John Lee Posted June 5, 2017 Share Posted June 5, 2017 The wing of the Wot4 foam-e mainly consists of two large full span foam mouldings forming the top & bottom skins. These are bonded together and contain some carbon reinforcements and the servos. Yesterday at the field a club mate was performing some mild aerobatics when there was a loud 'pop' and the wing separated from the fuselage. The wing fluttered down in two parts, being the separate top & bottom skins which had delaminated. The fuselage plummeted vertically of course & upon recovery was found to have a small part of the trailing edge (about 5cmx15cm) still attached by the wing bolt. The wing parts were also recovered and it was obvious upon inspection that the 'glue' holding the top & bottom skins had failed allowing them to delaminate, the air then entered the wing causing the catastrophic failure. The 'glue' was a rubbery compound which could easily be picked from the surfaces & had clearly failed in its job. This is the second such failure I've witnessed recently. Two weeks ago at the RC Hotel a model lost the underside of one wing panel in flight, fortunately on that occasion it was able to land successfully & the wing was repaired with cyno. Both models were new, it was the second outing for my club mate's model whilst those at the RC Hotel tend not to grow old! My club mate will be taking it up with the Retailer &/or Ripmax &/or the credit card company for recompense. Has anyone else experienced such a failure? If you have a newish WOT4 I'd suggest a careful inspection and perhaps a precautionary wicking of cyno around the joint of the two skins. Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted June 5, 2017 Share Posted June 5, 2017 Certainly the older version with the blue and white scheme could take a lot of stick, including unplanned impacts, and though I've seen the foam living hinges fail the wings have hung together. I had thought about retiring mine and replacing it with a nice new orange trimmed one but maybe not... Quote Link to comment Share on other sites More sharing options...
Neil67 Posted June 5, 2017 Share Posted June 5, 2017 Although I haven't experienced the specific problem with wing construction I have had to re-glue several parts and I, like many others I suspect, have been disappointed with the poor quality and design of these models. Don't get me wrong, they are great flyers and I have several, but I often wonder how Chris Foss feels about the comments about the obvious shortcomings inherent in these versions (which have been covered many times in this forum). Buying a model and then having to ditch or changing bits you have just paid for seems crazy to me but I fully appreciate why and I have done it myself. Has Chris Foss signed away his design input? I cant believe he has passed some of the clear design issues! Yes these are made at a price, but good design doesn't have to be expensive. John I do hope your mate succeeds in his quest for reimbursement of some kind. Quote Link to comment Share on other sites More sharing options...
Nightflyer Posted June 5, 2017 Share Posted June 5, 2017 I also fly a Foam E and have done since early March without any problem, as have others in my local club for some time. From what you describe it could well be a bonding issue of the adhesive used. The use of cyano on foam - I trust you mean a foam friendly one as there are some around which people might use one that attacks the foam. The models are light in comparison to the full size wood and foam wing Wot 4's but would have expected a good development programme before the model went into production. Hope you mate gets his issue sorted out. Quote Link to comment Share on other sites More sharing options...
John Lee Posted June 5, 2017 Author Share Posted June 5, 2017 I don't think there is anything wrong with the design, like Bob I got the blue one years ago plus an Acrowot and a Wots-wot and all have been trouble free over hundreds of flights. The problems I witnessed with the new orange trim batch is specific to the glue used in constructing the wing. Nightflyer - no I don't mean foam friendly cyno. Conventional cyno works perfectly well on the EPO foam used on the Wots. I reserve foam friendly for depron & the likes. Quote Link to comment Share on other sites More sharing options...
ChrisB Posted June 5, 2017 Share Posted June 5, 2017 I've thrashed my old blue one to near extinction several times without any failure on the part of the aircraft. Mine looks a right heap of junk but keeps on going. I rekon you were just unlucky. Like Bob I've been tempted to replace mine...I might hang on until the tail meets the spinner again.Edited By ChrisB on 05/06/2017 13:36:28 Quote Link to comment Share on other sites More sharing options...
Simon Chambers Posted June 5, 2017 Share Posted June 5, 2017 I had a blue one many years ago that I flew until I smashed it in. This was repaired and crashed many a time. The replacement was flown until one day I misjudged a fence trying the flying under it at ever increasing speeds! Again repaired over and over. All those times I never debonded the wing. I've had to glue massive cracks straight along them and heat up to pop out big dents, but the glue never went. I threw that one out a year or so ago when it was looking very worse for wear. To get back into flying I purchased another this year - the revised model. I've not had debonding issues but I might have a good look at the wing to double check. Maybe they've changed the glue used? The old one was some white, rubbery sealant type glue. I have noticed the decals have a lot less stick than the old ones. They keep on curling up and trying to depart company with the surface.Edited By Simon Chambers on 05/06/2017 19:25:07 Quote Link to comment Share on other sites More sharing options...
og Posted June 5, 2017 Share Posted June 5, 2017 john - what did spiros say about it Quote Link to comment Share on other sites More sharing options...
John Lee Posted June 5, 2017 Author Share Posted June 5, 2017 It was just repaired at the RCHotel and was regarded a one-off. The second incident yesterday made me wonder if there is a problem batch, hence the question as to whether anyone else has suffered such a failure with a new model. Quote Link to comment Share on other sites More sharing options...
Glyn44 Posted June 5, 2017 Share Posted June 5, 2017 Simon, I totally agree re the decals. The nds just come unstuck and then look really tatty. CA no use for re sticking either. Quote Link to comment Share on other sites More sharing options...
John Lee Posted June 5, 2017 Author Share Posted June 5, 2017 I use UHU por to stick down any lifting decals Quote Link to comment Share on other sites More sharing options...
Guvnor Posted June 5, 2017 Share Posted June 5, 2017 I dare anyone here to ring Foss and see what he thinks... Quote Link to comment Share on other sites More sharing options...
ChrisB Posted June 6, 2017 Share Posted June 6, 2017 I'd contact Ripmax or best off going back to the retailer who can take it up with Ripmax themselves Quote Link to comment Share on other sites More sharing options...
Former Member Posted June 6, 2017 Share Posted June 6, 2017 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
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