Xigris

[can773]

No problem John   Just make sure you don't use so much glue that it goes into the socket with the pin   That will make a mess!  You can always add a nice fillet after the fact if you have some gaps around the edge.

Chad

[Eatin Crow]

Alright!
All those years at NASA weren't wasted after all!!!
OK...OK...So I never was at NASA...
Got the wing sockets glued in last night and when I checked this morning the wings slid on and
off as smooth as silk!  
They must be dead on.
I decided to use a little bit of Chad's method and a little bit of my tapered shim.  
I have not glued the shims on yet but they are held in place with the screws and nuts for the adjusters.
Before gluing the sockets I roughed up the outsides with sandpaper and then capped off the the ends that
are inserted in to the wing with clear tape.  I didn't rap them...just stuck them down on the adhesive side
and then trimmed as close as I could with an Xacto.  I again used Gorilla glue and was careful to watch
the first hour to two for any glue blowouts.  It appears everything worked great!
If I had to do it all over again I would use Chad's method for the final fitting but also use tapered shims to get as
close as possible.  The thing about the shims on this airplane is you have to realize you are tapering in two axis.
One for the downward curvature of the fuse and the other axis for the rearward taper.  For me it was easier to work a
different side of the shim for each axis.
Here's some pix.
Because the camera is aimed at a downward angle it appears the adjusters still angle out.
It's only a "trompe d'oeil".  If I had taken the picture with the camera lower in the fuse they appear
pretty much straight up and down.  I was in too much of a hurry to take the wing nuts off for the picture.
Today I'll finish building my "V" block fixtures to hold the stab in place for trammeling and squaring them up.
Then tonight glue the shims in.
Onward!
 

[Eatin Crow]

I finally have each wing's incidence matching.
The fixtures that Tom G. and Mark W. showed me really, really lock the plane in.
I have about 5 pounds of lead resting on the floor of the fuse where the gear plate
will go.  The weight is at the point where it's resting on the fixture's shelf so no stress
on the fuse. 
I made a couple extra "V" block fixtures and converted one of them in to a quick and dirty
adjustable tail rest that I can move up and down.
Moving around the plane and working on stuff...taking the incidence meter on and off, etc. every thing,
all measurements are repeatable. 
Another plus is my work bench is on casters so I can easily move it when I need to step back and eye the
wing/stab relationship or shoot the laser on something.
Shoot!
This thing might actually end up being straight!
 

[Eatin Crow]

I should be ashamed letting everyone see what a pit my garage is...
I need some advice and opinions on this next picture.
I have written J-P asking him what point on the fuse should be used as a reference to establish the
"water line" and what the various settings should be like downthrust, wing and stab incidence, etc.
I haven't heard back from him so I'm going to make some assumptions.

1- that the design down thrust is molded in to the nose and is down .5 deg
2- the wing should be set at +.5 deg
3- stab at 0 deg

I didn't want to open the garage door to pull the van out so the picture isn't quite square on to the fuse side.
Now the question, I have the spinner ring set at 0 deg, wings at 0 deg, don't pay any attention to the stabs, they are just
stuck on.  I probably should put the canopy and chin cowl on but as the plane sits in the picture, does it look level to everyone?
In other words, if I raised the tail to add the .5 deg down thrust I'm assuming I should run, would the plane look right in the air?

[Rune]

Here is some data that I recived from J.P. Zardini:

Wing incident +0.25


Air flow incident -0.5


Stab incident 0°


Down trust 2°


Right trust 3.5°


The air flow has unhedral

CG is at 220mm from TE


found this in Najary's tread at RCU...I have just ptu my stabs on and the holes for the stab/wings was ready when I messured at the stab I could move it from -0.5 to +0.5 and then the front (spinner surface) was -2 wing was about +.5  right thrust I dont know but read some about adding a bit more.

[Eatin Crow]

Rune,
Thanks so much!
I appreciate the numbers.
I'm sending you a PM about another (non model airplane) subject.
JLK

[Chris Moon]

ZN sells a firewall pre drilled for the Xigris and a Plettenberg motor.  Here is a template of the firewall.  I printed the .pdf file and it matches up fine so the scale is correct.  The pic shows the firewall and you need to download the .pdf file below it to print.

[Eatin Crow]

The plane comes with three balsa framing pieces for the rear of the fuse:
- a tailpost
- a bulkhead
- a horizontal plate that ties the other two together
In an earlier post I showed the bulkhead and plate glued together.
Tonight I'm going to glue in the bulkhead but only dry fit the plate.  After
the bulkhead glue cures I'll glue the plate and this time dry fit the tail post, allowing
the two to key together to help get them positioned correctly.
I've always wondered how I'd get glue down in to the fuse for something like this.
I came up with using a syringe, some fuel tubing (which I now have a ton of since I've gone electric  )
and a piece of Nyrod. 
I used a piece of copper wire to hold the tubing on to the end of the syringe.
All that's left is to pull the plunger out, fill with glue and squirt away.

[Eatin Crow]

Here's the bulkhead dry fit in.

[Eatin Crow]

And finally with the glue.
It's still a little bit messy but I could have done a better job if Mark
had brought his Xigris down for me to practice on first!
 
To make sure I have the bulkhead spaced down the fuse correctly I used a piece
of scrap ply to check that the trailing edge of the balsa plate was flush with the
edges of the fin.
We'll see how it looks in the morning.

[MarkW]

John

  I like your glue rig.  Your glue job is better than mine in the tail area.  I still need to complete the gluing of the bulkhead it is tacked in place on top and glued on the bottom.
 
  All alignment is complete.  That is the wing is set and the stab is set.  When I glue in the tail post that  will complete the alignment.

Plane set up going to start with .5 down on the nose .5 up on the wing and .25 up on the stab as a place to start.
 
   Mine guess is we may need more down thrust   and some side thrust.
   The large diameter prop may push to more thrust changes.  The folding props may not need as much thrust, as changes are made in the flight path: the force will be taken up with the movement of the prop in the hub.

  Snow here today 7 inch’s new on the driveway this am.


  Mark
 

[can773]

Hi Mark,

Thats pretty much how mine is set, with the CG at 280mm from the TE I have no (or very minimal, I never mixed anything out) pitch in knife edge and the uplines were straight, and just a slight pull on downlines which I mixed out.

I added about 1 deg of right thrust with the folder, maybe with the APC you might need a little more but I never flew with the APC on this model, so I can't be certain.

For me the kit reference were nearly a perfect starting point, I only added maybe 1/2 turn more positive on the wing adjusters and 1 turn on the stab to get it where I wanted.  I never changed the downthrust.

Chad

[Eatin Crow]

OK, the glue job on the bulkhead looked pretty good this morning.
Below is a picture from the front side.  You can make out a little
pooling of the polyurethane glue in the bottom of the fuse.  Wish there
was a way to prevent this.  I thought about trying to go in while the glue
was setting up but not yet fully hardened and remove it some way but was
afraid I'd disturb things.  Out of curiosity I filled a 6cc syringe with glue and
weighed it.  1/4 ounce, so it will add up if you're not careful.
I decided to glue the balsa plate in now, gluing it only along the edges that
didn't interfere with the stab tube socket or adjuster wire holes.  I dry fit the
tail post in to hold things in the proper orientation then, using an idea from one
of the other build threads, I clamped aluminum angle to the rear edge of the fin
to hold it straight.

[Exfokkerflyer]

I had a difficult time trying to reconcile the stab and wing incidences as it turns out. When I first set it up, the wing and stab were pretty close to right on between each other, but I wasn't able to locate the lines on the fuse until later on for reference. Even so, it looked like I would be able to fine tune it with the adjusters.

Not so... last week, I plugged everything together to do a final tweak before sealing up the tail post I realized I had a problem. In order to get the nosering to read -2, AND have the wing at +25, AND have it anywhere close to the lines, I had to move the adjusters down 1/8". Even then it didn't look right and hours of headscratching let to the assumption that the tail holes were in the wrong spot as well. Which I knew since the stab tube and adjuster pin didn't line up.

What I have now is the nosering at -2 as per JPs direction (according to the posted emails), wing at .25 degrees (that is close to the .5 degrees positive to the line that Chad references) and the stab is at zero. The stab does not line up with the line scribed in the fuse side... I'm on a trip and can't look at it right now, but I want to say that it's slightly positive to the line.

It's unfortunate that most of the holes were off on my kit, and it wouldn't have been a big deal if I hadn't make that critical mistake in assuming that all would work out early on. All is fine now, but it's not as 'clean' as I would like it to have been.

Tom M

[can773]

Tom, I think the mistake is trying to make the nosering at -2, with the scribed lines on the stab set to zero on my kit the nose is at -0.5.  I don't believe at all that the nose of this airplane is -2.  The Integral is -2 or maybe -2.5, and I removed most all that downthrust on mine and it flew like the Xigris, but I never made any changes to the downthrust on the Xigris.  The stab should always be referenced as zero, and everything else measured to that.  If you try and set the nose at -2 you will end up with a funny flying airplane IMO. 

How I measured my kit is I set the scribe line on the fuse at zero using a digital torpedo level, and then used the level to measure the angle of the nose ring downthrust.  I don't think I would be at 1.5 degrees of error doing that.

Chad