Extra 300S Help
 

Hi All,

I have a small problem with the wing section of the Extra 300S. I am working on the wing and the Rib tab's on R2 & R3 will not stay in contact with the building board when trying to glue the LE and the Main Spar on. I tried what G/P suggested as far as putting T-pins in the tabs however the tabs keep breaking. So now I am at a stand still. Anyone have any ideas? Should I tried to wet the ribs down with the vinegar/water solution and place something heavy on both ends?

Your comments/suggestions are very much APPRECIATED.

Thanks,

Extra 300S Help
 

Happens all the time... I solve that problem by using a drop of thin ca to hold the tab securely to the rib. Of course, removing it later will be a little more work, but it saves the agro while building.

Which GP Extra is it btw? I built the 64" wingspan version and flew it over 3 seasons - loved the thing (R.I.P)

Extra 300S Help
 

Hi RSprinkel: I have had good luck useing duct tape on both sides of the scored line. Then when it's time to take the tabs off, they come off with the tape. Just be carefull not to break off part of the rib. Good luck Garry

Extra 300S Help
 

LuvBipes - I have the 58" W/S. I can't wait to finish this bird. Have heard nothing but good things aboout them. Sorry to hear about yours.


$ircra$halot - May have to try that idea. Sounds easy enough.

I may try both ways as posted and see which is the most effective way.


Anyways thanks again for your help. May get this done in time for Christmas now and then I will hopefully have a few more kits on the ole Work Board.

Thanks and Happy Flying/Building.

Extra 300S Help
 

The question is WHY is it lifting? Sounds to me like there's a problem with the connection to one (if not both) of the spars. You may want to remove the rib(s) from the spar and open up the spar slot slightly so the rib sits flat without help. If it does not, it could result in a warped wing!

Extra 300S Help
 

Well I removed both ribs from the spars and sanded the spar slots more to see if that would do any good and it is still the same. However if I sand anymore I will have gaps or the spars will sit lower then the ribs. So I have stopped sanding. I cannot think of anything other ideas to keep the ribs flat on the surface. I talked to a friend of mine who built one of these and he had the same problems with his Extra 300 with the same ribs too. He said he just put weight on both ends of the ribs and glued them to the spars and L/E.

Whats your thoughts/comments on this? Should I try and contact G/P?

Thanks again,

Extra 300S Help
 

You want to sand (or cut) the front and back of the spar slot. If there is a gap, that's no biggie, it can be filled later. What's important is getting the ribs to sit straight withOUT putting pressure on them.

Extra 300S Help
 

Thanks for the good tip MinnFlyer, I'm just starting mine.

Bob

I'm on my third one of these
 

and boy do I have tips for you........here goes.....Most of my mods have been to lower the weight of the plane. As such. Mine with a glass painted cowl and .91 2s, it comes in just shy of the bottom weight limit.

1. Wing- go with 4-40 rods and better control horns. You don't need to build the GP ailerons. Just get some similar aileron stock, it works fine. Use hs-225bb's on the wing. Less weight, same or more torque than regular. Use blind nuts to mount it.

2. Fuse- Sand, Sand, Sand. There is a ton of weight to get off with all of the rough edges and stuff. Go with 1/32" ply on the turtledeck both front and back. Be sure to use triangle gussets on the engine box, both inside and out. Beef up the rails for the landing gear and use nylon bolts so that you only beat up the wing when the gear comes off, not tear of the whole bottom of the fuse.

3. Control surfaces. Use hs-225bb's in the tail for individual elevator setup. 4-40 rods. Lighter and help control the nose heavy problem in stock form. Go with a pull-pull on the Rudder with a good digital servo. Max throw!!! Be sure to bevel the edges to get smooth throw on all surfaces. Ditch all the metal rods. Any hard flying will make them flex like crazy.

4. Electronics- I used an EMS Jomar battery backer with a 1100 on the main and a 600 on the backup. Twin switches (Hobbico HD's are great).

5. Go with the fiberglass cowl and pants. Lighter and stronger.

Email me if you have any questions about building. Like I say, I have built three.

James
Decatur, Texas

Extra 300S Help
 

Minnflyer, Thanks for the diagram. I will give that a shot. I have though sanded those areas somewhat but will do some more and hopefully will turn out good results.

LawDog101, Thanks for the tips will give them a shot and see what happens. Can you tell me where a good plcae is to get the GLass Cowl and pants?

Again, THANK you for your tips and very much APPRECIATED help.

Extra 300S Help
 

MinnFlyer,

I have tried your sanding method and still no changes. Below is a pic of what I have. I have a 1/8" gap from tab to board. In the photo I am holding the front of the rib down.


http://www.rcuniverse.com/gallery/sh...papass=&sort=1

Thanks,

Sorry don't know how to put actual thumbnail in post yet.. :rolleyes:

Extra 300S Help
 

I looked at your pic. Are the spars aligned correctly when the rib contacts the building board at both ends? If not, the spar notches are cut wrong in the rib.

You can sand the notches out to fit and fill the gaps later with scrap balsa, no probs.

CR

Extra 300S Help
 

I agree, something there just doesn't make sense...

Compare the rib to another and see if they are the same. maybe you just got a bad die-cut. If they are not the same, make sure that they are the correct rib #s. If it definately the correct rib, cut away whatever you need to in order to get it to sit flat. Then eyeball down the wing to make sure all the ribs are lined up. You may even want to do this right away, after all, you may just have a broken tab that is shorter than the rest.

Extra 300S Help
 

Hi Charley & MinnFlyer,

Ok after careful examination this is what I have so far.

I took all the ribs off the spars and measured them with the ribs of the opposite wing. The ribs are all the same size of the ribs of the other wing ribs, tabs same size and the notches for the spars are the same. I have also looked at the spars and they seem to be pretty straight on. I also tried turning the spars over and I get the same thing. I am just wondering if I should just try and split the difference of the gap when attaching the L/E and the T/E as it seems I am basically out of options and I think everyone else is out of ideas on this.

My wife tells me no more kits from Santa if this project doesn't go any further. :cry:

Thanks for any and all IDEAS. :cool:

Extra 300S Help
 

Hi Sprink,

Read the "build the wing" section carefully. If that and aphone call doesn't provide enlightenment, recut the spar notches and remember this before you buy another GP kit.

CG had the same sort of problem with their Suhhoi kit.

CR

Call GP
 

I agree. Give a call to GP and ask them. Be sure that your spars are straight. GP will probably just send you another set of ribs. I doubt that it is a problem with this kit as a whole b/c there have been tons of them built without any problems that I have seen on here or anywhere else. GP is a great company to deal with. I will let you know what they did for me sometime. AnneMarie and the gang at GP will always get my vote.

James