geometry is an issue. 1) would a 3 or 4 blade prop be better?
2) is the geometry better on some planes than others? > On 19 Sep 2016, at 9:31 PM, Matthew Scutter <yellowplant...@gmail.com> wrote: > > 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 > <mailto: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 <mailto:mborg...@borgeltinstruments.com> > Sent: Monday, September 19, 2016 10:40 AM > To: Discussion of issues relating to Soaring in Australia. > <mailto:firstname.lastname@example.org> > 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 ðŸ˜œ >> >> Kind Regards >> >> David Holmes >> >> Sent from my iPhone 0439 734 646 >> >> > On 19 Sep 2016, at 10:24, DMcD <slutsw...@gmail.com >> > <mailto: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 >> > Ausemail@example.com <mailto:Ausfirstname.lastname@example.org> >> > http://lists.base64.com.au/listinfo/aus-soaring >> > <http://lists.base64.com.au/listinfo/aus-soaring> >> _______________________________________________ Aus-soaring mailing list >> Ausemail@example.com <mailto:Ausfirstname.lastname@example.org> >> http://lists.base64.com.au/listinfo/aus-soaring >> <http://lists.base64.com.au/listinfo/aus-soaring> > > Borgelt Instruments - design & manufacture of quality soaring instrumentation > since 1978 > www.borgeltinstruments.com > <http://www.borgeltinstruments.com/>tel: 07 4635 5784 > <tel:07%204635%205784> overseas: int+61-7-4635 5784 > <tel:%2B61-7-4635%205784> > mob: 042835 5784 : int+61-42835 5784 > P O Box 4607, Toowoomba East, QLD 4350, Australia > > _______________________________________________ > Aus-soaring mailing list > Ausemail@example.com <mailto:Ausfirstname.lastname@example.org> > http://lists.base64.com.au/listinfo/aus-soaring > <http://lists.base64.com.au/listinfo/aus-soaring> > > > > _______________________________________________ > Aus-soaring mailing list > Ausemail@example.com <mailto:Ausfirstname.lastname@example.org> > http://lists.base64.com.au/listinfo/aus-soaring > <http://lists.base64.com.au/listinfo/aus-soaring> > > > _______________________________________________ > Aus-soaring mailing list > Ausemail@example.com > http://lists.base64.com.au/listinfo/aus-soaring
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