I think what Mike was referring to was not the drag of the blades in gliding flight but the efficiency of the nose-mounted propellor in climb. Reliability through simplicity is definitely a factor, but the FES is not much good if you want to self-launch (prop clearance).
On Mon, Sep 19, 2016 at 8:37 PM, Bob Ward <wendo...@westnet.com.au> wrote: > Mike, B and others interested in FES, > > Mike, I am simply amazed that in a recent post, you described the FES > system as “Silly” and in this post, you seem to be implying that it would > probably be much inferior to the same system if on a retractable pylon, > Mike, all who have used FES describe the degradation of FES in the glide, > even at high speed, as simply not detectable by any pilot flying one. You > may or may not be aware that it is now the preferred “not land out” system > offered by Schempp Hirth, who are now offering it for Discus 2, Ventus 2CX, > and when it is certified, the new Ventus as Schempp call it, but already is > known in the general gliding movement, as the Ventus 3. > Tilo himself flew a FES equipped V2CX FES in a recent Grand Prix and was > far from disgraced! And against other pure and retractable engine gliders. > Mike, I have to tell you, and anyone else who is prepared to listen, that > as an operator of a self launching Ventus 2CM, since purchasing mine in > 1998, the first of two eighteen metre gliders to come to Australia, (twenty > two years ago) that regarding reliability issues, it has not usually been > the reliability of the two stroke power system, but the notorious > *UNRELIABILITY > *of the retractable engine system that is the important issue, Both with > respect to safety, and even more so, maintenance issues, I had my first > failure of the linear actuator, which raises and lowers the propeller > pylon, when the glider was only about ten years old, and was forced to > operate the glider for about two years as a pure glider with engine out, > because Schempp, in there inimitable *“could not give a shit about spares > availability”* were unable to supply me with either the linear actuator > itself, (screw jack) or a new motor driving it. The total time then, of the > whole engine and erection system was as I remember it, fifty miserable > hours, Then total failure of the pylon erection system, and a two year > delay until I was able to repair it, using my own recourses, with not any > help from Schempp, or indeed probably worse than simply no help, a simple > shrug of the shoulders, Their response? *“Sorry, the firm making the > actuator that we used in your glider is now out of business,so we are > unable to help you”* the reliability of the two stroke power system > itself has had its moments too, but, overwhelmingly, it has been the > unreliability of the erection system that has given me the most grief. > After two years, I was again able to restore the linear actuator to working > order with from memory, the third iteration of self sourced motors. Even > then, the motor I sourced required much modification of shaft bushes to > make it work reliably, with linear thrust loading on the shaft, which is of > course what is required for a motor driving a worm gear, meshing with a > screw drive on the linear actuation shaft of a typical electro / > mechanical actuator of the typical motor or propeller raising system as > used by Schempp and others. Almost all small 12 V DC motors of this size > are designed for torque shaft loads only, As I found, it was quite > impossible to find one designed to accept considerable thrust loading on > the drive shaft as well. The only solution to this conundrum that I could > come up with was to purchase a standard motor and modify it to accept > thrust shaft loads as well as torque loads. By no means impossible, but > certainly, would be for the average bear, including Shempp themselves, who > were blissfully unaware of this vital issue. It was only my rather unique > access to a glider pilot friend, who had such expertise as his kit of > tools, after a career of forty years as a production repetition engineer. > You too, of course know this man almost as well as I do, so that I was > eventually able to work my way round a problem that even Shempp could not > will probably be no great surprise to you. > Would a simple hydraulic system as used I believe on an LS turbo erection > motor be more reliable and less troublesome? Of course it would! Any > engineer worth his salt could tell you that, but the miniscule engineering > expertise of Schempp Hirth engineers twenty two years ago, with respect to > engine installations,was such that they chose a linear actuation system > from a company which went out of business in less than ten years! Am I just > a little pissed off with the support provided by Schempp? You can guess! > Woolly Pup 3, I do hope that with your incredible confidence in the > Schempp Hirth product and ethic, you are reading this post! As you can no > doubt tell, your opinion and mine on this matter are very, vert different! > The retractable system in my twenty one years of operating the V2CM, would > have killed a much less experienced pilot at least twice and in the case of > the other V2CM, operated by the other DDSC member who you know well,caused > a serious safety issue at least once. The owners son in law was flying it > at the time and once again what happened could have had much more serious > consequences for a n early hours motor glider pilot. > Mike B and others, I can sincerely say that I will *NEVER*, as long as my > bum points to the ground, ever again own a retractable power system, > manufactured by Schempp Hirth..That of other manufacturers? I have no first > hand experience with other manufacturers systems, so will reserve my > judgement, but would certainly be a very cautious person if I was > considering purchasing one! > *Mike B, in my opinion, you are completely missing the point about FES, > which is this. *You will be sacrificing a miniscule of glide performance > for a system which will save you a land out, climb away at about 2 M/S even > in an 18 M glider, and then allow you to cruise under power at least one > hundred kilometres at better than one hundred KPH to either home, a safe > airport, allowing a safe aero tow, or back to an area that is still > thermic.. What could be better than that! > > In my opinion, Mike, the system would be better named, KISS FES! *“Keep > it Simple stupid. Front electric sustainer ! “* > > Mike, you may know that Andrew Madocks is currently working at the Schempp > factory, having training to return to Aus with all the qualifications to > undertake all glider maintenance including major repairs, and approved > modifications. He has been well involved with the installation of FES in > new Schempp products. He has been briefed by me to return with knowlege of > what is involved to retro fit FES to my Ventus 2CM, which would then become > , I guess, my Ventus 2C FES!. I expect that this will be done some time in > 2017, soon after Andrew returns to Australia. My extremely unreliable Solo > motor retractable motor system which is now, at last, working perfectly and > reliably, for the first time in eighteen months,* (Due to another > instance of Schempp saying, “Sorry, Mr Ward, the engine in your Ventus 2CM > is no longer supported. We are of course able to support your airframe, > virtually forever!”* *, *will be then hung from a hook in my hanger! > My self launching motor glider has operated in the experimentalcategory > for the last year due to a failed mechanical water pump. Yes, you guessed > it. Not available from either Schempp or Solo! It is now equipped with an > approved modification, an electric water pump, for which the pump > manufacturer claims a service life of from memory, twenty thousand hours! > From memory, the total engine system has less than 90 hours, on VH-GBW, > for about 2600 airframe hours. And all the bloody pain of owning a > retractable engine system for the twenty two years of operation! > Mike you are aware that I rarely post on this site However, I chose to do > so today, as I believe that you are on completely the wrong tram with > respect to retractable systems and FES. > My advice to you would be this. *Please consider carefully before you > again call FES a “Silly FES”* > *In conclusion, Mike, I must say that I find it truly amazing that you, of > all people, who for years operated a piggy back Top Engine on your Ventus C > , and which, conservatively would have depreciated your gliders glide > performance by say 20% or so, would be so concerned about the absolutely > miniscule depreciation, on glide performance of FES, when considered along > side its attributes, and its simplicity. And as I recall it, you repeatedly > sang the praises of the TOP system! * > Mike, regardless of your or other responses to this post, this will be my > only post on this subject! Please do not even try to draw me out with your > usual invective. It simply will not work. I know you too well! > My prediction, Mike, is that within 10 years, FES will out sell all other > “lets not land out” systems. And it will be easily retro fit table to just > about anything.! > Lets just agree to wait and see if you or me is correct! > > > Regards > Bob Ward. > > > > From: Mike Borgelt <mborg...@borgeltinstruments.com> > Sent: Monday, September 19, 2016 10:40 AM > To: Discussion of issues relating to Soaring in Australia. > <aus-soaring@lists.base64.com.au> > Subject: Re: [Aus-soaring] [gfaforum] DIana 2 > > LOL! Good point. You might need a Honda generator running most of the > night. Yep, clean green motorgliding. > > Lange Antares has been around for a while. I think it was the first > PRODUCTION electric SLG. Uses some Saft V44 Li-ion cells. 72 of them I > think. Lots of very careful cell management is required. There are > microprocessors all over the battery pack and they report to Germany via > the cell phone network. > > Silent Electro uses the FES system. Someone should really put one in a > Silent Targa 2 as a retractable installation to compare performance with > the front mounted FES. > > Mike > > > > > > At 10:26 AM 9/19/2016, you wrote: > > Umm. I believe solar panels don't work so well overnight. > > Not in australia anyway 😜 > > Kind Regards > > David Holmes > > Sent from my iPhone 0439 734 646 > > > On 19 Sep 2016, at 10:24, DMcD <slutsw...@gmail.com> wrote: > > > > HA, > > > > There's an interesting article in the current S&G about a casual comp > > done in Italy, flown with the Silent Electro. Was this the world's > > first electric SLG? I know it proceeded things like the Antares by > > almost a decade. > > > > Anyway, the innovation with the comp was that they were allowed to use > > the motor during the comp and motor runs were counted in the overall > > score. From memory, the Silent could do about 8000' of climbing with a > > full charge (on new batteries no doubt). So this would mean one launch > > and two or three retrieves which is pretty much all you need for most > > comp or safari flying. > > > > With an ultralight glider, you could probably do all the recharging > > overnight with Aldi solar panels. > > > > As far as noise levels go, the first electrics failed EASA noise level > > checks because they did not appear on the scale. > > > > D > > _______________________________________________ > > Aus-soaring mailing list > > Aus-soaring@lists.base64.com.au > > http://lists.base64.com.au/listinfo/aus-soaring > _______________________________________________ Aus-soaring mailing list > Aus-soaring@lists.base64.com.au http://lists.base64.com.au/ > listinfo/aus-soaring > > *Borgelt Instruments* - > *design & manufacture of quality soaring instrumentation since 1978* > www.borgeltinstruments.com > tel: 07 4635 5784 overseas: int+61-7-4635 5784 > mob: 042835 5784 : int+61-42835 5784 > P O Box 4607, Toowoomba East, QLD 4350, Australia > > ------------------------------ > _______________________________________________ > Aus-soaring mailing list > Aus-soaring@lists.base64.com.au > http://lists.base64.com.au/listinfo/aus-soaring > > > _______________________________________________ > Aus-soaring mailing list > Aus-soaring@lists.base64.com.au > http://lists.base64.com.au/listinfo/aus-soaring > >
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