Rib Stitch or glue

[Tipsy Flyer]

Hallo nipper engineers,
If i'm correct, the fabric on the nippers wings and tailplane is glued to the ribs. Would rib stitching not be safer?
Why an i asking, well i took the plunge and removed all the covering on the wings, tail and control surfaces. The start of getting my nipper back were it belongs, in a hangar at the airfield and few thousand feet above the planet!!

I was always a little put off by the way the fabric bulged up between the ribs on the top surface while in flight and "pulls" at the ribs, hence the question, glue/ ribstitch??

I know what i'm about to ask is not original on the nipper but has anyone ever made wing tips of their nipper. I know about the tip tanks, which make a nipper look really mean!!, the tips i'm reffering to would be something like a piper cherokee 140 type, simple things.

While i'm at it, i'v read a number of articles on control flutter, is it not viable/safer to some how balance the ailerons. I know one should leave sleeping dogs sleep, but in the interest of safety should one not consider this!

regards
GLEN

ps; Have bought a new camera, will post pic's soon!!

[G-NIPR]

Hello Mate,
When mine was covered this time around it was deemed not necessary to rib stich, something about the spacing of the ribs if I remember.
There was also no evidence of it being previously stitched last time either when we took it off.
I never noticed the bulging before, but I have done recently with the new covering. It is only slight and is on the wing root area.
It doesn't give me any cause for concern.
I have never heard of a flutter problem with the Nipper, and there was no evidence (thankfully!) when I carried out a VNE dive last week for its airtest. Anyone heard of this problem with Nippers?
I have also not considered modding the wing tips, how dare you!! I think any 'modern' airflow techniques would have very little effect on the Nipper when you look at the rest of the airframe. I know Barry Smith is developing a super low drag Nipper and a lot of changes will be revolved around the cowling design.
Good luck with the rebuild, keep us informed..

I have just done an hour in mine today, and can tell you its is worth the pain/expense/time that you will inevitably face!

Paul
G-NIPR

[Tipsy Flyer]

Hi Paul,
Thanks for the reply, I think if one uses the correct grade of ceconite or what ever covering one chooses to use and the correct glue APPLIED correctly, rib stitching should not be nessessary.
I have also not heard of flutter on nippers but i'm just putting out a feeler to see what response we might get. Better to find out before one ends up having a really bad day!

The wingtip idea is purely cosmetic, the blunt wing tips look a little 'unfinished" if you see what i mean. The Spitfires tips were "cut" off in the PR version which evidently made it faster.
Basically the nipper has a built in head wind and as you correctly said, not much will help it aerodynamically.
You are making me jealous that you did some flying today, it is a perfect day, blue skys, little breeze, perfect for flying here in sunny SA. Been raining/overcast/cold for a WEEK here !!!

Anyway thanks for the motivation, i'm sure the end result will be worth it.

chatter latter
Glen
ZS-UAD

[Mr.Tipsy]

There are at least two Nipper that had wingtips.

OO-NIK had wingtips factory-made.
HB-SPQ was also modified with tips.


But I don't know the results..

[Pat Blenkinsopp]

Glen,
read all the stuff about covering and wing tips. I have just recovered my nipper (ASXI) and have used ceconite 102 and have put rib tapes (Polyfibre light weight) tapes over all the ribs etc. (I will endevour to get some photos before I put the uv and top coats on. Now I have no commercial conections with Polyfibre but I have been using the system at work as well as on my Nipper and I am sold on it. Very easy to apply and a great finish that is flexible and very hard wearing.
I seriously reccommend the system to you.
It is slightly more exspensive than traditonal butrate dope systems but much easier to apply. The lightweight tapes go on easily and look great. The real key to getting the fabric to adhere to the ribs is to coat the ribs etc with at least two coats of neat Polytack (The system specialist fabric cement) You should then let the Polytack dry between coats. Next step is to arm yourself with a 50/50 mix of Polytack and M E K (methyl ethyl ketone...sp?). Next one coat of the mixed Polytack/MEK on to the rib and then put the fabric on whilst it is damp. What is happening here is the MEK reactivates the prexisting neat Polytack coats . You then sponge down the fabric/glued joint with a lint free rag that is damp but not soaking in MEK. This further activates the glue undeneath. Any areas that do not stick to your satifaction can be treated by working into the glued area with the 50/50 mix. Any stray glue can be cleaned away with neat MEK. (The MEK has the added bonus of getting you as high as a kite on the fumes !!!)
Rib tapes are simply applied using Polybrush ( the system equivilent of non taughtening dope/sealer) Simply brush on a line of Polybrush lay the tape on top then using the brush work in the Poly brush untill it is soaked right in but not awash with the stuff. You then go back to the tape when it is almost dry and go over it again to fill in the tiny bubbles that appear as part of the drying process. once gone over a second time they disappear.
You get used to the techniques involved very quickly and a bit of trial and error pays dividends. It is worth getting the little handbook of the Poly system as it more or less explains what I have very quickly described here. It also lists all the products. I have developed a few sensible shortcuts that speed things up a lot and can let you know if you choose the poly system. It is a shame you dont live in the UK because the dollar/£ rate makes it relatively cheap at the moment as the agent sells at the $ on the day. The glued fabic to ribs joints done this way are INCREDIBLY strong and if it aint broke... I cannot recall any Nipper falling out of the sky because the glued fabric/lack of rib stiching issue. Oscar Tips was a very tallented designer . Why deviate ?
Regarding wing tips, I agree. The "sawn off " tips of the original look as though the designer forgot to add them as a last finishing item. I think that simple Cherokee type tips would be very easy to make using a balsa wood former to make a mould from.
Anyway sorry to have gone off on a diatribe of the vagaries (?) of my techniques. Thing is they work ! Glen I wish you all the best with the recovering and PLEASE let us all know how you get on. I for one find it all a most absorbing pastime and am thoroughly enjoying the process. Long may it be so.
All the best,
Pat.
Ps Never had a flutter problem even after a bodged half roll and pull through that saw 5G and 155 mph at the bottom (happy in the knowledge that as a certified C of A aircraft (originally when it first hit the scene) the G limits were +6 -4 and the limits are factored to 1.5 anyway !!!
Get slapping that dope (Polyfibre) on.
See ya.

[Pat Blenkinsopp]

Mr Tipsy
That is a seriously cool photo of a Nipper taxing out in front of a Carravelle (is it ?)
"Speedbird 1234, you will just have to wait... I have a one page check list to go thruogh here before i get airbourne.............
Regards, Pat

[Pat Blenkinsopp]

Paul,
I am guessing that you are familiar with Barry Smith's much modified Nipper (no dihedral, lower turtledeck, tail dragger, symetrical aeorofoil, inverted system, spades etc etc ) bloody nice! It looks just like a mini Extra and all on 80 HP of VW power. I wish we could get plans for that one.
Missing the flying......... must get spraying soon
Regards,
Pat

[David H]

Has anybody any experience with Hipec said not to need rib-stitching and I've seen some very smart finishes with the stuff.

MEK! That brings back memories - my Dad used to get me some as an additive for my model engine fuel as a kid - made the old Club 20's sing - powerful stuff!

Just a note on the Acro, I made the same mistake in thinking it was based on a Nipper - Barry said it wasn't at all, to quote him "The AA is not a modified Nipper – it’s in a whole different aerobatic league."

[G-NIPR]

Hello Pat,
You must be meaning Barry's Acro Advanced. It is a remarkable machine and he knows just how to fly it! I think
I am right in saying that it is a completely new design and not Nipper derived at all, although of course Barry was well known
for his Nipper displays before designing the Acro.
I had the pleasure of popping in to Barry's strip to see him briefly on my way home with NIPR. Kindly provided me a little AVGAS to bridge
the gap between stops. Although I didn't get time to see the Acro this time as he was in a hurry, sunday lunch on the table.
I have seen it previously when I night stopped at his strip. He VERY kindly took off and gave me a personal display just for me of about 15mins. He has still got superb flying skills, precise and accurate.
I recommend anyone interested in meeting him to arrange directly with him for PPR and drop in to Yearby.
Catch him on a quiet day and he will give you all the advise and hospitality you could want for.
The strip is just on the edge of the Teesside (formerly Middleton St George, then Teesside, now Durham Tees Valley!) zone.
Glad the covering is going well Pat, I am awaiting my permit to come through in the post..to have some more airtime.

Cheers to all.

Paul
G-NIPR.

[Tipsy Flyer]

Hi Pat,
Thankyou for the detailed covering lesson, one can learn from experience.
The polyfibre system, i believe is very good and easy to work with. We have ONE serious problem here, anything $ priced, we must multiply by 10, yes 10!!! This makes polyfibre a tad expensive and yes, it is a pity i do not live somewhere, where one can buy stuff at a fair price, first world-third world syndrome!
We have a local system that is similar to ceconite, dopes etc, that was developed to cover a small aircraft that is a ripoff of the Kitfox and a nice little plane it is! This aircraft's covering is also glued to the ribs and the process you described is much the same as this local coverings recommendation on how to glue the covering. I must make up my mind soon as things are progressing well with the preparations. The tail surfaces, ailerons are ready to be covered, the new ply for the wing leading edges arrived last Friday.
I must modify my treasles a wee bit as they are to low to work on the wing. or i'm to tall!!
The intention is to complete the wooden bits up to UV coats and move on to the fuse and engine.
Pat, if you are taking photos of the covering, please take some of your engine installation.
The reason been, i have no examples to look at and i like looking at lots of ideas and chosing the best ones. If anyone reading this has engine pic's, please, lets see them, thanks.

If one of the site mod's reads this, is it possible to create a "sticky". This way, i for instants, can up date my little project in my sticky and not all over the forum.
Visit www.microlighter.co.za and see all the stickys for the projects that are in progress

Anyway, today is the first time i could log in for some time, thank goodess for that.

Regards
Glen

[G-NIPR]

Glen,
If you go to the 'THE AIRCRAFT' section of the board you can start a new thread about your aircraft.
I can try a sticky, but the level of traffic we have means it wont drop of the bottom of the thread anyway.
Please start another thread with your reg and 'restoration progress' or similar, and we can watch with interest.
That way just rib stitching comments will be posted on this thread.

Cheers.

Paul
G-NIPR

[David H]

I agree with what Paul says - with just a general note which could be useful in this instance - make the first post you see, the latest/most recent post - do this by going to:
'User Control Panel' > 'Forum Preference' > 'Edit display options' > 'Display post order direction:' Set as 'Descending'

I can't set this as a forum basic setting, it will have to be up to the individual, but would save a lot of scrolling for a big topic!

[G-ARBG]

Glen, I have rebuilt a couple of Nippers over the years and have not seen the necessity to rib stitch when using approved covering methods. Slingsby built Nippers were never ribstitched and used the time honoured and proven glider method of gluing the fabric (cotton) onto the structure.
Regarding another comment on 'flutter' on this site, I have not experienced this problem with the correct cable tensions (see handbook). However I have had an aileron 'snatch' the stick when the cables were incorrectly tensioned i.e. too slack. Obviously very quickly sorted!
I have many photos of engine installations on both MKII and MKIII but this site will not accept them as the files are too large. Please contact Paul Gibbs (who owns this website) for direct contact with my email address if you wish more information.
Regards,

David G-ARBG

[Tipsy Flyer]

Hi All,
Cool Paul, i'll do just that, must load my pic's onto photobucket before i start.
Thanks David, do you rebuild as a hobby? If you are bore,feel free to pop down and help me ooo i forgot, we are not round the corner from each other dam!!!
My Nipper is a Belguim built version (s/n 10 MK 1), i assume there was not much change structurely in the latter versions. I ran out to the workshop to measure the width of the rib caps which are 15mm. Is this the same as the latter versions, if so, gluing the fabric to the ribs becames the preferred (and easist) method.
The flutter thing started after i read a good articule on flutter and control balancing in an old Sport Aviation. I'm well aware that the Nippers are well engineered and if assembled by the book, one should have little to fear.
Yes, i'm very interested in your pic's, will ask Paul for your email

This is great, i'v learned a lot from this thread, thanks to all but lets not stop, everyone has something to contribute to this site.( Even if it is how we won the rwc) coathatdoor!

Chat latter
Glen
ZS-UAD

PS: go'na be 30 c tomorrow and it's not even summer yet