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    ThermalBoy
    It's been over a year since I (Colin Paddon) and Kevin Beale first posted details of our home built and designed 3.8m composite F5J glider, PROGLIDE. This update brings us up to date with the project.
    It’s all very well designing and building your own competition plane but its not worth a lot if it turns out to be lacking in performance compared to the professionally manufactured gliders that it will be flying against. There seems to be a general misconception that home built F5J competition gliders are in some way inferior to the professional commercial offerings in terms of their flying performance.  Straight away lets dispel this myth. The prototype PROGLIDE in its first full year of competition use won three UK F5J league competitions and finished 2nd in the 2016 National UK F5J league with an overall score of 99.06%. Myth dispelled.
    The only downside of designing and producing your own composite F5J plane is the time and effort it takes to do. If we paid ourselves 50p per hour for all the time we have put into this project we still wouldn’t be able to afford to buy them! It’s a complete labour of love in every way but the sense of achievement makes it all worthwhile.  A quick look at the web gallery that accompanies this article will give you some idea of the time and effort that has gone into achieving our original goal which was that it must be economical to build, use techniques that anyone with reasonable building skills can learn/do and most importantly have as good a flight performance as the commercial offerings.  Achieving the 100% perfect finish compared to the hollow moulded professionally produced planes was not a high priority. We were only interested in its flight performance and were happy to accept a good finish as opposed to a perfect one.
     
    During the development period we worked in parallel on different areas of design/construction. For example I decided that I wanted to be able to split the fuselage in half for ease of air transport which meant that the elevator and rudder servo’s were both enclosed within the tailplane mount pod with the boom being secured to the Fuselage Pod spigot by two carbon tubes that could be removed and the boom slid off. Ditto the fin/rudder assembly. Kevin worked on optimising his layout with the servos under the wing at first followed later by the elevator servo in the tailplane pod and the rudder servo under the wing. For his Fin/Rudder he went along a similar route that the Nan Xplorers use. Finding easy to do home build solutions to problems took time, effort and testing. 
    One of the things that several people asked us about was how we made the wing joiners. In the end it was so simple that I wondered why I hadn’t thought of it before. Buy yourself from HobbyKing a protruded 10x10mm square section carbon rod which comes with a 8mm dia hole all the way through it. Cut into required joiner lengths and angle the two inner end faces to the required angle. Roll up 40mm of unicarbon tows to achieve a tight fit inside the hole, wet out fully with epoxy and slide it half way into one half of the joiner and then the other. Put balsa caps down the hole so that it just very slightly compresses the central wet unicarbon and keeps them centrally located within the length of the joiner and then clamp into required position and allow to set. Result, pair of carbon joiners that weigh 23g total. The plane would be destroyed before the wing joiners broke. This technique wouldn’t be strong enough for F3J planes but more than adequate for our lesser stressed F5J models. Quick, cheap and foolproof with the ability to create any angle of joiners you require. Kevin went a different route by using straight solid round carbon rod which allowed him in our normal wing section to get the required dihedral tip angle he wanted. 
    All this problem solving sounds as if it was a PITA, and at times it felt that way,  but in reality we both enjoyed finding home build solutions to these challenges.
    The first two Proglide’s produced used cheap fibreglass cloth on the flying surfaces which enabled us to learn the required composite skills knowing that when it goes wrong (it will BTW!) that it hadn’t cost the earth in materials. However, the aim was always to eventually use Carboline which is a fantastic cloth but it’s not without good reason that it’s called “Black Gold”, its very expensive but gives a strength to weight ratio that is unbeatable for our purpose. 
    The early fibreglass skinned versions of PROGLIDE achieved RTF weights of between 1450-1580g, ie still reasonably light for a full house 3.8m electric plane. With each new plane we tried different lay-up’s, build techniques and incorporated various detail design changes along the way. Lots of time was expended in producing test pieces during this period to prove the viability of what we were doing. We had failures along the way on pieces that we felt sure would work well but turned out not to be of the standard we were seeking. Amongst the various failures though we managed to have some light bulb moments which were always welcomed! One such moment came when we started to investigate how to achieve repeatable 100% success with shaped inflation bladders in the moulding of the fuselage pod in order to minimise the weight.  After quite a few failures it turned out that a fine tipped soldering iron and Recycled black rubbish bags (yes really) worked brilliantly. The variable air pressure for this task was handled by a £50 EBay airbrush compressor which had a small air reservoir tank.  After trying various layups, like most of the professional manufacturers, we have now settled on using all carbon for the fuse pods. 
    Another light bulb moment came in regard to hinging the flying surfaces. At first we used silicon hinges which did work but were relatively heavy and difficult to get perfect every time. We later moved to using Diamond tape for the hinge along with Microfibre tape on the inner faces of the foam. (Microfibre tape sticks like the proverbial to raw pink foam). This resulted in strong, lightweight quick to apply, field serviceable (if required) hinges that were very free in their movement. They have turned out to be every bit as good as silicon hinges and in many respects far better. 
    After building a few Proglides we felt confident enough to move onto using Carboline. We also decided at this point that we would again take advantage of having two of us involved. Kevin’s first Carboline PROGLIDE was to use our normal wing section whilst mine was going to use one of the new F5J Syner ultra-thin wing sections. We had hoped to use a friend’s CNC foam cutter for this new prototype wing but unfortunately he moved house just at the wrong time and we all know how much time they take up to get sorted out. So, yet more wing /spar templates to make! Using such a thin wing section on a 3.8m wing brought with it a host of new structural problems to overcome and additionally neither of us was totally convinced that these Ultra-Thin wing sections were the right way to go for F5J.  
    Kevin progressed quickly on his first Carboline build as we now knew exactly how and what to do. He made no attempt to get this plane down to be a super lightweight and used standard sized servo’s with a heavy motor/ESC/battery in the fit out. Even so the finished RTF weight came in at just under 1440g. He estimated that had he used lightweight equipment the finished RTF weight would have been easily under 1300g. The project was moving in the right direction.  After flying it Kevin liked his PROGLIDE so much that he immediately decided to press on and make a full on lightweight  Carboline version. This ultra lightweight PROGLIDE, which he seemed to put together in record time, came in at 1280g. It fly’s superbly. 
    Meanwhile, it took me a while to iron out the new structural issues raised when building a 3.8m solid core ultra-lightweight thin section wing. Eventually though we were ready to proceed with the build. Did it go smoothly, of course not! Due to a stupid error on my part during the bagging up of the centre panel, I managed to ruin the entire panel. It was an expensive and time consuming mistake to make.  After the required amount of San Miguel I decided to build a new centre section straight away. I took this “opportunity” to try a different approach with the spar structure. The rest of the build thankfully went without a hitch. The plane RTF came in at 1245g using lightweight radio gear, 1000mah 3S Hv Lipo and a 85g direct drive motor. All that was needed now was to test fly it to see if it performed as well as we hoped it would. Following several test flying sessions we can report that its flight performance has exceeded all expectations. All preconceived negative thoughts on whether ultra-thin wing sections would work well for F5J have been dispelled. 
    In light of the successful flight testing of the first thin wing PROGLIDE we have decided to build a heavier windy weather version using the same thin wing section. In the meantime the Carboline Ultra light just tested can be ballasted to 1550g AUW which hopefully will be capable of handling a decent amount of wind (yet to be tested). But as we all know, here in the UK there’s times when you just need a heavy plane.
    For those that are interested in weights here they are.
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    Part Finished Weight With Gear Installed Weight Carbon Fuse Pod 89g 135g Boom & Tailplane Mount 35g 55g Centre Panel 263g 333g Left Wing Tip 128g 150g Right Wing Tip 130g 152g Elevator 33g 35g Fin/Rudder/Tube 24g 24g Prop/Spinner/Motor   113g ESC   50g Other installed equipment   78g Total AU RTF Weight   1245g
    In terms of airframe material costs, the fibreglass skinned versions come in at around £100-£130 and Carboline versions at £200-£250. Labour cost….well let’s not go there! Overall, somewhat cheaper for an equivalent commercially produced 3.8m F5J model at this kind of weight!
    So what next? We are confident that we can further reduce the overall weight with minor detail changes, improved lay-ups etc, but recognise that we are getting close to what can realistically be achieved in this regard with home building.
    A picture really does say a thousand words, so if you are interested in seeing how the PROGLIDE is constructed, the photo web gallery that accompanies this write up shows all. If you have any specific questions about the plane or its construction please feel free to ask on this thread.
    Colin Paddon/Kevin Beale

    BARCS INTERGLIDE 2017
    24th-25th June, Near Ashford, Kent
    This year’s event will be run by the British Association of Radio Control Soarers. Traditionally an F3J event, to reflect the rise in popularity of electric launch soaring this year we will be run to International F5J rules. The competition is registered as a EUROTOUR and World Cup event and will count towards all relevant National and International Leagues.
    Location and Dates
    The site is a large, private airfield located approx. 5miles south of Ashford, Kent allowing easy access from the M20, Eurostar, Ferry Terminals and local Hotels.
    The Hamilton Farm Airstrip, Bilsington, Ashford Kent, TN25 7JJ.
    Website for more information: http://www.hamiltonfarmairstrip.co.uk/
    Enter online or by form to be found on the Interglide website. https://www.interglide.co.uk/
    Closing Date Friday 16th June. Restricted to 60 entries
    Download BULLETIN 1
    BARCS INTERGLIDE 2017 F5J Bulletin 1 Final.pdf
    Forum Topic below
     

    By PeteMitchell, in Articles,

    Most will know of the new development in glider construction which was pioneered by DLG model makers. The difference from what we are used to with moulded construction is that the new method uses one precision cut solid foam core rather than the several layers of thin foam used in the construction of hollow moulded wings. The solid core is covered with the, also new ultra-light carbon fabric, in a mould. There are a number of other differences in the construction but I don’t have all that info.
    This new construction enables wings to be built with a much thinner section, and much lighter in weight.
    I must say that when I first read of these developments I had my doubts. How could the weights be achieved, how could they be strong enough for our conditions, how could they be of any use in ‘our’ conditions.
    I always have to try something new, so when Hyperflight imported a few, I took a chance and bought one of the new Ultima F5J models.
    All I can say is that the hype about these gliders is true. They are fantastically light and very strong. There is nothing ‘flimsy’ about any part. With some light weight models I have seen, the fuselage is very flexible because of the light cloth and minimal amount of epoxy used. I have a standard Ultima fuselage and it is very rigid made of carbon. The wall thickness is substantial and there is nothing flimsy about it, and it also is very light.
    There are a number of build threads on the web so I won’t try to compete with those. Only to say that it requires a few different techniques which are more usual to hand launch models. I did take a few pics as I put it together as below

    Flap Servo

    Servo Mount and Ballast Tube

    Cutting nose to length after balancing the model.

    Servos and ballast tube.

    Traditional pic before first flight.
    I have only had 6 flights with it so far, including 4 flights at the Tonbridge F5J comp where the conditions really did not suit it. But I am very pleased with what I have seen so far.
    Any questions please ask away.
     
    Tonbridge BMFA F5J League Event - Sunday 19 June 2016 – THE RESULTS
    With an entry of 27 pilots, Tonbridge club hosted what we believe to be the largest UK domestic F5J league comp to date.
    Following a week of torrential rainfall we were glad to find that with care getting onto the field and not getting stuck wasn’t a problem other than Phil Ramsey who unfortunately got stuck with his large heavy motor-home. Farmer to the rescue with very big red tractor!
    The day looked like it would be ideal RC Soaring weather starting off warm and calm but progressively getting windier as the day wore on. The first slot which enjoyed wall to wall lift gave no clue as to what was to turn out to be extremely challenging days flying with several slots not being flown out by a large margin. When the sink came through it was what can only be described as massive blanket sink which covered unusually large expanses of sky. This coupled to the strengthening wind resulted in many missed landings and land outs. We managed to complete 5 rounds with a break for lunch making for a nice relaxed comp. With storm clouds forming after 5 rounds were completed the general consensus was to stop at that point as no-one fancied getting stuck on the field if the rain reached us.
    It was good to see some “new” old faces competing in F5J for the first time with Ricky Shaw and Chris Foss attending. Special mention must be made of Ricky Shaw who flew excellently in his first ever F5J comp to secure second place overall. Despite this being Rick’s first F5J comp his launch height management and skilful flying really made its mark. We hope to see him and his team mates at more F5J comps in the future.
    Thanks to the Tonbridge members who helped with the organisation and also to all the pilots who supported this comp, it makes the organisation/work involved worthwhile. We will post some pics of the day soon.
    The full results can be found below:

    By ThermalBoy, in Articles,

    Homebuilt F5J Soarer  (Kevin Beale & Colin Paddon)
    After a long gestation period, we are pleased to announce the birth of a rare beast … a competition homebuilt 3.8m F5J soarer!
    When the F5J class came into being, it shone out as a great opportunity to once again be able to produce a homebuilt model which would be able to compete well against the superb moulded manufacturers offerings. With no F3J launch stress to consider, Kevin Beale & I (Colin Paddon) decided this was a totally feasible option albeit one that to date had not been taken up by many other F5J competition pilots, at least here in the UK. So we decided that together we would design and build our own “Medium Tech Composite” 3.8m F5J Soarer. To be able to do this would however require that we master some new building skills and techniques and that turned out to be more involved than we originally thought! We weren’t however starting from scratch as Kevin had a lot of experience in producing moulded fuselages and ditto myself in producing foam wings. It did require though a lot of time and effort in pulling together the requisite moulds, building the automated foam wing cutter, many jigs/templates, vacuum pump rig etc. On top of that many tests were undertaken to understand/achieve the best utilization of materials and hone the required composite skills/techniques of which there were many. 
    It was decided from the outset that if cost effective commercially made components were readily available then we would use them. In our case this meant that we bought the carbon fuselage pod boom and the protruded 10x1mm carbon wing spars and wing joiners. Everything else is self-built. 
    The first thing we needed to do was to hone down a general design brief. After some discussion we ended up with the following:
    3.8m wingspan Medium Tech composite construction Vacuum Bagged wings, tailplane elevator/Fin Rudder coupled to a composite fuz pod and boom. Total AU finished flying weight of between 1.4 -1.7kg Proper ballasting capability  Good working space within the fuz pod  Wide performance envelope to cope with different weather conditions Light enough to be able to use a direct drive motor if required Kevin was tasked to come up with the wing plan-form/ spar layout and I think the finished wing shape is very nice. The fuz pod design/implementation works well and his moulding technique improves incrementally with each one he produces. Again many different lay-ups have been tried out to see what works best. An airfoil section was chosen that would provide good all round performance. We decided to try out various alternatives of tail end layouts including all flying tailplanes through to separate tailplanes/elevators both on the fin, in front of the fin and under the fin/rudder. It came down to personal preference in the end but a fixed tailplane with a separate elevator regardless of layout proved to be our preferred type. 
    The fin/rudder on the version shown here is completely removable from the boom itself to aid transport (i.e. to get it to fit in the transport box) and also to provide access to the tailplane/rudder servo’s. Whilst the finish on the wing is acceptable, with the further testing on surface finish we have now done, we are reasonably confident that we will be able to obtain an excellent paint/surface finish.
    For his first full prototype, Kevin has gone for the under the wing Elevator/Rudder servo set-up and increased the tip dihedral slightly as we felt Prototype No1 may have been slightly less than optimal although the initial flight tests have proven this may well not to be the case. (see photo of Kevin’s plane in garage)
     
    The first completed full prototype is the version you see here and despite several mishaps/mistakes during construction with the worst being when the vacuum pump decided to go open circuit over-night and pulled massive vacuum pressure rather than the 15-18Hg it was set to, it still turned out to be relatively OK though. (I can now vouch for the compressive strength of pink/peach foam although it did mean that the spars on the centre panel were a little proud!  Another mistake occurred in the painting of the mylers in as much as we didn’t extend the black far enough along to cover the servo well reinforcements on the tips.  As it was only a prototype though, it didn’t really matter. 
     
    We tested four different types of paint on different weights of glass to see which provided the best release/finish. Halfords spray gloss black turned out to be the best for the black with fluorescent tree marking spray being best for the fluro Orange as it did not require a backing coat of white to achieve the bright fluro result required, i.e. lighter.  The wing control surfaces are all hinged with silicon as is the tailplane/ elevator. You wouldn’t think there is much to do to get silicon hinging right but again the right silicon coupled with using the right application technique & custom spreader tool took a while to nail down along with yet mini samples to get it 100% right. 
    This first completed PROGLIDE prototype seen here weighs 1460g ready to fly which for a first prototype isn’t too shabby. It uses a direct drive 28mm diameter outrunner motor turning a 11x7” Aeronaut folding Prop, 40 Amp ESC and a 3S 1300Mah Lipo. The gadget with the two green LED’s is a home built Ubec/ESC BEC change over unit. (If one of the BEC’s fails the other takes over automatically). 
      
    How does it fly? Well we only managed to fly it twice before it poured down but so far we think it fulfils the design brief nicely. We are extremely pleased with its handling/flying performance but the true test of how good a plane is, comes when its flown in competition against other planes. 
    The feeling of achievement derived from designing and building our own competition models once again is amazing. Yes, the journey involved a steep learning curve with many ups and downs along the way, but if we can do it so can others. Knowing what we now know, we are confident we can get the overall AU flying weight down to around 1250-1300g if required. For UK flying this is really not required but with mainland Europe in mind, an ultra-lightweight model at 3.8m will be worth having in the quiver. The next PROGLIDE versions will be laid up to achieve an AUW of around 1700-1750g ready to fly.
    We now plan to continue to refine and further develop the PROGLIDE series along with our composite building skills. 
    Hopefully this article might provide the inspiration for others to try similar projects.
    Kevin Beale/Colin Paddon

    By PeteMitchell, in Contest Reports,

    The weather on Sunday 22nd Sept 2013 for the first F5J Lite comp at Bartlett’s was, after the early morning mist had cleared, just about perfect.  Except the 1.4 hours of sunshine which my forecasting App promised never appeared and  the day was totally overcast with 10/10 cloud but it was  blessed with very light wind.
    This was my first attempt at running a comp since I last run a dlg glider league, and I was fairly anxious that things should go well. With many hands offering help we were soon set up and at about 10am the pilots briefing was called.
    As this was in no way an official event, the rules for the day were set out as essentially BARCS rules, but with the addition of F5j launch height penalties. These needed some discussion to ensure everyone was happy, and after checking height limiters for a few pilots, we got the comp under way by 10.30.
    Early conditions were quite misty, and good flight times were not expected. But the first slot was won with a flight time of 9.55, and this sort of thing continued during subsequent rounds. In most slots of the first 3 rounds during the morning, at least one pilot flew the slot out whilst others struggled.
    Obvious lift was hard to find, the air just seemed to be buoyant and this did require very careful flying to get the best time, also a good launch height was usually needed to be sure of finding this buoyant layer of air.
    There were some notable flights during the day. Not least of these was during the 3rd slot of the 2nd round.  In this slot it looked to all that Brian Austin, flying his cross tail Stork, would easily out fly all others. But Randy Taylor, flying his 2m Omega stayed up in air that Brian just could not work and he was rewarded with a well-earned 1000 points.
    The stats for both flights are interesting.
    Brian’s flight time was 9.27 landing bonus 45 launch height 194 metres
    Randy’s flight time was 9.50 landing bonus 40 launch height 171 metres
    After 3 rounds we had a shortish lunch break and then flew a further 3 rounds. The afternoon air was more difficult. Max times were hard to get and many slots were won with a time of less than 8 mins.
    Despite the calm conditions, this was not a day for low launching, to ensure max flight time it usually required a launch height of around 180-190 metres. The lowest launch heights to actually win slots were by Tony Merritt and Peter Mitchell. Tony flying his 2m Taser launched to 124 metres and flew for 8.10. In another slot, Pete who was flying an F5j Xplorer2 launched to 128 mtr and flew for 7.40. Everyone tried hard to limit their launch height, and throughout the day only 10 launches exceeded 200 metres.
    All who flew the event, and most had not flown to the ‘F5J’ launch rule before, said they enjoyed the extra challenge the format called for. Also not being allowed a re- launch, meant that on this day launching at the slot start with everyone else was not always the best option.  It paid to wait and watch before launching. Remember that?


    At the end of 6 rounds, and with one round score dropped,  top scorer was Brian Austin, which just goes to show that it don’t matter what format of comp we fly, you still have to be a master at thermal soaring to win.
    Peter Mitchell
    Results
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    Rank Name Rnd1 Dur Rnd2 Dur Rnd3 Dur Rnd4 Dur Rnd5 Dur Rnd6 Dur Drop1 Dur Plty Score Pcnt 1 Austin, Brian 1000 949 1000 1000 1000 1000 949 0 5000 100 2 Mitchell, Peter 1000 1000 804 652 883 1000 652 0 4687 93.74 3 Mathews, Gary 865 1000 803 377 1000 750 377 0 4418 88.36 4 Taylor, Randy 451 1000 305 979 1000 652 305 0 4082 81.64 5 Ott, Jef 447 745 1000 943 857 413 413 0 3992 79.84 6 Merritt, Tony 791 293 556 1000 606 1000 293 0 3953 79.06 7 Gadenne, Ray 1000 809 729 425 781 626 425 0 3945 78.9 8 Mexom, Russell 622 619 1000 692 661 630 619 0 3605 72.1 9 Connell, Mike 121 600 637 973 556 675 121 0 3441 68.82 10 Godbold, David 498 153 157 1000 913 170 153 0 2738 54.76 11 Burns, Jason 0 0 0 470 985 783 0 0 2238 44.76

    By PeteMitchell, in News and Information,

    After a lengthy and by some accounts a sometimes difficult consultation between representatives of the many interested countries via the web, a set of F.A.I. rules were finally agreed a few weeks ago. This now internationally accepted set of rules is provisional for the next 12 months during which time it is expected some ‘fine tuning’ will be found necessary after a few comps are run.
    As with our UK ‘height limited’ competitions, virtually any electric powered model glider is suitable, and all must be equipped with a micro ‘data logger’ which has to be fitted between the receiver and the esc., but that’s about the only similarity.
    With UK ‘height limited’ rules (BARCS version or BMFA) the data logger cuts the motor after 30 seconds run time or when the model reaches 200 metres, whichever comes first. The data is available to download via a computer for checking after the event or if it is required by the competition CD. This has evolved into a popular event with several leagues now running and it is felt that the limit on height ‘levels the playing field’ for everyone.
    The new international class is different in a number of respects, the most important being that there is no ‘limiter’ to cut the height you can launch too. But the rules have been written so that the 200 metre mark is still recognised as a launch limit for scoring purposes.
    The aim of the class is to have a competition similar in most respects to F3J. A slot is 10 minutes duration, but unlike F3J, flight time starts as soon as the model is launched.  No re launch is possible and apart from that it follows long established and similar rules for landing precision, overflying etc.
    The data logger controls the motor run time, and it will allow you to run your motor for up to 30 seconds. You can use the full motor run time or cut off earlier, the choice is yours, but it will not stop the motor at any given height. It’s worth noting that you only get one chance of a scoring flight in each slot because once you start your motor and launch, the data logger will not allow the motor to be restarted until it has been reset, and this requires all power to be disconnected.
    What the logger records is the height your model reaches 10 seconds after you cut your motor run. Once your flight is finished, your time keeper will plug  a hand held ‘card reader’ into the logger which reads the stored  launch height data and this is recorded along with your flight time and landing bonus or penalty. The recorded launch height is vital to calculate your score and if you fail to record the figure you get a zero flight score.
    Scoring works like this.
    Half a point is deducted for every metre of height your model reaches on launch up to 200 metres. If you launch above 200 metres a penalty of 3 points per metre is deducted.
    This all makes for a very challenging competition, which will be won by the pilot who launches low, has the longest flight time and has the highest landing bonus. Oh and just like F3J you don’t have a motor to get you back if you fly too far down wind.
    Peter Mitchell.
     
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