After an unsuccessfull attempt at this one about 12 months ago, I decided to try again. Spent some time researching the real thing, and found out some interesting bits and pieces, none of which is probably relevent to this thread For those unfamiliar with the plane, it was a 2nd generation single engined luftwaffe jet that very nearly reached prototype stage by the end of WW2. The design was further developed in Argentina a few years after, and was produced in limited numbers as the "Pulqui". For a variety of reasons, it never achieved any notable success, and disappeared into aviation history. I got the drawings from the Luft 46 site, and some from a couple of specialist books, and set to work. Putting a protractor on the wings indicated a 40 degree sweep, so I cut a set from some blanks I had left over from a previous project. My budget has had a drastic cut back (i.e, I'm broke), so I have had to do this on a shoestring. Luckily I have everything I need in the spares box, unless, of course, I break something......The fuse will be a slightly modded GWS Me 262 nacelle, with the option of using either a HET 6904 70mm unit, or a standard 64 mm GWS one. Not overly fond of the standard item, but I'll be impartial. The tail section will be coreflute, and interchangeable, hence the 2 or 3 version. Other models of the plane show the "T" style tail with dihedral, as do some of the factory drawings, but the free flight original model has anhedral. The "3" version also has a choice of tail style as well, but more conventional. I did have aspirations of a pusher version, but the tail section was simply unsuitable. I'm not a great fan of EDF, but I have high hopes for this one. If I keep it light, and balance the fan as close as I can get it, it looks promising. Another option is vectored thrust, but I'll have to make something up to suit the rear of the nacelle, and make it as simple and robust as possible. I have enough scrap EPP to flesh out the fuse and fashion the nose and tail, and will use balsa fillets where neccesary. This one won't be an overnight build, as too many other things are taking priority, but it won't be drawn out either. It's more of a personal challenge to get it to fly properly, and still look close enough to the real thing to have some credibility. Post some photo's next time.....cheers
Hey Hank and Barry; put the wings together last night, and started looking at the fuse shape. Version 2 and 3 are a little more different than the documentation suggests. The "classic" Huckbein with the "T" style tail has a shorter nose and a longer tail than the "3" version, which strongly resembles the Mig 15 ( funny that) What this means is having to decide which way to go early on, as both aircraft are visually distinct from each other. Maybe I'll figure out an interchangeable solution The "3" version looks much more practical and airworthy, but does not get anywhere near the popularity of the earlier one. Not surprised the Russians took an interest in the latter. Apart from that, I'll be experimenting with a different style of building this time-balsa sheeted foam Not destined to be a combat plane (EDF is useless in combat) It does not need to be bullet proof, just generally crash -resistant. I'll actually get it flying long before the cosmetics are applied, as I don't intend to waste my time on a non performer. My faith in EDF is lacking, to say the least. However it turns out, it will still be an exercise in a different construction technique, and that can only be of benefit The photo's will come....cheers
Sounds great Michael. I can really understand your thinking on making a basic build to test the concept before you take the time and trouble to finish the model fully. I have done just that with the last four scratch builds and it works very well. Means the model is as light as it can possibly be and gives me a good idea of how much finishing weight it will be capable of handling.
Had a major disruption over the last week, and have made only limited progress. Finally decided on the original, as it will be more of a challenge. Put the GWS 64mm edf unit together, dropped in the most powerfull motor available, and balanced the fan. I know they have a good name, but the gws units look really cheap and flimsy compared to the HET 6904 that is/was the alternative powerplant. Seems to run smoothly enough though. The wings have been stucturally completed now and the elevons cut out. After much pondering I decided to make it elevon only, as the sweep is more than adequate. I know other versions of this plane have an elevator, but i decided to use that less than inspiring "T" tail just for trimming, as was the original concept. The vertical stab was cut from coreflute, and the fuse top built up from scrap epp. When I get home tomorrow( I am currently interstate), I'll try and get some pics together.....cheers....
Very interesting call on not using the elevator and going for elevons only Michael.
I noticed that the original drawing for the BV 215 showed ( if I read them correctly) control surfaces on the winglets. These are fixed on the model which relies on elevons only. No problem with pitch control ( so that should be positive for the 183) but the roll rate is much slower than I would prefer. Not sure if the lack of winglet input affects this or not.
This is taking forever , but here are the first photo's. 40 degree sweep on the wings, 60 on the vertical stab, and the oddball tail for trimming only, as in the original specs. It already feels too heavy, but I am probably just being paranoid: Cut the elevons to shape, and got all the running gear sorted. Another week/10 days should see a test flight
This is looking really good Michael. I am very interested to see how the elevons work out as it'll be much easier to rig up the controls without having to work that tail mounted elevator.
As I seem to be following your build list, Komet , BV215, I guess this will raise it's head at some stage.
Can't wait for the maiden flight report!!!
Thanks for the encouragement Barry Attached the elevons yesterday, and grafted the vectored thrust unit onto the back of the fuse. I know that this is not a standard fitting on this plane, but after the problems with thrust angles on previous luft jets, I can learn to live with it. Hoping to get some more done tomorrow.......
Seems my reservations were well founded about the weight. With such a small model, the wing loading was too high, and there was no real practical way of reducing it. Even on full power, the plane really struggled, and had a very high landing speed. It had a glide like a piano. Oh well, at least the wings can be used for something else, and no build is ever wasted, as there is always something to learn. This kind of failure always heralds a resounding success for the future
Did some more investigating on this one and found out some more interesting bits and pieces. I put the wing into another pusher fuse, in the guise of making a canard experimental along the lines of the Henschell "Schnellbomber". The first test flight showed the COG was much further back than first thought, and the elevon response was totally inadequate for elevation. As a canard it flew very well, but only after moving the COG nearly 30 % rearwards. Disabling the front elevator, it still flew well, but could not loop to save itself. The 40 degree sweep displays good lateral stability, as well as a good turn of speed, but it appears the chord is too narrow to support true flying wing capabilities. Increasing the width of the elevons made it wildly over sensitive, and did not improve any thing really. Like wise with changing the ratio of servo arm to control horn. Exciting stuff, but not practical flying So apart from the marginal power supplied from the gws 64 mm fan, the high wingloading, and the totally non operating tail surfaces, it seems that I eventually figured out the rest of the puzzle. Seems with all the ARF, parkzone culture Wattflyer has, this Wright brothers, seat of the pants stuff is in the minority. Learning by crashing obviously does not appeal to everyone next is to figure out how to keep out of trees......
Michael, I hope you get your "issues" sorted out. We all have them don't we (not just our airplanes either! LOL!)? I love your posts as you always (okay, usually) have some humorous insight to share with us. How good is that? I know the Tasmanian Luftwaffe is alive and well, but man do they take some attrition!
looks like this one just won't go away Salvaged the wings, made the "3" version fuse and tail, and will try it as a pusher for now. The 40 degree swept wings were very slick through the air, even with the miserable edf power plant. The original Ta 183 which came to life as the pulqui in Argentina was a miserable failure, but the alternative version(s) are asserted to be the fore runner of the Mig 15, which had some success. The Russians have always said that the Mig was homegrown, but the drawings and diagrams tell a different story. Then again, the F86 Sabre owes a lot to Messerschmitt as well..........Will try and get some pics up soon, cheers
Great work Micheal you certainly stick at it but then the rewards when it eventually works are so much greater!!
Do you think the improved efficiency of a pusher set up will make all the difference? I hope it does.
Hi Barry; this one is certainly a scrap yard special. The fuse was made from leftovers from the EPP junk bag, where I keep all the off cuts. I just saw or hotwire the pieces into lego style blocks, and use them to build my "totally experimentals" with. If worth pursuing, I then cut a "proper" fuse, nacelle, etc from a new block of foam. The interlocking, laminating, overlapping style of building from numerous small pieces is surprisingly tough, and is always a good learning tool anyway. Not always that prettty, but very functional. The pusher set up is light years ahead of the edf setup in terms of weight and performance, it just does not look scale. Form always follows function, to use the engineering adage, and having something that looks the part, but flies like a piano, does not interest me. The first few testflights were done yesterday, and the plane flew extremely well, showing great promise. The horizontal stab was removed, and tried again using elevon control, so the descision now is in what direction to go.......like the Luft 47 Henschell, I seem to be taking the next step in developing a has been that never was. Cheers
Taking the scenic route here, but I am determined to see this one through. After salvaging the nacelle from the original He 162, I spent some time modifying the underside to accept some restructuring. The original wings, with the specified 40 degree sweep, were then grafted on to the upper section, after being somewhat lightened . The original edf was replaced with a GWS one, and a really hot motor added, as power to weight ratio is everything with edf's. Some wingtip fins were added just to get it airborne, and we'll see if it works before progressing any further.......
I basically just taped the battery, rx, and ESC to the top of the "fuse" when I figured out the COG, set the elevon reflex, double checked everything worked and just hand launched it, hoping for the best. After all the flops so far, it was very encouraging to see it just fly away at a slight climb, with no hint of stalling or rolling inverted The next 4 flights were all stress free as well, with basic aerobatics presenting no drama at all. Later, the wind blew up to its' usual 20-25 knots, and with some hesitation I tried again. Amazingly enough, she handled the wind really well, and was totally controllable through out the whole flight. It almost makes me think I should just keep it like this, but I'll start on the tail section next, remove the wing tip fins, and persevere with this quirky design....more later
It's been nearly a year since i started this project, but it looks as though perseverance once again is paying off. The Winglets came off, replaced by the 60 degree swept tail of the Mk 2 version, which was supposed to be the factory production model. Once again she flew no problems, so on went the "T" horizontal stab. A bit of a dubious appendage this bit, as the original black and white pic's from WW2 show the tail with anhedral, and the drawings/plans show dihedral. Oh well, I'll try both. The extra weight on top of the big fin produced some flex, but once again she flew, if somewhat "fluttery" at times. The glide really suffered though, although it was not anything too dramatic. So on with the Mk 3 tail, a more conventional cruciform type. This time it was markedly better; no flutter, better glide, less of a hassle in side winds. I know there are more variables than this, but the basics will suffice for now. Next step is to add a working elevator, and change the elevons to ailerons. Performance wise it is going quite well, although with the usual edf drawback of short flight times. Threw in some pics of the two tales, and as you can see, it is very much an ugly duckling right now., still, I can't help but think I'm designing the first prototype of the Mig 15......
Just to conclude this convoluted tale, I tried elevator and aileron control using both types of tails, and as you might expect, version 3 tail once again performed better. Not surprisingly, as the successful 2nd generation jets such as the Mig 15 and F 86 both used a cruciform tail section, and the ill fated Pulqui stuck to the 'T" tail with predictable results........shoulder wing mounting not withstanding. I've actually "discovered" that elevon only control, on a tailless design does perform better, for a variety of reasons, from a modelling point of view. The conventional tailed aircraft appeared to offer no determinable advantages, and in fact flew worse in wind, had more complexity, and a higher wing loading due to the greater AUW. Not being an aeronautical engineer means that through trial and error, I've come to conclusions that others may have reached using a slide rule or computer programme, but that is 1/2 the fun for me What stands out though is that a lot of these luft 46 type ideas had great potential, and I look forward to many more years of developing these planes that never were. As for the Ta 183......in its' original conception, it appears to be a dead end, as the Pulqui clearly demonstrated, and was well behind other concepts being engineered by Heinkel, Messerschmitt, Arado, Blohm and Voss etc. Inspirationally though, the prototype Migs look suspiciously like the Mk 3. Onto my next project......cheers....
Thanks very much for taking the time and the trouble to share the results of your experimentation with these aircraft Michael. I, for one, really enjoy hearing all about your battles and successes and the information you have gathered along the way has been very useful indeed.