HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Sep 25, 2012, 01:06 PM
Lloyd Robinson
fishboy77's Avatar
USA, MO, St Louis
Joined Jun 2007
781 Posts
Latest setup = :)

This morning I flew the following setup: 16/25/2 (2500 Kv), Zippy Compact 5s 2700 25C, 4.75x4.75, HW 100A. Wow, the speed was awesome! I might have to take back what I said about <5" props not making enough thrust. A while back I tried the 4.7x4.25 on 5s and it didn't seem any faster than the 5.25x4.75 on 4s. But the 4.75x4.75 on 5s rocked. I'm going to guess around 175 mph at the bottom of a big half pipe. I'll try to get some dopler readings this weekend when I go to the club field. The field I was flying at today is littered with trash cans and soccer goals that make low passes a little more exciting than they need to be.
fishboy77 is online now Find More Posts by fishboy77
Reply With Quote
Sign up now
to remove ads between posts
Old Sep 27, 2012, 05:43 PM
Registered User
Jabberwocky_'s Avatar
Montreal
Joined Aug 2009
291 Posts
Finally maidened my Reverb after work today (I finish early on Thursdays so the sun was still high). At my flying field 6 minutes walking distance from my pad, the wind was nonexistent. Dead calm. So I knew that the launch would be a little tricky with no headwind for lift.

After a couple warm-up flights on a 77mph, 20 inch David wing, I was basically ready for the Reverb. Hardly a good match for the Reverb but there it is.
I throttled up to maybe 2/3 and gave her a good shove into the air. I should have gone full throttle because she didn't hook up in the air for a least 20 feet further, and she was maybe only 2 feet off the ground when she hooked up but the path was predictable and I could tell she was on her way up. And up she certainly went. But yeah, more headwind on launch is definitely easier for these larger birds. I was amazed at how it flew perfectly with zero trim. This thing certainly has a gorgeous whistle as it flies by with the motor off.

Did some pylon circuits and some hotliner style and it was a pussycat in both styles. Very gentle flier and magnificent presence in the sky. Landing was easier than I thought it would be.

Two big thumbs up! What a great value this thing is.

Relatively mild set up:

HET 2W-20
Ice Lite 50
Zippy Flightmax 2200mah 30C
Graupner 4.75 x 4.75
3x Hitec HS-65HB

Speed guesstimate: between 140 and 150mph.
Jabberwocky_ is offline Find More Posts by Jabberwocky_
Reply With Quote
Old Sep 28, 2012, 05:30 AM
What is Highspeed ?
Rolf D.'s Avatar
Germany, BY, Bergen
Joined Feb 2011
526 Posts
Quote:
Originally Posted by Jabberwocky_ View Post
Finally maidened my Reverb after work today (I finish early on Thursdays so the sun was still high). At my flying field 6 minutes walking distance from my pad, the wind was nonexistent. Dead calm. So I knew that the launch would be a little tricky with no headwind for lift.

After a couple warm-up flights on a 77mph, 20 inch David wing, I was basically ready for the Reverb. Hardly a good match for the Reverb but there it is.
I throttled up to maybe 2/3 and gave her a good shove into the air. I should have gone full throttle because she didn't hook up in the air for a least 20 feet further, and she was maybe only 2 feet off the ground when she hooked up but the path was predictable and I could tell she was on her way up. And up she certainly went. But yeah, more headwind on launch is definitely easier for these larger birds. I was amazed at how it flew perfectly with zero trim. This thing certainly has a gorgeous whistle as it flies by with the motor off.

Did some pylon circuits and some hotliner style and it was a pussycat in both styles. Very gentle flier and magnificent presence in the sky. Landing was easier than I thought it would be.

Two big thumbs up! What a great value this thing is.

Relatively mild set up:

HET 2W-20
Ice Lite 50
Zippy Flightmax 2200mah 30C
Graupner 4.75 x 4.75
3x Hitec HS-65HB

Speed guesstimate: between 140 and 150mph.
congrats for maiden the bird ;-)
have fun and crashfree flights
Rolf
Rolf D. is offline Find More Posts by Rolf D.
Reply With Quote
Old Sep 29, 2012, 12:13 AM
"RC ADDICT" in Toronto!
wollins's Avatar
Toronto Canada
Joined Aug 2004
1,739 Posts
Quote:
Originally Posted by fishboy77 View Post
This morning I flew the following setup: 16/25/2 (2500 Kv), Zippy Compact 5s 2700 25C, 4.75x4.75, HW 100A. Wow, the speed was awesome! I might have to take back what I said about <5" props not making enough thrust. A while back I tried the 4.7x4.25 on 5s and it didn't seem any faster than the 5.25x4.75 on 4s. But the 4.75x4.75 on 5s rocked. I'm going to guess around 175 mph at the bottom of a big half pipe. I'll try to get some dopler readings this weekend when I go to the club field. The field I was flying at today is littered with trash cans and soccer goals that make low passes a little more exciting than they need to be.
Hey FB, how did that 25C pack hold up for the flight? What amps were you pulling?

Colin
wollins is offline Find More Posts by wollins
Reply With Quote
Old Sep 29, 2012, 08:12 AM
Registered User
Canberra
Joined Nov 2003
59 Posts
Great to hear this bird flys so well,
Hope to maiden mine this weekend.
About throws and CG does this sound correct?
CG 50mm

spoilerons 20mm no elevator

+15/-9 aileron 50% expo (looks like its too much)
+6/-5 elevator 50%expo
should I use dual rates and drop these numbers by 30%
Thanks
LOONY BOY is offline Find More Posts by LOONY BOY
Reply With Quote
Old Sep 29, 2012, 02:10 PM
Lloyd Robinson
fishboy77's Avatar
USA, MO, St Louis
Joined Jun 2007
781 Posts
Quote:
Originally Posted by wollins View Post
Hey FB, how did that 25C pack hold up for the flight? What amps were you pulling?

Colin
The pack did fine - came down just warm. The static current is around 65 amps which is good for a little over 37,000 rpm with the 4.75x4.75.
fishboy77 is online now Find More Posts by fishboy77
Reply With Quote
Old Sep 29, 2012, 02:16 PM
Lloyd Robinson
fishboy77's Avatar
USA, MO, St Louis
Joined Jun 2007
781 Posts
Quote:
Originally Posted by LOONY BOY View Post
Great to hear this bird flys so well,
Hope to maiden mine this weekend.
About throws and CG does this sound correct?
CG 50mm

spoilerons 20mm no elevator

+15/-9 aileron 50% expo (looks like its too much)
+6/-5 elevator 50%expo
should I use dual rates and drop these numbers by 30%
Thanks
Those number look perfect to me. I would pass on the dual rates. It's just another thing to worry about. With a lot of expo they are unnecessary IMO. You could probably use a bit more expo. I wouldn't use less than 50%.

With your spoilers at 20 mm be ready for just a little bit of ballooning. I don't think it's worth any elevator mixing but these days I like to get the plane down low (like a few feet above the ground) before I deploy the spoilers. Again, just personal preference.
fishboy77 is online now Find More Posts by fishboy77
Reply With Quote
Old Sep 29, 2012, 06:04 PM
Registered User
feefo's Avatar
Staffs, UK
Joined Apr 2009
3,646 Posts
I prefer to use as little expo as I can these days. I find it better to dial rates down a bit at 1st and increase them as I get more comfortable, but usually just use dual rates.

While I wouldn't recommend anyone changing their expo settings dramitically, I would suggest you to try dialling expo down as much as you can. It saves the need to give large stick inputs to achieve what a smaller input can do, just takes a bit of getting use to.

On my Blade 450 I only use 7% expo.

Personal preference tho.....
feefo is online now Find More Posts by feefo
Reply With Quote
Old Sep 30, 2012, 05:05 AM
Registered User
AndrésMtnez's Avatar
Madrid, Spain
Joined Dec 2004
2,111 Posts
When I asked about the CG a mayority told me 50mm, except RolfD who said 55mm. It was odd, but now after some flying I have to agree with him

Mine is around 53mm now, and it´s still a bit nose heavy


About the throws, it depends on the CG. I did the maiden with those throws too, with the CG forward they´re fine, but if you move the CG further than 50mm you´ll need to short them up. Well, the elevator throw, the ailerons and spoilers can´t have too much throw in this plane, they´re small

With the spoilers-elevator mix it´s the same, it´ll depend on the CG

My Mini-Hawk (from ModellHobby) manual said the CG should be 45mm and that was my balance point the maiden day, but now I´m sure best CG around here is RolfD´s one at 55mm. I wonder if someone at ModellHobby has tested this plane to recommend that CG
AndrésMtnez is offline Find More Posts by AndrésMtnez
Reply With Quote
Old Sep 30, 2012, 05:22 AM
Registered User
AndrésMtnez's Avatar
Madrid, Spain
Joined Dec 2004
2,111 Posts
Quote:
Originally Posted by feefo View Post
While I wouldn't recommend anyone changing their expo settings dramitically, I would suggest you to try dialling expo down as much as you can. It saves the need to give large stick inputs to achieve what a smaller input can do
What makes thinghs more dificult to fly smooth

As you said it´s a matter of personal preference, but any expo below 25% (more or less) will actually be negative expo because of the rotational movement of servo arms. The first 10 degrees of movement will move the control surface a lot more than an intermediate 10 degrees, and the last 10 degrees of movement will barelly move the surface, so if you want a perfectly linear movement of the control surface, you´ll need around 25-30% expo, depending on the servo throw

I always use 50-60% or even higher expos. I also have dual rates but it´s mainly for the maiden, just in case my throws are too large and the plane becomes hard to control, after that I never use DR. Expo is much better as you have the best of both worlds, smooth movements and the whole capabilities of the plane at the same time. So what´s the reason to bother about another switch?
AndrésMtnez is offline Find More Posts by AndrésMtnez
Reply With Quote
Old Sep 30, 2012, 07:37 AM
Registered User
feefo's Avatar
Staffs, UK
Joined Apr 2009
3,646 Posts
Manufacturer's CoG's will always be conservative and nose heavy. But I agree a lot of the times they are very far forward and when you start to move it back, you get concerned by about how much you've moved back. Sort of 2nd guess yourself you're doing something wrong.

I've never noticed 25% expo or less acting as neg expo , I just reduce as I can. Ailerons is easiest to start with, and as a flyer who seems to rest his thumb on the ele stick and subconsciously puts in 'up', I have more expo on ele than ailerons. But I use 2 different radio systems (Spektrum and Multiplex) and having just checked, my Spektrum planes have a smaller % of expo over my planes using MPX. Spektrum is around 30-40%, MPX is around 45-55% depending on which control surface.
feefo is online now Find More Posts by feefo
Reply With Quote
Old Oct 01, 2012, 12:28 AM
Lloyd Robinson
fishboy77's Avatar
USA, MO, St Louis
Joined Jun 2007
781 Posts
Just got some dopler readings on the 5s setup I first tried earlier in the week. Can't say it was totally legit since I was doing big dives but the fastest pass was 179 mph. Had a few more at 175. It's definitely a fun setup - I'm going to order more of those 5s Zippy Compact packs when they come back in stock at the HK USA warehouse.

179 mph Reverb (3 min 10 sec)
fishboy77 is online now Find More Posts by fishboy77
Reply With Quote
Old Oct 01, 2012, 04:59 AM
Registered User
AndrésMtnez's Avatar
Madrid, Spain
Joined Dec 2004
2,111 Posts
Quote:
Originally Posted by feefo View Post
Manufacturer's CoG's will always be conservative and nose heavy. But I agree a lot of the times they are very far forward and when you start to move it back, you get concerned by about how much you've moved back. Sort of 2nd guess yourself you're doing something wrong.
Exactly, but this case is a bit more surprising, since this is not a beginner plane, so they don´t need to be "carefull" in that respect

And 50mm is a good point to start, plenty nose heavy yet, 45mm is way way too nose heavy. Actually with the CG at 45mm and their recommended control throws you don´t have enough elevator authority and doing some tight turns you can have some scare if flying low


Quote:
Originally Posted by feefo View Post
I've never noticed 25% expo or less acting as neg expo , I just reduce as I can. Ailerons is easiest to start with, and as a flyer who seems to rest his thumb on the ele stick and subconsciously puts in 'up', I have more expo on ele than ailerons. But I use 2 different radio systems (Spektrum and Multiplex) and having just checked, my Spektrum planes have a smaller % of expo over my planes using MPX. Spektrum is around 30-40%, MPX is around 45-55% depending on which control surface.
25% expo is more or less the neutral point for a linear movement of the control surface, as it does compensate the angular movement of the servo arm. The first 15-20 degrees of the servo arm move the control surface a lot, but the next 10-20 degrees move the control surface less than the first ones, and the last 10-20 degrees move the control surface very little if any, and that´s negative expo, so 25% compensate this. The percentage depends on your tx settings, if the servo arm turns less than the common 45º then you´ll nedd less expo, and if you increase the servo turn, you´ll need even more expo for a linear movement
AndrésMtnez is offline Find More Posts by AndrésMtnez
Reply With Quote
Old Oct 01, 2012, 05:25 AM
Registered User
feefo's Avatar
Staffs, UK
Joined Apr 2009
3,646 Posts
Quote:
Originally Posted by AndrésMtnez View Post
........if the servo arm turns less than the common 45º then you´ll nedd less expo, and if you increase the servo turn, you´ll need even more expo for a linear movement

I doubt I ever use that sort of movement from the servo arm. Except on a delta wing for the ailerons..... maybe.
feefo is online now Find More Posts by feefo
Reply With Quote
Old Oct 01, 2012, 07:50 AM
"The Judge"
sebbe's Avatar
Sweden
Joined Feb 2006
5,817 Posts
Quote:
Originally Posted by fishboy77 View Post
Just got some dopler readings on the 5s setup I first tried earlier in the week. Can't say it was totally legit since I was doing big dives but the fastest pass was 179 mph. Had a few more at 175. It's definitely a fun setup - I'm going to order more of those 5s Zippy Compact packs when they come back in stock at the HK USA warehouse.

http://www.youtube.com/watch?v=R9fHW5KPmuE
Great man, looks fast and it is really not a slow airframe as you are getting 179mph with that setup,, REALLY nice..

I wunder if you would gain more speed with a 4.7x5.5 prop
sebbe is offline Find More Posts by sebbe
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Question Will Wasp V4/Belt 250 parts fit on Wasp V3? cfanto Skyartec 8 Mar 24, 2010 05:02 PM
Wanted Spirit E by mibo FASTBEN Aircraft - Sailplanes (FS/W) 3 Dec 07, 2009 02:36 AM
anybody know Mibo Modeli "spirit e"??? trashmanf High Performance 3 Jul 23, 2005 09:33 PM
Mibo Modeli Spirit e 207 Electric Sailplanes 15 Jul 23, 2005 08:26 AM
Any info about Mibo Spirit E? AndrésMtnez High Performance 27 Jun 20, 2005 10:21 AM