs.co.uk/forums/   

Scoring flights must be submitted within 24 hours of the flight taking place.

A flight log graph from the Altitude limiter should also be submitted if entering with a F5-RES glider.

All scoring flights must start with a hand release from Ground Level with (if applicable), the motor running.

No flight information telemetry permitted except for Received signal strength and Receiver battery status.

Submitted scores will be amalgamated into an annual league. Points will be awarded as follows:  1st -15 points, 2nd - 12points, 3rd - 10points, 4th to 12th, 9 to 1 point respectively.

You may enter as many times as you wish using as many different models as you wish, but only your longest duration flight will count towards the league position.

Please enter your scores below...

[cirrusRC]

Got out yesterday, windier than forecast. Lovely in the sun, perishing out of it.   Good mix of sun and cloud until 3pm, when clouds took over. Had field to myself.

Picked up an F3RES Fresh on Thursday.  Treating it as a project.   Bit of a bloater at 520 grams.  Managed to get it down to 490 grams.  Despite the crazy long nose, still needs 35 grams in the nose to get CG.   You can see the large lump of blutak in pic below

The rear stab/elevator doesn't look stock (different from plan) and weighs 18 grams which I think is 8g over weight!   Covering - I'm told it's oralight but I'm not convinced given model weight.   Needs changing ASAP.

First test launch surprised me as it traveled full length of field.  Too windy for X-Res but the fresh handled it nicely.    Toehook needs adjustment but early pings can be mitigated with careful elevator control.

Had a nice flight circling low with 6 buzzards and 2 kites.  Was a little worried about a mid air as we were all very tight packed.  Certainly an impressive sight.  Even the farmer came over and commented on it.

The clear transparent covering is crazy, it was like a stealth glider at anything over 200 meters.  Better in the blue and sun but invisible in the grey.   Doesn't core or center as well as xres but pleasantly surprised and has potential. 17 mins 49 seconds.

Best flight of the day was surprisingly the Andreas.  Zero penetration until I moved CG forward 10mm (from 75 to 65 mm) which transformed handling and got rid of the nasty stalls .   Still not best in marginal lift but great in good air.  I think the air flattered me as I didn't have to do much.

David | 3rd April | Andreas | F5Res | 19min 43

[cirrusRC]

What is your opinion on transparent oralight colours for Res models?  Very low weight but visibility?  BMFA article not very complimentary.   I was thinking of red and white?  Otherwise I can go with oralight non transparent at expense of little more weight.

[mikef]

You might remember seeing my Purito.  That's done with oralight from Hyperflight.  

 

[cirrusRC]

Thanks Mike, for some reason I thought you used packing tape, maybe that was another model or Graham's from the club.

I understand contrasting colours are important, which you have.   Do you see the separation of all 3 colours at height or would you stick to 2 if doing again?  I was thinking red white red stripes.

Ta

[mikef]

Three colours does significantly increase the initial cost of the covering but you are looking at a colour scheme I have used on almost all my see-through competition gliders for the last 50 years - mostly free-flight.  It's easily recognised in a crowded thermal.  That's a 2001 F1A on my avatar!

Do I see the colour separation at a great height?   I've put a picture taken at twilight below - so it's low-contrast - walk away from your screen and watch what happens to the avatar and the picture.   I'm sure the colours show up better in a brighter sky.

I normally come done before I reach the limit of constant visibility.

 

[AnthonyB]

If I were to chose one transparent colour it would be red.

If a solid surface it is black underneath. The best on top being (in order) Glow red, glow orange, glow green....... Otherwise white or yellow. Carbon effect is neat (underneath).

I know that my eyes prefer red. I have met those that prefer darkish (trans) blue. Transparent tangerine works.

Here is 3.4m covered in red.

However it can look boring, so I have used white as well. This is NOT white, but semi-trans white – there is a large difference....... It lights up (a little) in sunlight. I NEVER do white on the tips, but further inboard. You would do the tips in black, which works better.

I have grown to like glow red so much, I am happy to gain a little weight for thr better visibility.

I once did a full 3m glider in glow pink. It looked horrible on ground – amazing in the air.

In transparent – NEVER yellow, pale blue or pale pink.

Remember, it is the visibility at a distance – AND ONLY THAT. Looking good on the floor in front of you is very secondary.

Oh – never, never, never ever, never never ever clear transparent.

Go out fishing with feathers for mackerel and the experts will tell you “when the colour goes out of the land – stop fishing, it's pointless.”

Once at a distance, or at sunset, everything becomes grey. So either black or white.

[AnthonyB]

Here is another, which was very high to photograph – It was taken at 10mpixels and then blown up. The fully transparent parts stand out better.

And this scheme has been on a long time.

[StraightEdge]

Well done David for sorting out both new (used) models - and scoring convincing duration times!

Re colours, as you know my PuRES wing is all transparent yellow with opaque broad black stripes - the yellow shows up pretty well against a blue or overcast sky, helped by the tonal contrast with the black.  I assume similar would happen with transparent red and opaque black, more so with additional white stripes as per Mike's scheme.  But keep everything nice and wide - once the model has any height narrow stripes soon get lost.

[martynk]

Great start David - especially as it wasn't calm..

 

     

Regarding colours - back in the late 60s, I remember Elton Drew (who became F1A World Champion in 1969) discussing colours in an aeromodeller article. His view was (and this was repeated in a different article (by a different author) in Aeromodeller Annual a couple of years later) that as models all appear grey in the distance then the best colour for viewing from underneath would be black. He considered that Yellow as the worst colour.. Personally, I find black very difficult to orientate at a distance so I tend not to let myself get in that state but I have had a couple of all Black RC power models and I find them a nightmare to fly. 

I had one white/yellow aerobatic (on top, blue underneath) RC model that would disappear at certain viewing angles - especially on a dull day - which was very disconcerting, even when it was quite near.

Mikes Red White Black scheme is very distinctive, I have timed his FF models on many occasions (many years ago) and can vouch that the colour scheme does stand out (especially the wingtips) at a distance..

[cirrusRC]

Thanks Martyn, yes I'm used to black from DLG.  No issues with those at 400 meters.

Clear covering is just useless.

Red on X-Res and that is great.

One of best models I had for visibility was first DLG model.  Fireworks, it had a balsa /disser layup wing.  It used to light up in the sun like a beacon.  Super visible.    I hear people say the same about transparent white covering.

Cheers

[AnthonyB]

All above is about the view from below. I spend far more time not so high and a few hundred metres down wind, and that is where the fun starts. More so when coming directly back to yourself, with a dark background.

The best colour here is big, but we can only have 2m. 

This is black (carbon) underside, with glow red and white topside, with glow red - works for me.

Occasionally I do vary my schemes, but glow red is better than black (carbon effect), having tried both on similar models.

 

[AnthonyB]

I'll do the comp entry first, to save confusion.

I have chopped off the 20sec launch part, to give only flight.

I am claiming 23:09. Using my lightest model – The HarrHee

The last 4mins were getting back to myself, because the last bit of lift I worked was followed by a lot of wind. I spent long periods just hovering, but as I got closer, did a few circles, if it bounced up.

I was just glad to land it back on the ground.

[AnthonyB]

I had an hour or so before lunch and the cold northerly wind did nothing for anything.

I did 8 or 9 flights and most were two or three mins.

There was a gap in the middle to charge the battery.

The best was over 6mins and I was proud of that, being better than all the others.

I am still not used to 300g models (having done decades with heavier and higher launching models) and I still (obviously) need far more airtime. They really do fly different. They have no momentum and you have to watch, to keep some speed on.

So, had lunch and charged the battery.

I was walking to where I was to fly and spotted a Buzzard flying from my left to right. It did not flap, it did not circle and it did not come down.

By the time I had the model plugged in, it was a good 200m away.

I decided to fly straight towards it and see what happened – the air just had to be good......... Well it was not and I just sank.

The Buzzard was gliding far faster than me, so I broke away from following, to my left. Imagining that I was coming round in a big circle to land. Then off it all went – totally unimagined. Up to that point it was just the same as all morning............ You really do have to keep on trying.

After that, it was far too windy for such a light model.

PS I had plugged the model in a few times, just do do bits of work (over the previous weeks)

The Altis records these brief periods and then when you want to download the flights, seems to be upset at the short periods. So I decided to delete the memory. Perhaps I should do that more.

[StraightEdge]

What wind speeds were you flying in?

[AnthonyB]

4 minutes ago, StraightEdge said:

What wind speeds were you flying in?

Started at zero (in the morning) then it was 2 to about 4mph. All was good until the last flight and then it probably went between 5 and 9mph. I know I was hovering at a few points, so that would have been 9mph. I then switched to "speed mode" which is just a small bit of down - which only adds 1 or 2mph....... But increases the sink more than it should. After landing it went up more, probably 10mph. 

I would think I had been flying in a lifty area and as it moved away the wind followed to fill in.

During the morning the clouds were fluffy and melting off. After lunch the clouds started to build and became far darker. 

During the morning I spent more time watching and feeling than I did flying.

Looking out now, the trees are moving, so over 10mph.

[AnthonyB]

During the morning I started - facing north into breeze. When I did find some lift, most of the times I ended up crossing the sun (south east). Which usually ended that nice part. The cloud has now built a lot.

[cirrusRC]

300g!  Wow. That's crazy light.

Why cut off the launch phase from the graph Anthony? Makes sense to include it surely.

[AnthonyB]

12 minutes ago, cirrusRC said:

300g!  Wow. That's crazy light.

Why cut off the launch phase from the graph Anthony? Makes sense to include it surely.

It was 310g ready to fly and then it got 10g of altis and some 6g of tail weight - so really 325g for now. Prop and spinner are 27g, which is too much - I could lose half that, but it would be expensive on a model that is meant to be easy and cheap. It really is strange for me to fly, but I am still learning. eg you can circle far smaller than I am used to - but then I have found that it can work little tiny bits of lift. But then you will know that flying <250g DLGs.

I cut off the launch phase, so you can see the time better. For F5 it does not start until after the 20sec motor.

[AnthonyB]

The one above is No1_2 because I cut the launch off. (it is 2 of 1)

This is No1, because nothing is knocked off - You have to cut off the start which is awkward.

Then if you take No1_2 and magnify the landing it is easy to see the time - Which is clearly 23:09.

You can also see that I took 2 paces forward, bent down, took off the canopy and then disconnected the battery, which took 16sec.