Multiplex Fun Cub

[Stephen Grigg]

With the difficulties at the field with horses,we cant fly alone as we keep having to  shoo them away.With this in mind Ive sent off to Galaxy for a Fun Cub.Should be able to fly with the electric fence up and on

[birdy]

I'll be watching; I quite fancy one.

[Stephen Grigg]

Hi Birdy,Ive already had an Easystar,Twinstar,Easy Cub and Mentor,so this on is a natural progression.Ive ordered there Power Pack also,not sure if Ill bother with the glider towing bit though

[Stephen Grigg]

There is a delay because Galaxy hav run out of Power Packs

[Stephen Grigg]

The Fun Cub arrived from Galaxy today.Multiplex have run out of Power trains so Galaxy have supplied the following,A JP 650  O/R 1100(c35-201)  motor with aJP40amp ESC and Overlander 200mph 11.iv 3s batteries,I say batteries because I bought 3.Theyrecomend a 12x6 prop,let the building begin.Our club is having an indoor meet next Thursday and Ive bought the Parkzone J3 Cub for that.

[Stephen Grigg]

Ive checked it all out,same usual construction,same top quality.Looks smaller than th Mentor,apart from the wheels,looks ideal for the job.Ill start it tonight

[Stephen Grigg]

After a couple of repair jobs were completed I started the Fun Cub.Drama ,instead of having 2 left and 2 right wing nut halves,I had 3 of one and one of  the other.Problem solved,I found a complete one removed from a previous Mpx Model,whoopee.I had soon completed the fuselage,secured the u/c and fitted the rudder,stabiliser and elevator.I then secured the wing rods and glued the wings together.Im about to do the aileron servos,and cut the ailerons free.Im going to fit flaps,an option also.Ive managed to find plenty of servos kicking around to use as well.

[Stephen Grigg]

Ive done the ailerons and cut out the flaps,the hinges for the flaps are unusual,so ive left them to dry overnight

[Stephen Grigg]

[Stephen Grigg]

As you can see,its coming along nicely,it has unusual aileron horns,and different flap hinges.The big wheels are BIG, Ive found no fault with the build so far.its all been the usual Mpx efficient build.Its the first time Ive managed to get the cowl clips to hold it on perfectly

[Stephen Grigg]

Fitted the flaps and tested them and the ailerons.As I suspected,you need areverse Y lead for the flaps,so Ill wait until that arrives bsfore I continue.Want to get the flaps right before I glue the servos in position

[Klippy]

What sort of radio do you have Stephen, surely you can fit the servos to different channels and then reverse in the radio. The plus is that you can program some differential, I think you might need it.

Edited By Tony Prince on 18/05/2010 06:58:46

[Bruce Richards]

Tony what does differential do on flaps?

[Klippy]

Exactly right Bruce! Stephen was talking Ailerons, then switched to Flaps Duh, it was early in the morning though.

[Pete B]

Stephen, I think Multiplex missed a trick here. I've just looked at the instruction manual and they have indeed cut the flap servo spaces so that they are laterally reversed, thus needing a Y lead or programming to set them up.

 

It will be easier and quicker to just cut a new location next to one of the servo locations and mount the servo so that both are in the same sense laterally - saves a lot of messing about. Cut the hole so that the plane of servo rotation remains the same to line up with the flap horn.

Pete

[Stephen Grigg]

I did consider this Pete,but went for the Y lead option.Ive the Futaba FG8,more than capable to carry out your suggestion Tony,but Im the weak link.Itll be enough for me to figure out how to programme the switch to the flap channel.I fitted the Power train this evening and Sat confused as the ESC played copius tunes at me.As I couldnt find any instructions I moved the throttle and all went deathly quiet.I then found I had movement except for the throttle.I discovered that needed reversing .Seeing one of the tips on electrics I had not fitted the prop so all was well.AtA safe distance I checked the prop direction and watched as the model sailed backwards across the floor.Swopped 2 motor wires and all was fine.I then tested the motor,and all I can comment is there is bags of power and it is very responsive.Its coming along very satifactorily.

[Frank Skilbeck]

MPX probably designed the plane to work with their entry radio set which has very good 4 servo wing programming, but then again your FG8 should be more than capable. Be worthwhile checking out, you could then mix flaps in with ailerons (faster roll rate) or have crow braking for steeper landing approaches. But probably more importantly you will be able to program the flap positions separately so you can get them moving the same without messing with the mechanical linkages too much.

 

Be brave ditch the Y lead, put a post on the Futaba section I'm sure somebody will be able to help.

 

As regards the ESC, yep Futaba throttle direction is the reverse of JR/Spektrum and MPX.

[Klippy]

Stephen, I'm a bit concerned about this 'Y' lead, in my experience a 'Y' lead will parallel the output from the radio to 2 servos, but the servos will still move in the same direction. If you want to reverse the sense of one of the servos you're going to have to use a reversing lead, it's a lead with a bit of electrickery in it to reverse the signal pulses so the servo moves in the opposite direction. Hope I've made sense and not misread the postings, again

[Pete B]

Afraid you have, Tony - Stephen mentioned his need for a Y lead a while back

 

With his 8FG, I'd do as Frank suggests, use the flap channel for one servo, a spare channel for the other and mix the two, which will give him the means to precisely adjust the flaps individually.  Far better than using any sort of Y lead with the associated problems of setting up the flaps mechanically.

 

Pete

[Stephen Grigg]

The way Mpx have there push rod connections and a diagram of where to put the servo arm at 70 degrees when the servo is centred I believe will make the setting up of the flaps quite easy.The reversible Y lead arrived today,and yas Tony you made perfect sense even though you were a little late.Galaxy feel the way Im doing it should be the safest nothing can go wrong,can it

[Stephen Grigg]

The Fun Cub is completed and ready for its maiden flight tomorrow.C of G is spot on with the battery at its most forward point maybe a little nose heavy,but if so easily altered by moving the battery back,plenty of room for this.Only problem is Its been a while since I charged Lipos and I cant find the charger lead.May be have to charge them at the field tomorrow

[Stephen Grigg]

[NigelH]

I've seen the vids.  Looks good.

 

[Stephen Grigg]

And I can report it is good.The power train gave unbelievable take off,around 15 min flights with a lot of gliding,didnt use the flaps yet..Vertical climbsand up very high in seconds,Acrobatic,flies upside down well,so much fun I kept running out of battery

[Stephen Grigg]

Had 3 good flights tonight,havent managed to get a landing I consider satisfactory yet,but did some touch and goes.which helped.There is a club competition ,you take off.climb for 30 seconds,power off and glide until you land.Longest flight wins.The Fun Cub climbs vertically  so fast,Im fairly sure that if I climb for 30 seconds Ill have trouble seeing it.Im going to ask a club mate to time it to a comfortable height and see where that takes me and how long.After my last flight I horse watched for others, then these things passed over our strip,whilst takinf off and landing.I missed the best shots as usual