MM PT-17 AND 40" PT-17 Stearman

by aviator08 | July 19, 2016 | (17) Posted in Projects

I have always been a big fan of biplanes; just something about them that is enticing. Watching the FF Gotha Gaggle unfold was a real treat, especially with the "skins" that Stephen  ( Rasterize)  designed for them. The only thing missing was the biplanes. I started to design a Sopwith Camel, but decided that a better initial design/build would be the PT-17. The goal was to make it as scale as possible, with out being overly complex.

 

 MM size PT-17 Stearman

 FT Power Pack F

CG = 1 3/4" from leading edge of top wing 

MM size PT-17 Plans

MM PT-17 Plans ( full)                          MM PT-17 Stearman Plans (tiled)

 

 

40" PT-17 Stearman 

FT Power Pack C

CG = 2 3/4" from leading edge of top wing

Flying weight = 31oz

40" PT-17 Plans    ( Updated )

40" PT-17 Stearman fuselage ( Full )                    40" PT-17 Stearman fuselage ( tiled)

40" PT-17 Wings ( full)                         40" PT-17 Stearman wings ( tiled )

40" PT-17 Poasterboard ( full)               40" PT-17 Stearman Posterboard (tiled)

 

40" PT-17 Stearman maiden flight

 

 

 Twins :-)

 

The MM size appealed to me with the 24" wingspan, so that is what I started with. It took a couple of modifications to get it to fly the way it should. Slight scale variances were made, but unless you really know the aircraft, you would not even notice them. 

 

 

 The MM size PT-17 is made out of two sheets of foam board, poster board, and skewers. I opted to add the landing gear and wheels for scale appearence sake. Because of the heavy radial engine on the full scale, additional wieght in the nose is needed to get the correct CG.  

I would clasify the MM size PT-17 as an intermediate build and flyer. It floats rather well, but does have a definent stall point. Because of the short wingspan it is very nimble. I used the FT "F" power pack on it . This gives it ample power for scale flying. 

  

 Here are some build sequence photos with descriptions.

 

Top wing built, Bottom wing ready to assemble. 

 Fuselage and tail assembly built, bottom wing attached.

 

Top wing ready to be attached. ( Note the wing guides that set the proper distance and incidence.) 

Top wing and power pod installed. Power pod angle is specific to this aircraft.

 

"Dummy" engine and landing gear installed. Ready for maiden flight.

 

 

Maiden flight 

 

 

 

After building the MM size PT-17 and successfully flying, I decided to enlarge the plane to a 40" wingspan. The build progressed relatively well and with surprisingly scale flying characteristics, it is a very stable flyer. The large wing area enables the aircraft to float really well. No extra weight was needed as the battery provides the correct weight/ CG.  I would classify the large-scale build as intermediate and a beginners second plane to fly. 

  

  

 Here are some build sequence photos with descriptions.

 

 Fuselage assembled with covering. ( I later removed the covering on the top side as it is covered with posterboard.)

 Lower wing assembled and covered.

 

 Power pod inserted, as well as horizantal stabilizer installed.

 

  Rudder installed and lower wing glued in place. 

 

Canopy hatch finished. 

 

 Upper wing ready to be glued in place. ( note wing assembly guides included in plans)

 

 Upper wing attached, Landing gear installed.

 

 Rear view.

 

 Close up of cockpit area.  This style of landing gear differs from the plans.   Aluminum flat stock was used instead of a wire rod.  Extra reinforcement needs to be added inside the fuselage floor for this type of landing gear.

 

 Decals installed. Rear view.

 

Servos location. Battery sits inside back of power pod mount.

 

 Finnished bottom af the 40" PT-17

 

 

 Top view. Ready for maiden flight.

 

 

40" PT-17 Stearman second flight

 

 

Building the two PT-17 Stearmans has been a lot of fun. The 40" Stearman flyes more scale then the MM size does, however the MM PT-17 can still slow down for some gorgeous fly-by's. The MM is a little easyer to assemble, and the 40" PT-17 is easier to fly. The ailerons on just the lower wing are very effective.  Both are well worth the time to build and fun to fly. 

 

 

  

COMMENTS

planebreaker2000 on August 13, 2016
Great looking plane. Clean and neat plans. Good build pics and instructions.
I am going to be building this one.

Thank you for posting and sharing.

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jrvalentin62 on August 14, 2016
Downloaded the plans. Thanks for the share. Cheers!
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alibopo on August 14, 2016
Lovely builds, nice flyers, and I have to agree, biplanes are great to fly. I also liked your solution for the radial engine. Was that a lamination of several sheets of thin foam? Cheers.
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aviator08 on August 15, 2016
Yes, it is just layers of DTFB.
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Air-headed Aviator on August 14, 2016
Looks real awesome! Oughta build one definately.
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Michael763 on August 14, 2016
Thank you for sharing. Both look awesome. I will add them to my winter building queue.
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FoamTest on August 15, 2016
What CAD software do you use for the plans?
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aviator08 on August 15, 2016
These were done on AutoCAD, but future builds I will be using DoubleCAD XT.
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aviator08 on August 15, 2016
Thank you for the nice comments. let me know how it goes.
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AcroMode on August 15, 2016
Nice build! Looks really good.
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p-air-o on August 16, 2016
Great job! Love both planes.
Are both of the main wings parallel?
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aviator08 on August 16, 2016
Thanks,
The top wing leading edge sits in front of the bottom wing, with the bottom wing having dihedral . The top wing has no dihedral.
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Curmudgeon Air on August 16, 2016
Is the covering Ultracote or something else? And did you leave the paper on before covering?
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aviator08 on August 16, 2016
Yes, It is Monokote. Ultracote would work as well, use the lowest setting that will stick it to the paper. I left the paper on the DTFB.
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jordy123 on August 16, 2016
I cant print with windows 10!!!
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aviator08 on August 17, 2016
Hi jordy123. I'm not sure what the problem is. They are PDF files. I can print from windows 10 and windows 8 computers. Maybe someone on here has an idea?
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bluebird1 on August 17, 2016
jordy 123
Windows10 may not have shipped the correct driver for your printer.Have you checked the support section for your particular printer to see if there may be an update or new driver for your printer?

Just a suggestion
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barryg69 on August 16, 2016
Hi love this plane just finished printing plans thank you so much for all your hard work
The only thing that concerns me is how the top wing is attached to the bottom wing do you just add hot glue to the bbq sticks and push in?
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aviator08 on August 16, 2016
Yes , I get all the locations started first. Then dry assembled everything to make sure it is all lined up correctly, I then remove all the struts, and starting with the fuselage, glue and inserted the 4 struts . ( I squirt the glue into the holes, then insert the struts.) The next step I do is to put glue in the 4 center strut holes in the top wing and install it onto the struts that I previously glued into the fuselage. ( using the wing guides to hold the correct location.) Once the glue has cooled good, I work on one wing at a time.... gluing and inserting the struts into the bottom wing first, and then gluing them into the top wing. This is the most difficult step to the whole build. It is important to quickly glue each area and check to make sure once glued it stays in the guide properly. I give it plenty of time to cool before moving on the the next set of struts.
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barryg69 on August 16, 2016
Thanks for the reply one more thing have you got any pics of the servo placements for the 2 rear servos and battery placement
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aviator08 on August 16, 2016
No Problem. :-) Glad to answer all questions. Are you building the MM or 40" size?
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barryg69 on August 16, 2016
40 size

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aviator08 on August 16, 2016
Picture added in article of Servos and Battery location.
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barryg69 on August 18, 2016
What size wire did you use for the servo control rods?
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aviator08 on August 20, 2016
I used the ones I got from the Flite Test store.
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barryg69 on August 20, 2016
Do you know the diameter of the wire?
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aviator08 on August 20, 2016
It is 1mm or .04 "
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bluebird1 on August 17, 2016
hope you don't mind my jumping in here, but I will anyhow...when looking at the Servo placement image there is an optical illusion caused by the camera' s angle that makes it appear as if the tail of the aircraft is on the left side of the image. Actually, the reverse is true - the nose of the aircraft is facing to the left.
this is in no way a criticism, merely an observation . . . . .it took me a couple of minutes to clue in on this. then again, i AM 74 and not as bright as I once was.
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bluebird1 on August 17, 2016
Aviator08: beautiful ship and like you, I favour the biplanes. Have not been active in RC for some time but want to wet my whistle again in this hobby.
Just a question on the lower wing dihederal- you provided a template which I assume is for that purpose. I am not sure how the dihederal is established fot the wing which is initially flat. Also, is the template for setting total dihederal or the dihederal for each wingtip? I am assuming also that incidence for the LW is established by the fuselage cutout for that wing.
This is a beautiful airplane constructed from foam board!
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aviator08 on August 17, 2016
Thanks. You are correct, the LW incidence is established by the cutout in the fuselage. The dihedral gauge sets the correct total dihedral. There should be a slight gap in the center of the lower wing, top side , that allows it to bend upwards for the dihedral.
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bluebird1 on August 17, 2016
Thanks for that info aviator08 - - - - - can hardly wait till I get bk home from vacation to get this underway as a Fall Project!

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laury415 on August 18, 2016
I'm building the 40" size. I already have to top wing complete.
1) I'm assuming there is no dihedral in the top wing, correct?
2) I have plenty of alum flat stock, and plenty of 3mm or 4mm piano wire for the landing gear. Do you recommend the alum flat stock over the piano wire? I don't mind doing the reinforcement you mentioned.
3) What size wheels did you use (40" plane)?
Thanks,
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aviator08 on August 18, 2016
Hi laury415.
1) You are correct. There is no dihedral in the top wing.
2) I personally like the alum flat stock, but it is purely the builders choice; with the wire you can use the strut covers. If you use the flat stock it would be more scale looking if the gear slanted forward a little.
3) 2" wheels

Tim
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Zalatos on August 19, 2016
Good Job. I would like to build that airplane but there are some questions.
-You don't have any construction video like Flite test team showing step by step to avoid mistakes?
-The wings for the 40" airplane can build in half's? because the foam board I have is less than meter.
-Can that airplane build on 3.5cm foam board thickness?
Thank you
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aviator08 on August 19, 2016
Zalatos, Thanks.

I don't have a construction video at this time. I did take some during the MM PT-17 build, but have not edited it.
Yes, you can build the wings in half's... no problem.
I would think you could build it from 3.5 mm, I think 3.5cm would be too thick.
Tim
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Zalatos on August 21, 2016
Thank you!
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Zalatos on August 22, 2016
Hi again Dear Aviator08. Because I started build the 40" span airplane. The small detail sometimes is a big question to avoid mistakes that are costing time and extra material and extra cost of course.
From the pictures we just have the shape but not the details. If is possible please to upload that video it will help to make the airplane fly. Thank you for attention!
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aviator08 on August 29, 2016
Hi Zalatos, I have not had the time to work on the MM build video. It takes a lot of editing.
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Zalatos on September 25, 2016
Well I finish the plane 40" and is ready to fly, of course with some mistakes but hopefully will fly well. My construction have no dihedral angle to any wing. I thing no need. The bottom shape is different than yours where the down wing is connected with fuselage and hopefully the barbecue sticks hold well the top wing during flying. I moved the power pod as long front can be ( and I add more sheets of Dammy engine to cover the distance) to have the correct CG with a light weight to rear. I have pictures to show but I as see I cannot post them. Finally I would like to thank you for the plans and the idea to build the Stearman....is so beautiful decoration in the house. The first flight will be on October :)
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laury415 on August 20, 2016
Hi Tim,

Thanks for your previous response. Build is coming along, but I have a few more questions.

1) Is the power pod supposed to be removable? If yes, what holds it in place, and how is it supposed to be positioned in the pod mount seeing it's much longer then the mount?

2) Are the dummy engine pieces of foam glued to the front of the fuselage, if not how are they attached? If they are glued it may answer my question #1. The dummy engine foam would hold in the power pod, and the power pod could be removed through the rear of the pod mount, and taken out the canopy hatch.

3) The bottom front fuselage looks like it has 2 options as there is a foam board piece, and a poster board piece. Both look like they cover the same area. It appears the poster board set up is a battery hatch with a locking piece. Not sure why it would be needed as the canopy hatch has plenty of room to insert the battery. Is the battery hatch in the front bottom of the fuselage an optional set up?

4) How do you keep the canopy hatch locked down? There are several methods I can use such as magnets, but was wondering how you did it?

5) What size battery do you use? I'm hoping to use a 3s 2200mah.

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aviator08 on August 20, 2016
Glad you are making progress.

1) The power pod is removable to the degree that you have to pull off the dummy engine first. I used a skewer to hold the power pod in place once I was happy with the location. I use the dummy engine to set the location of the power pod. ( The back piece of the engine allows for the power pod to be inset.... I push the engine against the power pod till the back of the engine meets flush with the front of the fuselage. )

2) I use just a small amount of glue to hold the dummy engine in place. That way it can be removed easily later. ( and only after I am satisfied it is ready to fly )

3) I only use the foam piece glued in for the 40" PT-17. I must have not deleted the poster board piece on the plans. ( The MM size uses the poster board piece for a battery hatch ) I use the back of the power pod mount as the battery holder for the 40" model.

4) The canopy is just a friction fit. The sides are folded in a little extra to provide a little grip. You could use magnets to hold it , but I haven't found it necessary.

5) That is the battery I use . It works very well.

I will start a build tread in the Forum " Swappables and other FT designs so pictures can be posted of the builds. I would love to see them.

Tim
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Yogenh on August 20, 2016
You did a great job on it and looks so good. Dose the Monokote stay on after a lot of use? Dose it help to keep the paper on the foam? Just keep up the great work!!! Thanks a lot

Paul
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aviator08 on August 20, 2016
Hi Paul. I have flown it about a dozen times or so. I have not had any issues with the covering coming off. Not sure if it helps the paper on the foam from coming off or not, but I would think it would help keep some of the moisture away from the paper.

Tim
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earthsciteach on August 23, 2016
I'm working on a DTFB PT-17 as well. You and I came up with the same solution for setting the top wing. Nice work on yours! I just need to mount the top wing on mine. I should get to that. LOL
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aviator08 on August 23, 2016
That's cool. Never too many biplanes. 😀
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Zalatos on August 27, 2016
Hi again. Still waiting your reply on my last questions I would like to ask you something more, if you have any pictures showing the finish of the bottom of the plane?
Thank you again.
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aviator08 on August 29, 2016
I will take a picture of the bottom and include it in the article. Thanks for the questions.
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aviator08 on August 31, 2016
Picture of the bottom of the aircraft now included in the article.
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DarkFire on August 29, 2016
What did you use to cover the 40" stearman and get that glossy look? I've never looked into covering my planes
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aviator08 on August 30, 2016
I used Monokote. I used the lowest setting on the hobby iron that would stick it to the paper.
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pintokitkat on September 3, 2016
I think there's a problem with the power pod and pod holder drawings on the 40" plans. Did you simply scale the plans of the MM version because the 90% cuts produce slots that are nearly twice as wide as they need to be?
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pintokitkat on September 3, 2016
Also the slots in the lower wing that the fuselage fits into are way too wide and the full cut marks on the top of the fuselage for the cockpit extend to the 90% lines, and they shouldn't. Otherwise you only have a very thin piece of covering paper holding the bits of the fuze together while you glue them.

Sorry to be picky because I think this is a great design and am really looking forward to flying it.I just wanted to suggest these couple of changes to make it more obvious to less experienced FT builders.
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aviator08 on September 3, 2016
Hi pintokitkat, I thought I had corrected all of those points when scaled it up, but I guess I missed a couple. Thanks for pointing them out. I will get them corrected.
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sverker on September 3, 2016
Great job! Thanks for detailed plans and photos. But I couldn't find data about flying weight. How much is total weight (incl. battery) of 40" Stearman?
Thanks in advance!
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aviator08 on September 3, 2016
It is 31oz. I will include it in the info at the top of the article.
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sverker on September 4, 2016
Thank you so much!
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T-Richard on September 10, 2016
I'll be building the MM sized pt-17. Always wanted a biplane and this one looks great. Good job, looking forward to building this one!
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mouse on September 27, 2016
Why is the motor mount in such a funny shape?

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aviator08 on September 27, 2016
That's what I found it needed to fly well. Right thrust for torque , down thrust to help minimize pitching up when going to full throttle.
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Zalatos on October 24, 2016
Hi again,..Right thrust for 40" is to much. I fly the airplane and need to reduce the thrust. What is the size of propeller you use? I thing this prop is coming with kit C is big and the battery loosing power quickly. Do you suggest any other size of propeller?
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aviator08 on October 25, 2016
Hi. I use the 9 x 6 prop that came with the power pack C. I can fly for 7 or 8 min before I land , with enough left over to go around if I need to. I do fly very scale speeds though, not full throttle. The right thrust is what I found worked for me. It would be pretty simple to try a power pod with less angle if you think that would help. Glad to hear you are getting some flying time with it.
Tim
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svu9376 on October 11, 2016
hi i am building the 40 size stearman and am wondering where do the spars go please ? :3
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aviator08 on October 12, 2016
The spars lay flat between the second and third score cut lines. ( the first score cut line is the leading edge that needs beveled on both sides)
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svu9376 on October 12, 2016
ahh kay thanks much :D

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mouse on December 12, 2016
OK I have got the bug. I am 75 years old I started trying to fly RC about 2 years ago. Sa yet I have not got one in the air. I have 2 Cessna 182. One is a 39" wing the other one is 55" wing. I have a Grand Cruiser 55" wing. I have 6 TX one is a Spektrum DX6i. I don't know how I found your web but I wanted to build the 40'' pit 17. Now I have it and now I am trying to build another one. I have also built the Nut ball. Flyer and Dealt wing and some others. I haven't hade a chance to try flying any of them yet. I like your web and the pit hopefully will fly some day.

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epicrcguy on July 29, 2017
I think its so epicly awesome that its foam board yet so scale
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kilroy07 on April 6, 2018
What a nice design! I was going to tackle the 3DLabPrint PT-17 but I think I'll give yours a go first. Well done and thanks for providing the plans.
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ed4353 on October 19, 2018
What are the recomended starting points for rudder, elevator, and aileron throws?
Thank you.
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ed4353 on October 19, 2018
Sorry, I forgot to specify these settings are for the 40" version.
ed
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aviator08 on October 29, 2018
Looks like I used 15* on the ailerons and rudder, and 10-12* on the elevator. ( I used the center hole on the control arm).
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brettdoughty@email.com on October 29, 2018
Wow grate build! I also would like to know the throws.
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aviator08 on October 29, 2018
Looks like I used 15* on the ailerons and rudder, and 10-12* on the elevator. ( I used the center hole on the control arm).
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aviator08 on October 29, 2018
Also, I used the wing dihedral gauge under the center fold at the wingtips on the lower wing.
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brettdoughty@email.com on November 2, 2018
Hi thank you for your post. And great plane. I have started building one of the MM. Im almost done but don't quite understand wear the battery goes do I just Velcro it on top the bottom wing under the removable cockpit? I think im missing something about the battery because I have a little tiny piece left its called the battery latch and a rectangular hole under the bottom wing that the bottom front fuselage piece lines up with. Also were in front of the plane is the best place to put the weights? sorry for all the questions.
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aviator08 on November 3, 2018
Hi Brett, Sorry for the confusion, the front bottom posterboard piece is only glued in the front, the battery I used fit in under the motor pod in front of the bottom wing. The battery latch goes through the posterboard, and into the bottom wing to hold it closed. Hope this makes sense.
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brettdoughty@email.com on November 3, 2018
thanks!
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Loiseau on March 5, 2019
Hello aviator08 and thank's for the job.
This week i build your stearman!
why the engine is crooked.
Why such an angle for the engine?
What’s the point of this?

I widened the ladder to 47 inches.
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Loiseau on March 5, 2019
Sorry, you already answered that question
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DrBern77 on June 17, 2019
did you build it???
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DrBern77 on June 17, 2019
hi,, excellent job!!! So nice you've done this. readlly wish there was a build video though.. Can you atleast post a walk around video of the 40" size upclose? the dummy engine how it goes on / off, the wing areas/struts upclose, and the battery compartment where it is and how to open and close it. thanks so much for your help!!
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DrBern77 on June 17, 2019
also what is the windshield made from? thanks!
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aviator08 on June 18, 2019
I made the windshield from a laminate sheet. Just ran it through without anything in it.
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aviator08 on June 18, 2019
1). I just put a little dob of hot glue at the top. That way I can pull it off if I need to.
2) on the battery placement, I slide it in the back of the power pod ( through the cockpit)
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aviator08 on June 18, 2019
1). I just put a little dob of hot glue at the top. That way I can pull it off if I need to.
2) on the battery placement, I slide it in the back of the power pod ( through the cockpit)
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DrBern77 on June 18, 2019
thanks! you need to do a close up walk through of this plane! I really think you'll spark new life in this build to many! thanks again!
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DrBern77 on June 18, 2019
and a build video :)
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aviator08 on June 18, 2019
The cockpit is removable for access to the battery and receiver. It just sets in place.
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MM PT-17 AND 40" PT-17 Stearman