AVOCET

The way things at going you'll need a tatto endorsement befor you can fly with it ( I spose you could always keep your sleeves rolled down )

Apart from crank balance , i found that a poor fuel distribution can feel like something's out of balance . Changing to multipoint fuel injection made a huge improvement in smooth running ,

Also balancing the prop on the engine ( dynamic balance) also takes pistons , rods , and every thing else that moves into account,

Pulling down a new engine and only doing the crank only does half the job ,

Cheers .

What's the history with the engine?

If you are talking rigger's angle of incidence ( which I assume you are) changing it will mainly affect the fuselage attitude in flight. The wing works the same.For a wing to lift at low speed , it needs lift devices like slats/slots for the Leading edge and efective trailing edge flaps,( slotted or fowler) or have "blown" wings. Other wise it will have a lot of area and a thick wing section, all of which mitigate against fast cuising. Nev

That's right , if you change the angle of incidence ( what your calling pitch ) will only change the position of the fuse in flight ,

The wing will always want to fly at about 3 deg . To the air flow .

In the situation you suggest ,as the aircraft left the ground (as you say 10deg pitch) it would pitch the the fuse down and Probly scare the "be -Jesus " out of you as the wing settles back down to 3deg ish

Cheers Mike

I'm grab'n my 7th. April 2013 rego sticker and making the 3 into an 8 , stuff em , now it's registered to 2018 ,then 2 months later at YBUD ....

Said I'm still waiting on my rego and I'm about to .........

Have you got you rego yet?

I think that thickness is only slightly thicker than the thickness of a Coke can. That should be pretty light.

I've also just sloshed fibre glass tanks with a product called "BILL HERSCH"

" gas tank sealer" , it's tested with ethanol , & alcohol at 80% for two years , a place in Sydney sells it , don't know about 2 stroke though.

I got 4quarts on e bay for $ 123.90

Google " fuel tank sealer , for the specs

Cheers Mike

I've found on the jaby type U/C that grass or rough ish dirt strips really vibrates the U/C ,on the avocet you get a good view of the wheel & leg and i was suprised how violent it moves back & forth ,even on the taxi , it looks like the bolts are loose . I would think this has a fatigue effect on the bolts , as I have replaced several over the years with slight bends .

It used to be the back bolt on the old Jabys

Doesn't seem to be as much of an issue if they are only used on the Tarmac .

Cheers Mike

SDS is a grate multi piont FUELINJECTION system and Ross is a great guy to deal with . The difference it's makes to smooth running is to second to none , coupled with liquid cooling , seems to be the way to go ,

Bex better, one tablet add water and fuel ,then fly ,,, I feel better already

Did you miss the laffing face by chance? It was a joke.But fair question anyway - I am slowly gathering components and intend for 25 engines to be both bench tested to death and appointed to various flyers for testing in various configurations.

 

I won't get into Jab engines other than to say I am looking heavily at cylinder head solutions for them.

Anyway,

I think what your doing is absolutely great ,

And if your looking for any help , testing , flying , installations , ect . I'm interested in engine options for further development for the Avocet & I think it's important to support Australian endevour ,( just got a set of EQ headsets , go Aussie go )

My be we could talk ?

Cheers mike

For how long?So what your saying is that this new engines going to work and stay working straight out of the box , I wonder if you'll have to eat your words (for how long?)in a couple of years or so ,

Who what ware when ????

If the nose wheel is faired then it would have a more significant effect. It certainly is large enough to cause a deflection in any case. Try holding something of comparable size with 10 degrees deflection out the car window at 100 kph ( or don't, but you see what I mean).

I agree , I've had the same issue when test flying new aircraft , it doesn't take much mis alignment of the nose wheel to rudder to upset the balance , it's even more pronounced with a front spat .

What I've done is get the plane to taxi straight with the rudder peddles in the neutral position & then offset the rudder 5 mm to the left or right ( depending on tractor / pusher ect.) flight test , and adjust accordingly ( you have to think it through which way to ajust )until the balls in the middle . This assumes that the wing & flap incidence are correct

Cheers Mike

I doubt that man will ever be able to imitate that.As for keeping it up................................lol. Oh, you're referring to 'the good work" Sorry.

 

I need an experienced design engineer to do the cradle. My attempts to incorporate thrust bearing(fore and aft) are somewhat childish and probably non workable.

The thrust bearing for a crank shaft isnt that difficult to reproduce on your boom , chech out the jabiru manual ,( that'll Probly keep you up tonight , sorry,... not) .whatever you do you'll have to incorporate some form of lubrication IDE imagine ?

My Son has designed a planetary gearbox for contra rotating props that mounts on a boom . He has a working virtual modle that has impressed his mech engineer uncle ( believe me that sayin something !)we are going to get (build ) a 3 D printer to make the prototype

So as soon as the Avocets up & sorted ill be starting on the light weight motor glider.

I need something cheep to run &

fly / glide around the Flinders on those glorious days .ide really like to go electric , or solar

Cheers

How about this configuration?

I was thinking the tractor arrangement would work well for c/g. The prop arc of many twins seems close to the cabin.

I've had a look at the c/g and it will work as a pusher , better assametrics as well .

Pushers work well ,especially with liquid cooling,

But the wings are too short for a glider.

One waiting for the batteries to get cheeper & lighter , & more reliable ,

The Avocet looks to be the ideal platform for a twin - wing mounted engines. It would be a very pretty aircraft and would really perform.

Yes I agree , it's possible to modify the 250 wing to mount engine pods , however as a tractor the prop arch's a bit close to the cockpit , same with the turret mounted tractor ( this my original design , but the prop arch was right over the top of you head ,not a good sales piont !)

So as a twin IDE go for a pusher setup ,

Could be 2x rotax , or D motors , or 2x 2200 liquid cooled ,

It's a great idea , just need some one to put up the $$ (maybe a few more ) and we are off , any time your ready ,

Cheers ,mike

Hi Phil , good to hear from you , I've got an insurance job at the moment so ill have a bit of materhorn white jabiru .

I painted the avocet with materhorn white Cessna , it slightly creamier , and not as glairy as the jab paint , come over for a cuppa and I can do some touch ups for you .

The 250 wing can lift a lot more weight than the 230 wing and has a lower stall speed 38 kt

They are prity much the same price

Cheers Mike

Avocet , an aboriginal name for a bird that crashes into trees when landing .

My wife an I carnt stop laughing

That's funny ,:roflmao:we'll done .

Why carnt come out with stuff like that ?

Yes , there are 25 moulds for the fusalerge & vertical stab , I've used the jabiru 250 wings and undercarriage , wing struts are theirs but 30 mm longer , also had to have control cables made to length ,

Cabin width is 50" & with the rounded fusalerge & has plenty of elbow room , 8 inches between pilot & passenger ,

Duel control columns ,throttle in the center .

Fuel injected , liquid cooled ,dynon skyview,

Cruise 105 kt at 2950 rpm ,22 lt/hr stall 42kt MTOW empty weight 375kg .

62" wood prop ( Brent Thompson , only one I could get to make a pusher , does a great job)

The take off & landing are pretty much the same as a j230

Sorry about the bad photos , ill take some more tomorrow with the prop on & the cowels,

What looks like a spinner is a 30 amp alt that bolts onto the vac pump attach spline on the 3300 . Not the belt version , this leaves the jabiru alt intact for a backup .

Yes it's got a new turret , got some help from an aeronautical engineer to design the basic structure , but it's just like a wing on its edge with a spar , a lot better looking than my first attemp

Cheers mike

I googeled " boom prop " and there's a guy in America who's made a similar assembly and used a 3D printer to make it . It's with a look .i don't know how to set up a link so you'll have to google it

Cheers & thanks

Mike .