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        Discussion Great Planes PT-40 twin electric

#1 king29 Dec 28, 2012 10:20 PM

Great Planes PT-40 twin electric
OK this is my first post on here so I hope I have made it in the right spot.

I placed an order for a PT-40 and my plan is to make it a twin motor electric by mounting a motor under each wing. Doing this will open up the front of the plane for FPV gear and give more then enough power to fly all the gear I could want. I am now trying to plan and buy the other things I need for this plane IE the batteries and this bring me to my question and I hope some one here can help.
1. On a normal pt-40 build how much weight dose the plane take in the nose to balance the plane.
2. What is the width and length of the compartment behind the fire wall

I know many of you will want updates on my project and as I get things in the mail I will do my best to post images and keep every one informed as to how things go.
Any questions you have for me I will do my best to answer.

#2 king29 Dec 29, 2012 07:05 PM

PT-40 twin electric
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I got my motors for the build in the mail today a pair of TACON BigFoot-25 870kv motors from hobbypartz.com they look sweet and on 4s will have a great deal of power

#3 dedStik Dec 30, 2012 06:54 AM

When I re-kitted mine to electric I positioned everything so I had no dead weight fore or aft. Mine came out slightly overweight at an AUW of 6 pounds. According to the manual I'm still good.

#4 king29 Jan 13, 2013 03:24 PM

PT-40 twin electric
4 Attachment(s)
OK my kit made it here but after talking with some people here and at the hobby shop down the road I made a trade and stepped up to the PT-60 from the PT-40 and I have to say I'm not sorry I did. Unboxing the pt-60 it was easy to see the larger plane would not only work better for what I am doing with it it will be much more fun to build and it has been. In the last 4 days I have had to work on it I'm loving it. The plane fits together very nice all the parts are cut so well they take almost no sanding or trimming. My first plane was a pt-20 and i must say i like building the 60 much more then the 20.
The specs on the pt-60 say it could weigh up to 8lbs so I was a bit concerned the motors I had picked would not produce the thrust needed to fly the plane so I did a test made a motor test stand out of some 1x4 I got from the hard wear store and found that with a 12x8 prop each motor would lift 5.4lbs on a 4s 3300 pack giving a total of 10.8lbs to fly an 8lbs plane. The funny thing about that is the pt40 said it was just 6lbs so it looks like I was going to way over motor that plane lol. Any way here are some pics of what I have so far you can see I have started the motor mounts in the wing.

#5 king29 Jan 15, 2013 07:29 PM

PT-60 twin electric FPV
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I have made a bit more progress in the past few days the motor mounts are just about complete I joined the wings but that is about all I have so far

#6 dedStik Jan 18, 2013 02:25 PM

I think I'd be a bit concerned about the leading edge of the wings not having that reinforcement. And the blocking up of the leading edge where the motors actually mount.

It is looking good so far. I'm interested to see how it flies.

#7 king29 Feb 02, 2013 07:16 PM

PT-60 twin electric FPV
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I'm not to concerned about it there is a video on YouTube that gave me the idea a guy took a large scale extra 300s and made it a twin with two gas motors I was impressed with his.

I have not had much time to work on it but here is some pics of what I have so far

#8 king29 Feb 06, 2013 09:33 PM

PT-60 twin electric FPV
3 Attachment(s)
I made time to install the tail on my plane today and I cut my hing pockets for my tail as well. I also stopped by the hobby shop and picked out the colors for my plane I'm using aluminum for the main color and insignia blue for the trim both are by monokote. I have also mounted a RX in the plane and done a true power test with the 12-6 props and the two batteries I'm going to fly her on and there is more than enough power for full vertical flight. I'm looking forward to flying her.
As I said before let me know what you think I love the feedback I'm sure many of you have done this much longer then me.

#9 king29 Feb 06, 2013 09:46 PM

cool twin mod
Oh I was going to add this a bit ago but go look this up on youtube. This guy
has done some cool stuff with this plane and I would love to see it in person some day

KMAC FF Hank 40% Extra 300 Twin Saito 300

#10 king29 May 13, 2013 09:58 PM

PT-60 twin electric FPV
This project has been stopped due to a state law passing that will kill my hobby. Sad to say house bill 912 should have never passed.

#11 dedStik May 14, 2013 09:56 AM

That law sucks, doesn't prevent you from completing the build and enjoying the aircraft though, just prevents FPV or cameras placed on it.

I saw follow what the law says, attach the camera to a balloon, the law is clear about what is disallows "unmanned vehicles and aircraft" doesn't say anything about a loose balloon.

Seriously though, this section

AIRCRAFT TO CAPTURE IMAGE. (a) A person commits an offense if the
person uses or authorizes the use of an unmanned vehicle or aircraft
to capture an image without the express consent of the person who
owns or lawfully occupies the real property captured in the image."

Seems to indicate it is legal with written consent of the owner of the property. Just fly in an area where you have written consent of the property owner.

It's Texas I grew up in Houston I remember tons of ranches with plenty of land to fly over, talk with the owner offer to do some work around the property in exchange for the ability to fly over and film their land.

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