Logo
Builders' Plan Gallery  |  Hip Pocket Web Site  |  Contact Forum Admin  |  Contact Global Moderator
October 24, 2019, 12:40:45 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 ... 21 22 23 24 25 26 27 [28] 29 30 31 32 33 34 35 ... 37   Go Down
Print
Author Topic: Show us your P-30's  (Read 61496 times)
0 Members and 1 Guest are viewing this topic.
rbrpwr
Bronze Member
***

Kudos: 1
Offline Offline

United States United States

Posts: 35



Ignore
« Reply #675 on: May 28, 2013, 12:50:26 PM »

From the US Mint website:
Denomination  Cent   Nickel    Dime      Quarter Dollar  Half Dollar    Presidential $1  Native American $1 Coin 
       Weight  2.500 g  5.000 g  2.268 g   5.670 g             11.340 g      8.1 g                 8.1 g 
Logged
Dave Andreski
Titanium Member
*******

Kudos: 82
Offline Offline

United States United States

Posts: 3,052




Ignore
« Reply #676 on: May 28, 2013, 01:03:04 PM »

From the US Mint website:
Denomination  Cent   Nickel    Dime      Quarter Dollar  Half Dollar    Presidential $1  Native American $1 Coin 
       Weight  2.500 g  5.000 g  2.268 g   5.670 g             11.340 g      8.1 g                 8.1 g 

Selling coins and precious metals to balance your P-30's with Huh
Dave
Logged

Aspire to inspire before you expire.
rbrpwr
Bronze Member
***

Kudos: 1
Offline Offline

United States United States

Posts: 35



Ignore
« Reply #677 on: May 29, 2013, 12:49:39 PM »

They were weighing quarters to calibrate their scales.  I thought they might as well have a reference.
Logged
Dave Andreski
Titanium Member
*******

Kudos: 82
Offline Offline

United States United States

Posts: 3,052




Ignore
« Reply #678 on: May 29, 2013, 12:59:35 PM »

They were weighing quarters to calibrate their scales.  I thought they might as well have a reference.
I understand now. Cool.
Dave
Logged

Aspire to inspire before you expire.
dephela
Silver Member
****

Kudos: 2
Offline Offline

United States United States

Posts: 131




Ignore
« Reply #679 on: May 29, 2013, 06:50:32 PM »

An ounce is 28.35g, interesting that 5 quarters equal 28.35g!
Logged

Dennis
jose
Bronze Member
***

Kudos: 6
Offline Offline

Argentina Argentina

Posts: 96



Ignore
« Reply #680 on: May 30, 2013, 07:08:19 PM »

To DerekMc
DerekMc I ask for help with my P30 helices because here not achieved any material imported by the restrictions to enter the country unless the mail with paypal buying them that well come. Regards Jose
Para DerekMc
DerekMc te pido ayuda con las hélices para mis P30 ya que aquí no se consigue ningun material importado por las restricciones a introducir al pais salvo comprandolas por correo con paypal que asi entran. Saludos José 
Logged
151-30
Copper Member
**

Kudos: 1
Offline Offline

France France

Posts: 6



Ignore
« Reply #681 on: May 31, 2013, 06:13:05 AM »

finished at last.....too heavy at 56 gr (prop:15,6 tail:3 wing:17,4 fus: 20)

waiting some spare time to test fly, intended for PGI trim with no wraps......and 4 strands of vintage 1/4 1986 pirreli

no carbon.....
Are you flying to the 40gm or 50gm minimum weight?
in France, P30 is only for spécial events as "coupe d'hiver" contests (2 or 3 a year with no more than 10 contestants it seems).
I built it with 50 gr rule in mind because it is more easy to build and fly for beginners. I think that 40 gr is an "builder expert contest"

I have not gone to a free flight contest for at last 10 Years. And I have no more contacts with free flight modellers. If some french modellers have interest in this class I would be happy to contact them.

I buid this P30  to remind "good old time" but i am now infected again by the virus and I am now testing carbon building but with only  home made parts (it is so easy to make a tubular carbon spar 3,5 mm diam at 0,25 gr/dm ... so why  buying it ? perhaps I will explain  it to you soon ).

my only problem is to find time and space for flying, not for experiment building technics. 
Logged
atesus
Gold Member
*****

Kudos: 26
Offline Offline

United States United States

Posts: 679




Ignore
« Reply #682 on: June 07, 2013, 02:28:26 AM »

This is my last build and the first P-30 in my hangar. Fantastik P-30 built from an Atalar Model kit. A little on the heavy side (50g) due to the tissue I used (Coverlite) but flies pretty good...

--Ates
Attached files Thumbnail(s):
Re: Show us your P-30's
Re: Show us your P-30's
Re: Show us your P-30's
Logged
Richard Ewing
Bronze Member
***

Kudos: 2
Offline Offline

Italy Italy

Posts: 87



Ignore
« Reply #683 on: June 27, 2013, 03:49:38 PM »

My big geared P-30 project.  It ended up as a development project for raised leading edge wing construction using home made D boxes. 

I started with the balsa wing and stab but was very disappointed with them after applying the 1/4 mil mylar covering.  They warped a lot.

So I built the slightly heavier carbon surfaces, and switched the wing airfoils to "sorta Low Drag" shapes to both lower the camber, and try building with raised leading edge, that fairs smoothly back to the spar.
Attached files Thumbnail(s):
Re: Show us your P-30's
Re: Show us your P-30's
Logged
jim_buxton
Silver Member
****

Kudos: 4
Offline Offline

United States United States

Posts: 153


Fly more gliders!



Ignore
« Reply #684 on: July 18, 2013, 12:05:56 PM »

Dan,
This is a picture from the NATS this year.  Is this the P-30 you flew to second place? 
Attached files Thumbnail(s):
Re: Show us your P-30's
Logged

~Jim Buxton
Columbus Ohio
Tmat
Titanium Member
*******

Kudos: 68
Offline Offline

Canada Canada

Posts: 2,933




Ignore
« Reply #685 on: July 18, 2013, 12:18:35 PM »

As I recall, Dan had a conventional model that he flew for all but the last flight as he lost his #1 model on the previous flight. Thus he had to fly the canard. Which flew very well by the way!


Tony
Logged

F1B guy...
But don't hold that against me!
jim_buxton
Silver Member
****

Kudos: 4
Offline Offline

United States United States

Posts: 153


Fly more gliders!



Ignore
« Reply #686 on: July 18, 2013, 12:31:26 PM »

Ah, that makes sense. I saw him launch a conventional one that went up like a rocket at around 1:00 pm or so.  That had to be the one he lost, it was going up like a homesick angel even after the power was off.  What was the design and power combo on your primary, Dan?
Logged

~Jim Buxton
Columbus Ohio
danberry
Gold Member
*****

Kudos: 17
Offline Offline

United States United States

Posts: 952



Ignore
« Reply #687 on: July 18, 2013, 01:37:44 PM »

Hey now.
Here's the thing: I flew a regular plane for 5 flights. It's been a work in progress. The new wing covered in tissue has made a big difference. I cut a 4 1/2 minute fuse to make the 3 minute max. It went over the river and beyond a pond. It took about 10 minutes to decide it wasn't up a tree on a little peninsula in the pond. I was knee-deep in poison ivy. Once I decided it was across the pond I came back and pulled out the canard. The canard has always used the tracker for noseweight. however, it used the tracker with small batteries which is in Texas. I made a guess on moving the bigger tracker back to compensate and guessed .... poorly. It was nose-down in the glide and couldn't do two. I do believe there was good air for the canard but it just drove through after the power ran out. Ah well.
Got the plane after trophy time. Easy get. It was at the edge of a gravel drive about 7 feet up the weeds. The lady of the house was very nice. Same area Larry davidson went to the day prior.

The canard weighs 55 gms without rubber. It does fine in windy thermals but it was nose heavy. Haven't flown it in almost two years.
It may also have lost it's washout. Without washout it will glide out od f a thermal. I forgot to check but I had no plans to fly it.

Ah well. Say " La Vee".
Logged
jim_buxton
Silver Member
****

Kudos: 4
Offline Offline

United States United States

Posts: 153


Fly more gliders!



Ignore
« Reply #688 on: July 18, 2013, 02:02:31 PM »

lets see a pic of theat second place model!
Logged

~Jim Buxton
Columbus Ohio
danberry
Gold Member
*****

Kudos: 17
Offline Offline

United States United States

Posts: 952



Ignore
« Reply #689 on: July 18, 2013, 02:13:53 PM »

I don't know if I have one.
It looks a LOT like Hatschek's Goblin. Different wing structure and pylon. Bottom fin (it's white).
About 42gms without the tracker.
Logged
Pappy
Bronze Member
***

Kudos: 6
Offline Offline

United States United States

Posts: 98



Ignore
« Reply #690 on: July 18, 2013, 08:06:50 PM »

Dan and David made this a great P30 contest.
Attached photo shows Dan launching his new
P30.

Pappy
Attached files Thumbnail(s):
Re: Show us your P-30's
Logged
jim_buxton
Silver Member
****

Kudos: 4
Offline Offline

United States United States

Posts: 153


Fly more gliders!



Ignore
« Reply #691 on: July 18, 2013, 10:13:32 PM »

Dan: You ready Bob?
Bob: What?

Must be one loud P-30 you have there Dan.
Logged

~Jim Buxton
Columbus Ohio
danberry
Gold Member
*****

Kudos: 17
Offline Offline

United States United States

Posts: 952



Ignore
« Reply #692 on: July 19, 2013, 08:56:52 AM »

Quiet airplane. Loud shirt.
Gotta maintain a balance.
Always check that your timer is alert to a launch.
Logged
Tapio Linkosalo
Platinum Member
******

Kudos: 28
Offline Offline

Finland Finland

Posts: 1,182



Ignore
« Reply #693 on: July 22, 2013, 04:24:27 AM »

My previous "new design" [ http://www.hippocketaeronautics.com/hpa_forum/index.php?topic=861.msg56594#msg56594 , http://www.hippocketaeronautics.com/hpa_forum/index.php?topic=861.msg56776#msg56776 , http://www.hippocketaeronautics.com/hpa_forum/index.php?topic=5069 ] did not turn out to be so good; even though XFLR simulations suggested much better glide than my older models, the actual measured sinking speeds of the models were rather similar. Maybe that big drag disk (= propeller) in front of the plane equalizes things so that all models glide the same?

With that in mind, I decided to take another approach for P-30. Instead of trying to improve the glide, aimed for a model that would climb better. Thus a new design, with a smallish area wing, simple tips that are not too narrow, and low-drag airfoil. The resulting wing has 10cm wide constant-width center sections and slightly tapering tips, and sports a Midic LDA airfoil. Wing structure has tubular spars that have proved to work OK for P-30. Attached a couple of pics.

Attached files Thumbnail(s):
Re: Show us your P-30's
Re: Show us your P-30's
Logged
Tapio Linkosalo
Platinum Member
******

Kudos: 28
Offline Offline

Finland Finland

Posts: 1,182



Ignore
« Reply #694 on: July 26, 2013, 03:30:16 AM »


Covered the wing. Center sections with 10 mils mylar (F1A tailplane covering), tips with 5 mils stuff, that was painted on the inside with fluorescent paint before covering. All-up weight (with 2mm carbon joiner) is 14 grams (the wing is in two halves for ease of transport). The pylon is the same one used in my previous models, with laser-cut sides and balsa bulkheads. The pylon is shaped so that the wing joiner fits in a pivot/fork in the same manner as F1A tailplanes (cut-out in the forward-center section of the wing), this gives a positive locating of the wing and also enables building a wing-pop-up DT if needed. But I think I'll start with conventional pop-up tail. It remains to be seen if wing wiggler would be needed, but I'll start without one.
Attached files Thumbnail(s):
Re: Show us your P-30's
Re: Show us your P-30's
Re: Show us your P-30's
Logged
Yak 52
Titanium Member
*******

Kudos: 66
Offline Offline

United Kingdom United Kingdom

Posts: 2,481


Free Flight Vagrant



Ignore
« Reply #695 on: July 26, 2013, 05:16:18 AM »

Looks good Tapio.

My previous "new design" did not turn out to be so good; even though XFLR simulations suggested much better glide than my older models, the actual measured sinking speeds of the models were rather similar. Maybe that big drag disk (= propeller) in front of the plane equalizes things so that all models glide the same?

I don't believe XFLR5 is that trustworthy when it comes to evaluating planforms. It appears that changing panel density can affect span efficiencies so a complex wing tip shape may give optimistic results:

http://www.rcgroups.com/forums/showthread.php?t=1576925

I've been looking at profile drag at low Re and I was surprised at just how important this is (apparently far more important than planform - especially with fixed span) So my P20 design ended up low aspect ratio to keep the Re up, with a similar planform to yours.

Any chance you could provide coordinates or a .dat file for the Midic airfoil? It looks quite low camber.


Ates, the Fantastik looks great. What size wood is the fuselage construction?


Cheers
Jon
Logged
Ross J
Bronze Member
***

Kudos: 3
Offline Offline

United States United States

Posts: 79




Ignore
« Reply #696 on: July 27, 2013, 12:24:05 AM »

A note to Richard Ewing:

The 2001 NFFS Sympo contains a paper by John O'Dwyer in which he tested three sizes of p-30, large, like yours or the Window Plane by Art Ellis, normal sized and small.  Overall the small model was best because it got more altitude than it lost in sink speed, and it was easier to build to 40g.  Since that article I've made my models smaller and they perform better. I will try to post some photos.

Ross
Logged
atesus
Gold Member
*****

Kudos: 26
Offline Offline

United States United States

Posts: 679




Ignore
« Reply #697 on: July 27, 2013, 03:15:35 AM »

Jon, thanks  Smiley. The fuselage of Fantastik uses 3mm square longerons with 3x1.5 mm2 cross members and diagonals (not sure what the proper terms are for those  Embarrassed)
Logged
Yak 52
Titanium Member
*******

Kudos: 66
Offline Offline

United Kingdom United Kingdom

Posts: 2,481


Free Flight Vagrant



Ignore
« Reply #698 on: July 27, 2013, 04:08:44 AM »

Thanks Ates. That's what I'd call 'em too  Grin
Logged
Tapio Linkosalo
Platinum Member
******

Kudos: 28
Offline Offline

Finland Finland

Posts: 1,182



Ignore
« Reply #699 on: July 29, 2013, 05:22:25 AM »

Any chance you could provide coordinates or a .dat file for the Midic airfoil? It looks quite low camber.

I could not recall where I got the coordinates so I thought if I should ask for permission first, but then thought to look at the 'net. And bumped into this link: http://tracfoil.free.fr/airfoils/profils/dat/mid103.dat


Logged
Pages: 1 ... 21 22 23 24 25 26 27 [28] 29 30 31 32 33 34 35 ... 37   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!