Peter Jenkins
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Posts posted by Peter Jenkins
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Tony
Have you checked the wing and fuselage for any twists? If you have any then you will have a constantly changing trim condition depending on airspeed. You will be able to trim for one speed and then increasing or reducing airspeed will cause the aircraft to go out of trim. Side thrust, as you mentioned in your first post, could also contribute to this. Easy way to check, once you've resolved the twisted issue, is to pull to the vertical and keep going straight up and see if the aircraft will track straight for at least the first 5 secs. If it goes left you will need more right thrust and vice versa.
Good luck.
Peter
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What I find best is to think about what I want the aeroplane to do or not do. For example, a Wot4 has very strong secondary effect of rudder i.e. left rudder leads to an almost instant left roll. If you want to do a slow roll and use the rudder as well as elevator to get a nice axial roll, you need to kill the secondary effect of rudder. To put it another way, if you apply rudder you just want a yaw and not a roll. Say you apply left rudder and the aircraft rolls left then you want your ailerons to compensate by rolling right so that the rudder induced roll is neurtralised and you just get yaw. Does that make sense?
Well, first rule of mixing is to make the mix value high so that you can see if your mix is going in the right direction. For the rudder to aileron mix you only need a very small amout of mixing - usually less than 5% so it's important you set it the right way - how do I know? The second rule of mixing is to use a switch to bring it in and to try it out at a safe height!
I find that helps with when I'm trying to put a mix in place. If this helps fine, if not just ignore this.
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Skippy, you raise a good point about the fear of trying new manoeuvres with a crunchie model. I see people trying to fly new manoeuvres when they are not 2 mistakes high and when they get disorientated part way through they either frighten themselves or prang the aeroplane. Most problems can be resolved if you have enough height to begin with. I was going to say all problems but there will always be equipment or structural failure to which there may be no solution. So, stay high till you are confident that you will not need the safety margin.
On the main topic, I think that people who fly on their own will find this Apprentice a god send. For club pilots, it may help but if you have a good instructor they are better. They can at least tell you why you got into that odd position rather than just relying on the Panic button and not knowing why you ended up in that position and what was done to recover the situation.
A further thought concerns a learner who cannot get out to fly regularly. I think these aids would help them to feel at least they are making progress and so encourage them to keep flying. However, they must wean themselves off these aids before they can be considered safe to fly solo or attempt an A test.
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Too true. The Irvine 53 is, in my opinion, the best of the breed at that size - OS included! Which is odd because OS manufacture it. That's probably why it's not back in production, although I did hear that the factory was demolised in the Japanese tsunami. Any one know if OS are going to re-start Irvine 53 production?
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Pete
Just to say that I'm using Win 7 (32 bit) and it's running both Chrome (Version 28.0.1500.95 m) and IE (ver 10). I have not cleared my cache but everything is working fine in both browers.
Of course, the majority of users out there will be wondering what the problem which is not to say I don't sympathise with those who have the problem.
It's so annoying when things go wrong with software provided by the big boys because you never know whether they have or are working on a fix, who's got the fix and when they are going to implement it!! Leaves the small fry, to try and produce the work rounds. Well done on the way you are handling these issues.
Peter
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If you use JR servos, they all come with a warning not to use 5 cell Receiver packs as the voltage will be too high. Some people get away with it but I found that with a 5 cell pack my JR servos just chattered away. They were fine on a 4 cell pack.
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Hi Chris
Yes, washout will reduce the total amount of lift but it will be a trade off where you will avoid a tip stall as the centre section will stall first. So provide your approach speed has a decent margin over your stalling speed you will be fine. Obviously, carry out a check of stalling speed at height and do several practice approaches. Pick a day with a bit of breeze and your ground speed will be signficantly reduced so the higher airspeed won't look so ....high!
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Chris
An easy way to achieve washout is to set both ailerons up slightly when at neutral - if you see what I mean. Try the stall at a sensible height with different amounts of up aileron to determine an optimum position for your "washout".
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You will find an interesting trimming article here **LINK** .
Note the importance of getting the CG correct before moving on to any other trimming work.
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Danny
The first thing to do is to move your Rx battery, or flight battery if lecky, to achieve the change in CG. If that doesn;t achieve the required change in position, I then use sticky lead stuck as far back as I can manage - just in front of the rudder on the fuselage is a good place. I use the sort of sticky weights they stick on alloy wheels when balancing them - tyre fitters are a good source for such weights. They come in 5 gm and 10 gm sections.
Safest way to determine your margin of safety is to pull the aircraft into a 45 deg climb and roll inverted. If you have to push a lot of down elevator in to maintain the 45 deg line, your CG could be moved rearwards. Do this a little at a time until you find that you need a small amount of down elevator to maintain the 45 deg angle. If the aircraft continues on track without the need for any down elevator, your CG has moved too far aft. Worse still, if you need up elevator to maintain the aircraft attitude (remembering it's inverted, you need to move the CG forward - quickly! You are a short step away from an unstable aircraft and you don't want to go there.
Once you gain confidence in moving your CG from the recommended position, you will be amazed at how you can adjust the feel of your aircraft and how much better it can fly if the CG recommended is not in the best place. Two identical aircraft with different CG positions will feel as if they are quite different. One will fly really well while the other will fly but will be hard work!
Give it a try and you'll be amazed at what you can achieve. Remember to experiment with small changes in CG at any one time!
Good luck
Edited By Peter Jenkins on 14/08/2013 23:17:21
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I became quite a Hitec servo fancier till I found that for precision aerobatics they just would not centre accurately. This is very noticeable in a full F3A machine. Fit only Futaba or JR I was told and even then only specific ones. My first proper setup has all Futaba but it looks like my second one will be all JR. Savox and some Spectrum servos also seem to find favour with accurate centreing. So, for which make do I vote. Well, as I seem to have more Futaba servos than any other, that's what got my vote but better outcome would have resulted if we could tick two boxes!
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Don't forget that setting up the initial CG position is only the first step. Check the flight characteristics and adjust as necessary to achieve the desired characteristics. I have found that most folks leave the CG alone after a "successful" first flight. However, remember that sometimes the stated CG is either wrong or merely serves up a far too foward CG position. Why does that matter? If you want a nice aerobatic sportser then having a forward CG is going to lead you to thinking that the aircraft is a pig to fly - indeed, you might end up with insufficient up elevator to produce a decent landing. I have found this on a number of aircraft that I've been asked to test fly. CG position is one of the most important factors when determining how you want your aircraft to fly. Experiment to see how moving your CG from its initial position achieves better (or worse) results. An optimally positioned CG will give you an aircraft that is a delight to fly - the obverse is also true!
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As an additional safety precaution when dealing with electric motors, I always remove the prop when first setting up the radio. There is no need to restrain the model in this instance since even if the motor went to full power the model won't move - unless it's precariously balanced on something and the torque of the motor starting causes it to fall off.
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Martin, from the photos I've seen taken in cockpit for full size aeros, the ailerons get used as well as the stick gets rammed into either top or bottom left/right corners. I find that sticks in the corner, apart from the throttle that is, works for me. My Wot4 flicks so fast it's difficult to stop it for one flick. Two flicks are easier. My F3A machine is much easier to stop as it resumes normal flight almost as soon as I return the sticks to their normal position so it's quite easy to do 1/2 a flick even.
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Hi Terry,
Yes it's a red Hanno pipe that I managed to get 2nd hand. Motor and Rotors do ST engines still and may have spares for the older ones - but I've yet to find out!
As for the Veco, it came without the exhaust restrictor so it has two holes on either side of the exhaust stack but a friend has volunteered to "sort it" and get a silencer on to it. Until I try to run it, it will not be clear if all the internal bits are still OK. It feels OK so I'm hoping for the best. However, it it proves to be severely damaged internally, then I'll stick one of my Irvine 53s in and even though that will be more powerful than the original Veco 45 I can always run a big prop on it.
Before I started building my Gangster 75, I traced round all the parts as well as the wing root and tip sections so I would be able to make myself a kit of parts if the worst happens. Mind you, I'll need to remember to cut the parts to the inside of the pencil line!
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I got the last Tauros kit from Jeff and have got a Veco 45 off e-bay that is being worked on for me at the moment. Always wanted a Taurus so I'm over the moon with having one after 50 years of waiting! I've got a couple of other build projects to get done first so I don't expect to have the Tauros built until mid 2013. I'll stick some pix up when I'm done. One of the projects before it is an original Gangster 75 kit with ST90 and Hanno Pipe - should have unlimited vertical!
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I'm in the 1% as I fly F3A. Once you've flown a 2 mtr F3A nothing else comes close to the flying experience. I do enjoy flying my trusty Wot 4 which has become even more fun after fitting a pipe to my Irvine 53. I do have some scale aircraft but will wait for the better weather to fly them. You can fly 2 m models in almost any weather but I draw the line when the wind exceeds 20 mph constant!
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Anyone tried Frog tape? They claim to have eliminated any paint creeping under the edge.
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Skoda Superb Estate! I can get a 2m F3a fuselage in behind the front passenger seat. I had my Capiche 140 in it this evening and that is 2010 mm but by deflecting the rudder slighty that fitted fore and aft without a problem! I had a Saab 9-5 estate before (loved it) but could only get the Capiche in by having it across the loadspace which made it very difficult to add other airframes. My diesel engined car gives a calculated 46 mpg while the on board computer states it as 52 mpg. Still not bad for a big estate!
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Just a point about rearward facing seats. The RAF specification required the floor to be beefed up as the seats exert far more force on the floor when the aircraft is under heavy decelleration. Just about your whole body weight is being restrained, including your head (heavy and a long way from the seat support) so the floor has to be stronger and heavier to stop the seat being ripped out. That means less payload and that's why commercial airliners don't do it. The other reason is that the safety record of airliners is such as to make the risk "acceptable" and none of this matters unless the aircraft hits the ground in a survivable fashion - as was shown in the programme. You may have also seen the earlier NASA attempt that went badly wrong when the pilot flying it remotely appeared to get out of synchronisation with the aircraft and piled it into the ground in a totally unsurvivable way. No rear facing seat was going to help those passengers!
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I've been using an XG11 for a couple of months and I've very pleased with it. I used to use a JR DSX9 and while that works very reliably, particularly with the JR RD921 and the Spectrum 9010 it does seem to take a long time (3.5 secs av) to reconnect if you lose the signal. The XG11 is almost instantaneous when the Rx is powered on - very comforting.
I'm still working through the varous clever programming bits and the Stick Position Switch is showing some promise but I'm trying to find out if when you use this to switch in more control movement if you can programme a curve as opposed to a sudden increase in control surface movement. Anyone know how to achieve this?
Thanks
Peter
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Graham
Buy servos that can provide you with a reliable centre. I fly 2m F3a aircraft and had problems with Hitec servos as they did not return to exactly the same place when returning from different sides. Futaba, JR and Savox servos are favoured in F3a circles but you could probably get away with the Spectrum digital servos some of which have received a good press. I have had problems with some Spectrum servos when used with more than 6 volts so check your Rx supply voltage. For the 2m standard, ESCs don't have a BEC so a separate battery is used for the Rx and servos but you can probably get away with the BEC supply at this size.
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Count me in. I'll have to get a move on with my Gangster and Tauros!
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Martin
Thanks for the advice. I am really keen to get the Tauros built and really would like to use the Veco 45 (bought on e-bay!) but I'll probably need to spend some money on getting the Veco going and getting a silencer made for it. Thanks also for the link to Ed Kazmirski's description of the Taurus development philosophy and trimming tips in MAN Jan '63 - very interesting to read.
Peter
Competition Flying
in UKCAA Chat
Posted
Having read the very interesting thread on classic aerobat photos and come across some harsh words on today's F3A scene I was going to put my viewpoint but as was rightly said, it needs a new thread.
I decided I wanted to enter competition aerobatics and after trying for 10 years to get my B finally achieved it when I retired! My first taste of competition was at the Seb Art Cup competition held alongside the first European Cup F3A competition. The rules were that you could only enter if you'd never flown in a competition before. So, I took my Wot4 along and was faced by mostly Seb Art Angel 50s or Winds S 50s. There were 10 competitors and I made 7th place with my Wotty. Yes it was a bit nerve wracking but also great fun and I learned a lot. I also saw for the first time proper F3A machines being flown by the best UK and European pilots - what a revelation. I want some of that I thought.
Well, the GBR/CAA has been extremely helpful to me. There is no sign of elitism and you couldn't meet a more helpful or likeable group. So, I would be really interested in knowing what has triggered all the negative views that have been expressed.
Cost of entry to fly in Clubman is - take your current aerobatic plane along and compete. Yes, there are not many in each of the lower classes but that's a direct result of folk thinking they need to be super pilots to fly in a comp. You become a much better pilot by flying in competition and you certainly reduce your crash rate which saves a good deal of money during the year!
I have run 2 New Pilot Open Days under the GBR/CAA banner and got financial help from my local Area Committee. Experienced GBR/CAA pilots come along to mentor the newbies. The 20 pilots who entered these found them to be a great learning experience and at least half of the last NPOD would have entered the next Competition - sadly that had to be cancelled. The point about trying to get more pilots involved is that we can then have more local competitions and thus build up the number of competitors who will then swell the ranks at the Nats and perhaps we will need more than 1 flight line.
I appreciate that the allure of some of the classic aerobatic designs is that they are cheaper than having to shell out for today's ARTF F3A composite planes but this is not always the case. I should say that I have a Gangster 75 in build and a Taurus kit waiting for my recently acquired Veco 45 both of which I intend to bring to a UKCAA event in 2014. However, in the class in which I'm currently flying, Masters (one down from FAI P), the winner was flying an Angel 50. Bears out Terry's point that the most important factor is the pilot. You could probably get a new Angel 50 up and running for around £300 if you make maximum use of some of the new Turnigy motors and ESCs. Furthermore, Extreme Flight entered the market with a cheap 2 m F3A machine, the Vanquish, which I bought and got airborne with all new stuff for £1,250. Yes, that's expensive but probably equates to the loss of 4 decent sport aerobatic models in the year - something that is quite common in today's climate.
So, it is sad that people express views based on what they think about other parts of the sport without finding out what it's actually like today. Other countries have thriving F3A scenes but for some reason we seem to have shrunk. I know this is something that the GBR/CAA is actively discussing with a view to improving the situation but the best way to improve it is for people to come along and have a go at flying in today's F3A competitions without first going out and spending a load of dosh. A well trimmed reasonably aerobatic airframe (Acrowot for example) could be a jolly good performer in Clubman but you do need to practice!
OK - stand back for the incoming.
Peter