Comp arf extra 300l 2.12m build

[my extra260]

Hi guys,

This is my first comp arf and i am amazed at the quality of the kit!! It puts all other arfs to shame! Well most of them lol.

Does anyone know any tips about building this model?? or do many people in NZ have this extra? I know there are a few 2x2's out there.

I am going to use A DA50 with the MTW minipipe setup and standard stand-offs supplied with the motor. A powerbox evolution 40/16. 4 Jr 8411s 1x JR 8711 and 2 JR 811. I am not sure what would be a good prop for this motor yet!! Has to be carbon!! ;-)

I have started With the undercarrige as per the instructions but then whent on to the motor as i am waiting to get the servos. I decided to glas the outside of the 2 formers to fuelproof it and give extra strength for the standoffs to sit agaisnt. I had a hell of a job trying to get my hads up to the front of the fuse to align the former and in the end had to get my step dad to help me!! It all worked out in the end and is SUPER strong! I am working on the cowling now and it is going ok although i had trouble fitting the upsidedown tnuts to fix the cowling when a bit of cyno got into one of the bolts!! The rest had vassaline on them and had no probs. I have epoxyed them in now and and waiting for it all to dry.

I have Made my own mould for the tail wheel and have made a nice looking carbon tailwheel bracket buut i have had to give it few more layers to stop as much flex.

So far i am very happy with what has been supplied and am looking fowd to flying it!!

Will keep you posted :-)

cheers steve.

[ampEater]

Nice mate!

[my extra260]

Thanks Alex.

Hows your katana going?? I still havnt sold mine but i have sold the digital servos.

Anyone want an O.S46AX?? Good pylon motor!!

Cheers steve.

[my extra260]

Well i moved on to the cowling and motor today and (so far!) it is all going ok.

I had to cut a huge hole in the cowl to fit the DA and the spak plug cap but I dont think it looks that bad once the its all together.

I have been reading on the net that the way C-ARF say to do there washers for the side and up-thrust is not correct and can damage the motor. Has anyone used the DA 50 with washers behind the stand-offs?? I was thinking as long as i did the bolts up tight on the motor first it wouldnt put as much twist on the crankacase?? Any thoughts here would help heaps

I wasnt to keen on the colour scheme at first but iam warming to it slowly!! :-) As long as it flys well im happy.

cheers steve.

[slosshycoho]

Hey there Steve,

I have one of these 2.12 extra's too, except mine is all white (at the moment) I too am curently putting mine together (it seems to take forever for epoxy to dry between steps)

i belive the prop to go for is the mejzlik 23x8 carbon, they are $AU99 from DA australia, i have also had pretty good sucess with the bolly 23x8 which it wooden and noisey, but half the price.

Take a bit of care with the washers behind the motor stand-offs, i have seen at least two people on the web (with this plane) with broken mounting lugs on the DA. My plan is to make tapered washers to go front and back on the firewall, to try and minimise the twisting force on the lugs.
Try and taper the washers at 3.5 degrees to match the right-trust. i might try and talk Johhny into making me some aliminium ones, or i have seen some just cut from 20mm dowelling, or you could take to some of the spare ply circles supplied with the kit with a dremel and sandpaper.

One other thing: i have heard the standoff setout for the firewall is wrong in the manual. there is quite a good thread on the 2.12 extra in the aussie discussion group here on FG - they supply some dimensions which i used - they seem about right to me.

Yip that hole in the cowl is big and ugly - but on the flip side: the cooling is great with the head poking out like that - one less things to worry about on hot days!

I am getting pretty keen to finish mine - looks like it will make a great little imac plane.

[sideways]

Have a look in here:

http://www.flyinggiants.com/forums/f...00l-2-12m.html

[my extra260]

Thanks for that guys i have been reading threw that thread all day looking at ways to do the motor.

I hadnt thought of using the Spare circles in the kit to creat off set!! I will work on them and post some picks.

You areright it takes for ever to do each step with epoxy!! Can you post some pics of where you are up to and what you are doing along the way??.

cheers steve :-)

[3dAndrew]

You can clean up your cowl with some fourmost. Its sold by TowerHobbies. Its called Fourmost canopy coaming rubber. I use it on all my planes cowls. It really neatens it all up. Adds some spice. I can post pics if u want. Let me know.

[my extra260]

Some pics would be good please as im not sure what you mean lol :-)

cheers steve.

[my extra260]

Hi guys,
Im still working on a nice tidy way to do the engine mount. I have gone with the comp arf dimentions as it was to late. They say to use these with the 3.5ince spinner which i am planning to use.

This is what i have come up with for the engine block. I wish i had already knowen this as i would have made a wedge and glued it behind the former berfore epoxying it all in!! Anyway to late now!

cheers steve.

[my extra260]

i cant get the pic to work!!

[billoliam]

Steve.
Keep it light you dont need a power box on a 50cc plane
Cher Bill

[ampEater]

Steve,

If you need anything machined up, send me some dimensions and a rough sketch and I'll machine them up at work, just buy me some beers at Nationals.

Alex

[my extra260]

Thanks alex :-)

Im Thinking of making some ply wedges to go front of the former and one behind it?

i will email you the pic tonight.

I already have the powerbox from by other pbg extra and like haveing 2 lipos.
What system did you have on the Yak??

Thanks for your help guys.

cheers steve.

[sideways]

Just keep an eye on the wooden wedges.
I found the thinner ones on the inside crushed a little when i tightened mine, giving a little to much right thrust.

Otherwise it seemed to work well.

	Quote: Originally Posted by my extra260
	Thanks alex :-) Im Thinking of making some ply wedges to go front of the former and one behind it? i will email you the pic tonight. I already have the powerbox from by other pbg extra and like haveing 2 lipos. What system did you have on the Yak?? Thanks for your help guys. cheers steve.