Paul Jefferies

If you bought the packs from SLEC, perhaps you could ask them? They have a website......http://www.slecuk.com/ with a contact section which gives their phone number. Paul

Percy, yes this seems to be a very sensible and well run forum. The moderators allowed me to make my posting on condition that it did not turn into a long running debate on the pros and cons of another forum. I don't want to say any more about it on this forum except perhaps to say that the forum in question is a truly excellent forum with several really knowledgable and inovative contributors from whom I have learned a great deal. I was not a major contributor but I like to think that such postings as I did make were constructive or at least, never negative. It is a good forum, my dispute is only with the moderator and the way he has treated me. Paul

And it doesn't only happen in Clubs....... There has been a very unpleasant bit of politicking going on behind the scenes on another modelling forum this past week. For no valid reason I have just been banned from another modelling forum. The moderator has acted as Judge, Jury and Executioner. Because I have been barred I have had no way to defend myself. He then went on to post a very defamatory statement about me which has thankfully now been withdrawn. The Moderators of this forum have kindly allowed me to post this as I am sure that some users of the forum in question undoubtedly also use THIS forum and my hope is that someone will recognize my name and tell the others (by private message) that I strongly refute what was said about me and there is very definitely another side to what has been happening. Paul

Very nice Martyn, I really like the kevlar elevator hinge....... How will you cover/paint/fuel-proof it and ensure that it doesn't get all gummed up or restricted? Paul

This amounts to a confession! I built a Ladybird back in the day (early 60s/my early teens). It flew very well with my trusty Mills.75 (which I still have)............ until one wing fell off! The box in the fuselage into which the wings plug, had become slightly cracked in a previous arrival causing the wings to become a bit loose. I wasn't able to properly repair it there and then but I had cycled for miles to the flying site and didn't want to stop flying so I wedged one wing in with some grass! (you don't need to say anything) The wing seemed reasonably secure so I fired up the Mills once more and the Ladybird soared back up into the wide blue yonder........ until the starboard wing fell off.  I can still see my most treasured posession spiralling down and hear the sickening crunch as it disintegrated on impact. So the moral of the story is firstly....... If your wing box becomes damaged, don't repair it with grassfibre and more seriously, I suggest winding some heavy thread round the wing box before you fit it so that it cannot split when the wing takes a knock. Paul Edited By Paul Jefferies on 14/06/2015 23:02:54 Edited By Paul Jefferies on 14/06/2015 23:07:39

"PVA or Balsaloc. Some people say they are one and the same.".......... I wondered about this so I did a test using "Litespan" on balsa. On one piece of balsa I used PVA and Balsaloc on the other. It was definitely harder to pull the litespan off the piece that used Balsaloc, ie., Balsaloc gave better adhesion. The test was prior to my first go at covering a model with Litespan and suffice it to say that I wouldn't use it again. As a finish I guess it depends on what you are trying to achieve but I was hoping it would look more like tissue and it looked nothing like I wanted. However my main gripe with it is that it has no adhesive properties of it's own and you have to paint the edges with balsaloc before overlapping with the next piece and inevitably some of the balsaloc shows. Also, heat shrinkage is pretty limited........ Paul

A picture or two might help........? Paul

Easy........ The one which looks best, which is unquestionably the Salto! Paul

Peter, I think it may depend on what kind of aerobatics we are talking about. More or less anything can be made to fly but when you DESIGN a model you try to design in certain characteristics........ For general club type "chuck about" aerobatics...... a loop here, a roll there and sometimes even turning it upside down (), you can get away with all sorts of things and as long as it flies that is all that many people want. However if you set out to design a model to do a particular job and fly in a particular way then that is when you have to consider how you want to achieve that and you design in certain features that will give the model the characteristics that you want. If it isn't quite right then you alter the next one...... May I refer you to a thread in the UKCAA section of this forum which features many aerobatic designs and my own contribution to that thread which shows the "development" of some of my designs........http://www.modelflying.co.uk/forums/postings.asp?th=78824&p=11 Admittedly that was all quite a few years ago but the principle has not changed........ I guess it depends on what you want the model to do and how you want it to respond to your commands. Personally I want a model that is smooth but responsive and so I can fly it fast or slow and it remains predictable. Sometimes you get it right and sometimes there is room for improvement....... Paul

Another alternative would be to use a ball link on the throttle arm. Some ball links stand well proud of the arm to which they are bolted and that would certainly take care of at least 5mm but also, because it is a ball link, alignment would then become less of a problem....... Paul Edited By Paul Jefferies on 11/05/2015 08:39:37

FWIW a couple of tips....... I don't know what you have in mind to go in front of those fuselage sides but it looks as though your model is going to have quite a short nose. A short nose often means that the model ends up tail heavy and you have to add weight to the nose to achieve the correct Centre of Gravity. Be careful that you are not designing in a CG problem, don't be afraid to add an inch or so to the nose...... it can be considered as "adding lightness"! For all models, and particularly aerobatic models, do ensure that the tailplane is big enough. For aerobatics you will probably want a fairly rearward CG which will tend to make it a bit sensitive in Pitch. Therefore the tailplane needs to be big enough to have "authority" over pitch. Also, if you look at an arrow or a dart with their flights at the back, a bit of extra drag at the back only helps to keep it flying it the direction it is pointed....... I have designed many aerobatic models and I go for a tailplane area of about 26% of the wing area. Paul

"Good strong glass fibre fuselages Paul? Sounds like shades of Pat Teakle to me. " Percy, Pat was certainly another regular at Crook's Peak......... Is he still flying? As for "good strong fibreglass fuselages", I used to make my own and didn't stint on glass or resin. These models were certainly not lightweights but they did the job! Paul   Edited By Paul Jefferies on 03/05/2015 22:17:34

Back in the mid 70s (was it really 40 yrs ago?!) I was into slope soaring and slope Pylon Racing in paticular. With four models racing up and down the slope in the same bit of lift Mid-airs were very common, an occupational hazzard you might say. So I designed my models assuming that they would be involved in collisions with other models and if and when it happened I wanted my model to sustain as little damage as possible and hopefully to keep flying. Weight was generally not a problem, indeed we often carried ballast, so they had good strong glass fibre fuselages and the wings had spruce leading edges and spars, had 1/32" ply leading edge sheeting top and bottom and were covered with nylon....... 'Flying battleships really but they did quite well and I don't recall one ever being "taken out" by another model! Paul

Apology for Absense..... 'Fraid May 10th is too short notice and I am already committed for that day. Paul

Another idea!............ Could you mount the DF unit in the reverser so that the reverser slots would then become the main intakes? I guess that could present a weight/balance problem but maybe you could move the battery further forward......... Paul

How important is the length of the tailpipe? I have never played with ducted fans so forgive me if this is a silly idea......... Could you have a shorter tailpipe, the tail end of which is supported just forward of the reverser slots? You could even find that you get an increase in trust as the eflux is "augmented" by the air entering through the reverser slots......... or maybe not. 'A great opportunity for experimentation! If that is not doable, with your present setup it could be that there would be a build up of pressure in the "reverser" and that in itself would prevent any further air from entering and the outside airstream would simply flow round and over it........ maybe? I think I would try it and see how it flies.......... Paul

I suggest you keep an eye on ebay, such things do turn up from time to time........ Incidently,  I suspect that your beloved baby wasn't turning at 22,000 rpm but at only half that figure.  Reed tachos can respond to harmonics of the actual figure so I think your Atom was turning at 11,000 rpm but your tacho was reading twice that........  If you look at R.H.Warrings test of the Atom (http://sceptreflight.net/Model%20Engine%20Tests/J.B.%20Atom%20%282%29.html) you will see that it proced it's max power  at around 11,000 and ran out of breath long before it got anywhere near 22,000.  'Still,  I enjoyed your story,  memories are made of such stuff and I wish you luck in your Quest.  Paul Edited By Paul Jefferies on 05/04/2015 08:51:51

Peter, it would be possible to descend faster but if you have, or suspect, structural damage, you would restrict your airspeed which would also limit the rate of descent. Paul

Speculation, speculation...... We know it is wrong, pointless even, but we all do it. I think we can rule out double engine failure because if both engines failed it would probably glide with a rate of descent of around 1500 - 2000 ft/min. and it descended at a much greater rate than that. The indications seem to be that it was an, at least partially, controlled emergency descent (for whatever reason) and for some reason it did not pull out........ So what are the likely reasons for an emergency descent? The one most commonly practiced in the simulator is loss of cabin pressure but on it's own that would not cause what has happened......... Unless perhaps the pilots did not don their oxygen masks or maybe their oxygen supply was empty or in some way faulty? Another reason for an emergency descent could be some kind of structural failure, which may also have caused the loss of cabin pressure. A door, cargo hold or some other hatch blowing open would do it. This is what happened to the DC10 that crashed in Paris in 1974......... A cargo door had not been properly closed and under pressure it blew open. With the sudden loss of pressure beneath the cabin floor the cabin floor collapsed, taking with it the elevator control and no doubt a lot else as well. Much was learned from that accident and door closing mechanisms and control systems have been extensively redesigned so that in theory such a chain of events could not happen again but the point I am trying to make is that in a catastrophic failure, you can never be sure what other systems might be taken out as a consequence........ I heard at least two reports from people on the ground, who had heard but not seen the accident, that they thought it was a small earthquake. From my limited experience of being in an earthquake, they may have heard a kind of "rumbling" sound and if so, that could indicate either a door or hatch coming open or possibly detachment of some panel, hatch or even a control surface. I did hear that the Americans had said that it was unlikely to have been caused by terrorism. How can they say that at this stage unless perhaps they know something that they are trying to hush up. I'm afraid we live in an age in which the possibility of a terrorist attack cannot be discounted at this stage in the investigation. Why did the pilots not call ATC? My guess would be that they just about got the descent sorted out and then passed out due to lack of oxygen. ALL of this is pure speculation and I'm afraid we are just going to have to wait and see what comes out of the investigation. Paul There

Thanks Dom, 'very nice, it certainly looks the part. By way of an F16 anecdote, I once met an ex RAF pilot who had done a temporary secondment to the USAF and had had a ride in an F16.......... He said that they came burning down the runway at zero feet and then pulled up into a loop, the top of which was 29,000 feet! Now, that's what I call performance! Paul

+ 1 for Thunderstormer........ The Stormer had a shoulder wing. Paul

"By the way, that barrel has the same pilot jet and ball link that my carb has" OS No.7 used on my 61VF........ 'Bit grubby I'm afraid because they've been sitting in my bits box for rather too many years! Paul

As promised a pic of the OS sleeve...... These are the only two I could find, one is thicker walled than the other. Very simple to make out of a bit of brass tube though the diameter/wall thickness could be an issue. The tube needs to very slightly oversized and then the slit down the side makes it possible to squeeze it slightly and push it in. You have to remove the spraybar to get it in there and then when you put it back the spraybar holds the sleeve in place. I found it did not significantly restrict the power but it certainly did improve the "suck"! Paul