M61A1

You are probably right, but an electric motor is a fraction of the weight of current aero engines.When/if power, endurance and cost become competitive, designers will be freed from current limitations caused by a heavy engine and liquid fuel.

Boeing have been working on a hydrogen fuel cell that is very promising. They have had UAV's in the air for extended periods using the fuel cell and electric motors. I think that this will be the best option. The hydrogen fuel cell just makes electricity, then use a large brushless motor (high torque/low rpm) to spin the biggest prop you can physically fit. It's been done, it just needs to become affordable.http://en.wikipedia.org/wiki/Hydrogen-powered_aircraft

 

 

And I'd rather do screw and locknut than either. Its not the actual valves that are the problem but more the fact that you need to dick around so much with the bodywork, tank, and engine perhipherals before you even get the the valves.I'm just not a fan of Ducati maintenance logic. My old XR600R, for example, had two bolts to remove the tank and then you were at the valve adjusters after undoing their caps with a large adjustable wrench or 27mm spanner. WHole process including an oil and filter change took 30 minutes. Thats servicing logic.

 

As for racing, they do still do well, but Yamaha and Honda are the ones dominating GP races, and Aprilia and BMW are killing the Superbike field stone cold.

 

- boingk

That's not really comparing apples with apples. The Honda equivalent of most Dukes would be a CBRR (add more Rs if necessary) or an R1 if you're into Yamaha, now there's a pain to work on. I used to have a nice little Pantah, in 10 minutes, I could have the engine out and on the bench. Part of the beauty of the trellis frame design. I concur with Koreela though, the Guzzi in my 95.10 is very simple to maintain ( and it sounds good). I had someone ask the other day "is that your plane that sounds like a ducati going past?"(cruise @4800rpm)

Not cool Adam. Not at all cool.If your child's mum says no... IT IS NO. Don't be silly and muddy things with Lawyers etc

Suck it up and think of your kids.

That is exactly the sort of attitude that has caused a lot of these issues, meaning the idea that you can only do what mum says. These sort of partners need to be stood up to and put in their place, because if they're not, they continue to dictate everything (been there, got the shirt). You are right in it being about the kids, and of course an amicable solution is best, but, there are many separated couples out there who have one parent who will continually dictate the rules, yet refuse to be dictated to them selves. Mum's word is not he last word. Kids also need to know that someone will stand up for them if necessary.

haha missed that! good one, now to sit back and watch ;)Watch what? He's probably still scratching his head thinking of a reply that he can put on here without incurring wrath.

I'll have a go at replying..........in a factual and sensible manner.A good example of the truth in his statement can be seen any time a so called "legend" or "star" shows up in town, and there hundreds of young ladies who would gladly be of service because of "who" he is.

Occasionally in the media you will see a woman who believes she has been wronged because she slept with someone and parted with money/posessions then found out he wasn't the "legend" she thought he was, and that she wouldn't have done any of these things if she had known he wasn't rich/famous.

 

Let the "flaming" begin..........

 

 

One of Larry's clips showing a bit more of the engine installation.

 

 

 

Well you know ...female pilots and all.........................................................Maj.....

You might want to google Svetlana Kapanina.........

Its also an outdated technology from an era when you started to get valvefloat at 6,000rpm or so as they didn't have the materials needed for good valvesprings.They're also a massive pain in the ass to service... much prefer Hondas or BMW's in that regard.

 

Do sound good though!

 

- boingk

Well they still do well in competition, and I've never had much trouble servicing them, all you need is basic maths and a micrometer, in fact I'd rather do desmo than bucket shims.

One year at Bathurst I got to hear the difference Desmo makes. A couple of Ducatis in company with a pair of Moto Guzzi 850 Le Mans fitted with Conti pipes. Both 90 degree V twins of similar capacity. As they hurtled down to Forest Elbow and powered out down Conrod we got to hear the most beautiful of engines. Despite their similarity, the Ducati was quite distinctive.

I think the distinctive sound comes from the way the desmodromic system has a much steeper ramp up on the cam. The valves open faster and stay open for longer than a similar valve spring system.

Ducatis are proper motorcycles.

Damn right. gotta have a 90 degree V and desmo valve gear to make the right sound.

Personally I feel that the suitability critera should include the applicant being a current active UL, or recreational pilot, and a paid-up member of the RAAus or AUF for at least five years, (10 would be good). He/she should definitly hold a current RAA pilots' certificate with some endorsments. there should be no preferential selection treatment given to an instructor or cfi, and certainly no preferential treatment for GA only pilots, or CASA people. Tried that ...didn't work..I have no preference to either gender, Jill Bailey for instance would be the classic example of what I'd be looking for ..................................................Maj...

I personally think that these sort of criteria should be 'preferred but not essential', the essential stuff would be engineering quals and a good understanding of quality processes. It's not enough to love aviating, the right people will be able to work in a process based system. That is where we have been let down in the past, all the good intention in the world will get us nowhere if it doesn't comply with the system. Regardless of common sense (and I really hate to say that), boxes must be ticked, I's must be dotted and T's crossed. So what we need is box ticking, pen pushing legal/accountant types.

I dont know if this will help in you efforts, it was posted for me on another site, I found it useful. Apparently came from a Boeing design engineer some years ago.

 

 

 

Well, never judge 'by appearances' is my first tip. I don't know why the police came into this thread either, but seeing as they got a mention, many P platers I see appear to be driving faster than most others and by virtue of their inexperience, pose one of the greatest risks to themselves and in turn, others.I doubt the abilities some older drivers too, but don't see much extraordinary ability in detecting 'a driver having problems controlling a vehicle' from a km away if they are clearly of advanced age. I wouldn't think there would be much skill required in avoiding them either. A weaving P plater on the M1 travelling at high speed on the other hand....not as risky than grandad in the Holden?? You lost me....

When you get a bit further west,(I imagine you are well aware at Roma) the the one that crosses over in front of a road train is far riskier than the 'P' plater doin 3k's over. I witnessed what was almost a multi vehicle collision the other day, when and older woman doing 35 k's pulled out of a side road in front of a road train and other traffic doing 80. Which sort of illustrates what I was originally getting at, I could tell from a distance that this particular driver was incompetant (without knowing sex or age), which made me hold back because trouble was coming.I could write a truckload on this subject, but essentially all I was meaning for aviation purposes was that with a little experience you begin to see problems before they get too advanced.

The only reason I mentioned our police, is that I regularly see them ignore drivers who very obviously incapable.

 

 

Call me curious, but wish the Police would learn what??

Should be a completely different thread......After spending some considerable time in QLD traffic, it's not too hard to pick from quite some distance, someone texting or talking on the phone, smoking while driving(they all follow the same pattern), with depth perception problems, and the ones who are paying absolutlety no attention to the traffic ahead.By appearances QLD police would rather pull over a 'P' plater doing 3 k's over, or nothing wrong at all (I haven't been one for years) than the older guy that has obviously poor eyesight, and is incabable of staying between to white lines 3 metres apart.

Essentially, what I was trying to say, is that if I can detect a driver having problems controlling a vehicle from up to a Km away, why can't they?

 

The aviation side has nothing to do with police, just suggesting that with experience you begin to notice little things that tell you something is going to happen shortly.

 

 

I am a great believer in the adage that "you make your own luck'. The trouble is that despite YOU doing the right thing some complete idiot comes along and puts you into the next world, because he/she can't be bothered doing the right thing. Like texting while you are driving. Nev.

I agree that you can make your own luck......I have found you can most of the time, although it's not completely foolproof, also learn the signs that indicate one of those "idiots" is about, and take measures to avoid them. Something I wish QLD police would learn.

The spare engine has to working on the plane, so it's not really"spare". The trouble with small multi engined planes that have off centre engines they do require some precise flying to stay alive, when one stops. It is very unbalanced and a plane thst was going quite nicely now becomes something that has no real surplus of power at all and is not too easy to control as well. However that is mostly a big problem if it happens on take off. Your twin would be OK over "tiger country". but too costly to own and train on. Nev

I am very aware of the marginal performance of most small twins, the point was, without another means of sufficient power, why would you fly over tiger country at an altitude that gives you insuffient glide range just for the fun of it? And that doing it with a four stroke really isn't any better.

Ski

 

Skimming treetops over tiger country in a 2 stroke, natural selection at work..... They were lucky

One might also argue the natural selection case for people doing the same with a four stroke engine, the safest way to fly over tiger country (if you must) is to have a spare engine.

I wouldn't think so, dazza; unless I'm mistaken the Texans ran an R-1340 Wasp engine rated to 600hp or so at 2250rpm. That turned a 9ft / 108in prop through a 3:2 reduction to give 1500rpm at max power. This would give a tip speed of about .61 mach. If you overrev the engine to 2500rpm you'd be at around 1670rpm at the prop, giving .71 mach for tip speed - that is in the transonic region and would be making prodigious amounts of noise... but nowhere near supersonic.Cheers - boingk

You need to also factor in the aircraft airspeed on top of the rotational speed of the prop.

Hi M61A1I got in contact with Arthur Marcel he has his saphire hangared at Forrest Hill there are 2 hangars there and 7 aircraft. The strip is marked on the VTC and I used it as a turning point on the way to Lynfield. I did quite a few circuits at Bradfield when I was doing my pilot certificate training its a nice airfield. Arthur has told me how to get there by road etc it is about 800 mtrs long so heaps of room for my aircraft. Going to testfly her with the new CG on sunday so hopefully she goes as I expect which should make the stol performance better. I have to get all the women together to find the actual day I will be doing the taxi run but it sure beats driving to laidley again

 

Mark

Glad you found it. There must be a lot of strips around there, I've done a bit of driftering from Kev's, I know of at least 4 just off the top of my head.

No Kevins airfield is called Lynfield I have flown in and out of there infact did my pilot certificate test with Kevin there and if you havent been in and out of Lynfield you need to it will get all your skills happening at once. Forrest hill is about 3 or 4 nm northwest of Laidley. I flew over it as a turning point on one of my navsMark

I am familiar with Forest Hill, but not of any 'public' airstrip there, I suggested talking to Kev, because if there's one there, he'll know, if not he could probably help with his (Lynfield) or the nearby "bradfield".

m61A1 . I did not intend to imply doing it in that order. You need to balance the two carbs then adjust the mixture. The mixture is sensitive to the throttle butterfly position so if it is altered the mixture screw may need an extra adjustment subsequently. You should probably start by making sure the butterfly is closing fully with the idle stop screw backed off sufficiently. You may have to "centre" it by loosening the screws and retighten them with the butterfly fully closed. The carb will have to be taken off to access these screws. A lot of people don't check them carefully, but it does affect idle. Nev

No, but I was implying that, that is the best way. I do agree though that it pays to check your throttle butterflies, and often, yes adjust the idle mixture again after balancing. Keep tweaking back and forth until you get no more improvement.

I am looking at taking my grand daughter out to some relatives at Laidley to stay for some of the school holidays I think the closest airfield is Forrest Hill. Can anyone tell me if anyone can land there or is it a private airfield?Mark

Give Kev Walters a call, he'll have a good idea on what's what in his locality, he's on the RAA website under Walters Aviation (I think). Also, if he can't accommodate you he could put you in touch with the people at "bradfield" airstrip a few minutes away.

Putting the load on the engine will change the vaccuum. I think your mixtures are out just at or off idle. Keep clear of the prop and play with the idle mixture screws. They don't have to end up an equal number of turns out. Your throttle stops should be set equally to flow the same amount each carb. ( balance) Then ensure the cables actuate together for when you come off idle. I don't think it is the prop. Nev

Just to clarify- The mixtures screws should be adjusted to achieve best idle, then the balancing is carried out by adjusting the idle stops ( make sure your cable adjusters have a small amount of free play so as not to interfere with the idle stops) to achieve equal vacuum, and then adjust the cables to make sure there is equal vacuum ( or as close as you can get) as they open.

If you mean using a manometer - noBoth carbs are set as near as damn it identically and the engine runs ok without the prop.

No - wish I did have another prop to compare with. I'd thought of that one as well. I was thinking of trying a two-blade prop.

 

Paul.

I would look at borrowing a prop if possible, just to rule out or confirm harmonic vibes. Also try to balance the carbs with a manometer or vacuum gauges, the extra load of the prop could bring out carb balance issues that are masked without load.Good Luck

 

 

Hi All,Is there anyone out there that can assist with a problem I have setting up the engine in my Zodiac 601?

The engine is a Tom Wickers conversion with twin Bing 64 carbs. Prop is a new Bolly 72 x 60 three blade.

 

The prop is set at 13 degrees pitch. The problem I have is that the damn engine almost shakes the airframe apart at anything under about 2500 rpm. I've carefully dismantled the carbs to check for crap in the bowls - clean. I've removed the idle jet in each and made sure they're not blocked. I've checked the setting of the idle adjuster and set both to 1 1/2 turns out from fully clockwise. Still no good. Yesterday I took the prop off and ran the engine. I slightly adjusted the timing to give smooth running at 1500 rpm which gives a prop speed reduced by the rotax gearbox to about 700 ish rpm. Without the prop the engine runs ok but putting the prop back on causes the shaking. It's only at low speed though. My logic suggests the prop is ok as at high speed it's ok with little vibration. Anyone got any ideas? This three year build is tantalisingly complete but for this problem. Don't suggest buying a Rotax - had I the cash I would have!

 

I'm about to check the prop balance although the Bolly figures supplied suggest it's balanced perfectly.

 

HELLLLLP !!!!!!!!

 

Paul

1. Have you balanced your carbs?

2. If it's in that one rev range, it could be harmonics.......and that could be nasty, do you have a wood prop you could test it with?

 

 

With a wing loading like that the whole plane is a recovery chute. Nev

I thought the whole point of the recovery chute was for when the wings were no longer "loading".