YT Katana 46 undercarriage

[Bob Cotsford]

I bought this model last summer, and apart from a few niggles with the trim which you don't notice from a few feet away, it is generally a nice model.  YT also provide excellent backup (or maybe that's because I can go a couple of miles to speak to them in person?).  CofG and surface movement recommendations would help first flight confidence as there's no mention of what the prototypes used.

HOWEVER, the undercarriage mountings is a real let down - literally.

If you fly from a concrete runway, and always manage featherlight landings, it is ok.  In the real world though, it comes away from the fuselage far too easily, even on take-off once.  The U/C is bolted to a ply plate, secured into thin ply formers front and back by small tongues.  The biggest problem is that the slots to locate the tongues are only a few mm from the bottom of the formers, so the tongues rip out easily.

 After failed attempts to refit and reinforce the mount, I've now converted it to 8swg torsions bar, with 2 1/2" lengths of the legs going up into blocks set between the front two formers.  Now hitting a tuft of grass just flicks the wheel back, the leg springing straight back into position again.

[Alan Cantwell]

would this be the white one?  and have you contacted us before coming on here?     if it is the white one,  thanks for letting us know,   we will have words with the maker--who is NOT one of our usual suppliers

ALAN,  YT

[Bob Cotsford]

Hi Alan, yes it is the white one with blue underside.  I bought it at the YT do at Greenacres the year before last - what, 18 months ago?

No, I haven't contacted you, at least not recently, say within the last 12 months.   I did email several times regarding the lack of recommendations for movements or c of g when I first bought it, but never did get an answer.  If I recall the question was being passed on to the supplier.  Life's too short so I set it up with common sense settings and went flying.  I think I did mention the u/c at some point, either to Wilson or Martin when I bought a second kit for spares.

 

With the torsion bar u/c mod and an Enya 60 mk 111 up the pointy end, it flies a treat,  but like many artf's the u/c mount is a weak point.   As with any ARTF I'd recommend going over all accessible glue joints especially those joining the engine mount to the fuselage, and giving the internals a liberal dose of fuel proofer.  The CofG set on or slightly in front of the wing joiner makes it a nice mode for pattern style aerobaticsl.

 

This thread was originaly prompted by requests for info on design and manufacturing weak points in models, and was intended as a recommendation for anyone else having the same problem - not just with the YT Katana 46, but with any of the dozens of models that can't cope with anything more than bowking-green grass.

 

As an aside, with the exception of the c of g question, I found YT International great to do business with, both face to face and by email.