Albert,

Yes, that is the right length. After you've done all your test fitting, glue both (2) stab tubes to the fuselage from the inside. This will ensure the tubes don't shift one way or the other into either stab. This information has been provided by Richard Curry. He has the latest kit and just performed his maiden today. My kit is older and there have been some changes made. How the stabs are secured have been changed over time as well. Mine has screws penatrating the top of the stab. The latest kit has the screws going through the fuse into the stab. Run the screws into the stab with washer attached and make sure they are not too long. Richard found at least one about 1/16" too long, preventing the stab from fitting tight against the fuse.

While your working on the back end, make sure you have 3 bulkheads installed. Starting from the one at the rear, there sould be one about center of stab and one near the front of stab. While Richard was performing his maiden, we noticed the tail move on his touchdown. Further inspection revealed the factory left out the forward bulkhead for the stab !@#$@!. Picture attached. The blue tape represents the location of the bulkheads supporting the tail area in my bird. Fortunately, he just did a 5 minute shake down flight and never went above 60% power.

John

Maybe next weekend but in two weeks for sure.

Albert

John,


Thanks for the info, I just checked and it does have all of the bulkheads in place. I did have to cut the sides of the fuse to allow the elevator servos to go into the fuse since they stick out about an 1/8" from the stabs. I plan to add some carbon strips around the perimeter of the cut to give it some strenght. I also added a piece of wood with a blind nut to each end of the stab tube and a 4-40 bolt from the bottom of the stabs. BTW are you going to the jet meet in N.C. ?

Thanks
Albert

Well, the second weekend of flying my Dragon is complete. Have had a great time learning this new machine. My flying partner (Richard Curry) put the maiden on his. I've run about 17 gallons of fuel through mine and have just about got all the bugs worked out. A bad rudder servo and a leaking air connector are about the only issues I can think of.

Center of gravity: Since I did not get any input on a better placement than on the wing tube, I decided to remove 6 oz. from the lead shot pack in the nose. It did help knife edge, inverted flight and did not affect the landings in a negative way or slow flight. I'll fly it a few more times before taking any more out. You've heard that this bird needs weight in the nose. This is what both of us are running now, shoved about as far forward into the nose as you can:
-Two rx packs (Spektrum 4000 mah 7.4 volt) including sponge material and velcro: 12.8 oz.
-ECU battery (3700 mah Rhino 11.1 volt) including sponge material and velcro: 9.2 oz.
-Lead shot: 22 oz.

Total in nose: 38 oz. (2.37 lbs.)

Your milege may vary depending on radio gear placement, turbine weight, etc.. I'll include some pics of Richards install. His Dragon is the green, blue and white one. He moved some items forward based on his experience when he owned mine. They both balance 1/2" behind the wing tube now.

On the video I attached on the previous page, the wind was blowing about 15-20 mph down the runway. Today, winds were about 10-15 mph, crosswind in our face. Other than a small wing bobble right before touch down, it did not effect the flight characteristics. Touch and goes were still as easy as with a head wind. The 160SX really shines here. The near instant response from idle to full power really comes in handy here.

Just received a call from Richard about adding the bolts you mentioned to keep the stabs positioned close to the stab. Yes, we are both planning to attend the NC jet meet.

A few more from todays flying: I did not build mine but I understand the instructions are less than adequate. If any of you guys need some pics, let us know.

Not having much luck with the multiple picture attachment feature. I'll do this the old way:

Here is mine...

Ready for maiden. Only a few issues to solve...

Can someone post a picture of the mentioned bulkheads. I don´t exactly unterstand, how it has to look like...

Thank you!

Not sure if this will clear things up or not. The first picture is of my plane. Looking down the rear hatch cover, you can see the two formers in place. The second picture is of the kit that had the former missing. Note: for clarification, the second picture has the tail pipe slid out the back of fuse to get a better look. Also note the former in second pic has lightenholes where mine does not. Hopefully, this helps.

John

Thank you!

Now i have aproblem. My Dragon has only two bulkheads... The bulkhead in the front section is not there...

I have the latest version, with the holes, too.

I had contact with Skymaster...

The new Version has only two bulkheads... no problem...

So its no fault during assembly.

Regards

Dirk

I just finished a Skymaster Viper and my Green Dragon and found wood missing in a number of places, I just installed small pieces of sponge to make a pocket to hold the Hysol and the control horns. worked great and didn't have to do any extra cutting or repairing of fiber glass.

Here is another video of JT flying his Dragon. Great flying jet.

http://www.youtube.com/watch?v=pfM6Bsqx8v0

Hey Dirk, saw your thread about the bulk heads and just thought I would put my 2 cents in. Are you talking about the bulk heads in the rear of the plane? I am on my 4th Dragon this one being the new model in the GREEN/WHITE/BLUE color scheme. My previous 3 all had 2 large bulk heads under the FIN/ RUDDER section one app. 8" from the rear of the plane and one around 12" than a small one at the very rear of the plane to center the tail pipe total of 3. My Green dragon which I just finished as only one bulk head under the FIN/ RUDDER SECTION, 8" from the rear of the plane and one small bulk head in the very rear for the tail pipe TOTAL 2. when I hold the top of the fin and move it left to right the whole top of the plane under the fin move a 1/2 inch VERY VERY WEAK!!!! something I would not feel comfortable flying. Double check yours and anybody reading this with the new version please check and let me know how many bulk heads there are in the rear of your model. I will attached picture later tonight of mine. Final note talked with a friend of mine in New York who also has a GREEN/WHITE/BLUE color scheme and his has 2 large bulk heads under his FIN/RUDDER section and 1 small in rear for tail pipe.

Dirk,

If you only have two bulkheads in the rear section of your aircraft, it is not assembled correctly. For clarification, from the back of the engine hatch to the end of the tail section, you should have 3 bulkheads. Two for support of the stab area and one at the end of the fuselage to support the tail pipe.

The attached picture is a clearer example from Richard Curry's new Dragon that has the missing bulkhead. If this is what you see with the tail pipe removed, I would not fly it. You can see how weak the tail is if you only have two bulkheads by assembling your aircraft and attempt pushing it around on the ground by the tail. It will easily move 1/2" or more in either direction. Richard did perform his maiden with the missing bulkhead, but at no more than 60% power. I would not care if Extreme/Skymaster told me that is the latest design. The bottom line is that with the second bulkhead for the stab removed, the tail has been weakened. This by no means enhances the design.

What brought our attention to the tail was when we saw it shutter on a smooth touch down while landing. At that point, it was the first time we pushed it back to the pits by the tail. It was obvious to both of us that something was wrong. We performed the same test on my jet and the tail was solid. Upon further inspection of my aircraft, we found a extra bulkhead installed.

Hopefully, I have caught you before performing your maiden. When you said, "the bulkhead in the front section is not there" I thought you were talking about the front of the fuselage.

John

What I did, was used a heavy duty carbon fiber horn from BVM, slotted the rudder at the bottom at an angle so the pushrod is straight to the servo, opened the slot slightly so that i could slide a piece of wood in the rudder each side of the slot. This gives a wood support on each side of the rudder horn and aeropoxied the whole thing

Richard and I spent the evening making a new former to add to the tail section of his new Dragon. After a more thorough investigation, this is what we found:

1. the only bulkhead supporting the stab was cracked at the top. I'll include a picture.........the crack is located at the very top portion of bulkhead, the square section. The crack cannot be seen in the picture but it is at the very bottom section of the square.

2. the adhesive used at the top of this bulkhead did not adhere to fuselage on either side of square section described above.

We have repaired the bulkhead in question and have built a new one which will be located about 6" forward of the one in picture. (similar to previous design)

Even with two bulkheads secure properly in fuse, we are wondering if this is still strong enough to support the tail. On the previous designs there was a brass sleve imbedded with carbon fiber into top of bulkhead and a much longer post than the two "locating pins" protruding from rudder transferred load to bulkhead.

We'll see what happens after all the hysol cures.

Most of these words may not make sense to those who have not fully examined the tail section. We took a video that may clear things up:

http://www.youtube.com/watch?v=_MvprmLwXEw

John

Hi John and all other Dragon owners,

The latest update of Dragon has two bulkheads same as photo.We made this change to lessen the weight at rear fuselage.We didn't find the moving issue as in movie after thoroughly checking the stocked Dragon.If any of you have the similar issue as shown in movie,please send us e-mail and we will offer the drawings to make additioinal former at forward area of rear fuselage.

Best regards
John
E-mail: [email protected]

I would think a better solution would be to send the former not a drawing.


Albert

John,

First of all thanks for all of the great info. After looking at the picture of the single former you posted I noticed that the problem might be the fact that the socket for the rudder carbon rods don't go through the former at all. On my Dragon there's two formers and both sockets for the vertcal fin are attached to the formers. I'll post pics later.


Albert

Here's a picture of mine, you can see the two formers as well as the carbon cloth where the sockets for the rudder are. Even if another former was added but the vertical fin sockets were not attached to the former the fin would flex. My vertcal fin has two carbon rods about 3/8" in diameter and about three inches long that slide on to the sockets that are attached to the formers.


Albert

Hi John and all other Dragon owners,

The latest update of Dragon has two bulkheads same as photo.We made this change to lessen the weight at rear fuselage.We didn't find the moving issue as in movie after thoroughly checking the stocked Dragon.If any of you have the similar issue as shown in movie,please send us e-mail and we will offer the drawings to make additioinal former at forward area of rear fuselage.

Best regards
John
E-mail: [email protected]
[/quote]

John,

Thanks for your prompt response! Just for clarification, when you said the latest update of the Dragon has two bulkheads, didn't you mean that there are two in the tail section, one that support the stab/rudder and the other that simply supports the tail pipe and that the third bulkhead visible in my (white, yellow, blue) dragon has been deleted to lessen weight in tail?

My point is, that the bulkhead removed in the latest design carried a sleeve (secured with carbon) that allowed a much longer post (spar) from the rudder to slide into. Didn't the previous design have two carbon spars that connected to both bulkheads in stab area? I think this omission is what lead to the flex you see in Richard's video. With the single bulkhead that is in the latest design, you simply have a short square section of ply that provides the strength for the rudder. This is the piece we found broken after the maiden flight.

To make things clearer, the tail of Richard's Dragon did not have this flex prior to the maiden. He pushed it out to the flight line by the top of the tail (as most of us do) and it felt normal as compared to his previous Dragons. His flight consisted of mostly level laps around the field to trim in three different flight conditions (gear down/ flaps half down, gear down/flaps full down and gear up/flaps up) with a couple of rolls thrown in. I believe if I would have had the radio in my hands and flown it the way I fly mine (previous design) the outcome would have been worse.

I don't think that simply adding the bulkhead that you guys removed will give the strength to the tail that is needed without adding the sleeve to bulkhead and spar to rudder.

Have you considered adding the additional bulkhead and spar back to rudder? I am considering purchasing another Dragon but would not do so if these parts are omitted. This is a great flying airplane and the cost is very reasonable. Yes, we are having to add 16 ounces of lead to the nose but that number could be reduced by moving other componets forward vs. removing strength from the tail. No one likes to add unused ballast to a aircraft but in the case of the Dragon, it does not hurt its performance.

We will not fly this latest design without hearing from you.

Regards,

John Thomas

John,

I could not agree with you more !


Albert

Albert,

I'm glad to see someone else posting pictures to help clarify this issue. I only wish I would have taken pics of my rudder when I had it removed a week ago to replace the rudder servo. The carbon rods (spars) that are ommited is what I was trying to explain and hope are included in new kits.

On another note. Looking at your picture, I would install some type of shielding for your servo wires before perfoming your maiden. Some thin aluminum tape is what most are using to help protect wires from heat. Look at the picture in post #64. Some of the tape has been removed to replace servo but 100% of all wiring is covered in aluminum tape prior to flight and prevents damage in the event of a hot start.

John

Skymaster:

As previously mentioned, we have already installed the bulkhead deleted from the previous design to Richard's Dragon. After much thought, we don't feel comfortable flying it until we add the spar(s) to the rudder and securing to bulkhead(s). If we were to do this, what is the best method to install carbon spars (tubes) to rudder? Would you use one of two aluminum pins of the latest design to secure a carbon rod? Adding a sleeve to secure this rod would be simple to the added bulkhead. The latest design uses two short aluminum pins to secure rudder to stab with screws. The old design only used one screw. I think that one screw is plenty to ensure the rudder does not slip away from stab. What we are after is the added strength provided by spar from rudder when attached to bulkhead(s).

What is the proper way to return to the previous design without damaging the paint? We have no way of knowing where to modify/add to rudder without tearing it apart.

Thanks,

John