I here you Russ...

It is in these moments I keep telling myself "You only paid $130" which is what I got mine for through tower with one of the discount deals and free shipping too.

I should be working on mine this evening instead of playing on this computer.

my wing rod was appx 1/2 in too long as well had to use the old cutin wheel there and the pull pull rod exits in the rear were clogged with some crap and had to cut some of the red trim to get to it and run a drill bit through it all this just to glue the stab god knows what i am going to run into next

Ya, russ. I think Everyone had to cut the tube a bit. I found a regular pipe cutter handy.

PS: thats about the worst of it, but I also found the rudder base (that traps the top of the stab) stuck out the rear more than the rudder post almost 1/16". I uncovered just the back face enough to sand it down so that the rudder could mount flush to the fuse without rubbing on that piece. The only good news is that Oracover can be removed and restuck- the color and the glue are separate.
If you wanna be picky and know what you want in a fin (no, not a Finn), you may want to look at the rudder alignment, too as in my post yesterday. I knocked ~1.5 degrees effective right rudder out of the fin- i.e the fin pointed to the left in front. That pocket was kinda tight anyway. I just filled the remaining gap with epoxy that had microballoons mixed into it so that it wasn't too runny and didn't weigh too much. I used the same mixture to fill the gap between stab and its slot, then even smeared a little on the rudder base/fuse joints. Ended up looking pretty good because the filler is white like the fuse.
Good luck with the rest. Once the stab was on, and the fin slot straightened, it got to be kind of fun, mount servos, gear, engine and tank. I did find the firewall is cut for right thrust, but their mount seems to take it out, ...magic? I ended up about 0 down, 0 right first try. Flew great- no dive or balloon on power changes.
My personal choice is to never shock the rudder servo (anymore) so I put a nice Sullivan tailwheel mount on- now the wheel is sprung softer vertically and also goes thru a spring to the rudder- no shock on the servo. It also bolts on quicker- no slots to cut into the rudder- just a tiny hole for the steering spring to glue into. I planted some balsa once because of a stripped servo- had it all tailheavy trying to learn flat spins and it went into a death spiral as I slowed for landing because the rudder was at 40 degrees. It was acting funny before the flight and I gave it a push and then it seemed to be working but the gear was probably stripped- confidence in a plane leads to its death!

OK, its still a b-t-h ahead, but well worth it, so I offer advice with words of encouragement!!
Maybe its and ARDUC, not an ARF after all:
Almost
Ready to
Drive
U
Crazy!

Russ, once you get this one finished, you'll be an old pro!

My new cowl arrived today, and I plan to begin the engine switch Wednesday or Thursday. I have the Slimline Q Pitts muffler, but there is no difference as far as the engine mounting procedure.

Now THAT's a breeze! You won't want to fly your Extras in wind like that.

Hey Bob,

I expect we will continue to keep the Extra’s in the Hanger on days like that. But I have to tell you we had a blast messing around with those sticks. That day was the first time I finally pulled off a landing with 0 mph ground speed. Did it several times just don’t have video of all of them.

Back to the Phoenix Extra….

On the vertical fin offset issue we left that as is on Rich’s plane and I will leave it as is on my plane (as long as it is creating right rudder). I am assuming (risky making assumptions like that) it was a design intent because that is what is done on many full scale aircraft to counteract torque. I can say the Rich’s plane flew strait as an arrow on the maiden flight with the exception of needing several clicks of down elevator.

Russ,
You have made it through what I consider the worst part. There will be other PITA’s but not as bad as the tail section alignment. The last big pain is getting the elevators to move evenly. Certainly don’t try to get it done after drinking a pot of coffee. Meaning you will need a ton of patience but it can be done.

well the rudder is on now and drying it all looks good i might add a little white oracote trim around the joints to make it look a little more professional but over all i believe i did well i got to take a iron and orr heat gun to get the wrinkles out that i make from making a snug fit on the joints i am not sure why but it looks like the tail portion has a slight upwards angle than the fuse

guess this is normal i just looked and it is lined up with the rear wheel mounting block in the rear of the fuse

I always breathe a huge sigh of relief when I finally confrim that the fin and stab are straight.

Getting the elevators operating identically is no problem with the Smart-Fly Equalizer. With Futaba, slaving Ch8 (or Ch7, whichever is last on the Rx) off Ch2 works quite well, although it does exhibit a very tiny lag in the slaved channel. Still, separate end points, centering, direction are very handy and works well for all but the most critical applications.

One servo with a split pushrod works well if you lay the servo on its side with the servo arm in the same plane of rotation as the elevator. Otherwise, the side-to-side motion will create unequal movement.

Russ, be very careful with the heat gun because it is easy to cause the different colors to separate where they overlap, and once that is screwed up it is very difficult to unscrew.

I have finished with the root rib addition/spacer to fix my short wing.

Picture shows the finished balsa rib that was cut with an xacto knife and sanded to finish size using a sanding block.

I was able to use my trim iron, xacto knife, small screw driver, and finger nails to pull the covering off the face of the original root rib.

The new rib was glued on using “Titebond II� and using the trim Iron once again, I wrapped the covering back around the face of the root rib.

alright men and women now is time for more questions
1 where do I put holes to exit the servo wires from the wings to the fuse I could imagine where ever is out of the way
2 remounting the engien mounts to fit my 0s.91fx with pitts muffler is there a certain way I have to line the engine up or ??hummmm.... just go off the center hole in the middle
3 what is the worst that can happen drilling the engine holes off meaning not exactly 90deg

pictures references or some kind of jig would be excellent i see alot of guys have done it i have read the post numerous times looking for details or pictures but i guess i am fked up like a football bat heck i don't even know the difference between a wet fart and a sneeze i just want this motor mounted so i can start the engine

Nice work. And that's a lot of work!

I don't mean to make more work for you, but there is a [link=http://www.rcuniverse.com/forum/fb.asp?m=6730856]not-insignificant design flaw[/link] with the wings that you uberkonstruktors might want to consider. Definitely something to think about when doing crazy-hard snaps or parachutes or blenders.

Bob,

Uberkonstruktors??? [sm=50_50.gif]Even Goggle could not help me with this one.

I am taking a guess that you are referring to the shear webbing for the “spar� - grain running with the spar as opposed to vertical to the spar. I read that post quite a while back and find it somewhat concerning. The good news is that I have not read of people exploding the wings on this thing.

Also I noticed mine is built a little different. [sm=devious.gif]The wing tube cardboard (the one in the wing of course) splits the shear web. I’ll try to get a picture later. I’ll throw in a sketch here to show what I mean. As I remember, Rich’s wings were like your pictures-the shear web glued behind the wing tube.

I surely do not know if this is better or worse. Depends on how they have that tube glued in to the wings that have the shear web glued behind the tube. It is what it is…

I believe you wrote before and I believe it whole heartedly…with all the power we are bolting to these Phoenix Extra’s….throttle management is a absolute necessity. I can see this thing exploding in mid air on that 160+mph run…..[sm=what_smile.gif] With a 90 2 stroke and the right prop I have no doubt it can be done.

Speaking of props, we have more experiments to do, but we are looking at using the APC 15X4 wide or 16X4 wide on our Super Tigre’s. I have done some test with the Wild Stik and the 16X4 version already with interesting results.

Hi guys,

With regards to propellers; I've been using a 14x6 propeller with my Extra, what would be the effect of changing for a 13x8?

Actually, how do you get torque? With prop diameter? And speed with with pitch? Or isn't it so easy?

Thanks a lot,

Nicolas

Zero down is correct for this model, but zero right?[sm=confused.gif] All models need some right.

The plane won't dive or balloon because it doesn't need downthrust, but it will pull hard to the left unless there's a LOT of right rudder trim. Or magic.

Also, if there is zero right then the prop drive face should be off-center to the left, requiring the cowl to be tilted to the left a little.

well if someone will tell me how to post pictures i'll post my work on my extra and you guys can possibly point out my flaws or anything else i might have done or missed i used a y harness and the elevator is fine unlike alot of other guys issues with the elevator not moving in unison with dual servos

To upload a photo, first save a photo to your hard drive (a folder in My Pictures, for example) as a JPG file, then resize so that the width is in the range of 640 to 800 pixels, JPG quality setting around 5.

To upload to RCU, reply to a message and then click the upload link at the bottom of the message which says "Click here to upload images and files."

Another smaller window will pop up that will let you Select Files to Upload, and below that will be a list of blank fields with "Browse" beside them. Click on Browse and find your photo on your hard drive and double click to add it to the blank field, then click OK. Your file will upload. Then click OK to upload the whole message and the photo will be included with your reply.

quoting cmoulder:

"Zero down is correct for this model, but zero right? All models need some right."


Agreed, cmoulder, despite all of the long winded debates at the airfield (which I have learned to avoid, too smelly) a tad of right thrust usually counters the PEE factor or whatever as the propwash comes around helically and kicks the fin, yada yada yada..... I generally just stay on the rudder the whole time whether hovering, KE, landing and prefer the motor and fin straight- right thrust and fin only cocked in the right direction by my "tolerance" or measurement error which I think (pray) is about 0.5°.
To be honest, the one thing that I really "ARFED" is bolting on the motor to the stock mount. I twisted it between the rails to get rid of downthrust and figured that I could washer the side thrust later. I cannot go by the incidence meter numbers or my eyes on the right thrust. My eyes work for right thrust if I get up in a chair& look down....but that all goes away if I mount the engine at 45°/RHS per kit instructions- just can't see it. (BTW that 45°will mean no cutting the cowl for the Saito 91's valve covers!) (EDIT:Iwas wrong... had to cut the cowl for the valve covers.)It seems a little dicey (in my limited experience) to use my incidence meter's prop drive washer mount with the plane sideways to measure right thrust- no good 0° reference. But measuring the same blade on LH and RH sides to the center of my (straightened) fin reads zero. I've only flown in high wind so far, so the rudder comps are full time anyway. Yes, right thrust would be good, but at the 1 degree level, its not noticeable in puffy 15-25 knot winds. What IS noticeable is my severe pucker factor with such a light plane in those conditions for the first 5 flights!!!
Gotta love the airbrakes for landing without rolling over, bouncing or stalling in a puffy crosswind.

MAGIC?!?!: Good point about the cowl-the whole motor appears to be CL slightly to the left(3-5mm?), which does effectively give a tad of right thrust IMHO- as in standing on the rudder in a twin when one engine goes out. The center of force is left of the center of drag, so it goes right. But now you have me questioning my prop tip L/R measurement- which is only good if the motor is on centerline.
Dam- there goes my evening!

Ha! Sorry to ruin your evening.

Actually, when I switch to the .91 FX I am going to add a tad more right thrust. I like to run 13x8 props, and higher pitch props also work better with a little extra right thrust.

As for getting the prop drive face centered horizontally on the firewall, the best gauge IMHO is a long CF rod taped to the centerline of the fuse. The pics below are from another project, but the application is identical for most models. Once the desired right thrust is achieved, just move the engine mount around with the engine attached until it lines up.

With your 4c engine I think you will be happier with the 13x8. 4c has more torque and lower RPM's, therefore higher pitch is usually better. However, the best way to find out is to try the 14x6 and see if you like the performance.

When I install the .91 FX (2C) I will likely use a 14x6, though I know it also works well with a 13x8.

Hey Bob,

The post that is two above this one sure looks to have a Decathlon in those pictures. Another one of my favorite birds.

Min2,
I do believe the right thrust debate will never end. For those that use it no one will talk them out of it. For those that do not use it no one can talk them into it.

Once upon a time I did not beleive in it. Even when I built a plane that was designed with it I would remove it. I had/have a little biplane that taught me the difference because I was bold enough to experiment and saw the difference first hand.

An alternate way to measure right thrust is to use a prop. This assumes the fuse wing and tail are square. Mark which ever tip you prefer so that you can use that tip for measuring each side. Measure from the prop tip to the elevator hinge line.

Here is the picture of my wing showing the spar/wing tube and the shear web.

Also a little tip that can be taken with the grain of salt that it is served with:

The second picture is an attempt to show the little numbers that are molded into the ball links supplied in this kit.
When mounting these ball links the numbers should go toward the servo horn you are mounting them to. In this manner if the link should wear out and fail some day it will not completely fall apart thus allowing you at least some control with that linkage.

Maybe they're out there somewhere, but I have never seen or heard of a model that tracks straight without some right thrust. My Venus II has a lot of right thrust - I don't know exactly how much, but at least 3 degrees, perhaps more - and it tracks straight as an arrow with dead-neutral rudder. It would not do that without right thrust.

Okay with me if guys want to fly with a lot of right rudder trim or use a throttle/rudder mix, but these simply mask the issue of insufficient right thrust.

One might be able to calculate right thrust measuring tip-to-tip, assuming the plane is built square (which is a BIG assumption with most ARF's), but the purpose of the CF rod method posted above is to get the prop to exit the cowl on the centerline of the fuse, not to measure right thrust.

Bob,


sending you a PM