If, like me, you spend a lot of time pondering how to best throw an f3b model, here's a video you might enjoy. Or if you just like cool stuff in slow motion. Previously posted on the Barcs Forum, but worth another airing.
F3B SM 2012: einige Starts from Kurt Eichenberger on Vimeo.
Some more slow motion launches:
Entry numbers in flat field soaring classes have been in decline in recent years in the UK and elsewhere. Most people feel that electric flight is the future of many aspects of flat field soaring. The benefits are many - space requirements, simplicity, ease of use etc. The concept of F3B electric is simply to replace the traditional winch launch with an electric launch to a height determined by a limiting device - several such devices are available for e-soaring and F5J. Otherwise the rules remain the same with each competitor flying duration, distance and speed tasks. Using height limiters means it is possible to fly electric F3B models against winch launched models, in a mixed competition.
The technology of brushless motors and particularly lipo batteries has improved enormously in the last few years. This has also coincided with significant advancements in composite technology for rc gliders. At the time of writing it is possible to buy a 4m glider that weighs under 1.8kg at flying weight. With the increasing popularity of F5J there are now a number of airframes for electric flight that are even lighter than their "pure" glider F3J equivalents because they don't need to be built to withstand a two man two or winch launch.
The situation is somewhat different in F3B, where the power requirements are considerably greater than F3J and F5J. Clearly an electric version of an F3B model requires a power-set that can launch the model with ballast for the speed and distance tasks. F3B launch heights are typically well over 250m, so an equivalent electric set up needs to be able to launch a ballasted model (say 3.5kg) to height in a reasonable time. The model will still also require a strong wing due to the g-forces encountered in speed. F3B models are also designed for minimum drag and therefore have very thin fuselages.
An F3B-electric power-train set up needs to 1) Provide a large amount of power 2) Fit in a small space 3) Not increase the weight of the glider to the detriment of its duration soaring abilities
To that end electric F3B pioneer, Clive Needham, has been working with Tony Fu of Sloperacer to find a suitable motor combo for for F3B electric. Clearly inrunner motors have a smaller diameter than outrunner motors, but offerings from the likes of Kontronic and Hacker typically state max power outputs of around 500 watts, which is inadequate. The motor/gearbox combination that Tony has devised is a special long Leopard inrunner coupled to a Reisenauer gearbox. Diameter is 28mm, max power is over 1kw, with high efficiency. Clive has done a considerable amount of flying with his electrified Dingo and has found that the model performs very well.
With the availability of 70C batteries, at the time of writing, and no doubt more in the future, the setups we have been experimenting with are not adding significant weight to the airframes. Nor are they spoiling the look of these graceful models.
Advancements in battery and motor technology will no doubt continue apace, which will result in lighter more powerful setups. Currently we are looking at power outputs of around 1.2kw with a 4 cell lipo with the Sloperacer motor (the logging facilities of Castle Creations ESCs have been useful). These models also make great sport fliers as well, of course.
| Pilot | Score | Model |
| Steve Haley | 100 | Fosa |
| Mike Challinor | 98.12 | Fosa Lift |
| Simon Haley | 94.06 | Precious |
| John Whittle | 94.02 | Ascot |
| Tom Satinet | 91.62 | Stinger |
| Bob Dickenson | 88.94 | Fosa Lift |
| Mike Holtby | 85.25 | Cobra |
| Dave Worral | 77.86 | Crossfire 1 (elec) |
| Brian Johnson | 74.96 | Ascot |
| Clive Needham | 68.89 | Dingo (elec) |
| Phill Goddard | 66.74 | Ceres Lift |
| Bill Haley | 53.16 | Precious |
The first post is a report from League 4, 2013. With the recent "heat wave" (aka summer) that we have been experiencing it was possibly a relief that the weather for Sunday was overcast and fairly mild (with even a few rains spots at times). Personally I didn't fancy lugging the gear around in 30 degree heat all day.
However, the overcast conditions and the fairly bright light made for a sky that was difficult to pick out models in, and was a challenge all day when flying at duration distance. What was generally reckoned to be a wave was fairly consistent from the east at a considerable distance beyond the winch line. With the general lack of obvious thermals, the best tactic for duration was to push out in front and carefully ride the wave in combination with the slight slope lift from the right of the field. In spite of the difficulty in seeing models, there were few low scores in duration with most people achieving good times. A good launch was very helpful, giving you the chance to range out to find the lift.
Conditions for launching were quite decent, with a moderate wind. If you could steer your model off to the left and swing back in to the wind a decent launch was definitely possible. Not too much score separation happened in Round 1 of duration. A few people dropped a minute or two or messed up the landing, but there were no real clangers. Mike Holtby's Cobra again showed it's ability to pull big tension on the line and float very well when required.
Distance conditions were reasonable but not epic, with the lift again being most consistent to the right of the course, with most people choosing to fly that direction. I think Bob had a go on the other side and did okay. In fact Bob was unlucky as he had a huge launch it to great air on his first distance round, but the round was cancelled when a parachute being wound down in a cross wind knocked down base B (sorry Bob)!
Clive put in a good stint scoring a very respectable 23 legs in round 1, which was the best score of the competition. Young Simon put in a good performance scoring 21 legs in both rounds and only dropping 45 odd points. Clive, Steve Haley, Mike Challinor and John Whittle scored the maximum 1000 points in both rounds. Distance scores were fairly close without most people dropping or gaining too much over the field.
On to speed where times were generally in the high teens for a good run, with the exception, again, of Steve Haley who took a couple of seconds out of the best of the rest following a good launch and consistent flying (15.xx seconds). This took nearly 130 points out of his nearest rival which would prove critical in the final scoring. Bill wasn't quite back to his usual self, but it was good to see him flying again. Round 2 of speed followed a similar pattern to the first round with times of about 17 seconds being competitive. I put in a new personal best of 17.31, which to my surprise, took the 1000 points for the first time, beating Mike and Steve by few tenths. Happy days! Brian dropped quite a few points in speed, which I am sure he will be looking to improve with his Ascot, which seemed to be showing good potential - it's a well proven model of course.
Round 2 of duration followed a similar pattern to the first with mostly high scores. Unfortunately Clive was not able to fly the round due to technical problems with his electric model, which was a shame as he had scored well to that point. I enjoyed a fun round against Steve were we both gently rode the wave, indicating lift and sink for each other and swapping heights and position throughout the slot. Eventually I came out just on top with a 10.00 / 100 point flight that was a nice way to end the comp for me.
So all in all another very enjoyable round. I don't think there were damaged models. Perhaps Clive's prop blades took a bit of a beating when he tried to repay the farmers kindness in helping get Steve's esoaring model out of the tree, by strimming the grass for him. Kudos to Steve, as it takes a top drawer flyer to truly park a model in a totally inaccessible place. The model only being retrieved thanks to Bob's slightly disturbing expertise with a chainsaw. Whether he just carries it round in the back of his car in case of emergency, I don't know.
Special mention must go to Phil Goddard who flew most, or all, of the competition with his transmitter set to the model memory of one or more different models, which may or may not have had something to do with f3b or even gliders. The word on the flight line seemed to be "Wot4," which we can only assume is a model that doesn't have the same trim settings as a ceres lift. The winner was Steve Haley, with his round 1 speed score proving to be decisive over 2nd placed Mike C. Simon Haley came in third having flown consistently all day. He narrowly pipped John Whittle, who lost a few crucial points in the final duration slot. I was fifth, follwed by Bob and Mike Holtby. Dave Worrall and Brian Johnson scored good points and will be looking to the nationals no doubt. Clive and Phil suffered non serious "technical" problems and Bill was still feeling his way back after recent ill health.
The Wetlands Sunday June 9th by Clive Needham
Following the cancellation of L1 due to a poor weather forecast and the abandonment of League of L2 when the weather closed in at midday, it was with anticipation during the week leading up to the contest at The Wetlands as the weather was set fair for a good day’s flying. Unfortunately due to the NE winds off the North Sea the forecast for the East Midlands changed on Saturday from one of glorious sunshine for most of the UK, to low cloud for Sunday which might or might not burn off by lunch time.
It did not look good when I set off from the Lancashire side of the Penines in bright sunshine but hit low cloud on top of the hills in Yorkshire all the way to The Wetlands with a cloud base of about 8ooft at Doncaster airport.
However by mid morning as we were ready to begin the contest, after a slow start setting up the course, the cloud base was gradually rising.
As you may be aware we have been experimenting for some time with models launched by fitting an electric motor instead of using a winch and towline
Apart from the expense of the cost of winches and towlines, plus the time to set up before the contest, there is a feeling that some possible newcomers are prevented from trying out F3B because of lack of confidence in the use winches. A bonus point for those who are not able to launch as high as the top pilots is the use of height limiters to cut the motor, so all start at the same height, therefore no excuses if the top pilot’s scores are not matched, it’s still their skill that counts. We are now in a position to demonstrate that electric motor launched F3B models are viable and not at a disadvantage compared with the traditional launching method.
I have been flying a Dingo electric for some time and Dave Worrall self converted a Crossfire to E earlier this year, resulting in him returning to F3B after 2 to 3 years, Bob Dickenson had his Crossfire converted by Tony Fu (Sloperacer), in addition Norman Quirk has also returned after a break with a Strega supplied by Tony, this design was used very successfully by Alan Flockhart a couple of times last year, including a speed run of 17xx secs, many other designs such as the Rotmillan, Ascot and Skorpion which I have also flown are very suitable.
Most of the models are using Leopard motors (Sloperacer) with gearboxes and lipo batteries, 4cell 1800mah in either a single block (fuz size permitting) or 2x2 cells end to end, most models are convertible as long as at the point the nose has to be removed it has a minimum inside diameter of 30mm. Some manufacturers are now beginning to offer E- fuselages, Output required to launch the models, which can now be built down to about 2.4kgs including motor, gearbox and battery pack, is approximately 1000watts, this will launch an un-ballasted model to the average height of 250m in 12 to 15seconds. Models ballasted up to 4kgs take a little longer but each launch only take about 250 to 300mah from the lipo pack. Therefore each pack is very good for 4 launches and possibly 5 if pushed.
Back to the comp, it had been hoped that all four of us with suitable electric models would be able to use them, unfortunately Dave Worrall was on holiday and Norman Quirk’s new Strega had a problem with the motor pinion not being fully secured on the shaft, Bob Dickenson decide to fly one round with his Fosa and the other with the E- Crossfire for comparison, his scores were very similar 2742 in R1 (Fosa) and R2 2633 E- Crossfire.( The lower score reflects the faster time of the top scoring pilot of 15.13 -R2 as against 17.01-R1) I elected to fly the whole contest with the E-Dingo although I had a “normal” Estrella with me.
As usual we started with duration and apart from the first slot won by Norman with 9.35s and 100 landing bonus (chat man 14 year old Simon Haley) flying his untried Vampire model with Mike Challinor and Brian Johnson well behind, all the other 5 slots were more or less flown out. That is excluding my 6.43s after a re-launch. Mike’s unexplained 6.43s probably cost him second place overall. Two rounds of distance followed with mostly good air in all, the winners being Bob Dickenson 2 one each with his two models, Mike Challinor 2, Jon Whittle, and Steve Haley one each.
The slot with the greatest number of legs was closely contested by Steve Haley, Norman Quirk and myself scoring 25, 23 and 21 legs respectively.
Back to back rounds of speed were next both won by Steve Haley, Fosa 17.01s R1, close behind Mike Challinor, Target, 17.20s and R2 Steve with 15.13s, this time second Jon Whittle, Ascot, with 16.45s
Norman lost out in R2 due to lack of familiarity with the Vampire set-up resulting two pings off the line below full launch height, meaning he had to make the best of it before running out of time.
There were some very close calls at Base B, the pilots with the best scores usually only clipping the line. They generally have an instinct regarding the 150m turning point and very often have the best callers assisting them, it also helps to have a good launch height, but of course if we all use electric motors to launch we will start even, whatever the conditions.
All in all an excellent contest enjoyed by all with good weather all day including a steady breeze to assist the winch launching, the height limiter was set at 250m but could have been altered if conditions changed sufficiently enough to warrant such a change. No Line breaks or broken models, these days it is very rare for a model to fail, one of the concerns of those who have not been prepared to try F3B. Any damage is usually due to finger trouble as is the case in all disciplines.
Models flown in order of final results:- Fosa, Ascot, Target, Fosa/E-Crossfire, Precious, Cobra, Vampire, E-Dingo and Ascot.
| # | Name | Raw | % |
| 1 | Steve Haley | 5938.3 | 100 |
| 2 | John Whittle | 5668.1 | 95.45 |
| 3 | Mike Challinor | 5471.3 | 92.14 |
| 4 | Bob Dickenson | 5376 | 90.53 |
| 5 | Simon Haley | 5344.4 | 90 |
| 6 | Mike Holtby | 4976 | 83.8 |
| 7 | Norman Quirk | 4803.8 | 80.9 |
| 8 | Clive Needham | 4767.8 | 80.29 |
| 9 | Brian Johnson | 4330.4 | 72.92 |
Team Haley - Holland 2011
