Tech Question: ARF Build, 3D Plane
#1
Thread Starter
Senior Member
My Feedback: (2)
Joined: Jan 2005
Posts: 137
Likes: 0
Received 0 Likes
on
0 Posts
From: Rome,
GA
I am assembling a 40 size Hangar 9 Twist. While the horizontal stab is centered in the fuselage, the measurement between the wings outside rear edge and the horizontal stabs out side rear edge is off by 3/8 inch from one side to the other. The fuselage is the problem, it's not quite straight. I've checked the distance from fuselage to out side wing edge on both sides, it is the same. The problem is the fuselage appears to be slightly bowed.
OK, now for my question.
Measuring this distance squares the horizontal stab to the wing.
Would it be preferred:
A) to square the horizontal stab to the wing?
B) to square the horizontal stab to the fuselage?
C) to split the difference between the two?
Thanks
bbell
OK, now for my question.
Measuring this distance squares the horizontal stab to the wing.
Would it be preferred:
A) to square the horizontal stab to the wing?
B) to square the horizontal stab to the fuselage?
C) to split the difference between the two?
Thanks
bbell
#2
is the right side the shortest measurement? if so it may be that the firewall has built in right thrust. i dont have one and dont know if it is built in but its a good guess. if it does then you need to adjust yor stab.
#3

My Feedback: (3)
Both would be best. It all needs to be pretty straight, but 1/8 or so is not going to be the end of the world.
Im thinking on the fly here but if your fuselage is bowed probably the best thing you can do is draw a straight reference line on a flat surface to represent the centeline of the fuselage. Then center up the fuselage at the front and rear on the line. If its crooked it will be somewhat shaped like a banana compared to that reference line. The you just need to rig up a jig to force the fuselage in line with your refernce line and restrain it there. You might be able to just heat up the covering and straighten it if its just slightly bowed. If its worse you might have to remove the covering, dampen the wood and then holding it in a straightening jig let the wood dry out.
If its just a slight bend it probably wont really effect a little plane like a twist enough to make a whole lot of difference. If its 1/4" off then you might have some issues. I bet that you can work most of it out by bending the fuselage a little at a time and then while its bent, shrink the covering tight wherever it loosens up. Repeat that process until the covering wil not shrink anymore of the fuselage straightens out. That should cure it unless its severe. If its bowed THAT bad you can probably get some help from whoever you bought it from if its new.
Im thinking on the fly here but if your fuselage is bowed probably the best thing you can do is draw a straight reference line on a flat surface to represent the centeline of the fuselage. Then center up the fuselage at the front and rear on the line. If its crooked it will be somewhat shaped like a banana compared to that reference line. The you just need to rig up a jig to force the fuselage in line with your refernce line and restrain it there. You might be able to just heat up the covering and straighten it if its just slightly bowed. If its worse you might have to remove the covering, dampen the wood and then holding it in a straightening jig let the wood dry out.
If its just a slight bend it probably wont really effect a little plane like a twist enough to make a whole lot of difference. If its 1/4" off then you might have some issues. I bet that you can work most of it out by bending the fuselage a little at a time and then while its bent, shrink the covering tight wherever it loosens up. Repeat that process until the covering wil not shrink anymore of the fuselage straightens out. That should cure it unless its severe. If its bowed THAT bad you can probably get some help from whoever you bought it from if its new.
#4
Thread Starter
Senior Member
My Feedback: (2)
Joined: Jan 2005
Posts: 137
Likes: 0
Received 0 Likes
on
0 Posts
From: Rome,
GA
Thanks for the advise!!!
I will try the bending and re-heat the covering.
It's my third Twist. I really love the planes abilities. It's a great first Sport/3D plane. And the price is right!! I rebuilt the first one 5 times, four of which were due to flame-out. And one, I was trying to learn to hover. The second, I just tore it all to heck. I really want to get this one set-up correct from the beginning. I want it to loop straight....
Thanks
bbell
I will try the bending and re-heat the covering.
It's my third Twist. I really love the planes abilities. It's a great first Sport/3D plane. And the price is right!! I rebuilt the first one 5 times, four of which were due to flame-out. And one, I was trying to learn to hover. The second, I just tore it all to heck. I really want to get this one set-up correct from the beginning. I want it to loop straight....
Thanks
bbell




