Logo
Builders' Plan Gallery  |  Hip Pocket Web Site  |  Contact Forum Admin (Account/Technical Issues)  |  Contact Global Moderator
January 19, 2021, 07:20:57 AM *
Welcome, Guest. Please login or register.
Did you miss your activation email?

Login with email, password and session length
 
Home Help Search Login Register
Pages: 1 ... 103 104 105 106 107 108 109 [110] 111 112 113 114 115   Go Down
Print
Author Topic: Walt Mooney Cook-up 2020  (Read 44832 times)
0 Members and 1 Guest are viewing this topic.
Squirrelnet
Platinum Member
******

Kudos: 54
Online Online

United Kingdom United Kingdom

Posts: 1,372




Ignore
« Reply #2725 on: June 26, 2020, 08:22:17 AM »

Well that worked well. The Beaver looks lovely in the air, another stable flyer by the look of it
Logged
Don McLellan
Titanium Member
*******

Kudos: 67
Offline Offline

Canada Canada

Posts: 2,488




Ignore
« Reply #2726 on: June 26, 2020, 11:46:42 AM »

Very nice flight Pete!  There is nothing like making a slight change and getting a huge result. 
Logged
Tim Horne
Gold Member
*****

Kudos: 24
Offline Offline

United Kingdom United Kingdom

Posts: 288




Ignore
« Reply #2727 on: June 26, 2020, 02:16:55 PM »

Very nice flight Pete, got to be happy with that.
How much potential for more turns have you? I know you wouldn’t want to crank it up in your smallish field but it would be nice to do so at Barkston.
Logged
MKelly
Platinum Member
******

Kudos: 106
Offline Offline

United States United States

Posts: 1,096




Ignore
« Reply #2728 on: June 26, 2020, 03:10:37 PM »

That's looking very nice Pete - nothing beats a big light model for realism in flight.

Keleher Lark

Yesterday morning was beautiful (although hot), so FlyAce1946 and I met up at our usual field for some aviating.  His Andreason did some nice flights while I struggled to tame the Lark.  Best I could get out of it was 20 seconds or so of wandering flight barely scraping over the recently cut grass.  The model seems to be flying on the ragged edge of stability - adding a few tenths of a gram of clay up front helped a bit.  My suspicion is that the homemade prop isn't doing its job, as the model doesn't seem to get to flying speed even when a short loop of 3/32" is wound up fairly tight.

The good news is that it appears to have sufficient dihedral (it will recover from roll upsets and doesn't seem inclined to tighten up into a spiral), the bad news is that it seems to tip-stall violently to either side if airspeed drops too low or AOA gets too high.

I've scraped down a 4.75" Peck prop and will give that a shot.  Once I get a feel for what that's done to the model I'll consider warping a bit of washout into the wing panels if the tip stall persists.

Mike
Attached files Thumbnail(s):
Re: Walt Mooney Cook-up 2020
Re: Walt Mooney Cook-up 2020
Re: Walt Mooney Cook-up 2020
Re: Walt Mooney Cook-up 2020
Re: Walt Mooney Cook-up 2020
Re: Walt Mooney Cook-up 2020
Logged
Pete Fardell
Palladium Member
********

Kudos: 162
Offline Offline

United Kingdom United Kingdom

Posts: 5,989


Topic starter


Ignore
« Reply #2729 on: June 26, 2020, 03:54:50 PM »

Thanks chaps. Yes, VERY pleased with that!
How much potential for more turns have you? I know you wouldn’t want to crank it up in your smallish field but it would be nice to do so at Barkston.
Tim, the motor is 4 strands of 3/16 and is 22 inches long. I'd have to consult the Don Ross table to see how many turns that'll take, but that flight was 900 and nothing was squeaking so I think there's room for more. Although the model's almost as big as the Comte it is significantly lighter and that motor is exactly half the size of the Comte's (12 strands of 1/8) so I'm really pleased about that too. Everything is much less scary when there isn't a fat angry rubber python in the fuselage wound up to near its limit!

Mike, those in-flight shots are great. I'm sure it'll soon fly well in your capable hands. I posted off the 'Golden Rib' trophy a couple of days ago. Let us know when it arrives safely.  
FlyAce, the Andreasson looks very happy in its element!
Logged
Indoorflyer
Platinum Member
******

Kudos: 27
Offline Offline

United States United States

Posts: 1,353



Ignore
« Reply #2730 on: June 26, 2020, 09:27:51 PM »

Pete, what is the diameter of the prop you're running on the Beaver?  I'd be tempted to try a different (smaller) dia and pitch.  If you were to remove the prop assy and re-ballast the plane accordingly, how does she glide?  I've always been suspicious of wingtip weight "solving" a power/thrustline issue, or compensating for a warp or incidence problem.  Is the plane laterally balanced (static) without the clay on the wingtip?   I've found the 10-step trimming guide (in our HPA plan gallery) to be an invaluable aid.  It may take a little longer, but it is a methodical process that takes care of things one variable at a time.
Logged
bobson
Silver Member
****

Kudos: 10
Offline Offline

United States United States

Posts: 130




Ignore
« Reply #2731 on: June 26, 2020, 09:43:36 PM »

Beautiful Pete!! Just joy-inspiring to watch in flight.
Logged

Oliver
FLYACE1946
Platinum Member
******

Kudos: 27
Offline Offline

United States United States

Posts: 1,660


AMA and Flying Aces Club Member



Ignore
« Reply #2732 on: June 26, 2020, 10:19:19 PM »

The Andreason flew well enough for me to make repairs to the tissue where the motor blew when in winding process. My new motor is already to go and we just need to fly after the postal kicks off in a few days. The Lark will be happy with what the new prop installed wants to do.
That's looking very nice Pete - nothing beats a big light model for realism in flight.

Keleher Lark

Yesterday morning was beautiful (although hot), so FlyAce1946 and I met up at our usual field for some aviating.  His Andreason did some nice flights while I struggled to tame the Lark.  Best I could get out of it was 20 seconds or so of wandering flight barely scraping over the recently cut grass.  The model seems to be flying on the ragged edge of stability - adding a few tenths of a gram of clay up front helped a bit.  My suspicion is that the homemade prop isn't doing its job, as the model doesn't seem to get to flying speed even when a short loop of 3/32" is wound up fairly tight.

The good news is that it appears to have sufficient dihedral (it will recover from roll upsets and doesn't seem inclined to tighten up into a spiral), the bad news is that it seems to tip-stall violently to either side if airspeed drops too low or AOA gets too high.

I've scraped down a 4.75" Peck prop and will give that a shot.  Once I get a feel for what that's done to the model I'll consider warping a bit of washout into the wing panels if the tip stall persists.

Mike
Logged
Jack Plane
Platinum Member
******

Kudos: 42
Offline Offline

United Kingdom United Kingdom

Posts: 1,925




Ignore
« Reply #2733 on: June 27, 2020, 02:48:23 AM »

Beaver - lovely flight Pete!  Indoor might be right... how does it work without tip-weight?

Lark - Mike, if violent tip-stalls, would it work to steam in wash-out on both tips?
Logged
BG
Platinum Member
******

Kudos: 84
Offline Offline

Canada Canada

Posts: 1,741


Me with F1B - epic retrieval (flew 10km after DT)


WWW

Ignore
« Reply #2734 on: June 27, 2020, 02:57:44 AM »

Mike I agree that you may need an "outdoor" prop ... I have seen Tom Hallman use similar (to yours) props on his peanuts with great success but perhaps they were a bit lighter and so were ok at the low flight speeds. I know that I tried something similar to you years ago and only found success when I switched to a smaller narrower bladed plastic prop. I bet she will go great once you make that change.

oh! and yes on the washout too ... can't hurt.

BG
Logged

CEO,Chief designer, production line manager, factory worker, shipping and customer service manager, and janitor at Hummingbird Model Products.
Pete Fardell
Palladium Member
********

Kudos: 162
Offline Offline

United Kingdom United Kingdom

Posts: 5,989


Topic starter


Ignore
« Reply #2735 on: June 27, 2020, 04:51:05 AM »

Thanks Oliver, Jon and Indoorflyer. Without the tip weight it still tends to spiral in a bit, but more gently (ie less banked) than before I put the gurney on. I'm not yet committed to trying it indoors. It's somehow harder now I know it flies outdoors.

Pete, what is the diameter of the prop you're running on the Beaver?  I'd be tempted to try a different (smaller) dia and pitch.  If you were to remove the prop assy and re-ballast the plane accordingly, how does she glide?  I've always been suspicious of wingtip weight "solving" a power/thrustline issue, or compensating for a warp or incidence problem.  Is the plane laterally balanced (static) without the clay on the wingtip?   I've found the 10-step trimming guide (in our HPA plan gallery) to be an invaluable aid.  It may take a little longer, but it is a methodical process that takes care of things one variable at a time.
The prop is 10.5" inches. It's a Japanese Peck-type 11 incher, cut down slightly. Like all my models, it's got the biggest prop I can fit that will still allow for a ROG. I do sometimes wonder about the wisdom of this policy. Essentially, the length of the undercarriage is determining my prop size, and I'm always going as large as possible within that limit. This no doubt makes it harder to get them flying to the right, and so the doffing in left tendency is nearly always the main trimming issue. My Comte flies right, but only by accident, and it is easily my best flyer. My big Fairchild goes either way, but is much better going right. As Bill said, duration models fly right too. I probably do need a shift of mindset, but for this one I expect I'll leave it alone now.
I can see too that tip weight might be a clunky solution to purists as, apart from maybe hang gliders, weight shift is not really a control method used on real aircraft is it? On the other hand, I'm more of the "if it works" school. I'm also quite lazy when it comes to trimming. I didn't glide it without the prop assembly for instance, and I haven't checked its lateral balance either. In my defence, remember that here in the UK outdoor scale models are (usually) judged for flight profile, not duration, so anything that looks nice in the air and stays aloft for 30 seconds or more is considered "trimmed" by people like me!

« Last Edit: June 27, 2020, 05:33:21 AM by Pete Fardell » Logged
billdennis747
Palladium Member
********

Kudos: 64
Offline Offline

United Kingdom United Kingdom

Posts: 4,342



Ignore
« Reply #2736 on: June 27, 2020, 06:08:31 AM »

Hi Pete. I find trimming other people's models from my armchair one of the most enjoyable parts of this site!
To me, it looks like the Beaver is fighting something and is on a knife edge; it wants to spiral in left but is being kept up by the 'improvements'. If a model like that needs gurney flaps and tip weight to keep it flying, there must be something wrong, and one of the photos seems to show a lot of port wing washout - perfect for a duration right pattern!
On the subject of prop size, Trish and I have been flying the Gollywock mini vintage model. It has a much smaller, higher -revving prop than usual and the model flies as if on rails with none of the rocking about you sometimes see with bigger props.

PS i just saw the photo where it is nestling in the KK grass, showing a big washin warp on the right panel. Add that to the washout on the port......
« Last Edit: June 27, 2020, 06:38:56 AM by billdennis747 » Logged
Pete Fardell
Palladium Member
********

Kudos: 162
Offline Offline

United Kingdom United Kingdom

Posts: 5,989


Topic starter


Ignore
« Reply #2737 on: June 27, 2020, 06:39:34 AM »

Thanks Bill. If I’m feeling brave, and when the wind drops drops again, I might just remove the gurney and tip weight, bung on a smaller prop... and make it go the other way.  As has been said, at the moment it’s flying a typical indoor left pattern. Perhaps indoor flyers are usually flying on some variation of the knife edge you mention, but are trimmed to land before anything bad happens?

(You’re right about the port wing wash-out too. Not much, but a bit.)
« Last Edit: June 27, 2020, 07:22:15 AM by Pete Fardell » Logged
billdennis747
Palladium Member
********

Kudos: 64
Offline Offline

United Kingdom United Kingdom

Posts: 4,342



Ignore
« Reply #2738 on: June 27, 2020, 06:43:48 AM »

You can see the warp at the beginning of the flight. That's the problem.
Logged
Pete Fardell
Palladium Member
********

Kudos: 162
Offline Offline

United Kingdom United Kingdom

Posts: 5,989


Topic starter


Ignore
« Reply #2739 on: June 27, 2020, 07:12:42 AM »

You can see the warp at the beginning of the flight. That's the problem.
Here you mean? I can’t deny it. Useful though, as you already said, if it can be persuaded to go the other way. I’m wonder how much smaller than the current 10.5” to go with the prop. I’ve got these two. 8.75” and 9.5” respectively. Any smaller really does look a bit incongruous.
Attached files Thumbnail(s):
Re: Walt Mooney Cook-up 2020
Re: Walt Mooney Cook-up 2020
Logged
billdennis747
Palladium Member
********

Kudos: 64
Offline Offline

United Kingdom United Kingdom

Posts: 4,342



Ignore
« Reply #2740 on: June 27, 2020, 07:22:16 AM »

Yes, although it seems to bend both ways! What's the other one like? I'd sort out the warps before changing props
Logged
vintagemike
Gold Member
*****

Kudos: 10
Offline Offline

United Kingdom United Kingdom

Posts: 257



Ignore
« Reply #2741 on: June 27, 2020, 07:27:24 AM »

Pete just a thought, with the wash out on the left wing, why don't you try and send it right? Right thrust, rudder and the left rolling warp you have on it would see the model climb right with the washout rolling the model left which brings the nose up a bit giving you a higher climb and should be longer flights.
Just like trimming an Ajax or Senator really!!
Logged
Pete Fardell
Palladium Member
********

Kudos: 162
Offline Offline

United Kingdom United Kingdom

Posts: 5,989


Topic starter


Ignore
« Reply #2742 on: June 27, 2020, 07:55:42 AM »

Thanks Mike- that’s already the plan (see last few posts).
Bill, the other wing’s TE is a bit wobbly too, but does the opposite- goes up and then down. I think there’s even some wash in by the time it gets to the tip.
Attached files Thumbnail(s):
Re: Walt Mooney Cook-up 2020
Logged
billdennis747
Palladium Member
********

Kudos: 64
Offline Offline

United Kingdom United Kingdom

Posts: 4,342



Ignore
« Reply #2743 on: June 27, 2020, 08:10:24 AM »

Bill, the other wing’s TE is a bit wobbly too, but does the opposite- goes up and then down. I think there’s even some wash in by the time it gets to the tip.
The answer is obvious - a gyro!
Logged
Pete Fardell
Palladium Member
********

Kudos: 162
Offline Offline

United Kingdom United Kingdom

Posts: 5,989


Topic starter


Ignore
« Reply #2744 on: June 27, 2020, 08:27:14 AM »

Bill, the other wing’s TE is a bit wobbly too, but does the opposite- goes up and then down. I think there’s even some wash in by the time it gets to the tip.
The answer is obvious - a gyro!
Not a Prosper pendulum?
Logged
Pete Fardell
Palladium Member
********

Kudos: 162
Offline Offline

United Kingdom United Kingdom

Posts: 5,989


Topic starter


Ignore
« Reply #2745 on: June 27, 2020, 08:42:19 AM »

The prop is now off. Not because I’m necessarily going to change it, but because I discovered another thing that’s stopping it flying to the right... Namely that the shaft was much too loose in the bushel so the noseblock’s built in down and right thrust was probably completely negated once it was wound up. I’ve now drilled it out and inserted a bit of brass tube.

(Sorry, this is fast turning info a Beaver thread, but someone else must be chucking or finishing their Mooney today?)

Logged
Pete Fardell
Palladium Member
********

Kudos: 162
Offline Offline

United Kingdom United Kingdom

Posts: 5,989


Topic starter


Ignore
« Reply #2746 on: June 27, 2020, 10:11:08 AM »

Yes, although it seems to bend both ways! What's the other one like? I'd sort out the warps before changing props
I'm not quite sure now whether to try and get rid of all the warps, or leave the ones that might be helpful to a right hand circle.
Logged
billdennis747
Palladium Member
********

Kudos: 64
Offline Offline

United Kingdom United Kingdom

Posts: 4,342



Ignore
« Reply #2747 on: June 27, 2020, 10:22:38 AM »

If it's all stuck together and would need disassembly, I would first look at it from behind and come to an overall view whether all the undulations and twists amount to generally more washin on the right than the left, and if so, right thrust it, now the noseblock works, and send it right. It might fly right with left bank!
Logged
Pete Fardell
Palladium Member
********

Kudos: 162
Offline Offline

United Kingdom United Kingdom

Posts: 5,989


Topic starter


Ignore
« Reply #2748 on: June 27, 2020, 12:31:14 PM »

If it's all stuck together and would need disassembly, I would first look at it from behind and come to an overall view whether all the undulations and twists amount to generally more washin on the right than the left, and if so, right thrust it, now the noseblock works, and send it right. It might fly right with left bank!
I'll give it a go. Tempted to put a smaller prop on too, just to give it less to fight against. Probably Wednesday before it's calm enough again. (It's not all stuck together though; the wing is all one piece banded on at the centre section, so I could easily take it off and squash each wing flat on a board, one side at a time.)
Logged
DHnut
Gold Member
*****

Kudos: 20
Offline Offline

New Zealand New Zealand

Posts: 877



Ignore
« Reply #2749 on: June 27, 2020, 04:52:02 PM »

Pete,
       I normally use a prop diameter about one third of the span as in the Don Ross book and McComb uses a formula of 0.75 the square root of the wing area that works well as well and gets you into the ball park. Also pitch may be an issue azbut unless you carve a balsa prop or do an Ivan Taylor prop you are limited. Jjust some thoughts possibly for the future. Also Derek's nose thrust buttons are worth considering.
Ricky   
Logged
Pages: 1 ... 103 104 105 106 107 108 109 [110] 111 112 113 114 115   Go Up
Print
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Valid XHTML 1.0! Valid CSS!