Nexstar problem - Loose horizontal stab
 

Hey guys,

I'm still trying to set up my Nexstar and I've come across a problem when installing the horizontal stab. When installing using the screws provided the stab won't sit securely, but it can wobble slightly from side to side.

Basically the screws slide in from the bottom of the fuselage and up through 2 holes in the stab which is meant to secure it. The screw's are tapered, and the rear screw is fine because it slides up far enough for the WIDE part of the screw to be through the hole, which is a snug fit. However for the front screw, it only slides up enough for the tip of the screw (the skinny part) to be through the hole, which allows for left-to-right movement. Even after I install the fin it still moves.

Any ideas on how I could fix this? Or has anyone else had the same problem?

I'd really like to find a solution without having to strip the covering and gluing it, if possible. I hope theres another way around it.

Would love to hear some suggestions. Thanks!

RE: Nexstar problem - Loose horizontal stab
 

You're gonna have to work with me a bit here Chris as I haven't built one of these before so I'm working by what I've seen at the field and am reading in the manual, OK?

First I am assuming that you are saying that you can't get the plastic screw/nuts to install properly on the studs that are mounted in the vert fin and stuck down thru the horizontal stab. These screw/nuts are not supposed to go up inside where they will be unseen.

Is the front hole simply too small and if you enlarged it slightly would all be OK?

RE: Nexstar problem - Loose horizontal stab
 

I had that same problem with my avistar. Put the horizantal stab on and with a sharpie draw a line were the horizontal stab meets the fuselage on both sides. Then cut out all the covering in between those two lines put some 30 minute epoxy on it and slide it back in.

P.S. do it to the top and bottom.

Tony

RE: Nexstar problem - Loose horizontal stab
 

Ok, forget the vertical fin for now, thats not the problem. I've inserted the horizontal stab so the holes align with the holes in the fuselage. The holes are the same diameter. When the REAR screw is pushed up so the head of it is flush with the bottom of the fuselage, the end part (skinny part) of the screw sticks up through the hole until the wide part is now through the hole in the horizontal stab, therefore securing it nicely because the wide part is the same diameter as the hole.

When I insert the FRONT screw in the same manner, all the way up so the head is flush with the fuselage, the top of the screw only just reaches the hole, which means the skinny part of the screw is through the hole, therefore allowing for the movement. In other words, because the screws are tapered, it appears as though it needs a longer screw so the wide part of it can reach up to the hole in the stab. Does this make sense? If not let me know i'll try to clarify it further.

Cheers

RE: Nexstar problem - Loose horizontal stab
 

Thanks, I realise this will work but like I said I'd prefer not to glue it if possible.

RE: Nexstar problem - Loose horizontal stab
 

No, actually the opposite. The hole is too large, thats why i get the movement. If the hole was smaller, it would be same diameter as the TOP of the screw which means it would be a tight fit.

RE: Nexstar problem - Loose horizontal stab
 

When you insert the forward screw through the horizontal stabilizer (without the vertical stabilizer in place) does the screw insert all the way up into the hole?? Meaning that the head of the screw is sitting firmly against the bottom of the fuselage?

Can you take a picture of the problem and post it? That would help a lot if we can see what you are talking about.

Ken

RE: Nexstar problem - Loose horizontal stab
 

Yes, the head of both screws sits firmly against the bottom of the fuselage. However, the other end of the front screw doesn't come up as far as the rear one, because that part of the fuselage where the front screw goes is higher than the rear part where the rear screw goes in. Because both screws are the same length the rear one comes up far enough for the wide part to reach the hole in the stab. But the front one only comes up far enough for the skinny part at the top to reach the hole in the stab. Does this make sense?

I don't have a camera here at the moment but I can try to get a pic later.

RE: Nexstar problem - Loose horizontal stab
 

A picture would help a lot if you can manage it.

Ok, let me ask this. Even though the front screw is loose in the hole, does it still securely thread into the vertical stabilizer? Does it get enough thread on the vertical stabilizer to tighten it down against the fuselage? I understand that you still have a little bit of wobble in the stabilizer because the hole is bigger than the screw, but other than that is it tight??

Ken

RE: Nexstar problem - Loose horizontal stab
 

Sorry about the poor quality pic, but its the best I could do with the camera phone. Hopefully you can see that the rear screw protrudes further through the hole than the front one. Once again, they are both sitting flush on the bottom side of the fuselage. The rear one comes up far enough so the top of it comes up about 3/4 of an inch past the top of the stabilizer, therefore the wider part of the screw is sitting through the hole in the stab, securing it. The front one only comes up far enough so the top of the screw actually sits flush with the top of the stab. That means because the top of the screw is skinnier, there is space between the edges of the screw, and the hole allowing for movement.

RE: Nexstar problem - Loose horizontal stab
 

Yes, does it hold the vertical stabilizer tight against the fuselage other than the wobble??

Ken

RE: Nexstar problem - Loose horizontal stab
 

Yes, but I have to screw it in quite tightly to get the vertical stabilizer to sit flush against the fuselage. Once this is done, the horizontal stabilizer still moves.

RE: Nexstar problem - Loose horizontal stab
 

Do you have an O-ring or something that you can put around the bolt that will secure it inside of the hole? Do this and it will keep it from wobbling around in the hole.

Ken

RE: Nexstar problem - Loose horizontal stab
 

Actually I've just checked it again. There is a small gap of maybe 1 - 2mm between the vertical fin and the fuselage. See pic.

RE: Nexstar problem - Loose horizontal stab
 

As I understand it, the tapered plastic screws pass through the holes in the stabilizer and the clamping action is supposed to be done by squeezing the vert stab down on the stab. The plastic screws acting more as alignment pins as they go thru the stab.
Does this sound correct?
Wish I had a Nexstar sitting here to refer to.[&o]

RE: Nexstar problem - Loose horizontal stab
 

Yes in terms of the horizontal stab they act as alignment pins. The vertical stab has two threaded metal rods that stick through the holes in the horizontal stab and into the fuselage. When the screws are inserted they screw onto those rods. (the screws are hollow in the middle, thats where the metal rods go)

RE: Nexstar problem - Loose horizontal stab
 

I dont have an o-ring but I do have sticky tape! I've wrapped it around the end of the screw therefore increasing the diameter to match that of the widest part. This worked in terms of securing the horizontal stab and stop it from moving, but is it a good enough fix ??

I'm also now wondering about the gap underneath the vertical fin as seen in the pic before, is this a problem?

RE: Nexstar problem - Loose horizontal stab
 

The screws should be pulling the fin down tight on the top of the horizontal stab and pressing it tight against the lower surface of the groove cut into the fuse. I'm not too worried about the gap between the vert fin and the fuse if the other part is good. I'm just wondering it the bottom of the vert stab is hitting on something and not settling into place properly.

I don't know about the sticky tape. I would have used a layer or 2 of heatshrink tubing. But I have a lot of that available and many people don't. Tape SHOULD do it as long as all stays tight.

RE: Nexstar problem - Loose horizontal stab
 

Hi Chris,

I had the same problem with my nexstar and found that if you CAREFULLY put some drop of thin CA on the horizontal stabs rear hole and some 5minute epoxy on the front holes (just be ready with a fine sand paper) you protected the balsa from exhaust residue and strengthen the mounting holes. and still you have the the option of removing the tail for transporting or storage.

RE: Nexstar problem - Loose horizontal stab
 

OK I've decided I will probably just secure it with epoxy after all. Seems to be the best way, plus i checked the alignment of the horizontal stab to the wings and it doesn't even align when the holes in the stab/fuselage are lined up anyway. I guess that means I need to drill the holes again as the bolts still need to fit through.

RE: Nexstar problem - Loose horizontal stab
 

I had the same issue with my nextar... Being lazy I simply Lined the Horizontal stab with Epoxy.. On the outside Covering.. and just took a toothpick and pushed into the crease.. I havnt had any problem with it.. but *Shrug* its not the "Cleanest" way to do it

RE: Nexstar problem - Loose horizontal stab
 

just wondering is the hole at the rear shorter than the front hole?

RE: Nexstar problem - Loose horizontal stab
 

Yes, because the fuselage is not as high at the rear.

RE: Nexstar problem - Loose horizontal stab
 

did you say that the bolts are the same size they are not differentsizes

RE: Nexstar problem - Loose horizontal stab
 

Yes, they are exactly the same size. Weird huh!