Electric Acro Wot ?

[Mike Stevens]

Jon

Servo mounts from Balsamart.  Servo Mounts , wheels are 2 1/4" If I remember rightly. I used a mix of CA and PVA glue - ca for tacking stuff on and CA for main joints and epoxy of course where required.

Mike

[Jon]

Hi

The build is progressing very well but a little slower than normal due to having to work out where to fit the electric bits and still have a C of G in the correct place while at the same time keeping things cool. This is further complicated by the need for access to the batteries and the Synth RX etc.

Having never built anything like this before and the supplied instruction sheets which is lacking a little Q.A. testing! Its proving to be an interesting build for me.

I started as normal... see Pic 4 below

Pic 4I laid out the main electric bits to help work out what will go where and where access will be needed. Two servos will be mounted behind the batteries... see pic 5 below

I decided to mount a ply box to the front of the Fus to take up the position marked on the cowl in the pic above.

Pics 6,7 & 8 below show my intended way of mounting the motor, I also plan to screw fix the cowl to the Fus so that by removing the prop and the cowl screws will allow me access to the Motor and its mounting. Should I ever need it........ you understand

Me thinks that by using the long M5 x 40 bolts I will be able at a latter stage to both adjust the CofG a little and the angle that the Motor is mounted at.. Please I need your comments chaps before I fix it all in place.. Any and all comments please... I can take what ever you chuck at me..thats how I'll learn..Jon

[Tim Mackey]

have you considered mounting the ESC on the motor box too ?- then you could open up the usual holes in the cowl for venting, and it will help keep things cool.

Looking very nice Jon - well done

[Jon]

Yes I have Timbo but I shall not commit to it until I can check the CofG .... I think there is plenty of room for it but the cables may also prove to be a problem.

At the moment I'm a little concerned about the planned Cowl fixing and the damage it may cause if the nose should touch the deck prior to the U/C.... its bound to happen at some time so I have put a little extra ply inside the Fus just behind the engine mounting bulkhead so the cowl screws can spread the load a bit better...

I'm not used to flying a tail dragger and have seen what happens to a nose wheel if it is asked to take the full impact

Next problem is to invent a battery hatch, think it may be on top just in front of the cockpit... or the cockpit itself... again battery position and thus hatch position could be as a result of the CofG check... I don’t want it to be one of those Mod’s that ill wish I had made before I put the covering on.... whats the betting?

Anyway thanks for the vote of confidence...  it really helps when your blindley finding your way..

jon

PS why is it that the spelling checker only seem to work sometimes, I have to keep cutting pasting between Word and this forum to over come it. Is it due to Smiley's maybe..?

[Tim Mackey]

We hope that these sort of niggly problems will be sorted with the new forum website which is now well under way and should be released on you poor unsuspecting folk in the new year !

[Jon]

oooooooower!  lookforward to that Timbo.    A forum that can sort out all our niggly problems... one niggly I have is having to get up a couple or more times each night, I really cant wait for that Timbo...

[Tim Mackey]

[Mike Rolls]

With a 6.5 ounce motor and 17 ounce battery, my AW needs 5 ounces of lead immediately behind the firewall toget the CG right. Only had one flight so far, which went fine due to weather etc. not letting me get to the field much. Power train is a 650kV motor spinning a 13x8 at 7,500 on 4S 4800 Xpower pack, pulling 43A. ESC is a 70A item from Giant Cod.

My battery hatch in in the top decking from the cowl to just in front of the canopy.

Mike

[Jon]

Hi Mike

She looks real smart...cant wait to fly mine.... I will be very interested in your feed back on how it fly's etc

I could have done some build input from you a little ealier .... thank you very much for your in put, glad to find I'm not the first electronut to build a E-Acro-Wot...

My Motor plus my home brew mounting (see above) flattened my scales at 13 & 7/8 oz but my batteries are 17oz just lick yours.... looks like I might not need to much lead up front... finger crossed.

I have already made my hatch in the same place as yours, you should be able to see the catch magnet in the photo ... just need to fill in the bottom of the Fus now.

I plan to screw fix the glass cowl and have fitted some a nice bits of ply behind the bulkhead for them to bite into. ..... would like to know how you have fixed yours?

[Mike Rolls]

Hi Jon

On the battery front - my Xppowers are quite slim. I also have a couple of other packs which are heavier - by lucky chance 5 ounces heavier, so a chunk of church roof goes on top of the Xpower pack, attached by Velcro and trapped between the battery and the top decking so that it can't escape and only relies on the Velcro for positioning, not security. That way I can use the heavy or light packs interchangeably. It alsomeans that if/when the Xpowers are time expired, if I can only get heavier packs I don't have the pain of having to dig out permanently fixed weight.

Although my motor only weighhs 6 1/2 ounces, it is mounted via a substantial 1/8" ply box which I never thought to weigh, but must be at least 3 ounces ot so.

Your hatch is identical to how I did it, -even to the amount of decking left in front!- other than I have the screw at the front, the lip at the back. Cowl fixing - yes, that's how I have done it as well - works fine.

Hopefully, I will be able to get some more flying in with it soon. The 'numbers' indicate that it ought to have about the same performance as my ST 51 powered version from some years ago; even the take off weights are very similar, althought he IC version was a few ounces lighter at landing!

[Jon]

Hi Mike

OK about the landing weight....pity we cant drop the battery out by parachute when about 2 foot or so off the deck

Great minds think a like re most of the mods then?..... have not got a small plain in my tool box for removing the corners and shaping the Fus so I nicked the wife's spud stripper to remove the bulk of it, it worked just great Its starting to look like a real good job now

[Mike Rolls]

Now that's a neat idea!

Mike

[Jon]

Just to show a little progress

Have just fixed the tail in position on the wife glass top aircraft construction table (she knows it as a coffee table).. Just the ticket for keeping it square...

[Jon]

Have now started on the wings....

The Acro Wot now comes with cut outs in each wing for 2 servos and tube type cuts in the foam to feed the the servo cables to the Fus... also by the look of things the wing root is already cut ready for fixing the 2 wings together, but I wont know for sure until I offer them up to each other.

I have decided not to use the supplied loop servo system for the rudder but have opted for the flexible "Gold-N-Rod" control set.... Also made some small mods to the tail to firm up things that work hard and maybe take a few knocks...

Until its all built and fixed together  I can not work out the precise positions of all the electrics so as to get the right CofG so the underside of the Fus is still wide open... initial checks holding things in about the right place indicate that the CofG of the E-Acro Wot wont be far out if at all.... my fingers crossed

 Will post some more pic's soon..

Jon 

[Jon]

Below you can see the servo mount I have decided to use and the hole in the wing foam for the cable.

The next shows the tail and the small mods made which are small triangles of 1/32 ply fitted to both the elevator and the bottom of the rudder, this helps strengthen the points where the hinges and horns fit, also showing is the red "Gold-N-Rod"

The tail wheel fixing and the RX aerial tube are shown here...

I prefer to use non metallic rods for the control surface's as then the 35mhz RX aerial is free of any signal strength distortions caused by near metal objects... this would be even more important at 2.4 Ghz

[Ben Mullins]

looking good jon, did you make the hole in the foam wing for the servo wires or were they pre made? I know if I tryed there would be many a hole

[Jon]

Hi Ben...Hope al is well with you... No, the new Acro Wot comes with the holes already in it plus a drilled out slot in each wing for the servos... I had to enlarge the slot due to the way I am fixing my servos.

[Jon]

Time for a further update... All going well... Have seen the plane assembled for the fist time today

Wings are made but still as two wings, Ailerons are held in position but the hinges are not glued... both wing servos and horns are also in position but not yet fixed.

Reason for this is I needed to work out the positions of the electrical installation wrt the CofG. The whole thing less its final covering has been put together (see pic) so as to confirm each position. Only item that wont fit just where I would like it is the ESC, it needs to be inside the Fus and not just up front behind the motor... Shame, but I'll open up some vents for it. Other than that all the other main bits will fit and balance just great...

With the whole plane held together with tape I was able to balance it on the point indicated in the plans... so apart from the final adjustments I can now finish the Fus and bit all the heavy bits.

Re the wing servos, I am not so happy with the way the I have had to fit the rods to the servo arms.. the side mounting servo boxes I have used are to small at the point where the rod fits onto the arms... so have had to use the bent Z shape plus an extra bend to clear the wing surface ... would have preferred to use the little plastic clips that prevent the rod from detaching... or do you olden’s know a better way?

[Jon]

Here ar the wings held together with tape

[Jon]

Since my last post I have installed the Motor, ESC, Receiver with its own battery & switch, Lipo Batteries for motor, Ruder & Elevator Servos and connected them up to control lines and horns.

I have even managed to switch on and test the electrics... I was very suprised at just how much quieter the motor sounds than my other planes, it runs so beautifully smoothly, sounds real COOL according to my grandson that is!

Fitted the ESC inside and directly onto the 1/4 inch ply plate that supports the u/c also created some ventilation holes in the fire wall directly in front of it...Its mounted on its own stiff suspending foam.

The main battery box is big enough that the final position of the batteries can be decided at the time of the final CofG checks and simply pack out with foam.

The RX and its battery can both slide in and out easily of specially cut pockets in the foam.

You'll note from the photos that the main battery box area has a thin ply base fitted and also some small red tubes (3 each side) to direct some air onto the battery box while in flight.

Its all seems to be coming together quite well rearly, just hope it fly's toooooo

[Jon]

[Tim Mackey]

That looks like a nice neat job there Jon - well done !

[Ben Mullins]

looking COOL ! Did you come up with the cunning idea for COOLing straws? You build quick compared to me!! Im still putting the servos in my E-Pioneer, which i got 2 months ago!

[Jon]

Hi Ben

The idea of air intake tubes is not new Ben... its used on Satellites to vent component heat and also the Suns heat from the hot side to the cool dark side.  Think its also used in many other equipments also.

keep going... you'll soon up in the air

Jon 

[Tom Foreman]

Hi Jon, with regard to cooling, I tend to steer clear of foam packing and try and get a nice un-interupted passage way for the cooling air to enter at the front of the model running over the motor, ESC and battery and then exit at the rear of the model out of an air exit hole. The general rule of thumb is the outlet hole should be twice as big as the inlet, but this tends to depend on how much heat your generating. Nice build though!

Cheers,

Tom