Mike Haddox

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I didn't use mine.

lavi rider

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Oil gauge ...

lavi rider

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������ left and far right pictures were taken in a zero gravity environment ...

lavi rider

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He , he , he

David Gladwin

Another one almost ready for first flight after: fixing 310 grams of TAIL weight, stiffening springs in MLG, replacing landing light cover and adding final details and pilot. .

AMT Olympus, 6.7 l tank, full ducting, all gear doors working 100%, JR 12X with Weatronic 12-22R with gyros on rudder, NS and ailerons. JR servos (6311 HV on stab.) throughout and PowerBox lipos and smoke pump. Home made centerline tank.

David G.

Blancr

Looks terrific David - clearly no luck needed for the maiden!
Bob

bruno borges

Hi Lavi Rider,

Which site I can buy that gauge?

Tks

Bruno

bruno borges

Which site I can buy that gauge?

skymaster68

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Great looking plane David, congrats and the best wishes for the maiden !!

lavi rider

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I made them myself...

lavi rider

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Here you go....

Dave Wilshere

Yours next Bob!

Blancr

Am getting there - slowly!
Bob

David Gladwin

Thanks guys, thought the test flight would be very soon. However, the springs in the MLG need to be much stronger, one completely bottoms, the other almost does.

Question is does anyone know how to get at the springs ?
There appears to be a set screw near the top of the leg but it isn't a set screw and nothing will engage it to turn it.

(The larger set screw retains the pivot and comes out easily )

Any help?

David.

Dave Wilshere

After the leg trails you have no movement? The soft spring just takes up the extension on the lower arm, there should be another 10mm or so of damping. This makes it nice and stable on the ground.
You unscrew the hex collar in the upper leg

Dave

David Gladwin

Thanks Dave. I may have got a Friday job ! I found the hex bolt under the "casings: I had installed and got the spring out. The springs are woefully inadequate. I replaced these with same length but much stronger springs as used in the Airworld Hawk (original spring there were far too soft too, the gear easily bottomed)

With these new springs the gear will still "bottom" with a little extra download. To fix this I will install a second, inner and shorter spring which will only start to compress when the main spring is within about half an inch of full compression giving two stage shock absorbtion. This may well cope better with a "firm" landing.

I'll report later as it may help other Hawk builders, but remember, mine is a 5 year old original Skygate kit, CARF may be different and mine is quite heavy with the Olympus and big tank etc !

David.

David Gladwin

Now have it sorted. Initially the legs fully compressed with full fuel and the secondary doors came very near to the ground. There appeared to be no further damping and if there was to be any further compression the doors would get even closer, just too close. After that initial compression the struts appeared to be "solid".

I have found a short strong spring inside the leg but it appears to have no effect.

So the replacement of the original long soft spring with a much stronger Airworld coil PLUS a 1 inch length of an internal spring means the landing gear just compresses the new spring until it touches the short spring then there is further shock absorbing as the small spring compresses, a sort of mechanical metering pin.

I will fine tune this if needed after flight test but so far it all looks good.

David.

skymaster68

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Well, after reading your previus post last night I went to the club this morning and noticed that the main LG is fully compresed, the plane has no fuel on it and built pretty light, no cockpit or pilot inside yet, so I will have to take a better look next time I go there with a little more time..
Mine is the CARF one so Lighter than yours, anyone else with the same issue?

marc s

Had the same issue many years back, somewhere I had the details of the spring combo I used on Ali's Saudi, think I got them from Springmasters in the UK.

Its incredible just how strong a spring you need in this levered compressive system....

marcs

DUCMOZ

I seem to see a lot of posts in various threads about the spring in the landing gears and most like the plane to sit on the top or lowest the middle of the dampening and all complaints are about the gear bottoming out. But, many ground handling problems could rise from having a strong spring. If we look at the real planes up to 747. They all have the gear fully compressed when sit on the Tarmac. I played with my plane a little. I have not flown it but it seems that it has good dampening and then bottoms out under full load. Therefore, I am planning to leave it as is. Also, I know of a few people that are flying theirs without playing with the springs and have had no issues.

Thanks, Behzad

wayne1965

Hi david
im half way through building mine same as you original sky gate with larger tank and upgrade on inlets and oli going in, just having a nightmare right now trying to fit the operating canopy from detail4scale, anyway question being have you still got rough dimensions of the smoke pod as I'm also doing red arrow think it's only colour hawk shoul be thankyou for your time
Regards wayne

David Gladwin

If we look at the real planes up to 747. They all have the gear fully compressed when sit on the Tarmac.
Thanks, Behzad[/QUOTE]

No they don't. Never flown the 747 but guess most jets are the same, even at full fuel there is some extension still to go on the oleos, otherwise taxi-ing (and landing when the spoilers extend) would be quite awful ! A completely bottomed oleo means the pressure in the strut is inadequate. At least that's what I have always believed/ been taught by engineers for my entire career.

Anyway, it may be that some guys operating SG Hawks at normal, 20Kg weights have not had a problem (or a hard landing) but I would rather not see the strut fully bottomed. My two AW Hawks don't bottom even at full fuel and ground handling and landings are excellent. With the original springs the gear fully compressed and the model was very "squirrely" on the ground, stronger springs transformed ground handling.

There was an excellent article in a recent edition of "Sport Aviation" (EAA mag) and oleo design and maintenance and a very good explanation of metering pin design.

Yes, I have some basic drawings for the smoke pod (and scale stab pivot covers) if anyone wants them.

Model balance, new springs installed, ready to go !!

David.

DiscoWings

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well so now someone needs to post a tutorial on how to modify the carf skygate hawk gear with better springs.

wayne1965

Hi david
if there's a chance of drawings for smoke pod that would be great , I don't think anybody produces the pod as far as I'm aware and it would be the finishing touch, just a question to anybody with this hawk , who's tired fitting the operating canopy from detail for scale as its pushing me to the brink of madness ,
Regards and happy landings

Mike Haddox

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No problems with mine.