Ed Kershaw

I use the Harwin crimp terminals from Farnell www.uk-farnell.com They work fine and have the same pitch as JST but don't have the tangs on the back so they're not poke yoke - i.e. you have to make sure you plug them into the balancer the correct way round.  They do everything from 2 to 12 way (not 9 way, though).  I just use the 12 way for everything and cut them down to size a/r.  The12 way is part no 865-680. Cheers Ed

I have just bought one of these with the intention of an electric conversion.  I was considering an Axi 5320/32 with 10s 5000mAh lipo and 20x12 prop. Has anyone got any experience of this model at all or even an ep conversion?  Cheers Ed

Brian,  It sounds the same as mine.  I think the same model is marketed under JP, Green models and Pacific Aeromodel, as is the Super Tigermoth 90. My instructions also quote 105-115 cg (some seem to quote 110-115mm), although, as I wrote previously, my cg is a lot further back than that at 150mm.  Mine seems to fly better that way and spin recovery is no problem either, provided proper spin recovery action is taken.  It won't just recover by itself like most other rc models seem to. From the above, some of these models appear to be a real handful and unfortunately we don't seem to have identified why this might be during this thread.  All I can say is that mine flys really nicely, the only vice being a tendency to tip on its nose at the end of the landing roll.  My rearward cg helps with this, though.  With the more forward cg, someone did suggest to me on landings that "it arrives like a plumbers toolkit" and I found I had to give it a burst of power at the end of the approach to initiate the flare.  Please let us know how you get on. Ed

Brian,  From the above, it would seem that there are two types of these models which can be identified, at least, by the width of the centre section.  Which type is yours?  Is the centre section 130mm (like Adam's) or 155mm wide (like mine)?

That's interesting!  My centre section is most definitely 155mm wide.  If yours is 130mm wide then it's a different model, even if it's roughly the same shape and size and JP are marketing it as the same. A 130mm wide centre section would not fit either the wings or cabane struts on mine. And if that dimension is different, then the model may well be different in many other respects which could explain why yours and Andy's don't fly very well and mine does.  I bought mine over two and a half years ago and it may be they come out of different factories now to a different design.

Hey!  Why am I always last?  Perhaps I spend too much time at the building board.....

 The reason I was able to get mine to balance 150mm back from the LE of the centre section is because the centre section's 155mm wide. If your centre section's only 130mm wide, then I'm not sure we're all discussing the same model here.  Mine's a 7th scale 50" span JP Tigermoth - red fuz - silver surfaces - reg G-ARAZ - recommended motor SC30.  They also do a military version, I believe. Also marketed by Green Models and Pacific Aeromodel. Do JP do another one?

Adam, Judging by what mine's like, I would say it should still be fine at 4.5lbs.  It's got plenty of wing area.  I'm going to stick a camera in sometime without any qualms about weight. One thing I forgot to mention previously is that I had to fiddle around with the rigging wires quite a lot at first to get the wings straight.  It's easy to rig it up with a warp if you're not careful.  My first flights were quite hairy now I remember it (that was over two years ago) because I hadn't bothered to rig it carefully.  Also, hauling it off the ground early is a recipe for disaster - it'll end up nose in the air with no air speed and on the wrong side of the drag curve.  Under those conditions, it's very difficult to accelerate out of it.  On a full size you actually push the stick fully forward as soon as it starts rolling to get the tail up whilst it accelerates to flying speed, before rotating.  It's the same with the model, although it doesn't need full down elevator to get the tail up, just a small amount. I would certainly not say the model is a dud.  Most people who see it fly think it looks great.  If yours only flies with full up elevator, something is definitely wrong.  The CofG of mine is 150mm from the LE of the centre section of the top wing - behind the rear cabane strut fixing.  Also, because it is balanced from a very high position, being out of balance doesn't have a dramatic effect of the angle it hangs at, unlike a normal low or mid wing model, so it is easy to make a false measurement.  A more sensitive measurement can be obtained by translating the CofG position onto the upper surface of the lower wing and balancing it upside down.  It's then like balancing a normal model. One final point I would make:  JP claim this model can be used as a trainer.  I would strongly disagree.  I find it more difficult to take off and land nicely than my Goldberg Pitts! Please let me know how you get on! Regards, Ed

I've had one of these for over 2 years now (powered by an Axi 2820/12 with 12x6 APC-E prop and 3400 3s lipo - 300W setup) and it's had countless flights.  I've also got over 100hrs hrs on full size tigermoths.  As far I can tell, it flies a bit like the real thing, i.e. the ailerons don't do much and you need to balance turns with plenty of rudder (I use 50% rudder/aileron prog mixing).  Otherwise it's quite nice and looks a bit like a tigermoth in the sky, although it flies too fast to be that reaslistic.  You can actually fly it quite well on rudder only and just use the ailerons to level the wings on approach. I did the electric conversion myself so I was in control of the thrust line.  Differential ailerons are a must - on the full size there is so much differential that the downgoing aileron (which doesn't go down much) actually starts rising again at full control throw. I found the specified c of g was far too nose heavy - mine balances right at the back of the "fuel tank" (centre section), otherwise you run out of "flare" at the critical moment and it is then difficult to stop it tipping on it's nose, although a little burst of power can sort it out.  AUW is 1840g (just over 4lbs).  No additional weight was added to balance, just flight battery positioning. Take-offs are more realistic with 1/2 throttle, otherwise it does tend to leap off the ground in a nose up attitude. Personally, the only thing I really don't like about it is the awful fully symmetrical wing section.  Why did they do that?  It looks so stupid.  Also, it might have been nice if they'd sanded it a bit before covering it.

Hi Guys, I had to add 50g of lead to the tail end of my Goldberg Pitts Monster 12 EP to get it to balance. I've got an Axi 2826/10 up front (OK a bit big, but only 30g heavier than the recommended motor) and the 2100 lipo is absolutely right at the back of the battery box. I maidened it today and it flys on rails, but I'm surprised to have to stick such a big lump of lead in the tail. BTW, auw is 1250g, including lipo and ballast, which is 100 - 150g lighter than quoted in the spec. Has anyone else had any experience of this?

Yes, I believe H9 have updated the Cub - according to my local model shop. I don't know what the updates are, though. But judging by Chris's review they have removed the threaded rod control set-up for the rudder and replaced it with a push-rod, at least. I did actually phone H9 in the US and ask them what the updates are because I was thinking of doing another (I know - what do I want another one for??) but they told me that they didn't know about any updates because "H9 UK IS NOTHING TO DO WITH H9 USA"! So what's that all about?

Strange indeed! And, Chris, if by "torque rod" you mean "push rod", then the design has definitely been updated as mine most certainly specified the use of a long threaded steel rod running inside a plastic tube for the rudder control, as stated in my review. If, however, you do mean "torque rod", then I can't imagine what it looks like at the back end of your Cub. The only place I have ever seen torque rods used on model aircraft controls is on "single servo" aileron and flap set-ups. As I use 35MHz for the Cub, I am well aware of the other plastic tube used for the rx antenna.

Hi, does anyone know how to achieve a matt finish on iron on films, such as solarfilm. I have a Ripmax Spitfire that has a superb matt finish and I would like to replicate it on my own builds. Warbirds just don't look right glossy!