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Old Feb 18, 2010, 03:13 AM
Ozzie Express wiggy pilot
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YANKALILLA , SOUTH AUSTRALIA.
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Yes Treediver , Dave Hipperson knows whats what , he is a very experienced builder and did a good job on fitting oleo's to his Hawk , try it, you can thank us later...... LoL

Ian
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Old Feb 18, 2010, 03:25 AM
BrainFart RC-Pilot
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Echt, Netherlands
Joined Aug 2003
3,159 Posts
Quote:
Originally Posted by SON OF PALEFACE View Post
Yes Treediver , Dave Hipperson knows whats what , he is a very experienced builder and did a good job on fitting oleo's to his Hawk , try it, you can thank us later...... LoL

Ian
Hi Ian,

Yes, I did read that. Great. Only HC does not have these oleo's on stock.
But first I need to know..."what plane"....

SparrowHawk, Great Planes CosmicWind (little tony).......
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Old Feb 18, 2010, 03:27 AM
Ozzie Express wiggy pilot
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YANKALILLA , SOUTH AUSTRALIA.
Joined Nov 2002
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If you do a search on Ebay you will find some in Hong Kong , or just pre-pay for some at Hobby city
Ian
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Old Feb 18, 2010, 03:35 AM
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Kilsyth, Victoria, Australia
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The Little Toni/Cosmic Wind is a good aircraft but like most of some of the smaller (full-size I mean) the fuselage is quite large while the wing area is relatively low. Remember it is a racer built to do a specific job. The Sparrowhawk too was a racer but built to an earlier era, pre-war as opposed to post war.

The equivalent is like driving a Formula One car against a high performance sports car. One has limitations while the other can handle practical driving.

The Little Toni will fly well if set up properly (I know because one of my friends has one) but the Sparrowhawk is much more comfortable and rather like a Sunday flier. Obviously I'm biased but I know which I'd choose.
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Old Feb 18, 2010, 03:55 AM
BrainFart RC-Pilot
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Echt, Netherlands
Joined Aug 2003
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Quote:
Originally Posted by David Hipperson View Post
The Little Toni/Cosmic Wind is a good aircraft but like most of some of the smaller (full-size I mean) the fuselage is quite large while the wing area is relatively low. Remember it is a racer built to do a specific job. The Sparrowhawk too was a racer but built to an earlier era, pre-war as opposed to post war.

The equivalent is like driving a Formula One car against a high performance sports car. One has limitations while the other can handle practical driving.

The Little Toni will fly well if set up properly (I know because one of my friends has one) but the Sparrowhawk is much more comfortable and rather like a Sunday flier. Obviously I'm biased but I know which I'd choose.
Hi David,

For sure the Little Toni will be more speedy...and I love speedy.
I fly also a very fast pylon racer.
But I also love scale...and cool looking planes.

http://members.tripod.com/airfields_..._LeVier_49.JPG

Nice picture of the Little Toni.
Well....will be a hard one because the "SparrowHawk" is also very special.
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Last edited by TreeDiver; Feb 18, 2010 at 04:14 AM.
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Old Mar 01, 2010, 11:42 AM
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Germany, Kaufbeuren
Joined Jun 2007
11 Posts
Hi David,

I was very impressed about the Seagull Sparrow Hawk and I have searched for more informations about this racer. The only thing I didn't like, were the colours of the the small ARF Sparrow Hawk.
I found your very impressive modification, so I bought this plane.
Here You can see the result of my work.
I want use 6S 5000mAh with a motor similar an AXI 4130 with 470kv. I need this setup to get the correct CG. I don't know how you have reached it with 5S and a smaller motor
For the first flight I have to wait for green weather (too much snow at the moment).






Greetings from Germany.

Rolf
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Old Mar 01, 2010, 09:03 PM
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Kilsyth, Victoria, Australia
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Dear Rolf,
Thanks for the photo and your take on the Sparrowhawk.

With any models over 4S I prefer to use a separate receiver battery and this can be used to put the CG, more or less, where you want it. I created a ply "table" on the motor mounting and used this for both the battery (a 2000mAh Eneloop) plus the ESC. I hope the picture will help explain. As you can see the battery is moved well forwards and helps with the motor weight. Also added to this is an alloy spinner rather than plastic. It all helps.

The AUW on mine is 8.5 pounds or 3.86kg. Of this 5S is heaps of power for me and the aircraft is truly a delight in the air. Oh yes, In my endless heaps of junk (important parts retained for use!!!) was an old Pilot kit tailwheel assembly. This was back from the 1970's and has real quality including a spring steel arm. It was nearly 30 grams lighter than the supplied item so took weight away from the tail end.

If I can help any more just ask.

Good luck with yours. Hope the weather in Europe improves.
David
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Old Mar 14, 2010, 11:42 AM
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Germany, Kaufbeuren
Joined Jun 2007
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Dear David,

have you used the CG (55mm) from the manual? Does the Sparrow Hawk fly very well with this? To get this CG I must add 120Gramm in the nose, so I have a weight of 4Kg. I think it's Ok for this racer
Unfortunately we still have snow and the winter will not go away
Maybe we can drink our first-flight-beer next weekend...I hope
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Old Mar 14, 2010, 11:50 PM
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Kilsyth, Victoria, Australia
Joined Oct 2003
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Dear Rolf,

Not too sure about your figures. My manual calls for 75mm back from the leading edge at the tip leading edge (roughly the last rib) and this equates to 105mm back from the leading edge at the fuselage. Obviously due to the wing taper.

Personally I don't like this tip measurement as it can affect the CG testing due to the induced pendulum effect which dulls the sensitivity.

Anyway at 105mm back at the leading edge my Sparrowhawk flies beautifully. Smooth and very easy with quite axial rolls. Do note however that with my set up take off can be as short as 40 metres but looks nicer when held down. BUT!!!!! landings can go on forever. The aircraft is very clean and once down and presumably into ground effect it will just sit about 600 - 900mm off the ground and keep going.

Just to repeat mine is at 3860g so yours at 4kg isn't too bad. Apart from the remarks I made earlier I saved weight where I could so aileron servos are HS 225, I fitted a heavy -ish alloy spinner to put weight up at the very nose. Used the lightest tailwheel etc.
Anything you can do will help. Do remember that even a 6S rather than a 5S makes another 100g difference. A 6S will certainly ensure plenty of power.

Was flying mine yesterday and still love the beast.

Good luck with your maiden flight.
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Old Mar 16, 2010, 04:43 AM
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Germany, Kaufbeuren
Joined Jun 2007
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Dear David,

thank you for the informations.
In my manual the CG is:
"...locate 55mm back from the leading edge of the wing, measured at wing tip"
I don't understand why in your manual the CG is 75mm??? I think we have the same ARF-plane? From Seagullmodels? Do you think they have changed the CG in the manual in cause of some experiences from some customers?
But if your Sparrow Hawk flyes well with your CG I take this. With 105mm back from the leading edge at the fuselage I don't need the additional weight of 120gramm in the nose and the position is nearly at 1/3 of the whole wing measure.
Now I'm waiting for the next weekend.
Regards from Germany
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Old Mar 16, 2010, 06:18 PM
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Kilsyth, Victoria, Australia
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Rolf,
I double checked and as I sit writing this the manual is here on my desk. Yes, mine is the 63" or 1600mm span model from Seagull. The manual is listed as MS:SEA 93 and on page 21 the CG is stated at 75mm back from the leading edge meaured at the wing tip. This is then backed up with a diagram.

Personally I can't believe that the model would be as nice with the CG moved that far forward. I am not (repeat: NOT) a super flier but exactly as set up by my manual the Sparrowhawk is very smooth with no pitching or excessive sensitivity. I would imagine that moving the CG further forward that much would make the model nose heavy and very, very stable but sluggish to response.

If your manual is like mine there is a panel showing throws for the surfaces.
Initial Flying/Sport Flying
Ailerons: 3/16" up 3/16" down
Elevator: 3/8" up 3/8" down
Rudder: 3/4" up 3/4" down

I fly on these and like it because these settings seem to suit the scale-ness of the aircraft. Roll remains reasonably axial at around 1.5/2 seconds per rotation.

I have not tried the larger rates because I don't need them (I believe). My editor Stephen, who can genuinely fly anything, tested the Sparrowhawk and for his taste would have even taken it a little further aft. However, I have had him fly numerous models of mine in review and he always likes aft balance. The fact he can fly 3D and hover EDF models vertically might indicate his abilities.

Do what you think is best but if with the forward setting make sure that on your first flight do a stall check and have full rate available on elevator for landing as I could imagine running out of throw.

I really wish you the very best for your maiden flight.
Take care.
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Old Mar 17, 2010, 04:49 PM
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Germany, Kaufbeuren
Joined Jun 2007
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Hi David,
I have the same manual and the same Sparrow Hawk, but the CG is different
But I will use your CG, I think it's correct.
I hope the weather on sunday is good, so I will do the maiden flight. Two other friends have a Red Lion and a GeeBee R2, so we will have at this day three racer to bring in the air the first time.
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Old Mar 18, 2010, 03:53 AM
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Kilsyth, Victoria, Australia
Joined Oct 2003
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Just as a matter of interest check the CG % on the Red Lion and Gee Bee. See if the CG related to the chord of the wing is similar percentage wise. I assume their models fly well and despite differences are similar aircraft.
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Old Mar 19, 2010, 03:33 AM
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Newcastle, New South Wales, Australia
Joined Sep 2007
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Guys,
I reckon 28% is a good spot! From an earlier post:
With the 71 incher, the instructions say 115mm back from the leading edge of the wing, measured back at the wing tip. Now that we know from experience that they probably meant "wing root next to the fuselage" rather than the "wing tip" and given the wing chord next to the fuselage is 410mm, this places my current and possibly a little conservative CG position at 28%. (ie 115/410 x 100) as opposed to the instructions' (115 + approximately 35mm for the swept back of the leading edge at the wing tip)/410 x 100 = 36.6% (!)

Good luck with it Rolf!

Regards
Peter
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Old Mar 19, 2010, 03:51 AM
Ozzie Express wiggy pilot
SON OF PALEFACE's Avatar
YANKALILLA , SOUTH AUSTRALIA.
Joined Nov 2002
5,234 Posts
Guys , chek this out , it is a fantastic collection of tips and links , and you can find in here how to work out the CG of any wing/plane.....

http://homepages.ihug.co.nz/~atong/

No David "Murray's" Peter....
See you at the Grand Southern Rally , will be leaving on Chewsdee and will prob get there Thursdee
Cheers
Ian
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