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-   -   Great Planes PT- 17 Stearman ARF (https://www.rcuniverse.com/forum/arf-rtf-75/2929979-great-planes-pt-17-stearman-arf.html)

j301 10-29-2012 09:06 PM

RE: Great Planes PT- 17 Stearman ARF
 


ORIGINAL: mikmerl

<div style=''margin: 0cm 0cm 10pt''>I got a used PT-17 from a fellow recently with a 25cc ROTO engine.</div><div style=''margin: 0cm 0cm 10pt''>The plane flies amiably and I am happy with my purchase.

What is a source of concern is the climb tendency it displays under power.

Anything above 1/3 throttle has the bipe going up like a homesick angle.</div><div style=''margin: 0cm 0cm 10pt''>I think that this is one of the older kits as the arrows on the struts indicating forward are on the wrong way.</div><div style=''margin: 0cm 0cm 10pt''>Is this a trait of this model that everybody just lives with or is there something wrong with my incidences.</div><div style=''margin: 0cm 0cm 10pt''>The engine is simply bolted onto the firewall with whatever thrust that gives.</div><div style=''margin: 0cm 0cm 10pt''>It balances as per instructions.</div><div style=''margin: 0cm 0cm 10pt''>Any input would be appreciated.</div><div style=''margin: 0cm 0cm 10pt''>mike</div>
Sounds like it could be either of the two issues you have already mentioned. Mine does not have this tendency, and I don't recall having added any extra down/right to my standoffs. This being my first bipe, I am not versed enough to help you with the incidence of the wing, but I believe the top wing should be either level or (and this is where opinions very) 1 to 2 degrees pos or neg with the bottom wing (which also has an incidence). The incidence will effect drag, which in turn effects pitch and cg, also there is the idea that you want one wing to stall before the other, sort of a whole can of worms. This is more like a homework assignment then a quick answer question I know, thats why I never really finished my homework after finding my plane flew as it should! The thrust should be the easier thing to see, if you and see the angle, then its homework time, no angle, throw some washers behind the mount to get that 2+2 down and right and take her back up. Wish I could be more help, but I will say that this bird is worth the time to get right, its a great flyer and once you hammer out this issue you will hardly notice the number of socket head screws you have to mess with before you can fly!
Best of luck, and let us know how it goes!
J

Lifer 10-30-2012 01:49 AM

RE: Great Planes PT- 17 Stearman ARF
 
On my PT-17 the lower wing dowel holes were too high. When I first attached the wing, the front of the wing was touching the saddle and the trailing edge was still about a 1/4 inch or so away from the saddle. I rrelieved the holes until the wing set naturally in the saddle. Mine exhibits no ballooning at all.
My Super Stearman had the same issue, and it, too climbed under power. I had done the same process on it as well. Hope this helps.

mikmerl 10-31-2012 10:44 PM

RE: Great Planes PT- 17 Stearman ARF
 
<div style="margin: 0cm 0cm 10pt">Gentlemen thank you for your input.</div><div style="margin: 0cm 0cm 10pt">For the time being I have added a couple of washers to the four aft mounting holes between the cabanes and wing and struts and wing thereby reducing the angle of attack of the top wing. It does the job even though I know that this is sweeping the dust under rug.</div><div style="margin: 0cm 0cm 10pt">I intend to recover the bipe soon so that will be a good opportunity to give it a good going over and make any mods.

mike</div>

KNowAceHere 11-08-2012 08:17 AM

RE: Great Planes PT- 17 Stearman ARF
 
1 Attachment(s)
Mine is almost ready to fly. Just need to add the graphics and the flying wires. This Saturday looks good for the maiden. I'll post more pics later.

DaneMcGee 01-20-2013 03:18 PM

RE: Great Planes PT- 17 Stearman ARF
 
Maidened mine today with a DLE 35RA and Xoar 19x8 laminated prop and power was incredible! It balanced perfectly with batts in the fuse. The DLE 20 is great, but the DLE 35RA is out of sight!


..
http://img546.imageshack.us/img546/5332/photo4pg.jpg

http://img580.imageshack.us/img580/6180/photo2llp.jpg

j301 01-20-2013 04:23 PM

RE: Great Planes PT- 17 Stearman ARF
 


ORIGINAL: DaneMcGee

Maidened mine today with a DLE 35RA and Xoar 19x8 laminated prop and power was incredible! It balanced perfectly with batts in the fuse. The DLE 20 is great, but the DLE 35RA is out of sight!


..
http://img546.imageshack.us/img546/5332/photo4pg.jpg

http://img580.imageshack.us/img580/6180/photo2llp.jpg
And I thought the G26 was enough (now I have to re-define enough! :D) Hover much? :) Got and vids?

DaneMcGee 01-21-2013 05:16 AM

RE: Great Planes PT- 17 Stearman ARF
 

ORIGINAL: j301



And I thought the G26 was enough (now I have to re-define enough! :D) Hover much? :) Got and vids?

Thx to the contributors of this thread as it helped me in my build no doubt.

I find it silly to have to add dead weight to the airplane for balance. If it needs weight up front, make it up in engine.
I don't plan to fly it scale like.....I'm a hair on fire combat flyer and my airplanes have one speed....WFO!! I bought this airplane to fly the snot out of it like it's free.



Modifications were:

Replaced all horns and hardware with 30-50cc size G-10 dual control horns, aluminum and carbon fiber servo arms and 4-40 rods and and ball links. The included harware is made for .40 size airplanes.

Replaced fuel tank with a Fortitude 16 oz tank, .....much lighter.

Tied both elevator halves together with 1/8" music wire and use one 4-40- rod to the servo.

Replaced wheels with 5" Dubro Big Wheels......I run them almost flat for better shock absorbtion which is much needed for taking off and landings in a hay pasture as I do.

I will be replacing the stock tailwheel assembly with a 15-20 pound size sullivan tailwheel bracket ......I broke the stock tailwheel off on first landing


This is a very nice flying airplane with a take off roll of 50 feet or less with the DLE-35RA at about 1/4 throttle. I have full throws on all control surfaces on high rates. Rudder needs about -50% expo on 100% throw to smooth out take off roll.
The engine gives it unlimited vertical and would come close to a hover if I had more practice I think.
Landings are a breeze as it just floats in.

The Rear exhaust engine will make for a clean cowl install.....I'll post pics after I install today.


RipG 01-21-2013 01:34 PM

RE: Great Planes PT- 17 Stearman ARF
 
Your video is going to be awesome and can't wait for it to be posted!

j301 01-21-2013 08:37 PM

RE: Great Planes PT- 17 Stearman ARF
 
1 Attachment(s)



I will be replacing the stock tailwheel assembly with a 15-20 pound size sullivan tailwheel bracket ......I broke the stock tailwheel off on first landing

I replaced my tail wheel with a sullivan as well, it sat too high and allowed a lot of leverage for side force to tweak on it. I went with a bracket like the one pictured, but even then the amount of side force from any kind of cross wind would cause loss of control and tightening up the springs enough to stop this put a lot of stress on the rudder. So my solution was to run another rod back to the rudder servo on the next inner servo arm hole and link one side of the yoke. Now there is no more issues and it handles great, and doesn't sit too high. I also opened up the area underneath the fuse and epoxied in a 4-ish inch long hard wood block to screw the bracket to. Hope this makes sense, if not I can take some pics if it helps to see what Im talking about if you need.

DaneMcGee 01-23-2013 05:06 AM

RE: Great Planes PT- 17 Stearman ARF
 


ORIGINAL: j301




I will be replacing the stock tailwheel assembly with a 15-20 pound size sullivan tailwheel bracket ......I broke the stock tailwheel off on first landing

I replaced my tail wheel with a sullivan as well, it sat too high and allowed a lot of leverage for side force to tweak on it. I went with a bracket like the one pictured, but even then the amount of side force from any kind of cross wind would cause loss of control and tightening up the springs enough to stop this put a lot of stress on the rudder. So my solution was to run another rod back to the rudder servo on the next inner servo arm hole and link one side of the yoke. Now there is no more issues and it handles great, and doesn't sit too high. I also opened up the area underneath the fuse and epoxied in a 4-ish inch long hard wood block to screw the bracket to. Hope this makes sense, if not I can take some pics if it helps to see what Im talking about if you need.

Thx for the heads up. I think I'm gonna give the sullivan a try at least. One thing that had me concerned was the issue that you addressed about the soft wood on the bottom aft fuse area to attach the tailwheel bracket too.

If the screws pull out under stress, then I can do as you did and replace an area with some hardwood. The main reason I chose the sullivan bracket was the fact that it has a nice cushy spring that would flex easily in rough terrain. My airplane will never see an improved runway......hay pastures and cattle grazing fields are all I fly from.

j301 01-23-2013 09:15 AM

RE: Great Planes PT- 17 Stearman ARF
 
Perhaps the two types we are talking about are different. My sullivan's wire was thick, galvanized, and too tall so I cut it down and re-bent a 90 in it just long enough to clear the wheel and give it some bend room. Even before that though the wire was so stiff I couldn't imagine it flexing with the weight of this plane. If you are flying off grass its likely better for you anyway, my runway is asphalt so its characteristics are different. Best of luck, and hit us up with some video when you get a chance. The hard wood block in the tail was very easy, sounds harder then it is to do. Once you cut into it you will see what I mean.

Tom in Cincy 01-23-2013 09:00 PM

RE: Great Planes PT- 17 Stearman ARF
 
1 Attachment(s)
Hi guys, I just got my PT-1 7 last week during the daily sale at tower hobbies. I have been working on mounting the engine and getting the cowl cut out and finished.
The fuselage had a ton of wrinkles in it as I believe has been reported in this thread before. I did not think it would be a big deal since I have put together quite a few ARF s with wrinkles before and was a fairly simple matter to shrink them back down. This one is different. The wrinkles simply will not come out unless I use a dangerously high amount of heat with the heat gun. It seems that the film will only begin to shrink just before the melting point (I did end up melting a few small spots). And the hand iron will not shrink it at all. After spending over half an hour on a fairly small area I have given up. I'm going to call Tower tomorrow and either ask for a replacement or just send the whole thing back. I seriously doubt that this stuff is really MonoKote as it sure doesn't act like it or possibly was somehow damaged.

DaneMcGee 01-24-2013 03:27 AM

RE: Great Planes PT- 17 Stearman ARF
 

ORIGINAL: Tom in Cincy

Hi guys, I just got my PT-1 7 last week during the daily sale at tower hobbies. I have been working on mounting the engine and getting the cowl cut out and finished.
The fuselage had a ton of wrinkles in it as I believe has been reported in this thread before. I did not think it would be a big deal since I have put together quite a few ARF s with wrinkles before and was a fairly simple matter to shrink them back down. This one is different. The wrinkles simply will not come out unless I use a dangerously high amount of heat with the heat gun. It seems that the film will only begin to shrink just before the melting point (I did end up melting a few small spots). And the hand iron will not shrink it at all. After spending over half an hour on a fairly small area I have given up. I'm going to call Tower tomorrow and either ask for a replacement or just send the whole thing back. I seriously doubt that this stuff is really MonoKote as it sure doesn't act like it or possibly was somehow damaged.

Mine was about the same way. I used a iron with a cotton cover on high heat. I could only get it to stick back down with heat on the highest setting. The wings on mine were actually the worst, especially the ailerons. I have wrinkles and puckers that I will never get out. The decals also suck btw.....wrinkly and won't stick.

I just decided to fly the snot out of it and overlook the wrinkles.

RipG 01-24-2013 03:46 AM

RE: Great Planes PT- 17 Stearman ARF
 
I thought that mine was bad, but it wasn't that bad. I, too, used the hotest iron with a sleeve and ironed the wrinkles down to just slight .1mm ridges where they wouldn't be noticed. I spent about 6 hours doing that! In a couple places, I pierced it with a pin and it helped to reduce it. I would definitely check to see if they'll replace it.

j301 01-24-2013 08:54 AM

RE: Great Planes PT- 17 Stearman ARF
 
1 Attachment(s)
This is what came to mind when I unpacked mine...
Took a lot to get out most of it, but there still is a lot of "flat wrinkles", was the best I could do.

cstevenpeterson 01-24-2013 09:18 AM

RE: Great Planes PT- 17 Stearman ARF
 
I find this interesting as I had the same issue with my PT-17 a couple of years back - lots of wrinkles and hard to remove without melting the covering. I just received a Top Flite P-51 .60 size with some bad wrinkling as well. Difference is, the P-51 wrinkles were easily removed using moderate heat from an iron alone with only a bit of heat gun required. Much different behavior from the stuff they used to cover the PT-17. I know I am comparing Top Flite to Great Planes, but Monokote should be Monokote - right? Or maybe not....

Steve

Linkan2 01-24-2013 10:02 AM

RE: Great Planes PT- 17 Stearman ARF
 


Linkan2 01-24-2013 10:14 AM

RE: Great Planes PT- 17 Stearman ARF
 
1 Attachment(s)
<span lang="en" id="result_box"><span class="hps">Here</span> <span class="hps">are pictures of</span> <span class="hps">my</span> <span class="hps">UMS</span> <span class="hps">7-35</span> <span class="hps">mounting in</span> <span class="hps">PT17</span><span>.</span>
<span class="hps">I have flown</span> <span class="hps">it in</span> <span class="hps">2 seasons</span> <span class="hps">and 40</span> <span class="hps">air</span> <span class="hps">pass is</span> <span class="hps">myget</span> <span class="hps">satisfied.</span>
<span class="hps">now I'm</span> <span class="hps">here and</span> <span class="hps">waiting for</span> <span class="hps">spring</span><span>, it's</span> <span class="hps">cold</span> <span class="hps">now</span><span class="atn">-</span><span>17c</span></span>

Linkan2 01-24-2013 10:18 AM

RE: Great Planes PT- 17 Stearman ARF
 
http://www.youtube.com/watch?v=o9adZ3e2cL0

<span lang="en" id="result_box"><span class="hps">Here</span><span>, the video</span> <span class="hps">call</span> <span class="hps">with the exhaust</span> <span class="hps">of the engine</span></span>

DaneMcGee 01-24-2013 11:36 AM

RE: Great Planes PT- 17 Stearman ARF
 


ORIGINAL: cstevenpeterson

........ but Monokote should be Monokote - right? Or maybe not....

Steve
Unless its that Chinacote stuff. It acted different from any covering I've fooled with.

Tom in Cincy 01-24-2013 12:32 PM

RE: Great Planes PT- 17 Stearman ARF
 
Well, after a good six hours with the heat iron maxed out and a stick pin leading the way poking holes everywhere I did manage to get the film to lay down in a pretty good manner. The dove gray on the fuselage was the worst. The yellow on the wings seemed to shrink pretty good, the ailerons, especially over the plywood hard points required a lot of the hole poking but it finally laid down also. My speculation and it's just that, is that possibly these airframes were constructed in a very humid factory with little to no environmental control and the film was applied with a lot of heat. With the very dry winter air here I am sure there must of been quite a bit of shrinkage of the wood. Since the film did not want to shrink anymore they must've shrunk it down pretty good in China. Overall it turned out pretty good and I'm just going to continue with the build.

That UMS radial is really pretty. I would love to have one to put on my PT 17. However I'm just going to have to put up with a single cylinder four stroke for now.
tp

RipG 01-24-2013 01:38 PM

RE: Great Planes PT- 17 Stearman ARF
 
<div>@Linkan2<span style="font-family: tahoma, verdana, arial; font-size: 11px; background-color: rgb(251, 252, 255); "> </span></div><div><span style="font-family: tahoma, verdana, arial; font-size: 11px; background-color: rgb(251, 252, 255); ">
</span></div><div><font face="tahoma, verdana, arial"><span style="font-size: 11px;">Outstanding motor.  Love that sound.</span></font></div><div>
</div>@Tom in Cincy<span style="font-family: tahoma, verdana, arial; font-size: 11px; background-color: rgb(251, 252, 255); "> </span><div><span style="font-family: tahoma, verdana, arial; font-size: 11px; background-color: rgb(251, 252, 255); ">
</span></div><div><span style="font-family: tahoma, verdana, arial; font-size: 11px; background-color: rgb(251, 252, 255); ">Glad it worked out with the Monokote.  That is such a pain until it's all done when you can finally breathe again.</span></div>

yellerchamp 01-24-2013 03:44 PM

RE: Great Planes PT- 17 Stearman ARF
 
I bought a pt 17 from tower a couple of years ago and sent it back because of the wing covering was so bad, I then bought one here on rcu and recovered the tail and wings with ultrcote, I love it and it l flys and lands great, i did replace the tail wheel but cant remeber with what,also fly it with a saito 120 happy flying

yellerchamp 01-24-2013 07:19 PM

RE: Great Planes PT- 17 Stearman ARF
 
1 Attachment(s)
trying to upload a pix

randyta 01-31-2013 04:36 AM

RE: Great Planes PT- 17 Stearman ARF
 
Just purchased the PT-17 and like several of you, the covering job was really bad.  GP is sending me a new bottom wing.  I plan to use the Robart pin hinges and would like to know if the 1/8 should work o.k. or should I use the 3/16.

Thanks,

Randy


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