John Murdoch

My Feedback: (11)

Well, I too was one of the lucky ones that got a GP Christen Eagle for Christmas. I'm in no rush to get her together and to tell you the truth, I haven't even opened the box yet. I have however, downloaded the manual and have reviewed it a couple of times now.

I would like to start this thread that pertains ONLY to the building, suggestions, upgrades, modifications, pictures and comments relating to the Great Planes Christen Eagle. I've been a participant in other forums where the topic seems to wander into unknown regions of somewhere, far from the original topic[sm=spinnyeyes.gif][]. I'm hoping this forum stays on track.

So, after reading some of the posts in other forums to date, this is what I'm planning for my Eagle:

DA-50 For Power
Change all CA Hinges to Pin Hinges
Get Rid of Stock Tail Wheel Set Up

Things I'd like to be more informed about before I start building:
Methods for Setting and Checking Incidences
Available Carbon Fiber Landing Gear?

So, let's all participate and have fun building this beauty.

Crash90

My Feedback: (17)

Staying on track. Some other good information would be balancing. Will there be any weight needed to balance using the stock setup?

rcmiket

mine just got here.I'm shooting for making it as light as possible.I want to fly it on a Moki 1.8.Maybe moving the servos up front on a pull pull like the Byron which is a lead sled and still flys on the Moki.Will keep you informed on the progress-Mike

rcmiket

Started mine last night the covering needs a little attention in places.seems pretty straight foward at this point had to extend the firewall alittle over a 1/2 inch for the mokis radial mount.I think by moving the rudder to,a pull pull will make it balance just right.Im going with 119oz servos in the bottom wing only and driving the top with 40/40 rods .Have you satrted on yours yet?

Texas 3D

My Feedback: (16)

First of all the Eagle will balance fine with thge DA 50. You will need to order new standoffs. The correct size is 2 3/4"! I ordered mine from www.aerofrafixs.com
The poblem is to get the screws behind the box to screw the standoffs on. [:'(] Major pain in the butt. You will have to come through the fuse with the screws and insert then from inside the box to the standoffs if you don't want to weaken the box and butche it all open. Therefore you will have to drill a hole in the firewall on the fuse side. I did this by drilling the hole for the standofs screw in the box first through the firewall and then with a dremel tool saw drill make the hole in the firewall a little bigger so the head of the screw will fit through it. I also used large washer inside the box to spread the load. Worked out very nice in the end.

I don't think any major modifications are necessary. The stock tailwheel is just fine and plenty strong, as is the main landing gear.
I went over the complete feather scheme monokte with a q-tip and trim solvent to seal the edges to prevent them from peeling off. Worked great.
Don't even bother to add the flying wires. They will snap after first flight with all the vibration from the gasser.

I absolutely love my Eagle. Great flier.

rcmiket

Has anyone encountered any problems using the supplied cowl ring?Its seems like a good idea.I havent figured out if I just want to go with mounting blocks or not.-Mike

John Murdoch

My Feedback: (11)

Mike,
I haven't got mine completely done yet but one of the first things I did was construct the cowl ring. It looks like a great way to attach the cowl. There's a gap between the fuse and the cowl all the way around if placed on the cowl ring and I don't know what kind of gap affect you would get using blocks. I've never used a cowl ring before but if they all turn out like the one on the Eagle, that's the only way I'm ever going to attach a cowl again. Blocks seem to just waller out the mounting holes in the cowls. This seem like more of an even distribution of any vibration through the entire cowl plate and the cowl itself. Like I said, I haven't flown mine yet but the concept of the ring is something to take a look at.

Cuzlikedam

My Feedback: (22)

rcmiket ,

from what i've read on rcu so far i've got the lightest eagle so far. mine weighs 15.25 lbs. i'm fly'in a super tigre 3000 which is about the same size as the moki. 1.8 displacement. just flew it for the first time yesterday and it went great. don't expect a fast unlimited bird. it will fly really scale with the moki. i left my servoes in the back and the thing balanced great. if you've read farther into the manual there is a wide range for balanceing. mine balances just behind the farthest forward measurement. the tail gear and the main gear are plenty strong enough but i do recommened beefing up the wheel pants a bit. as far as the cowl ring it works perfect. this is the second plane i have with it and both work great, especially if your going for scale looks. as far as the fly'in wires don't bother on the wings but i put mine on the tail to cut down on the vibration and it helped a lot. always glad to help... david

lsnover

My Feedback: (19)

Ulf:

Where you able to use the spinner from the kit with the DA? Any modifications, extra parts to do this?

Also, did you have to drill a hole for the carb on the DA, as it is rear mounted?

Thanks,
Lee Snover

John Murdoch

My Feedback: (11)

Lee,
I've got the Patty Wagstaff that has the same spinner. I've got the DA 50 on it and used the GP spinner. But.. What I did was grind off the rivits holding the retainer mechanism on and put a regular spinner nut. It worked fine. I did, however, have to open up the hole in the spinner a little for the bolt to fit.

Tired Old Man

My Feedback: (1)

I used the supplied spinner with a Brison 3.2. The hole in the spinner was smaller that the prop shaft, so I used an old prop reamer to open up the spinner. It worked great.

Regarding balance. In all likelyhood, as you get used to the plane you will want to move the C/G way aft for great performance. You will probably end up with the C/G well aft of the lower wing leading edge and you will still have positive control.

Using a small Ohio tailwheel assembly will give you far less slop in the tailwheel linkage. The G/P version looks really good, but wears quickly. The Ohio assembly has the same mounting hole spread as the G/P assembly.

Driving both sets of ailerons with a single servo for each pair works just fine, but you should consider using the carbon fiber control rods that Central Hobbies markets with the 4/40 titanium ends. The 4/40 wire type aileron interlinks will flex A LOT, causing a different recovery from rolling manuevers every time. The C/F rods DO NOT FLEX.

WhoDaMan

My Feedback: (164)

I kept mine stock with a G-38.
She came right on the CG. I have yet to fly her
Dave R

Texas 3D

My Feedback: (16)

Nope, I did not use the Spinner and bought a new Tru Turn one. The supplied spinner would not fit with the Biela or MSC prop. It will only accept the narrower blades like the Pro Zinger. There is no need to drill a hole in the box except for the pushrods to go through (have my throttle and choke on CF rods). The supplied standoffs from DA are not leng enough. You will need 2 3/4" ones.
Good luck.

lsnover

My Feedback: (19)

Why are you pulling the stock tail wheel and what are you replacing it with?

Thanks,
Lee Snover


PS: I just got my CE II this weekend and started working on it. Waiting for a new DA-50.

hilleyja

My Feedback: (3)

Like the thread originator, I'm in no rush to finish this bird. I will take my time.

This is my current inventory:

1.) GP Christen Eagle II
2.) Fuji BT-50SA (-w- optional short propeller Hub and Fuji spring starter)
3.) (6) Hitec HS-5475 digital servos for airlons and elevator
4.) (1) Hitec HS-5975 digital servo for the rudder.
5.) (2) Hitec HS-425 for throttle and (maybe radio controllled engine cutoff)
6.) (7) Heavy-duty (20 guage) 12" servo extensions
7.) (2) Heavy-duty 12" Y-connectors
8.) (1) Heavy-duty 24" Y-connector
9.) Futaba R148DP RX (PCM)
10.) MPI Heavy-duty dual-pole switch assembly
11.) 1800mah NIMH 6volt RX battery pack
6.) Zinger 20x8 prop
7.) Sullivan 16-22 lb tailwheel assembly

Some thoughts:

1.) I want to replace the stock foam wheels with ribbed rubber 4" tires (brand undecided -- suggestions???) (18+lb airplane on foam wheels = flat spots during storage and transport)
2.) I have acquired Robart medium hinge points but the more I read (the gist is the hinge points do not have enough material to glue to) the closer I come to decide to use the provided CA hinges (thoughts???)
3.) The Sullivan tailwheel is the way to go -- no carving on the rudder needed and no impact to rudder during a hard landing, yet still maintain positive control of ground steering.
4.) Airlon servo wiring is still up in the air. My initial thought is to proceed per GP instructions and Y-connect the 2 top servos, Y-connect the 2 bottom servos, and then Y-connect the 2 pairs to RX channel 1. (Any other suggestions/configurations???)
5.) I also will go over the trim with a q-tip and trim solvent.
NOTE: Be sure you download the 2 addendums to the instruction manual.

Progress: To-date, all I have done is collect pieces and parts. I have glued the bottom wing dihedral brace pieces together and have gone over the wing with my covering iron to seal the trim. My plans are to hinge the airlons and glue the wing panels together this evening or the next couple of days. I have noticed during my trial fit, the top wing panels do not form a pure gapless joint so I will probably sand the roots a little to reduce the gap as much as possible.

Question: 30-minute epoxi is normally used to glue the wing panels together. Has anyone tried the new Gorilla glue? Is this a viable alternative to epoxi for this application?

I will endeavor to post pictures of my progress in the next few days.

John Murdoch

My Feedback: (11)

Like the thread originator, I'm in no rush to finish this bird. I will take my time.

This is my current inventory:

1.) GP Christen Eagle II
1a) GP Christen Eagle II
2.) Fuji BT-50SA (-w- optional short propeller Hub and Fuji spring starter)
2a) Moki 2.10 Had DA 50 but I want that in my Patty Wagstaff
3.) (6) Hitec HS-5475 digital servos for airlons and elevator
3a) (8) Hitec HS-635-HB standard servos all around
4.) (1) Hitec HS-5975 digital servo for the rudder.
5.) (2) Hitec HS-425 for throttle and (maybe radio controllled engine cutoff)
6.) (7) Heavy-duty (20 guage) 12" servo extensions
7.) (2) Heavy-duty 12" Y-connectors
8.) (1) Heavy-duty 24" Y-connector
9.) Futaba R148DP RX (PCM)
10.) MPI Heavy-duty dual-pole switch assembly
10a) JR Heavy Duty Charge Sw w/jack
11.) 1800mah NIMH 6volt RX battery pack
11a) 2000mah NIMH 6V RX pack
6.) Zinger 20x8 prop
6aa) Mejzlik 20X10 prop
7.) Sullivan 16-22 lb tailwheel assembly
7aa) Starting off with stock and then will change to CBA Tatone Leaf Spring

Some thoughts:

1.) I want to replace the stock foam wheels with ribbed rubber 4" tires (brand undecided -- suggestions???) (18+lb airplane on foam wheels = flat spots during storage and transport)
1a) Will change wheels when these get worn out.
2.) I have acquired Robart medium hinge points but the more I read (the gist is the hinge points do not have enough material to glue to) the closer I come to decide to use the provided CA hinges (thoughts???)
2a) Used Dubro pin hinge with polyurathne glue
3.) The Sullivan tailwheel is the way to go -- no carving on the rudder needed and no impact to rudder during a hard landing, yet still maintain positive control of ground steering.
3a) I like Tatone Leaf or Ohio Superstar
4.) Airlon servo wiring is still up in the air. My initial thought is to proceed per GP instructions and Y-connect the 2 top servos, Y-connect the 2 bottom servos, and then Y-connect the 2 pairs to RX channel 1. (Any other suggestions/configurations???)
4a) Aileron wiring.. The two lefts into channel 2 and the 2 rights into aux. Use flaperon setup
5.) I also will go over the trim with a q-tip and trim solvent.
NOTE: Be sure you download the 2 addendums to the instruction manual.

Progress: To-date, all I have done is collect pieces and parts. I have glued the bottom wing dihedral brace pieces together and have gone over the wing with my covering iron to seal the trim. My plans are to hinge the airlons and glue the wing panels together this evening or the next couple of days. I have noticed during my trial fit, the top wing panels do not form a pure gapless joint so I will probably sand the roots a little to reduce the gap as much as possible.

Question: 30-minute epoxi is normally used to glue the wing panels together. Has anyone tried the new Gorilla glue? Is this a viable alternative to epoxi for this application?

I will endeavor to post pictures of my progress in the next few days.
[/quote]
Be really careful of the cabane setup. There's an addendum on the GP website for the set up and installation of the cabanes. They don't match up with the factory drilled holes and you'll need to drill some new holes. Read the addendum when you get to this point. Also, look at the addendum for the aileron exit hole on the top wing. Don't use the factory hole that's hiding behind that Monokote...

hilleyja

My Feedback: (3)

Well, I made some progress in the last few days on my Christen Eagle. I've assembled both wings and installed the airlon servos. Everything lined up and the seams are minimal.

BUT!!!!! I made a wopper of a mistake. The graphics on the top and bottom of the top wing were installed with such precision the center panel graphics line up exactly with the left and right wing panels, rightside up and upside down. Yep, I glued it in upside down. I had to carve into the center panel at both cabane mounting points and install hardwood blocks because the original blocks are only installed just below the balsa covering on the bottom of the panel and do not extend the entire depth -- they do now and I have added a few ounses of weight to an airplane that will already by heavy with the Fuji in the nose.

I blame myself. If I had paid closer attention to the instructions and read through them in detail I would have noticed that the 6 tiny pin holes in the covering were there for a reason. At least I won't have to worry about the cabane holes not lining up because now I will have to mount the wing and let it set on the cabane struts to find out where to drill the holes.

One thing I have determined during my wing assembly and airlon servo installation. I can easily set this bird up similar to my Ultra Stick and not have to use any Y-connectors. This will give me a few flight options that might be interesting:

1) Full-span airlons -- this will be the norm. The top and bottom airlons will move in sequence. If your familiar with the Ultra Stick QUAD flap setup this is the same configuration used for full-span airlons.

2) Crow -- the top airlons with move up and the bottom airlons will move down. This creates a high-drag configuration and will operate like speed brakes.

3) Full or half flaperons -- depended upon the Futaba 9C's mixing capability I can use all 4 airlons as flaps and 2 airlons as flaps, etc; maybe even couple a combination with the elevator to enhance loops.

John Murdoch

My Feedback: (11)

Ohhh Jim,
I really hate to hear that you did what you did. Truly a bummer! You know, as I was ironing the wings before I even started mounting anything, I noticed that the tops and bottoms were damn near exact too. I'm getting to the point when I build that if I see something that I need to do or address later, I always have a pad and piece of paper to write it down and remind me of things. Otherwise, I know I'd forget something. So I wrote down not to forget to look before I glued. And, I marked the top of everything with tape so I wouldn't get confused when it was time to glue. I got to hand it to you though. Most people wouldn't have admitted that they screwed up. Or, at least, maybe I wouldn't have. Good luck with the rest of your project.
John

hilleyja

My Feedback: (3)

It is Friday and I spent 3 hours working on my GP Christen Eagle II last night. Progress and another WOPPER. This is getting rediculous. Maybe this plane is out to get me?

I finished installing the servos and push rods on the wings -- No problems, my soldering worked out well for a change. They are Hitec digitals so I also reset them and centered them as close as I could. One thing I noticed, was the airlons do not marry to the wings flushed on both the top and bottom -- the leading edge of the airlons seem to be slightly smaller in thickness than the trailing edge of the wing. I lined up the airlon's deflection with the bottom of the wing.

NOTE: One problem I had while installing the CA hinges on the airlons was that the hinge slits were not deep enough. I had to go over them with a long exacto knife blade.

After installing the airlon push rods my instruction manual told me to checkout the hinges on the tail surfaces and following the same procedures I used for the airlons. Unfortunately, I stopped reading there and commenced to install the elevator hinges. I had an exceptionally difficult time enlarging the hinge slits because the trailing edges of the horizontal stabilizer appears to be constructed out of very hard wood. At one point I gave up the effort and was going to install Robart hinge-points. Fortunately/unfortunately my hinge-point drill guide was too big for the medium size hinges. I retuned to enlarging the CA hinge slits and eventually managed and completed the CA hinge installation. Just about the time I finished the last application of CA it dawn on me to look at the tail end of the fuselage. Alas, the horizontal stabilizer is designed to be installed in the fuselage before hinging the elevators. JXYPHCMF!!!!!!, why did the instruction have me do anything with the tail surface hinges at this time? Well, it looks like I'm going to have to saw out the trailing edge of the fuselage to install the hinged horizontal stabilizer -- shouldn't be too much of a problem.

Is there anything else in this airplane's assembly that I can royally screw up?

BTW, I plan on editing my posts this weekend to add progress pictures.

Texas 3D

My Feedback: (16)

Bummer.
Another thing you forgot is also that the instruction book mentions to NOT install the hinges and control surfaces before the cowl and engine are mounted. Simply because you need to stand the eagle on it's tail [X(] [:@]. And trust me, you need to. Sorry.
Another thing you should have found out while reading through other threads (and I am sure you have) is that the supplied Great Planes CA hinges become very briddle and break after only a couple of flights. Most of us either upgraded the CA hinges or replaced them with Robart hinge points (I did). I know you don't want to hear this, but maybe you should do that while it is not to late. Look at it this way : You will again be able to stand the plane on it's tail
One thing I learned over the years, is that before starting any assembling step on my new kit or ARF, I read the whole manual. This not only prevents mistakes from happening, but also makes understanding each building step much easier since you have an idea what is about to come next and why this step is done now.

hilleyja

My Feedback: (3)

All of this is common sense, but you are right to preach at me because I'm obviously not following common sense.

Question: You are correct in that I have read the other threads on this bird. One thought that surface from those threads was the fact that the Robarts hinge points do not have a full-depth insertion and there is some question as to whether they will hold up because of that. My original intention was to install Robart Hinge Points right from the beginning (I even ordered them), I changed my mind because of the posts that said they will not hold. Now, it does look like the elevator/stabilizer surfaces will fully contain the hinge points. I'm not sure the airlons will. You are probably correct that given the need to stand the plain on its tail while installing the cowl ring and engine my obvious choice is to cut the CA hinges and install the Robart hinge points. I haven't yet installed the hinges on the rudder/vertical stabilizer.

Texas 3D

My Feedback: (16)

Hey Jim, I really didn't want to preach. Sorry if it sounded that way. Just trying to help.
OK, the hinge points will penetrate through the wood. But I made some tests and found out that gorilla glue will create a plug and you can not pull the hinge out. I tried it with pliers and you will tore up the wood before the hingepoint comes out. My Eagle is flying without any problems on the surfaces. I would change them out if I where you. It's not that hard, and like mentioned the gorilla glue works very nice.

CE Flyer

My Feedback: (110)

I have read several several times of people having problems trying to install the standoffs of a DA50 to the firewall of a GP Christen Eagle because the bolts for the standoffs are very difficult to maneuver and install inside the firewall. I installed the blind nuts in the firewall as usual. Then, I took four 1/4 X 24 one inch long studs and screwed them about 1/3 of the way into the standoffs. I let them dry before screwing the standoffs with the studs into the blind nuts on the firewall. I used Loctite high strength thread locking compound. This works great and avoids the acrobatic act of trying to use screws behind the firewall. I used the standard standoffs with the DA50 so I had to use a couple washers on each standoff to space the proper distance from the firewall avoiding more cost for longer standoffs. I hope this turns out to be a good tip for you.

hilleyja

My Feedback: (3)

I'm sorry, I didn't intend to accuse you of preaching to me -- I deserved to be preached at and believe me, my own stupidity has finally sunk in and my subsequent work on the Christen Eagle is going much smoother. I took your suggestion and cut off the CA hinges on the elevator and installed medium-size Robart hinge points (there not glued yet). I also picked up a bottle of Gorilla glue. I heard that the best way to use this glue is to first add a drop of water into the hole and then the glue.

Last night I fixed the hinge mistake on the elevator and installed both the horizontal stabilizer and the vertical stabilizer. I also mounted the tail surface servos. ((2) Hitec HS-5475s for the elevator and (1) Hitec HS-5975 for the rudder. Here's a question for a possible alternative: The fuselage is cut for (2) rudder servos. Has anyone thought to doing a pull-pull with (2) rudder servos?

NOTE: When I bolted the bottom wing to the fuselage in preparation for lining up the horizontal stabilizer, I found the wing does not sit fully into the wing saddle. I ended up creasing the trailing edge slightly when I tightened down the bolts. Both sides creased the same amount so the wing is straight. I'm trying to decide to either sand down the leading edge of the wing or the trailing edge of the saddle. I trial-fil the belly pan and found it slightly smaller than the wing chord so there will be a slight gap.

Good suggestion for those that are mounting the DA50 on this bird. I don't believe I'll have too much difficulty mounting my Fuji BT-50SA.

hilleyja

My Feedback: (3)

My Saturday progress was mostly installing the engine and working with the cowl ring. I didn't get as much done as expected because I also had to install a dishwasher in my kitchen. As expected, it wasn't too challenging. It wasn't a picnic either. The 2 access holes in the engine box are not even big enough to manipulate the blind nuts. I had to enlarge them. I've got virtually every cap screw a modeler would need, except the 1/4x20x1 for the engine mount. A visit to Ace Hardware resulted in hex bolts because they didn't have the cap screw. I'll live with them for now.

Since I am installing the Fuji BT-50SA with the spring starter assembly, I had to enlarge the center hole and drill another hole of top to recess the cap screw that hold the spring starter assembly to the engine. I found out the hard way that the Rotozip cutter doesn't do a very good job in 1/2" plywood. I ended up using the Dremel.

So far I have at least a couple of hours working with the cowl ring. This is frustrating because, frankly, it doesn't even come close to fitting properly. I measured the distance between the engine box and the prop washer -- exactly 6.5". The cowl still needs to be positioned further back to clear the spinner ribbets. The graphics between the cowl and fuselage is also way off. I am being patient and have sanded the edge of the cowl ring several times -- I want to be sure I don't miss-shapen it to the point it won't match up with the cowl for glueing. Each time I get a little closer -- I'll continue that effort today.

I'm surprised that Zinger 20x10 prop actually looks small on that bird.