Detlef Schmidt

Hi Chuck,

I like your idea very much with the additional tube inserted.

I have the fortune that we have welding facilities in our company so that I think about the possibility to insert a tube in each side and to weld it together in the middle after inserting. So I hope to avoid the grinding.

But first I have to ask our welding specialist if he agrees to the possibility to do so, or if the heat-emission during the welding will destroy all the vincinity of my centre-wing-section.

In this case I will start grinding same way as you Chuck.


best regards,

Detlef

scale9planes

Hi guys

I wouldnt go adding to much to strengthen the center panel the only one who I think should is the fellow who put the fuel tank in the wing as all the strength as now been cut away to fit the tank .With the model already over weight we should be very carefull of extra weight my personal opinion is the wing is strong enough as it is using nylon wing bolts could posably saved a great deal of damage. my wing has glass foam glass there is no wood for the leading edge as can be seen in the photos with my hand holding the wing. I have read every post from start to now we have all had the same issues with this model & at times i wish i hadnt bought it at all But after killing it i have ordered a new wing and i will only changing minnor things. i did note one fellow moving all the hardware out of the fuzz to the wing. Idont belive this would help asyou are adding more weight to an already over weight wing mine was 7.5 kg with no door covers or the extra servos for them.As i said befor when you fall out of the sky with 12-15 kg something has to give the left hand wing hit first which is why the wing broke as it did



Anthony

roncoleman

My Feedback: (14)

Anthony,

I just did a re-looked at your photos and I now see you did have the glass wing.
Using the word failed was a bad choice. I don't want anyone here to think that I'm trying
to talk down the aircraft. The I-beam spar is just my opinion as how I would have like to
see the/a wing built. Balsa spars capping off the ply web (which would not add much to the
overall weight) along with the other mod you guy are making should produce a much
stronger wing and everyone would have the warm and fussy felling about the whole thing.
Planes are made to fly, not to survive a crash. JMHO

VKerster

CHARLES AND T-CAT BROS, AFTER LOOKING AS CHARLES' PICS, I LOOKED AT MY WING FROM THE CRASH IN UDDER DISBELIEF. NOT ONLY DID MY CENTER SECTION LOOK LIKE CHARLES' PICS, BUT I FOUND THE LEADING EDGE HAS NO SPAR, AND THE TRAILING EDGE HAS ONLY A 1/8" BALSA SPAR!! I'M NOW CONVENCED I WAS RIDING ON BORROWED TIME UNTIL I WOULD HAVE HAD AN IN FLIGHT WING FAILURE. WILL POST PICS SOON.
FOR T-CAT #2, I'M GOING TO TRY TO INSERT A SMALLER DIA. TUBE FROM TUBE TO TUBE LIKE CHARLES, EXECPT I'M GOING TO TRY TO DRILL THRU THE RIBS THAT THE TUBES BUTT UP TO AND INSERT IT ONE INTO THE OTHER SINCE THE WING SECTIONS ARE NOT GLUED TOGETHER YET, AND USE J.B. WELD TO GLUE THEM TOGETHER. ALL OTHER IDEAS ARE APPERICATED. I WONDER IF THE FLY RC MAGAZINE ADDRESSES THIS ISSUE IN THEIR ARTICLE. I WISH KMP WOULD CHIME IN AND ENLIGHTEN ALL OF US HOW THEY WOULD FIX THIS MESS[:'(]............. TOLEDO IS NEXT WEEKEND.

CHARLES WINTER

Good morning T-Cat builders. The new center tube is installed. The installation goes as follows: Put soft paper plugs in each outer wing tube, (To help keep resin contained when installing center tube) Rough-up new center tube with rough file (Want BITE/HOLDING surface). Mix resin with a small amount of Chopped Carbon (Just enough so that it is stringy/gooie, thick enough that you can control the placing of it inside the two outer tubes. Put a good amount of resin mix in each outer tubes. Brush a good amount of resin on the new 10 inch roughed-up tube. Suggest you put a Visual Mark on new center tube so you know when you have it centered. I suggest you use GLOVES on your hands, this method can get a bit messy. Install new center tube and add epoxy to areas that appear to be without epoxy. I did add more Chopped Carbon to the mix after the center tube was installed so I could build up the the voids I could see. I also JAMMED round tooth picks into the void areas to insure the Chopped Carbon was pushed all around the entire assembly. The results (This morning) look very good. I will continue to develop a spar addition along side of the center tube. The total weight of this modification should be approximately 4 ounces. I am also in the process of "Laying-Up" formula ONE racing props. Picture shows molds with props in the "Curing Stage" and some of the completed props. PS: If anyone wants a 10 inch aluminum high strength tube and some chopped carbon I will give it to you FREE, all I would want is the shipping cost. This we can figure out if you are interested.

Col. Chuck Winter

n9331v

Charles Winter

It would be a great help if I could get the supplies from you to do this mod, I will be happy to pay for shipping plus additional for the supplies. Can you provide us with the measurements needed to cut out the material for this mod.

Thanks

Ed

Pylon2

I agree with you totally,I am going to leave my Tcat centre section alone. I should be flying it in a couple of weeks and will report back . This modification in my mind will only push up the weight further. Verster's original plane flew well with 2x Zenoah 26 and had no structural failure at all, only seccumbing to engine failure and a oak tree!

CHARLES WINTER

Hi T-Cat builders-- Next step in strengthening center section. I made a Spar/Doubler out of 1/4 inch plywood. This will serve as a Short Spar, Short Doubler and Barrier to hold resin/chopped carbon mix in place. Tack glue Spar/Doubler with CA glue so it stays in place. Roll some small soft paper towel plugs that will be softly jammed in the void areas around center tube to keep resin/carbon mix from dropping through voids. Mix resin and chopped carbon to a STRINGY/GOOIE mix. Brush resin mix in areas shown in pictures. It will take approximately 2 to 4 ounces of resin mix. When this combination hardens, the new center tube will be a permanent part of the center section. Tomorrow when this is hard I will start to cover this area. SAY TUNED TO THIS CHANNEL. PS. I will make the offer again to anyone that wants a 10 inch strong tube and some chopped carbon, you can have it FREE. Send me an e-mail with your mailing address. After you receive the supplies you can send me a check for the postage. The box should have what it cost me. My e-mail address is [email protected]

Col. Chuck Winter

CHARLES WINTER

T-Cat Builders -- I missed sending the first 2 pictures showing the Spar/Doubler and paper towel plugs.

Col. Chuck Winter

kochj

Did you miss what Verster's just wrote prior to your post about his wings and that he is now thinking that he was on borrowed time before he had a failure???


CW'S mod will add very little weight, and will give much added security!

Justin

CHARLES WINTER

Hi T-Cat Builders -- Fit and CA glued 3/32 balsa wood pieces in wing opening to make a base for 2 once fiber glass cloth. This process does not need to be very NEAT or ACCURATE, it's just a bottom for the fiber glass and resin. I like to use PACER Z-Poxy (PT-40) for this type of resin work. Very user friendly and sands easily. I mixed approximately 2 onces of resin. I brushed this mixture on top of the first layer of fiber glass cloth to insure good saturation. I then layed the second layer on top of first and brushed on more resin. This process only takes less than half of your resin mix. Now add filler/thickener to the remaining resin. You can use Micro Ballons or a favorite you may have. I use "Colloidal Silica" adhesive filler. I do alot of fiber glass work so I have cans of this filler. If your interested in fiber glass products, this is a "West Systems" brand 406-2. It weighs next to nothing but thickenes the resin to any thickness you want. I mixed a lot of filler to the remaining resin to make it into a soft paste. I now put this THICK mix on top of the fiber glass cloth. I use a brush to push the resn into all of the voids. I now take a Playing card or Old Credit Card and very - very slowly drag the Card over the thick resin mix. You must drag the Playing Card very slowly so the thick resin mix stays in place and you only take off the high areas. You can check for low spots and add or shift resin around. With a little practice you can get an adequate level surface. STAY TUNED for the next edition....

Col. Chuck Winter

VKerster

T-CAT BROS, THIS IS THE LEFT SIDE OF THE CENTER SECTION OF MY CRASHED T-CAT WING. THIS IS THE AREA WHERE THE TREE BRANCH WENT THRU. NOTICE NO LEADING EDGE SPAR. THE TRAILING EDGE SPAR IS ONLY A 1/8" BALSA. WHERE'S THE STRUCTURE?? ONE CAN PLAINLY SEE WHERE THE ALUM. TUBE BUTTED UP AGAINST THE RIB AND THE OPEN AREA WHERE THE TUBE SHOULD HAVE INTERSECTED THE LEFT TUBE. STILL THINKING HOW I MIGHT GET THE CONNECTING TUBE IN MY NEW WING WITHOUT CUTTING UP THE BOTTOM OF THE C-SECTION.
THE SECOND BATCH T-CATS ARE SKINNED WITH THE KEVLAR COMPOSITE SHEETING. MINE LOOKS MUCH STRONGER THAN MY 1ST BATCH(T-CAT #1) WAS. KMP MUST FEEL THIS NEW SKIN IS SUFFICENT TO HANDLE THE HIGH G- LOADS THIS AREA WILL EXPERIENCE. SINCE KMP IS SOOOO QUIET ON THIS FORUM ABOUT THIS ISSUE, AM GOING TO CALL THEM AND SEE WHAT LIAIBILITIES THEY MIGHT FEEL RESPONSIBILE FOR IN THE EVENT OF STRUCTURAL FAILURES WITH THESE T-CATS.......[X(]

chasrb

Sad to see that we have spent many dollars + many more dollars for the right parts just to get this plane where it is a truly flight worthy airframe. I mentioned in the earlier section of this forum my concerns for the strength of the center section and now I see my concerns were well placed or so it would seem.

I am questioning whether or not to keep this airframe. I have way too much money in this with radials, retracts, digital servos and Smartfly equipment just to have all that in an airframe that will, more than likely, fail because of poor engineering and quality control on the part of the mfg.

Maybe I'll just use all the original parts and build it as a static model and sell it to a theme restaurant...

It should not have been this much work for an ARF!!!



I feel beter now...

tahustvedt

Is there any indication of overstressing in the beam on any of the models that have not been crashed?

johangr

HI T-cat builders. I am from South Africa, and have been busy with my T-Cat for a while now. I am however still awaiting my retracts for this beauty[:@]. I have opened up the centre section of the wing, similar to what Col Chuck did, and I'm amazed at how little structure this wing has. I think that I will have to seriously enhance this structure, maybe similar to Col Chuck's. For all the money I spent on this plane so far, I reckon this should've been a much better built kit[]. Anyway, will keep you updated with the progress.

roncoleman

My Feedback: (14)

Check your PM

Ron

VKerster

T-CAT BROS, I TALKED TO A. KONDOR FROM KMP TODAY ABOUT THE CENTER SECTION ISSUE AND HE TOLD ME HE'S BEEN READING THIS FORUM, AND KNOWS OF MANY T-CAT OWNERS FLYING THE DAYLIGHTS OUT OF THEIR T-CATS AND DOESN'T KNOW OF ONE WING FAILURE. HE SAID THE ENGINEERING IN THE CENTER SECTION IS SOUND AND KMP IS USING A KEVLAR HONEYCOMB COMPOSITE SHEETING MATERIAL (SECOND AND THIRD BATCH T-CATS?) FOR SHEETING THE SURFACES ON ALL THEIR PLANES NOW. HE SAID THE TORTIONAL STRENGH OF THE MATERIAL IS EXTREMELY STRONG AND WHEN THE WING IS GLUED ALL TOGHTHER, THE NOW ONE PIECE WING IS GOOD FOR ANY SCALE FLYING THE T-CAT WILL DO. HE SAYS CUTTING OPEN THE T-CAT'S WING TO ADD REINFORCEMENTS ISN'T NESSASSARY. HE DOESN'T RECOMMEND ANY 3-D FLYING, EXTREME ABRUPT PULL UPS OR WIDE OPEN THROTTLE LOOPS IN THEIR ENTIRETY.(GETTING OFF THE THROTTLE AFTER THE TOP OF A LOOP) AS FAR AS THE LACK OF LEADING AND TRAILING EDGE SPARS, HE SAID THE ENGINEERING OF THE WING STRUCTURE AND THE KEVLAR SKIN MAKES UP FOR IT. EVERYONE WILL HAVE TO DRAW THEIR OWN CONCLUSIONS ON THIS ISSUE...........

duber3

So what your say it's this plane is very good for static display!!! [sm=omg_smile.gif]

Detlef Schmidt

Hi VKerster,


thanks for your comment about the conversation with A.Kondor.

My conclusion is to reinforce the center-wing-section.

Even if I would not have opened the section for my tank-layout I would have reinforced it after reading all comments here.

But as you mentioned, everybody has to draw his own conclusions.


best regards

Detlef

n9331v

WOW what a nice song and dance by KMP.................. I think the wings may hold up if someone is running small 90's like what's recommended oops I forgot they don't even fly with what's recommended.

Since I am running the Twin Cyl OS 160's I decided to take Charles Winter up on his offer I myself think its a well thought out idea and a good fix.

I feel with everyone working together on this forum we will eventually be able to make junk fly.

Vkerster thanks for contacting them.

kinverflyer

As previously mentioned the prototype weighed 22lb and was powered by two RCV91CD's, they where more than adequate. There are production T'cats flying with the same or similar power plants and simliar weights.

N215PB

I'm just finishing up mine tonight for 1st engine runs tomorrow....I have 2 SATIO 100's on her.......I did mount them straight up for reliablity. From all the posts I've kinda alreay written her off, are all the other KMP products like this, I have another KMP kit on order?
I was gonna think of upgrading the gear but why waste more money on this kit, I've done more damage just handling it in the shop. The kit gear is horrible. I'll let you know if i ever get the nerve up to fly it this week.

VKerster

KINVERFLYER, PRODUCTION T-CATS WEIGH IN AT ABOUT 26.5 LBS, AFTER ONE PUTS UPWARD OF A POUND OF LEAD IN THE NOSE TO GET THE BIRD TO BALANCE, AND CLOSE TO 28LBS. WITH FUEL. THIS WAS MY EXPERIENCE WITH MY 1ST T-CAT. MY 2ND T-CAT LOOKS LIKE A REPEAT OF T-CAT #1. KMP HAS TO KNOW THIS, UNLESS THEY NEVER PUT A PRODUCTION T-CAT TOGETHER. AT 28 LBS., THE WING LOADING IS SOMEWHERE AROUND 70 OZ. PER SQ FT.[X(] I MAY TRY THE "TUBE IN TUBE " APPROACH, THEN J.B. WELD THE TUBES TOGETHER IF I CAN FIT THE SMALL TUBE IN THE C-SECTION WITH THE DIHYDRIAL BEND. ARRGH, PUTTING 2 T-CATS TOGETHER IN ONE YEAR...I NEED A BREAK.... IS ANYONE OUT THERE FLYING THEIR T-CATS ON A REGUALR BASIS?

kochj

Vkerster...
I would be pulling my hair out!
2-of these... you at least know what you are doing!....
Perhaps, KMP can contract you out to put together a GOOD MANUAL!>...

I think you are ALL being way too critical or ADAM!.......
If you look at other scale or semi scale ARF's , You wouldn't get by for very long with out a wing or horizontal stab failure by doing PYLON Racing TURNS
and WOT bottom loops that are very sharp and FULL elevator!.....

You guys are running the GAs engines great, do some reinforcing and fly it scale..... YOu will not have any problems...
Do loops, stall turns and all your fun sport flying..... And you shouldn't have any issues.....

NO one on this forum or anyone here has heard of one failing!.....
This is a lot of speculation...... Other manufactures of twins have been getting scrutinized about there wing structure as well. But this was only AFTER the wing CRACKED!....[]

If you are running engines out of what the manufacture is saying is OKAY to run, then take what ever steps you think are neccesary to make sure it doesn't
fall apart!,,,,,

IF all you have to do to make it safe is add a tube and glue it, I don't think it is that big of a deal!.......
Also, there is no actuall proof that you need to do it!....

These are all JMHO though, so Perhaps I am a fool?

.... No one has had a failure. Perhaps your vast experience with building planes is much greater than mine, and your
assumptions are good from your personal experience...?


As with all the manufactures of aircrafts, they say right in the front of the manual...... BUILD AND FLY AT YOUR OWN RISK< WE ASSUME NO LIABILLITY<>

On the other hand, I do feel for you ALL!....
You have had a LONG and Involved Build of this aircraft..... If I ran KMP, I would not be taking a back seat on this one...
I would be quite involved, because if you are silent, then everyone talks about you.... Negative or possitive.....
Like the GOdfather said: "Keep your family close, but your enemies closer"

I don't Run there company so What I would do and what they do are two diff. things....
Adam is a stand up guy, and I don't think that he is getting just disserve on this one......

Justin

Justin

kochj

As I think about one important issue though!.....

KMP stated that due to the composite material on the wing, they believe it to be strong enough....

What about the NON-composite wing that is due out NOW???

NO updates on that wing? No composite to reinforce that wing!.....

I would think though, that a Balsa wing would be Much lighter, and would be much easier to modify and still have it look good..