Wing rib installation order/procedure

[Thruster87]

Having a bit of a problem in putting in the top ribs. As per the manual only the last two upper and lower ribs are put in and the skin is tensioned and then shaking the wing tips and so on.Anyhow with this method there is no way the upper ribs will go all the way in [the tails protrude] as per the photo. It appears these ribs are a bit long !!! Any ideas? [tried also to slacken the webbing joiners to see if it would help but had the same result] Cheers Alan[ATTACH]1802[/ATTACH]

 

 

 

[Barefootpilot]

I'm sure Tony will jump in here but as I have just done this I thought I'd jump in too. First check that the front of the rib is over the leading edge of the front spar you will be able to feel/see this. If isn't over the top it may take a bit of a thump to get the rib over the leading edge of the main spare if that isn't the case.... Tony????

 

Hope this helps.

 

Adam.

 

 

[Thruster87]

Seemed like it at the time but as I have to trailer the aircraft home every time I use it, I'll check that more closely at the next outing [takes about 2hrs to put together and 1 hr to dismantle and put it back onto the trailer].Some of the ribs had a short length of cord attached, is this a normal practice as you can pull the ribs a little easier ? I really didn't want to use anything that might cut the Dacron if one slips to put the little beggers in place. Cheers

 

 

[Guest TOSGcentral]

OK – Damn I feel as if I am rebuilding this aircraft myself!

 

 

First up – have you checked your batten profile? Good quality wing skin tensioning can flatten out the battens and so make them longer (as well as changing the wing section).

 

 

If you have not done this then get hold of a T300 or T500 and offer one of your own battens to the flat face of the wing tip (you cannot get this profile easily off a Gemini or TST wing as you have because of the wingtip design but they are the same section).

 

 

Now carefully re-bend the batten by the highly technical method of the amazing “across your knee†situation until it is right. Ensure that you tease it into shape and do not have big hauls on it because you will be work hardening the metal!

 

 

OK – next step is that despite the approved TOSG method of wing skin tensioning, even on aged skins they can be a bit hard to get the battens in fully. New wing skins definitely require “persuasionâ€Â.

 

 

This is achieved with a hammer!

 

 

You need a light hammer and force the batten in as hard as you can by hand first. Then lightly tap it into position whilst ensuring that any undue damage is not being done to the leading edge of the skins. You have to do this at every stage of the skin tensioning procedure that you now have!

 

 

When the batten is correctly seated the front duck bill will be over the top of the front spar and sitting neatly. Down the back the trailing edge of the batten should be able to be easily pushed down into the wing fabric slot, but should be sufficiently long as the inside radius of the rear spar will not allow it to descend further than that.

 

 

It is ESSENTIAL that you follow this procedure! I strongly recommend you do NOT start sawing up battens to make them fit! If they get too short it may look “neat†but you have a reflex section on the wing because the batten goes below the horizontal median of the rear spar!

 

 

Brief horror story. I have flown a Thruster in this condition and it nearly killed me. Everything seems normal until you pull the power right off and it points at the ground with no elevator control at all! I went through that three times in a single approach because I was there to find out what was wrong with it. I do not recommend it to anyone!

 

 

If you follow the directions given then you should be OK. If they still do not fit then there is a wing geometry problem, possibly from a faulty rebuild with shortened compression struts (as it seems clear that your wings have had some prior “attentionâ€Â!).

 

 

If that is the case then get back to me and we will work out a minimum pain cure – but I think you will be OK

 

 

Note also that the lower surface battens normally give no problem as there is only one localised bend in them up the front. However it is still worth checking that they are all symmetrical!

 

 

Aye

 

 

Tony.

 

 

 

[Thruster87]

I need all the help I can get. The wing skins are new, so the old adage get a bigger hammer fits the bill.I wasn't game to be so brutal and having the duck bill at the back as well it didn't seem possible to give it a hit with much success .The short bit of cord attached just forward of the rear t/e duck bill thru the hole does make a bit easier to pull .I did check that all the profiles were OK top and bottom first. You properly realize by now that this is the first time I have actually put one together [other then 707s' 747s' etc]. I hope to get my tail dragger endorsement in the near future and then up up and away.This little project was only to last 6mths until flying and that was 3yrs ago. Cheers

 

 

[Guest TOSGcentral]

You are going very well Alan and I really do not mind answering - because others read this who maybe do not want to ask, but do want to ask, or will get to a stage where they need to ask but they have already been answered.

 

A couple of key points: In your latest you state the rear "duckbills"! Now the front duckbills are obvious by where they get name because of their shape. But down the back end you should have simple plugs that are maybe 1/16" protrusion from the batten.

 

If you have the same down the back as down the front then that is certainly your problem - but I do not think it is.

 

Yes! A surprising amount of force has to be appled to the battens to get them fully home and owners certainly back off from this. But you have to be totally confident things are the right size and therefore will fit! Hence my comment of watch the leading edge to ensure that no damage is being caused.

 

Tony

 

 

[Thruster87]

The rear plastic ends are about twice as long as the front duck bills and taper to a very thin edge.The only ribs that had the plug ends were the 3 bottom ribs per wing and I assumed they go in the first 3 [from the wing attach end] held in place with the velcro [only 3 have the velcro per wing ] That's what came with the A/C Cheers

 

 

[Guest TOSGcentral]

OK - see my reply in the thread you have just opened.

 

To finish this one off - your aircraft has been illegally modified and passed on to you as is.

 

The velcro covers on the three inner battens are because these battens begin travelling and can work out in flight. The velcro covers keep them there!

 

Now do not make haste in too much of a hurry because your battens may be too long at the moment but the metal could also have been shortened. I will have to do some measuring for you but there is a relatively cheap and kosher way we can get around this.

 

I will be back to you tomorrow.

 

Aye

 

Tony