i just glued it on mate , full surface 5 min araldite and squeeze . i did drill 2 holes through it though and used blind nuts and screws as a 2nd measure . but really a good gluing wont come apart .
Don't forget to go over the all the joints and paint the timber up the front of the fuse and around where the Under carage mounts using West systems Epoxy and a paint brush.
That will toughen it right up and for not very much weight.
Thanks Frank & Jason, I did roughen the mating surfaces & used 30min epoxy before screwing with 4 self tappers. Painting frame with epoxy sounds a familiar & good idea.
Glued a section of thin ply into side wall of fuse above wing spar to secure Speedie with velcro, keeps the speedie away from RX to minimise "noise".
Next problem, I believe there is a need to put an air outlet at the rear of the plane for airflow over the speedie but cutting out the film inside a section of underside of fuse would seem to be tooo large.
Have considered gluing & ironing on an extra piece of frame to reduce the hole size. Did you put in a rear airhole Frank & if so how big & if not, does your speedie get hot.
Next problem, wings are a very tight fit into wing spar. A little scared to sand down carbon fibre spar as am not sure if I will remove/reduce an outer coating & thus weaken it.
yes mate i did put an air hole in the fuse under the horizontal stab, there is a servo hole opposite the elevon servo . i just cut the film there exposing it .
regarding your speedie , 2 things . they are meant to go inside the cowel , for max airflow and cooling , to do what you did , you wouldve had to extend wires from the motor , i'm not sure if that has electrical consiquences with heat and load .
your setup even on 5 s will be pulling over 70 amps with ease , that creates a lot of heat , if your speedie gets too hot it will fail or go into thermo safety and cut power , i'm not sure you've done the right thing there mate .
(04-02-2013, 07:41 PM)Flying fisho Wrote: [ -> ]... Did you put in a rear airhole? ...
You're asking for trouble including a sentence like this mate
I dont know the aircraft... but just a calming comment, don't get to stressed about your speedie location, unless it is working at peak load most of the time(and I'm sure it's not) don't worry too much about where it's at!
I've got a few in a lot worse spots than that...
But ....... like I said up at H in the H on Sunday..."get some airflow in there"
(04-02-2013, 09:48 PM)gbanger Wrote: [ -> ]...I've got a few in a lot worse spots than that...
Wow - it gets even better
It's looking Good Wayne, If the spar is tight I would sand it down a little bit the couple of tho' you'll take off to ease the tightness will have negligable effect on it's strength.
I had one that I machined about .010" off and it never failed in flight.
If you worried then you can allways sand more off then ends and leave it tighter around the middle. It takes more load around the center than it does at the edges. Actuallt it's probably most heavily loaded at the point where the wing joins the fuse.
I like to put the ESC up front in the cowl that keeps it far from the Reviever and also keeps the heavy leads as short as possible.
(04-02-2013, 09:48 PM)gbanger Wrote: [ -> ]But ....... like I said up at H in the H on Sunday..."get some airflow in there"
Sorry Gazz, wasn't meaning to sound like I was ignoring your advice. I do remember your principal of 2.5 x air intake for rear air outlet (do what you like with that comment Smuz).
Keeping with Gazz's size principal, I will frame up an air escape in underside of fuse.
[
attachment=3380]
Underside of cowl provides good airflow past the motor (hadn't thought of housing speedie inside cowl & may revert to that location to adjust COG if necessary).
Thanks Jason, happy to sand spar now.
Because I bought this plane as something inbetween my Eratix and my Pulse, the extra weight of the leads shouldn't bother it.
Wayne, I should be more clear some times, What I meant by heavy leads was, Leads that carry a fair bit of current. I wasn't aluding to the extra weight.
The leads that go between the motor and the ESC are carrying a fair bit of current they are also being switched quite rapidly from plus to minus by the ESC while driving the motor as well as on and off at the same time at some set frequency usually either 8 Khz or 16 Khz. All this switching of large currents can generate a fair bit of electrical noise wich can couple into servo leads and antennas and reduce the effictiveness of your radio link. It's best to keep all the noisy stuff (electrical noise) up one end of the plane away from your RX.
There should be heaps of air flow out the back of that cowl no probs with cooling in there I'd think !!
Hi Wayne
If you can put the ESC in the cowl now while you still building it, you can just place it behind the motor in the mount and Zip tie it.
It is the best place to keep it cool, it will always be in the air flow, and you can shorten the leads between the ESC and motor for best performance. No modification or trays required.
You chose a very nice scheme on this MX2.
The wings should be quite firm on the spar... you don't want to any play in them at all... so if you are going to give them a sand then proceed with caution... ie: sand a little and check fit a lot.
If you over sand them and the wing becomes sloppy you will end up with movement that will cause fatigue, and eventually failure... If the wing does end up moving around on the spar it is likely to give you some issues during flight that would not be pleasant.
Very good point Gazz, You only want to take the minimum off, just enough so that you don't have to force the wings on to the spar. They should go on nice and snug but not tight.
"The wings should be quite firm on the spar... you don't want to any play in them at all... so if you are going to give them a sand then proceed with caution... ie: sand a little and check fit a lot."
"Very good point Gazz, You only want to take the minimum off, just enough so that you don't have to force the wings on to the spar. They should go on nice and snug but not tight."
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Comments appreciated although a little unnecessary. Hand sanded with course & then fine wet'n'dry in small increments until spar ends slid snugly into wings.
Had to file out holes in fuse to accept positioning carbon fibre dowels.
Cursed a few times positioning screw holes for cowl, not much room for error.
Speedie now housed inside cowl.
Fine adjustment of rudder was a pain but pull wires retained constant tension.
Control surfaces utilise ball joints screwed to horns, will locktite screws after maiden.
Had 13x6 prop ordered for it but after watt/amp test on 6s 20-30c 4000 power up, i had heaps to spare. Upped the ante to a 14x7 APC and pulled 60 amps & 1350 watts (motor rated 2000watts & 80 amp speedie).
Wheel pants to go & I am finished & ready for a maiden.
Sitting a little nose heavy at moment, but waiting for wheel pants to mark a correct position for battery, initial test was full forward battery.
4000MAH 6S BATTERY , will be close to the spar tube for weight . my 3000mah 6s is 15mm back from the battery tray side wall . these things fly perfect neutrally balanced , you could go up to a 14x8 or 15x6 (80 amps) . the 14x8 on mine runs 78 amps . i have run a 15x8 @ 90 amps (2100 watts) , but the motor didnt last too long . 15x6 is my favourite .
cant wait to see this one Wayne . you will love it . mine weighs 2.2 kg . including battery .
i only get about 4 min 10 seconds out of it , you will get 5 minute flights . thest things master the sky mate .
I would like to thank everybody who has contributed to this build log and as Jason encouraged me to do so, pass on this encouragement to other members building a plane with limited instructions. It will serve to fine tune the building by getting info from the "gurus" & form a legacy for those building the same plane in the future.
As I said at the the beginning of this thread, I would be the blind leading the blind. As the months/years pass by I have increased my knowledge from abysmal to mediocre but am continuing to learn thanks to you guys. Hopefully I will one day be able to finish a plane without asking questions. Might even have a go at scratch building ONE DAY
Weather forecast is for no rain until a possible shower 1-5mm Saturday arvo, so looks like a maiden flight Saturday morning.
Looking good for Satterday Wayne. Don't be affraid of drawing heaps of current at full peg.
With this kind of plane. It all about throttle management. With 6S and the NTM 5050 It will have more than enough grunt to fly around on half throttle.
I run a 15X6 prop on my Edge 540 which is the same size and running pretty much the same power system. It never gets full throttle unless it's going verticly and that's the best way to fly it, using the power sparingly. If I flew mine for any length of time on full peg it would drain the lipos real fast and start making things quite hot. But it has massive power there for a short burst when needed
Yeehaaaa, finished & ready to rock & roll.
Bad news, promoted as having flying weight 2.0 - 2.4 kg , finished weight with 6s 4000 battery 2.8kg.
Good news, with 14 x 8 light wooden prop provided over 4kg thrust at full throttle with static 1500 watts (motor rated 2000watts) & 65amps.
This beast is going to kick arse
Don't worry too much about the weight, model airplanes are like women they are allowed to be lighter than they actually are
I used light servos (HS-5085s) and a lighter battery pack (6S 3000) with my Edge, that was suposed to weight 2.0-2.4 Kg and it came in at 2.5 Kg.
I must admit to being a bit envious of wingtippers MX2 being 300g lighterthan my Edge but I'm getting over it now........... slowly
Cant wait to see the new MX2 fly !! It will certainly have some grunt with 4Ks of thrust!! and it's a friendlier plane to fly than the edge. Not that Edge is in any way unforgiving.
I'm sure you'll enjoy it a lot !!
Well done Wayne. I'm looking forward to see it in the air.
RIGHT O " i'm desperate for some feedback . HOW'D THE MAIDEN GO ?
[
attachment=3391]
Placed the new baby onto the strip & gently increased throttle increasing speed for takeoff. Started moving off course so rather than start all over again, gave it a handfull of throttle (still just about 2/3 throttle) & it took of as though launched by Jasons pneumatic launcher. This baby has got biiiig balls. Climbed into the sky like a space shuttle at nowhere near full throttle then levelled off for trim checks. I tend to be a little heavy handed with throttle but with Jasons prompting dropped it down to 1/3 throttle which was ample to keep it moving nicely through the air. About 10% up trim & a few clicks left saw it at level flight. Spent most of it's 5 min flight checking its performances and it rolled nicely, needed a little down stick inverted, looped & performed a reasonable easy cuban 8. Came in a bit hotter than the Eratix but landed comfortably 2nd attempt (although skooting left off the strip at the end, damn that unreversed rudder
)
Second flight I had it doing it's stuff in the air, a comfortable knife edge, 3 slow rolls (reasonably level) and other practice gold wing manoeuvres. Sadly ended with a softish landing in the reeds but zero damage (misjudged distance perception created by a bigger plane & totally my fault)
Overall rating
Do not need it's top speed, so am going to switch from 14 x 8 prop to 15 x 6, less top speed, more acceleration. If that principal holds true, this beast will take off like Usain Bolt with chilli rubbed on his crack.
Nice one Wayne. I'm glad it went well.
nice one wayne . . it wont be slower with the 15x6 . but it will have about another kg of thrust
If flies great Wayne !!
All it needs is some contrast on either the top or the bottom of the wing to help with orientation.
At the moment it's red on the top and red on the bottom!!
As you get to throwing it around a bit more this will help a lot.
A TOP EFFORT I reckon !!
(09-02-2013, 10:18 PM)secant0give Wrote: [ -> ]If flies great Wayne !!
All it needs is some contrast on either the top or the bottom of the wing to help with orientation.
At the moment it's red on the top and red on the bottom!!
As you get to throwing it around a bit more this will help a lot.
It's actually mostly black on the bottom, but up high in the sky its black both sides. Am striping the black with white to assist with orientation. Thanks for your assistance with the stall spins Jason, needed the confidence of having your calming voice beside me.
Cheers
Day 2 of flying with the new beast, 15 x 6 prop & stripes under the wing. Can't say I noticed any difference in acceleration for take off and still definitely not lacking power rocketing into the air. Flies vertically at 2/3 throttle, prop hangs at a little over 1/2 throttle. Landings becoming easier now that I am becoming more familiar with it's characteristics. A very worthwhile build for stability, aerobatics.
Air frame ARF ............................................................ $179.00 (Sale over, now $219.00)
Motor: NTM Prop Drive 50-50 580KV / 2000W ................. $ 36.96
NTM Prop Drive 50 Series Accessory Pack ...................... $ 2.19
TURNIGY Plush 80A w/ UBEC Speed Controller ................. $ 39.99
Aileron & rudder standard servos x 3
BMS-621MG High Speed Servo (Metal Gear) 6.4kg ............ $ 39.39 ($13.13 each)
Elevator servo:
Turnigy S3317M Servo 26g / 3.0kg / .14sec .................... $ 6.81
Receiver: Spectrum AR6210 6 chanel ............................. $110.00
Turnigy 4000mAh 6S 20C Lipo Pack x 2 (AUS Warehouse)... $ 94.42 ($47.21 ea)
Turnigy Ultra-light wood propeller 15x8 ........................... $ 3.91
................................................................................... ______
.................................................................................. $512.05
Sure adds up but worth it
Yes - it did look very good today Wayne, plenty of power as you say and appeared to be tracking smoothly. Your landings are getting better too - they always look more comfortable when there's still some power applied.
You ought to give yourself a beer!
SOUNDS LIKE YOUR ON A WINNER THERE WAYNE . . well done . i have the week off and i'm looking forward to some flying .