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Author Topic: Show us your P-30's  (Read 72941 times)
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or_sh
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« Reply #950 on: October 06, 2020, 02:20:57 AM »

Hey everyone,
I start with i don't know why i need 5 P-30 models, but sometimes it was fun to build it or assemble some of the parts. If i not build my F1B at least i do this.
Two of my models was in my models box for 4-5 years at least , 2020 start with the crazy corona-virus , at the first quarantine i build my third model , i take the wing and the stab of the "Pirate" model and build the fuselage and the fin.
When i trimmed it , in is last flight of is life the DT wire was stuck and the model fly 4 minutes and land on the main road , 5 second after car make from him confetti, so i organize used wing and build another model but now i make it 2 pieces wing.
Now i finish 2 more models like Tony Mathews plan with small changes , i think is one of the best models for P-30 , yes its not easy plan.
My last model i used one layer of Kevlar and one layer of Carbon for the fuselage , it little bit more heavy so i think better only kevlar.
My Tony models wight between 42-45 grams ready to fly without beacon The 2 others model are 45 and 47 grams. 
The Kevlar / Carbon fuselage length are 500 mm On all my models i used: 
Liav timers wire burn 
Gorban rubber holder 
Czech prop 
some time i use half tube for the rubber and then i use also roller hook     

* Some of my models i upload here so sorry , now i will show you all of them.
* Tony Mathews thank you again for help and great plan
If some have a questions you can send me e-mail - [email protected] , i am not enter to this forum all the time .
Enjoy....



fantastic work, thank you for sharing these, there is something very beautiful about the P30 design !

Pat


You welcome , hope to trimmed them soon and also make a video , but know i have little bit problem with the trimming.
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Tapio Linkosalo
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« Reply #951 on: October 06, 2020, 02:51:11 AM »


Yes, the decalage and rearward CG is the secret.

This design is old, I first flew it in late 80's. Way back then I had a forward CoG, around 60%. I had similar problems as you describe, loops and wing-overs at high torque. I had to use a VIT to tame that, and with variable incidence tail the starts were easy and quite spectacular, straight vertical climb for the first 4 to 5 seconds.

Recently I have been playing a lot with E-36 and catapult gliders, to find out that the large speed envelope can be managed without VIT. So for this model I decided to move the CoG back, to 75%. With that setting the decalage is quite close to zero degrees, and thus the climb is nice and safe even without VIT. Yet the model is capable to fly in turbulence. I suppose the relatively large tailplane (300*70mm or 12" * 2 4/5") gives enough stability.
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or_sh
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« Reply #952 on: October 06, 2020, 03:03:10 AM »


Yes, the decalage and rearward CG is the secret.

This design is old, I first flew it in late 80's. Way back then I had a forward CoG, around 60%. I had similar problems as you describe, loops and wing-overs at high torque. I had to use a VIT to tame that, and with variable incidence tail the starts were easy and quite spectacular, straight vertical climb for the first 4 to 5 seconds.

Recently I have been playing a lot with E-36 and catapult gliders, to find out that the large speed envelope can be managed without VIT. So for this model I decided to move the CoG back, to 75%. With that setting the decalage is quite close to zero degrees, and thus the climb is nice and safe even without VIT. Yet the model is capable to fly in turbulence. I suppose the relatively large tailplane (300*70mm or 12" * 2 4/5") gives enough stability.


Thank you Tapio for your replay .
In my models now the C.G is 65% , i think i will try to take it back to 75% . I am also use in the past VIT but i prefer not to use it now.
about the front end , you use down trust , right trust? if yes how much?
second question you do something with the warps?

Or
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Tapio Linkosalo
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« Reply #953 on: October 06, 2020, 03:24:02 AM »

I did not measure the thrust line, but it looks like a little bit right and a little down. The wing tips have symmetrical washout (about 2mm) and right center section has a slight wash-in (about 1mm). The rudder is flat plate and the moving part is ever so slightly turned to right. There is practically no tail tilt.
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OZPAF
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« Reply #954 on: October 06, 2020, 04:44:30 AM »

Very nice climb Tapio - your settings sound very close to those recommended by PGI trimming techniques.

John
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Tapio Linkosalo
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« Reply #955 on: October 06, 2020, 04:47:34 AM »

Yes, with the exception that my thrust line is not through the (vertical) CG of the model, as PGI would suggest. Seems like that is not needed. And actually PGI would also suggest symmetrical fin and turn made my tail tilt. But rudder seems a safe way to make the turn, too, and I think the slight wing warp also helps the turn.
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gman
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« Reply #956 on: October 06, 2020, 11:39:32 AM »

Hi Tapio, that is a most impressive climb and pattern. Thank you for detailing some of the aspects of your design, warps, cg, tailplane etc. but have I missed the details of what length motor you are using? Is it earlier in the thread? Short fat motors and long thin motors pose different problems.
With this talk of VIT, in the UK the P30 rules forbid any moving surfaces and I just assumed that that was the case everywhere. In which countries can you fly with moving surfaces?
Gavin
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DerekMc
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« Reply #957 on: October 06, 2020, 11:52:16 AM »

Gavin, as far as I know moving surfaces are allowed everywhere but the UK.
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Derek
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« Reply #958 on: October 06, 2020, 12:24:05 PM »

Derek thank you, I am truly astounded by that. I've seen so few P30s with auto surfaces I thought the ban to be pretty universal. I think I need a strong coffee to get over it!!
Gavin
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Tapio Linkosalo
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« Reply #959 on: October 06, 2020, 01:04:27 PM »

Hi Tapio, that is a most impressive climb and pattern. Thank you for detailing some of the aspects of your design, warps, cg, tailplane etc. but have I missed the details of what length motor you are using? Is it earlier in the thread? Short fat motors and long thin motors pose different problems.
With this talk of VIT, in the UK the P30 rules forbid any moving surfaces and I just assumed that that was the case everywhere. In which countries can you fly with moving surfaces?

Thanks!

I mostly fly with 6 strands of 3mm (1/8") rubber. With the latest Chinese (Volare) props, the motor run is up to 50 seconds, which to me seems quite optimal for P-30. I have tried also 4 strands (or 8 strands of 3/32"), and while that gave a longer motor run for the smaller-pitch Ikara props, there is no need for such thin motors with the current props).

In addition to UK, also Sweden has a ban of moving surfaces for the model. In Finland and Slovakia (I think) the minimum airframe weight without motor is 50 grams, while other countries have 40 grams. So the rules vary from country to country.
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gman
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« Reply #960 on: October 06, 2020, 04:31:53 PM »

That's a reply full of useful advice, I haven't flow P30 for a while and when I did it was with IGRA and Peck props with 4strands of 1/8th.
Now I'm looking to build a couple of new models intending to fly next year (hence my interest in the thread). I will be using the current Chinese props so your advice on motor size is welcome as I would have certainly started out with a long motor otherwise. The last modification I did to my small fleet of "Bondy's P30" (see FFQ) was a drop off wing DT. This means that you can dare to follow another model which is in strong lift, before that with just tip-up tail you ran a real risk of throwing the model away!

Gavin
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Tapio Linkosalo
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« Reply #961 on: October 07, 2020, 03:06:19 AM »

The Chinese prop is the best I have seen for P-30. Higher pitch and wider blades than Ikara, and Peck I have not used for ages as they are no longer easily available. The Chinese looks bulky and heavy, but actually is not. Thanks to the pitch and wide blades it absorbs power well, and indeed gives nice longish motor runs. Might even work with 5 strands, but then again,I prefer my models to launch strongly, as on the video.
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gossie
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« Reply #962 on: October 07, 2020, 03:59:55 AM »

40 grams and NO auto surfaces in Australia.
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DHnut
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« Reply #963 on: October 07, 2020, 05:31:15 AM »

Same in New Zealand.
Ricky
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didierlouis
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« Reply #964 on: December 15, 2020, 12:22:57 PM »

Dear All

Or, your models are beautiful. Bravo and make them fly perfect!
Tapio I appreciate your comments. Your model climb is fantastic and I hope the glide is as good as it can be with a P30 and the drag of the propeller.
No problems for DT with a classical stab tilt up? Be carefull of big thermals!

I join here a design of Grorges Matherat.
It goes up to the time where auto surfaces were not current and it was necessary to control power burst w/o VIT.

The key is to have a decalage the smallest possible!

CG location has to move rearwrd as much as possible.
I remember some having  a 80 - 85% of chord CG location.
The good thing with a P30 (and E36 as well) is that we can increase the stab size in order to maintain the Stability Margin at a level acceptable!
The bad thing is the impact on model weight.
10 g too much is is 17% of the weight in a P30; may be 20% loss in altitude reached with the same energy!
Could be 1 strand differnece on  rubber for the same climb speed .
If I refer to the F1G experience we can put 400 turns with 12 strands and 500 turns with 11 strands...at least 10 sec more motor run!
Its a lot, especially with the poor glide of a P30!

Coming back to Georges Matherat model, you can observe the zero setting nearly everywhere.
I came back to model flying too lately before he died and could never talk with him about these setting.
As my modellers skills are not good enough to reproduce his models, I do not risk building a replica to check, but I believe that the design is good.

By the way Evgeny Gorban has designed a P30 a few months ago (you can see it on Facbook), and he kindly sent it to me with a batch of parts.
The 40g limit is reached, including DT with a modified Tomy, and a double ball bearing front end.
I will send a picture and comments after test  ( today France has released partially confinement and we can drive a little to get to the flying field).

All, keep safe and enjoy Xmas. We hope to see you all on the field when freed up!

Didier

PS
Tapio, to which design of Tony Matthews you refer to?
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Tmat
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« Reply #965 on: December 15, 2020, 01:26:27 PM »

My P30 flying surfaces. This was designed for an auto stab. For fixed surfaces I'd use a larger stab with a rearward CG.

Tony
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« Reply #966 on: December 15, 2020, 01:37:41 PM »

Hello Didier

You are well I trust? I had not seen the P30 of Georges before and the high tail model looks very interesting. Ray and Don were going to build a P30 during lockdown and I may try and persuade them to try one of these.
Cheers

Peter
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gman
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« Reply #967 on: December 15, 2020, 04:04:23 PM »

Hi Didier,
It's been far to long... like PeeTee I hope that you are well, and look forward to maybe meeting up when we are all able. Not at Viabon though I fear; too early for that.

Gavin
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didierlouis
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« Reply #968 on: December 15, 2020, 05:14:47 PM »

Hi Peter, Hi Gavin

It is really good to hear from you two!

I'm well and carefull to avoid any contamination.

As you can see on the design, it was published in FFQ quite recently.
I do not really lke the stab and fin which is a real difficulty to build and make it work!
Georges models are always a challenege to build and operate.
But the philosophy here is interesting.
I have now a box with 4 F1G + 3 P30 + 1 F1B to test as soon as I can; perhaps in Arbigny if not flooded next week!
By the way a big event is organised at the end of July 2021 in Arbigny and it will be on the FAI list but not counting for World Coupe.

Have a good time and my best wishes to all my good english friends.

Take care.

Didier
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Tapio Linkosalo
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« Reply #969 on: April 13, 2021, 03:00:27 PM »



Parts for a prototype beginners P-30 kit (flat-bottomed airfoil, balsa box fuselage).
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DerekMc
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« Reply #970 on: April 13, 2021, 03:08:33 PM »



Parts for a prototype beginners P-30 kit (flat-bottomed airfoil, balsa box fuselage).

Excellent!
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« Reply #971 on: April 13, 2021, 03:19:06 PM »

Quote
Parts for a prototype beginners P-30 kit (flat-bottomed airfoil, balsa box fuselage).

Interesting. Do you have a general arrangement drawing we could see?
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Tapio Linkosalo
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« Reply #972 on: April 14, 2021, 12:25:12 AM »

Quote
Parts for a prototype beginners P-30 kit (flat-bottomed airfoil, balsa box fuselage).

Interesting. Do you have a general arrangement drawing we could see?

The model is basically similar as my previous design [ https://www.hippocketaeronautics.com/hpa_forum/index.php?topic=861.msg262241#msg262241 ], but replacing the wing airfoil with a flat-bottomed one, and using a balsa box for fuselage instead of a kevlar tube. So no fancy or complicated structures, just laser-cut a few balsa sheets and grab your glue bottle!
 
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Tapio Linkosalo
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« Reply #973 on: April 15, 2021, 12:27:22 AM »


Framing up...
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betocastrucci
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« Reply #974 on: April 28, 2021, 06:21:22 PM »

Meteoro is my current P30, designed by Omar Grassetti, it has an unusual setup, just one central dihedral, short motor length, short nose momentum. It is intended to fly at turbulent air, with high speed launch. Has a RL pattern, then it is very easy to trim and fly. After more than 30 flights, had not even one poor launch.
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