Multiplex Cularis

[David Ashby - Moderator]

Hi Peter, I've just checked. I used channels 5and7 for the flaps and assigned them both to the side slider type switch.

[G]

I reckon transmitters could be designed better to make them easier to use.  I notice quite a few flyers don't use many of the features of their transmitters because they're just too hard to programme.

 I'd like a transmitter that plugged into my computer and a diagram of my plane appeared on the computer screen and it was all a bit more visual and drag-and-drop, more like an Apple computer than a 1980s DOS computer.  Maybe one day ...

[G]

Is anyone flying their Cularis that can advise me on what the stall is like?

I'm really enjoying flying mine, except that occasionally it suddenly plummets in a vertical dive, dropping for maybe 30 feet before it will respond to my up-elevator command.  Quite alarming.  I'm trying to work out whether  the Cularis has vicious stall characteristics and I'm sometimes trying to fly it too slow, or whether some fault is occasionally cropping up. 

Maybe I'm too used to Multiplex's other planes and their virtually non-existent stalls ...

If it is stalling, it means the Cularis needs to be flown with respect: keep the speed up and don't try any sharp turns anywhere near the ground...

[Peter Gallivan]

Thanks David, as mine is a 6channel RX the guys at Avicraft in Bromley agree winth Gary and have recommended a servo reverser plugged into the reluctant servo and a Y lead for both flap servos to channel 5. Channel 1 & 6 will remain for Ailerons, to keep differential an then use the'brake' (crow) function to in add both flaps down whilst both ailerons go up and a little elevator to stop ballooning!! Will let you know how it goes. Am hoping mine does not drop out of the sky!!

Gary, great idea of yours to use a graphic PC display for TX programming, I bet it will not be long in coming. Just imagine you could download and share ready made settings/mixes for almost all complex models!! 

[David Ashby - Moderator]

Gary, re transmitters - yes wouldn't that be nice, it's something that should have been done long ago - I recon the big manufacturers aren't trying hard enough to be honest.

The Cularis will stall and although I'm no glider expert I think it's because the model will be moving so slowly that when the stall comes along it will literally drop and take a few seconds to recover. Height is your friend here so if it's low then you're in the danger zone. I often find myself pushing in down elevator when landing especially with flaps just so the model penetrates and doesn't wallow about and drop a wing.  

[G]

I flew the Cularis again today and worked out that my unexplained dives are definitely tip stalls.

I wasn't too familiar with tip stalls because my other models don't do it (things like the Multiplex Gemini and Acromaster are perfect viceless fliers in my experience).  The Cularis normal straight stall is fine, just what you'd expect and easily pulled out of.  But the tip stall - the sudden flick into a dive that occurs on turns that are too sharp and slow - is quite nasty, you need at least 20 vertical feet to regain control.

Now I know that when I'm near the ground I must keep the speed up and the turns mild. 

This means that while the Cularis is a majestic, wonderful flier, I definitely wouldn't recommend it for beginners.  In my experience the EasyGlider is the perfect beginners' glider.

[G]

Went slope soaring today with the Cularis.  The winds turned out to be higher than I expected, too high for the Cularis really, but it flew a treat.  I was worried that I might smash it when landing, since the wind was getting ridiculous, but in fact with the butterfly braking it was stationary in the air, and settled down gently like a helicopter. 

I use reinforced wing joiners - a carbon spar above and below the wing with a bolt through the wing.  It's an over-engineered solution, but it's 100% rock solid and enables me to keep the plug-in wing servos.  The carbon spars go right through the fuselage so they reduce wing flex at the joiner as well as holding the wing on tight.

I'll add a couple of pics of my wing joiner mod in the next post if I can remember how to post pics ...

[G]

[David Ashby - Moderator]

Wow, that wings going nowhere Gary. Sorted eh!

What's with the trim down one half of the fuz?

[Peter Gallivan]

Hi Gary that looks great, a couple of quick questions. Is the upper joiner a plastic box section with the carbon section inserted? Also what have you done on the wing side, did you have to reinforce where the bolt goes through?

[G]

It's all carbon (the flat stuff that's sort of ice lolly stick shaped).  The top one just has some white profilm on it to make it match the wing.  You're right, the wing actually has some reinforcement as well, to make sure the bolt can't elongate the hole. 

I wanted to put it on the centre of gravity, but the servo leads are there, so it's about 1cm behind the c of g.  But this turns out to be so close it makes no difference to the balance.

On the top surface I have the same carbon spar cyanoed to the wing (with a hole drilled through it in the right place, covered in profilm that extends a little onto the wing to make it match the wing and further attach it to the wing).  The bottom surface of the wing just has some thin plastic sheet glued to it to stop the hole elongating.

The spars go through the fuselage and are held securely because I cut slots for them in the plastic wing joiner and used some hot melt glue.

The rigid top spar combined with the the bottom one (which actually gets pulled/flexed slightly upwards when I tighten the bolts), means the whole thing is very rigid.  Not only can the wings not loosen at all, but also the joiner can't flex, which is also important to keep the servo plugs properly connected in all conditions.  It doesn't weigh much either.  I used metal bolts but plastic ones could be a better idea.

I can't help thinking it's overkill!  However it's nice to fly a totally solid, reliable plane.  I slope soared it in ridiculously high winds yesterday and its performance was faultless - I suspect the original Cularis joiner would have failed within seconds in those conditions!

[Peter Gallivan]

Thanks Gary, I think I will pinch your and David's ideas. I have the same suspicion around the wing connections and as I'm not using the servo connectors at all it certainly feels like it needs beefing up. I think I will pick a very quiet evening for the initial flight and use Dave's quick fix, then after a couple of flights convert to your fix. Hopefully as we are now in BST the weather will start to behave!!! Will let you know how it goes.

PS was flying my Easy Glider and Twin Star in Fields close to Farnbrough Church this afternoon when the Jet crashed into the housing estate about half a mile behind me. Suddenly there were helicopters everywhere and my flying obviously ended for the day. Very sad, but almost an accident waiting to happen, there is now significantly more business jet traffic into Biggin Hill and the flight path crosses some very residential areas before it reaches the runway.

[David Ashby - Moderator]

Peter

I popped down to Old Hay near Paddock Wood about 2pm for a quick couple of flights in a little calm sunny spell and the air ambulance flew past from Marden (where it's based) on route to the crash. Very sad as you say. We see and hear so many aircraft these days from our office in Orpington, Biggin Hill seems busier than ever.  

I think Gary's fix is clearly suited to the slope flying he does with the Cularis, nothing wrong with that but see how the simple fix goes.

[Peter Gallivan]

David, no doubt this will reopen the whole Biggin Hill debate again!! I hope this does not impact the Air Fair as I'm looking forward to seeing the Vulcan again!!!

As you suggest will go with your mod first, and report, many thanks.

[G]

David asked about the trim on my Cularis.  It's nothing amazing - I just like to put my own trim on rather than use the standard stickers.  See the pics below.  It's stick-on Profilm - pearlescent white on top with sort-of-goldish stripes (what the car manufacturers would call champagne).  So actually rather unusual for a plane.  The bottom is black and dayglo orange - so I definitely can tell which way up it is!

[G]

Huh!  Somehow posted one wrong photo above.  Here's the actual top of the plane:

[G]

The photo you can see two messages up is the innards of my Cularis.  It's rather different from standard.  It has an MVVS 5.6 motor up front, an EMAX 60A ESC (with a powerful switching BEC that easily handles the six servos), and at the back the lipo (Loong Max 2250mAh 3S).  Above the lipo is the little Corona receiver.  The motor can do over 500W so I have larger prop blades - Graupner 14 x 9.5.

I used this motor because I had it - it's such a nice motor, and is slow-revving, relaxed, smooth, quiet and powerful as heck in the Cularis.  But it weighs 100g more than the standard motor, which is why the other bits are mounted quite far back to get the balance right.

I wouldn't really recommend this setup to others, just because it's rather experimental - I mean, the motor is verging on ridiculously powerful, I have no separate BEC or receiver battery, and the receiver is a little high-tech thing rather than a tried and trusted Multiplex one - but I have to say for me it's a fantastic setup that works a treat.

[David Ashby - Moderator]

Excellent scheme Gary - like it.

Have you been flying in the snow today then?

[G]

Yep.  I thought it was very pleasant flying in the sunshine with the fresh snow on the ground - but no one else was out, maybe I'm mad...

[Peter Gallivan]

Hi all, at last a weather window and the Cularis has flown!! First flight this morning nothing too exciting, balanced beaufifully at CG but needed a few trim adjustments, mainly to elevator. Very nearly got caught out on first landing as the speed decreased, but rembered Gary's post earlier and recovered just as she began to stall, Pheew !!

Second flight the wind had increased quite a bit and the Cularis felt very smooth and deceptively quick. Crow braking worked well and allowed a lot quicker final turn then slowed her up very quickly for landing, no repetition of earlier stall. However upon landing checked the wings, they had both mover outwards and David's wing retention mod (see earlier post) was stopping them going any further. If the same happens in the next few flights I will go your type of mod Gary ( I am not using the servo retention system in the wings). Overall though a very capable model and great fun. Here are a few pics of finished article.

[David Ashby - Moderator]

Well done Peter - nice one, and I like the colour scheme!

[Peter Gallivan]

 Hi all, thought I would update. Have now flown the Cularis at least 20 times now, it is a really great model with benign handling in general. However don't let the model slow dramatically at low level or she will bite!!! I did not use the suspect wing connectors and agree with David that the wings seemed a little loose. However since I have used David's simple mod i.e the screw in the wing connector catch all is well, however upon checking at each landing the screws are hardup against the retaining latch. This is usually after some hard flying, loops rolls etc!!!

All in all the Cularis is a great glider to fly either relaxing in the evening with a bit of thermalling, or throwing it around the sky to see what it will do!!!

I would always suggest the EasyGlider for anybody just starting out but the Cularis is a great second model.

I hope all Cularis owners are having as much fun as me!!!!

[David Ashby - Moderator]

That's good Peter, glad it's still going strong...and the wings are staying put!

[James Hope-Lang]

Hi

 I'm looking at the Cularis - can you do a quick summary of the power options? Either the MPX kit or what seems popular is the MWS motor, ESC/BEC and 2 lots of batteries?

 I'm likely to use a Futaba FF7 and R617FS with it. but not bought anything yet so if there are other recommendations out there like to hear them...

 Cheers,

 James

[G]

So many options ... the MVVS 3.5 (kv 1200 or 890) would be good.  I'd be quite tempted by the 890 just because I like large, slow-moving, quiet props.  There are cheaper options though.  You could go for a smaller motor if you wanted because the Cularis doesn't actually need a lot of power to rise upwards.  Or you might want a fast hotliner type motor. 

You'll need to decide whether you want a separate receiver battery or not since many ESCs won't handle six servos (personally I prefer to get one good ESC with a powerful switching BEC - such as a Hacker SB Pro or a HobbyWing ESC from Giant Cod - but others prefer to go the separate battery or separate UBEC route).  Personally I reckon it's best to go for a 45-60A ESC rather than cutting it fine with a 40A ESC.

Nothing wrong with the official Multiplex power set of course, except that it's not the cheapest.