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-   -   Pitts M12 26% plans available soon (http://www.rcuniverse.com/forum/scratch-building-aircraft-design-3d-cad-174/2645862-pitts-m12-26%25-plans-available-soon.html)

bbt 02-11-2005 10:00 AM

Pitts M12 26% plans available soon
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I am currently working on the plans for a Pitts Model 12. It looks like a Sukhoi with two wings. I really like it :)

It is slightly modified for 3D capabilities : increased fuse length, increased wings surface (over 120 dm²), increased control surfaces, ...
Should be OK for F3A aerobatics too.

Some characteristics:
175cm wingspan (26%)
175cm Fuse length,
Engine: 1.80 or bigger
Airfoil: E168 12,45%,
8 servos: 4 ailerons, 1 rudder, 2 elevator, 1 engine
Target weight : 5.5 - 6.5 Kg

The plan should be available for download in a near future.

What do you think?

Boogie 02-11-2005 02:03 PM

RE: Pitts M12 26% plans available soon
Wow!!! Very nice plane. How would it perform with mvvs 1.6 or 2.1 gas?? I would make it slightly smaller though. This is fabulous!!!!

cbcflyer 02-11-2005 04:02 PM

RE: Pitts M12 26% plans available soon
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I'm sure you probably have an example you're modeling, but I have a good friend about 1/4 mi down the road who built and flies a full scale one. I can take pictures, measurements, etc if you like. I've got probably 10 hrs of flight time in it. Incredible airplane, especially with the 3 bladed prop. The front cockpit sure is blind on the ground though - much better in the back. Keep us posted on the plans.


SilverEagleBW 02-11-2005 04:32 PM

RE: Pitts M12 26% plans available soon
Great bbt!Looking forward to the plans,,,,,,!!!:D,,,,Another plane to build! YAY!

bbt 02-12-2005 09:22 AM

RE: Pitts M12 26% plans available soon
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It will be difficult to reach the level of quality of your plans. I doing my best :D

Anyway, here is a preview. Still a lot of work but it starts looking good.


paof 02-12-2005 10:37 AM

RE: Pitts M12 26% plans available soon
Hi BBT another bipe to build,wonderfull.
PAOF from Maracaibo Venezuela South America,

SilverEagleBW 02-12-2005 03:03 PM

RE: Pitts M12 26% plans available soon
bbt,Your plans look GREAT!The formers are excellent,along with everything else that you have done!You are doing a very good job on this plane,after you are done with the plane i might work the plan set over for you.:DJust keep up the good work!

Gray Beard 02-15-2005 03:34 PM

RE: Pitts M12 26% plans available soon
Now that looks like A plane worth building. Are you designing it so the wings are easy to remove and install at the field?? That's the only problem I have with my Bipes and the reason I keep them under 70 inches.
When you get them finished and posted I will have to pick your brain as to how to download them and put them on A CD so I can have them printed. {{ Computer Stupid}
Thanks for sharing this plane with us.

mangolo 02-15-2005 05:54 PM

RE: Pitts M12 26% plans available soon
bbt: thanks for the offer,will be monitoring this so we can build one,beautiful plane

thanks again


bbt 02-15-2005 06:13 PM

RE: Pitts M12 26% plans available soon
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Thanks Slade. To be honnest, I am quite happy with the results so far :D

I just calculated the CG. It looks like I will have to make the tail as light as possible I will have to be creative to make it light and still strong or... may be move the wings a little bit backward. Any suggestions here ?

As a start, what do you think about the following value for the incidence?
upper wing 0°
Lower wing 0°
Elevator 0°
with engine Down thrust 2° & Right thrust 2°

Boogie, I read in a review that a MVVS 1.6 Gas is able to swing a 18x8 Menz-S, wood propeller at 7350 rpm developping a thrust or 6.5 Kg. This would be just enought for 3D if the weight stays within my target of 5.5 - 6.5 Kg.

I'll make both DXF and PDF files available (CDR format is for Slade only :)). PDF files are usable on virtually any PC and easy to print without specific computer skills.

Here is another preview:

SilverEagleBW 02-15-2005 11:37 PM

RE: Pitts M12 26% plans available soon
bbt,I wouldn't move the wings back,don't want a short coupled plane.On the incedences,you might want to add around one degree of positive to the stab,lotta biplanes need that,even the Ultimate.You don't need to make a copy in CDR for me,i can open DXF etc.:D

Not to sure about the 2 degrees of downthrust on the engine,if it was me i would set everything at zero except for two degrees right engine thrust,one degree positive on the stab.Then build the plane and make adjustments as needed,might even want to consider lowering the top wing a bit and see if that smooths things out any.Pretty darn cool plane,well worth taking the time to experiment with the settings to have a superb flyer.:D

LN-JET 02-17-2005 09:17 AM

RE: Pitts M12 26% plans available soon
Nice one!
My MVVS 1.6 gas swings a 18x8 APC @ 8300 rpm with the factory tuned pipe.
It flies my 6kg Cap 232 with authority through most IMAC style aerobatics,
but too little reserve for hovering and serious 3d.
I'd think you will be hard pressed to build this bipe any lighter than that.

Regarding incidence angles, why not use the angles from the original,
or from some of the similar sized Ultimates?


bbt 02-18-2005 07:03 PM

RE: Pitts M12 26% plans available soon
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The plane is largely inspired by the Pitts Model 12. As it is slightly modified, its name will be ... Spirit of Pitts

The plans are finished :D

Wing incidence will be:
- Stabilizer set at 0
- Bottom wing set at 0
- Top wing set at 0 with some adjustments +/- possible during the trimming out phase.

This weekend I will make some additional sanity checks. I want to be sure that everything will fit perfectly. I should be able to post the DXF & PDF files early next week but I still need to find a host. If not then I will make some time to create my own web page.

My intention is of course to build & fly the plane but ...first the laser cutting sheet. Yes, this will be available too ! I do not want to cut this manually .. I am too lazy [:o]

Here is a Spirit of Pitts preview:

canadagoose 02-18-2005 07:17 PM

RE: Pitts M12 26% plans available soon
Really nice job bbt, beautiful looking bipe, i would post them up along side Slades plans if you wanted.

phuffstatler 02-18-2005 07:58 PM

RE: Pitts M12 26% plans available soon
Hey bbt, areyou using an off-the-shelf canopy for it, or is it a custom made piece?

Fabulous work, by the way. I'm envious.

phil in georgetown

Looper 02-18-2005 11:38 PM

RE: Pitts M12 26% plans available soon
Excellent work! Are you planning to add the scale wingtips?

bbt 02-19-2005 03:26 PM

RE: Pitts M12 26% plans available soon
Terry, many thanks for your proposal.
To be honest, I was hoping that you would propose this :D.
When the plans are ready, I will drop an Email.

bbt 02-23-2005 03:04 PM

RE: Pitts M12 26% plans available soon
The Spirit of Pitts plans are finished. The laser cut sheet will follow.

The free plans will be available soon on Terry's site:

Let me know if you have plans to build this bird.
Believe me... it's an eye catcher[:-]. A future star on the flying fields.

Have fun !

Terry, I've sent the DXF & PDF files by Email. Could you please post them? Thanks ;)

bbt 02-23-2005 03:06 PM

RE: Pitts M12 26% plans available soon
I almost forgot ... when browsing the web site of Jim Kimball I discovered the Raptor A.S.
What is the Raptor A.S.? It’s a monoplane Pitts Model 12!!!!!

This will be my next free plans: some minor changes on the Spirit of Pitts fuse and a new wings plan. Easy :D

Gray Beard 02-23-2005 03:14 PM

RE: Pitts M12 26% plans available soon
My puter was unable to locate that web page?? Is it down for some reason??

bbt 02-23-2005 03:33 PM

RE: Pitts M12 26% plans available soon
Sorry for the links[:o] My mistake ... too many ////

Here is the link to the plans :

and the link to Jim Kimball's site for the Raptor a.s. :

canadagoose 02-23-2005 06:49 PM

RE: Pitts M12 26% plans available soon
bbt, i got the email and viewed the images you sent and that is absolutely an awsome job you did. This is definitely going to be a must build:D I know i'm impressed. I will post the files up on the site tommorrow morning after i get home from work.

SilverEagleBW 02-25-2005 03:24 AM

RE: Pitts M12 26% plans available soon
bbt,just downloaded the plans,Great Job!,soon as get caught up here i am going to build that plane.Should fly pretty nice with a Moki 2.10.:D

Boogie 02-25-2005 11:58 AM

RE: Pitts M12 26% plans available soon
Awesome work on this one!!!! So now I will have to think of size of it. Some people say that with mvvs 1.6 Carl Goldberg's Pitts s-12 would be great. Specs:

Wingspan: Top 60" Bottom 58"

Wing Area: Top 555" Bottom 534"

Flying Weight: 11¼- 12¼lbs.

Power: .90-1.08 2-Stroke 1.20 4-Stroke
With this combo it might be a good flyer. according to what LN-JET mentioned before it would give about 22lbs. of static thrust. Is this possible??
I was thinking of building it that size (CG size) with 4-hs475s for ailerons 1 of those for throttle and 3010s for rudder/elevator. Would this combo work? Maybe tuned pipe:D

Finn J. 02-27-2005 07:15 AM

RE: Pitts M12 26% plans available soon
Hi bbt,
What a great choice of model. It looks so cool! In my opinion you have done a great job with the plans. Very nice quality!

I am pretty sure, that I am going to build one, so therefore I am very interested in more details and would really appreciate your reply to the following:

1. When are you going to build a prototype? When will you start and how long will it take, do you think - hard to tell, I know ;)
2. When looking at the center of the fuse design, have you considered to increase the width of the plywood "spine" to gain more stiffness and to create more room for servos and stuff? Maybe it could also save some weight of the fuse formers
3. In your plans all of the formers and also the "spine" fuse sides are made in plywood. Which type of ply do you have in mind? (I think some weight could be saved in this area)
4. In my opinion, the suspension of the undercarriage and the upper wing is always a bit tricky - can you share your ideas in these areas?
5. I am considering to down scale it slightly, due to the size of my building room and to ease the transportation to the flying field. If it should be fitted with a ST90 or FX90 glow engine, which size of wingspan/length would you recommend?


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