Finished putting my ARF Avistar together. MY first build EVER! I think it went pretty well and I'm hopeful that it'll fly . I still have not measured my throws yet.

I have a few questions though.

1) My CG is at 1.5" with this setup. Very nose heavy with OS .46AX, What is the best way to add weight to the VERY back?

2) When I have my charge port plugged in, the light on the receiver (AR6200) come on slightly and it sounds like servos are getting power, but the charge light is lit on the power adapter and switch is in OFF position.

3) I was at 1.25 turns out on the needle on my OS.46AX and it was stilling spewing oil all over my wing. normal? Fuel is OMEGA 15%. after running, lot of oil drips out of the exhaust when I tip it.

4) What is the optimum RPM range I need to shoot for with a 10x6 or 11x6 propeller?

5) I'm also confused on the hinge gaps.... should there be any? None? Little? I have little gap, nothing huge but noticeable. Is it ok on a trainer?

6) the gas tank is fitted right behind the engine in a very tight cavity... there is no way to wrap foam around it..... is this ok? It is very rightly fit in there.

7) Anything abnormal with my setup in pictures?

8) Can you lend me $5?


Note: The propeller is beat up I know, It's not the one I'll be using.

TIA

1. The 46AX will make the airplane nose heavy. Did you try moving your battery behind the servo tray or securing it to a former down the tail?

2. I am not familiar with that receiver, but if the switch is on the battery shouldn't be able to charge.

3. Oil and raw fuel exhausting from the engine is normal. Just make sure your engine is adjusted (mixture) properly as stated in the manual. Once you get the hang of it you'll be able to adjust it without the book each time you go to the field.

4. I wouldn't worry about an "optimum" RPM. Raise the throttle and turn the high speed needle in until the RPM peaks then back off several clicks. Depending on your level of break-in the engine could turn those props anywhere from 10,000 - 12,000. Don't try to squeeze every bit of power from a new engine; you'll just ending up shortening its lifespan.

5. A little gap is normal. If you are concerned about an overly large gap you can use clear tape to seal the gap. It's a bit tricky to insert the tape so that the surfaces can still fully move. Basically, you fold a strip of tape in half the long way and deflect the surface all the way. You then take a credit card and slide the tape down inside the hinge gap. This way when the surface is fully deflected the tape will not be fully stretched.

6. No foam around the tank is not ideal, but the cavity in the Avistar is too small to add foam. It will be okay.

7. Your rubber bands are installed incorrectly. The rubber bands should stretch from front to back on the same side. The last two rubber bands are cris-crossed. You should be using 10-12 rubber bands.

7. NO!

Some other observations:

Replace that prop. Chipped props are an accident waiting to happen. I wouldn't want shards of razor sharp plastic spinning off my prop at 12,000 RPM.

Your rudder and elevator servos are slightly misadjusted. When your surfaces are centered (along with trim tabs), the servo arms should be perfectly perpindicular to the control rods. You can adjust the servo horns for center then adjust the clevises to recenter the surfaces.

You are going to get instruction from a club aren't you? Please consider it as flying models is more difficult than many people realize.

Move your receiver battery back as far as you can. This will help balance the plane a little better. You can fly it somewhat noseheavy without too much penalty, it'll just land a little fast. I wouldn't add extra weight to a trainer. If it still seems too nose heavy (as opposed to just somewhat nose heavy), you should seriously consider buying a lighter engine like a .46 LA or a Thunder Tiger Pro .36.

As far as props, an 11x5 APC sport prop should be a good match for your .46 AX. It will provide a decent amount of load so the engine won't rev too high, it will help the plane takeoff and climb out quickly, but it won't build up a ton of airspeed because of the 5" pitch. This prop will work with most any 2-stroke sport engine in .40 to .56 cu in range. Your .46 AX should normally peak out around 12K to 12.5K with an APC 11x5 sport prop.

The problem you describe with the power switch and the receiver makes me believe that the hole for the switch isn't cut out quite large enough and that it might be pushing the switch slightly over to the "on" side by default. The power switch for the receiver battery should snap crisply in both directions; if not then get a new switch.

Hinge gaps are fairly important, even on a trainer. You should seal the hinge gaps with clear packing tape along the control surfaces. This will improve the effectiveness of your control surfaces and help protect them from getting torn loose from "flutter" if you fly at higher speeds. Your .46 AX will test your CA hinges plenty well, even with an 11x5 prop. Push the control surface full up to apply tape to the bottom of the control surface, then move it full down and apply tape to the top.

Veteran builders will use Monokote to seal their hinges; if you feel up to the challenge you can forego the clear packing tape. The tape won't look as nice but the plane will fly better and nobody will notice it unless they get up close to look at it. I'm more concerned about my planes flying good than I am worried about style points, but that's just me.

Your overall set-up looks good; you're SOL on the $5 though!

Number 2. sounds like, and kind of looks like, you have the switch hooked up wrong. ie.. wrong lead going to your receiver.If so you are not trying to charge your battery, you are trying to charge your reciever. Switch the lead you are using for charging and the one that goes to your reciever. (after you switch you will find off will now be on and visa versa)
My guess anyway.

Oh... those are there for storage, the wing is not attached...i just kind set it there for the picture. I dont have enough room in the house to have the wing on the plane all the time.



That prop is not being used...it's just there to be there.

Also, the RX was off so the servos didn't center themselves. so its off a bit in the pictures.

I'm a member of AMA and am joining the club on Saturday when I take the plane out there.

Yeah, I was joking. When they're installed like that they don't secure the wing very well do they?

There's nothing wrong with your servo setup...beucase when you shut off power, it moves.lol

Yeap get a different prop after your done taxing it around. an unbalance prop is not too healty for your engine.
Put a piece of hose or tubing over whatever stick your using as a chicken stick to protect your future props.
Use 10x6 or 10x7 until you learn how to make softer landings...you'll save money on props.

It'll fly at less than 1/2 throttle on a .40 LA. You have plenty of power

Just a suggestion...I mounted my rear needle valve vertically..it didn't effect the tunning.
I refuel through the muffuler line.
i did that because i lost too many rear needles. Generally when it crashes, the fueslage will break the bracket.

There's room for you to sholve foam in the tank bay..just cut the foam into smaller pieces.

Put foam between the wing and saddle if havn't done so.

I use new rubber bands every weekend.

make sometype of a mark on your windsheild and wing. it'll help you mount the wing strighter at the field.


Put stripes , checkers , or whaterver on the bottom of your wing. At 2-3 mistakes high all you'll
see is white. it'll be less strain on your eyes. The most I could fly at first was 5 mins at a time then hand the
TX to my instructor,,becuase my eyes wernt use to focusing on a moving object at a distance.

The model will seem really touchy or fly really fast at first..you don't worry about max rmp at the moment.


Try to keep the gaps to a minimum.
You can use scotch tape later on to seal the hinge line, when you feel there's not enough throw for you.
As i said...it'll feel like there's too much throw at first

This is what I was thinking too. When I first installed my electronics I plugged the battery into where the charger gets plugged in, and then the charger plugged in to where the battery should be, so when I thought it was charging, it was actually getting powered up.

Personally I think it looks good. Just completed my Hobbistar 60 and I suspect they are similar airframes. My tank mounted in suspension in a precut cavity just behind the firewall. While I couldn't wrap it in foam I did shove some foam into the gap of the suspending formers that applies light pressure to the tank and minimizes vibration. The objective other than keeping things still is to minimize foaming of the fuel.

Balance to the CG as recommended in the literature that accompanied the plane. I went on and acquired a CG stand even though you can just use your fingertips. (I knew I'd be building other planes and I'm a sucker for gadgets anyway.)

Tie a piece of thread around a panhead sheet metal screw and toss it back in the fuselage to see if it will bring the balance in line. Remember, the further back the less weight you will need and overall weight is what the wing is carrying and the motor pulling. You can vary this by using a smaller screw and some washers but its difficult to access the inside of the fuse without removing some covering. Then note the position and screw it in the bottom of the fuse. You can also slide a large washer back and if you can access the bottom of the fuse behind the servos enough to slide it back....once you find the spot, drop some 30min epoxy back there, slide the washer into postion and then dribble a little more epoxy in the center. Just be sure you get it where you want it because you're not going to want to remove it later.

I was fortunate in not needing any additional weight for CG but did epoxy a washer in a wing servo bay for lateral balance. Also used monokote to seal my hinge gaps on all control surfaces. Its a pain and I notice some coming loose and I'll have to reheat it and or do it over. The clear packing tape sounds nice for electrics but I'd like to know how well the adhesive handles the oil residue of a nitro plane. Even after going carefully all around the covering on the ARF and then applying Monokote to patch wing servo bay installations and the control gaps I found both my monokote and some factory covering pulling up after a half dozen flights.

At any rate; if you're experience goes like mine you're going to have a ball!

Congratulations,

Clay

Thanks for all the replies. Couple questions.

1) "Put foam between the wing and saddle if havn't done so."
I know what the wing is, but what's the saddle? Is that where the wing sits on the fuse? I should have foam to cushion the wing?


2) The switch has three wires. two on one side and one on the other side. on the two wire side, there is a female and a male plug... how should it be wired?

The saddle is where the wing sits. I've never put foam there but some people do. They usually use thin foam tape that is probably some sort of weather stripping that is repackaged in small quantities to be sold at hobby shops.



The wire on the 'one wire' side plugs into the receiver. On the other side the male connector is for charging and the female connector goes to the battery.

Yes the saddle..where the wing sit's on.

You might also want apply a thin coat of epoxy on the right hand side of the saddle (muffuler side) to prevent exhaust goo from
penitrating under the film. It gets really messy right there. The film started coming apart on mine after a while.

The switch wiring looks okay to me.

The side of the switch with only one cable. That cable gose to the reciever.

The side with 2 cables. The male is use for the charger, the female is use for battery.
it's amlost fool proof.

You might wanna wrap your RX and baterry a bit more. Makesure there's foam around all the coners.
Bascailly during a crash, sometimes your radio equipments get exjected at a great vilocity
Generally the coners likes to impac the earth first.

Hmmm I tried that and the Receiver wouldn't get powered when I flipped the switch to on... Then I pluged the other wire into the receiver (the side with two wires) and then the switch works. it turns the receiver on and off but then only wire that's left is the lonely one on one side. That when plugged in to the charger just turns the receiver lights on faintly (as if it's charging the receiver, UNLESS it's charging the battery THROUGH the receiver)...

I get the feeling the switch I bought is toast

When hooked up were the single wire goes to the receiver does it power up by turning the switch off?
If you have it wired backwards it will be turning on when you turn the plane off, to be sure take the sitch out and make sure what you have labelled as on is indeed suppose to be on. The switch should be marked on the switch intself under the backplate.

it dose really matter in a since....flick the switch to off. Or turn that thing with the on/off logo around.lol

Once I get home, I will write the hookup in more detail . I'm just trying to avoid spending $10 right now .

I wonder if it's soldered wrong or something, in which case I might just have to resolder the points (My soldering is pretty good).

Most of these switches are simple 3 pole switches with a common, a normally closed contact and a normally open contact.
The common hooks up to your battery (usually the connector on the side that has 2 sets of wires) the normally closed contact is used for charging and has a complete circuit when the switch is in the off position. The normally open contact goes to your receiver. When you turn your switch on your normally open contact closes and your normally closed contact opens (that is why it is impossible to charge with the switch on.)
The charge lead should only go to the battery, if it is feeding your receiver then either you have a bad switch or the wrong lead hooked up to your receiver. (it can easily fool you because the switch will seem to work but you will actually be moving the switch to what should be the off position thinking it is the on position,)

Well, if you want to get technical they're single pole double throw switches (SPDT).
That's why it's bothering me that it can both charge and be on at the same time. Perhaps a leaf in the switch is bent, I don't know. I would replace it.

Well the wiring was goofed on the actual switch... Did some re soldering and now all is working. Here's what was wrong if you guys are still interested. Someone must have goofed on the soldering and one like that very person must have goofed on the Quality control section of it.
As Missleman and Nathan said, these are simple one way switches, directing the current one way or the other. In order for the switch to direct the current, the source should be in the center pole, flick left, and the left and center pole is connected, flip right and right and center pole is connected. If the center poll is battery, which it should be... and right poll is charge cable and left poll is output to receiver, then flipping the swith left should connect the battery to the receiver, thus providing power. If you Flip it to the right, it will connect the battery and the charge cable polls thus charging the batter and leaving the left pole alone..

long story short, what ever idiot did this, connected the battery to one of the outer polls.

problem is fixed now, just rearranged and re soldered the wires. Thanks for the help fellas.

I was just feeling dumb because electronically, I'm very capable. I was just feeling down that I couldn't figure out this simple switch..... little did I know.....thing was jacked up to begin with

That's what I meant
Glad you got it working, we can set another problem to rest

If you're joining a club on the weekend don't worry most club instructers will thoroughly go check your plane out before the first flight. I had an avistar, very nice plane to learn on.

Well, 15-20 MPH Santa Ana winds has grounded my plane.. didn't get a chance to take it out today. It's somewhat simmering down, maybe go see if someone is there this evening. I'm not counting on it.