I had some troubles with mine as well but found that if you put the hinges in the fin first and then insert the bottom of the rudder at an angle to clear the fin you can insert the rest of the hinges a little easier, clear as mud? I am looking forward to your speed brake hinging, I have been thinking a lot about it since Paul mentioned the pitch/roll problem. I was thinking of moving the hinges as far outboard from the center as possible to give it that sturdier platform that will resist twisting in flight. I can imagine that it is going to take a bit of engineering to get it this way due to the curvature of the fuselage but hey, that is the fun stuff anyway!

Chris

Do you sleep ! Yah, I guess there's no secret technique for the rudders but a bit of fiddling. I don't see why the speedbrake would twist . My method only changes the actuation but the hinging is the same. I'm heading out soon but will have a few pics posted tomorrow. The Stingray has been on the backburner lately because it's too cold to do any spraying outside. I'll resume work in a couple of weeks. You'll probably have yours done by then at your pace!

wrong thread post, sorry

Shaun, as I said, this is my first yellow kit and I am most impressed. I do agree with Strato on the rudder hinge issue and will try to come up with a fix myself. Anyone know about the clear canopy that Paul is using? What about the plastic looking main tanks that appear in the pictures supplied with the kit? Yellow sells them? How much? What other options exist for
main tanks. Tanks guys (HA!)

Strato, what carbon roving were you referring to?

In an earlier thread I believe Paul said that his clear canopy was modified from BVM Sabre. Not sure which version.

Coincidentally, I'm working on the stingray rudders right now too. I'm concerned about cutting a big square hole in the side, reducing the structural integrity of the fin. I'll probably try it as they recommend at first and see how it goes. If I need to patch a hole later, so be it I guess...

So anyone know how many Stingrays are flying, and has anyone ever heard of a rudder/fin flutter condition yet? Hopefully we're all be getting worried over nothing.

KW

Woketman,


He's referring to carbon roving that's glued to the inside of the verticals where the two molded sides are glued together. When you're drilling for the rudder hinges, you'll be drilling through it. If you don't expect it, you could have a problem like the one Strato is talking about where the bit gets deflected away, and you have a messed-up hole. Anywhere you see a line, and the line is black, there's carbon behind it. Start with a small bit and slowly graduate up.

I don't think the issue with pitch problems from the speedbrake is going to be common. If it is, then we're going to have to come up with Plan B.

As far as getting the rudder hinges in, it's always a pain with F-16 fin/rudder assemblies. Here's my method: First of all, I use Aeropoxy to do all hinging. Reason? I don't have to mix anything or suck up any glue in syringe (sp?) or straw to apply to the hole. I use the mix/applicator tips and just shove the tip into the hole and squeeze in some glue. After the hinge point is oiled in the center, I insert the hinge into the hole and take my sweet time to position it in the RUDDER FIRST. I do all the hinges at the same time for the control surfaces (takes about 20 seconds per hinge) and let them cure overnight. The next day, I 'crack' them loose, and carefully remove any excess glue with an exacto, then get ready to do the other side. In the case of F-16 verticals with that severe sweep back and a base to impede you, I squeeze the Aeropoxy into the hinge holes, wipe away any excess, then shove the rudder on. When you line it up, the holes are going to be far away from the actual hinge sticking out due to the angles, but I just take the very tip of the hinge and bend it down until it reaches the hole, then push! It sounds silly, maybe, but it works. The hinges that come with the kit are flexible enough to be bent like that for a few seconds without anything bad happening, and I've found this method to be easier than trying to coax and fiddle all day. This method has survived the test of time (and turbine full-throttle diving low-passes) for me.

Keep up the good work, and the very nice (and helpful) photos!

Sleep, whats that! I work from 2330 to 0700 so on the weekends I just stay on that routine, it is too hard to change back and forth with the sleep schedule, plus I can work on the planes all night guilt free after the wife goes to bed! I am trying to get this thing done in case I deploy so I work on it often. I believe that Pauls canopy was from the old version of the F-86, but I think I am going to use the yellow F-16 canopy since it is a little smaller/sleeker, plus it is an exact fit if I remember correctly. I flipped the servo over in the fin last night and it is going to work fine I think. I had to use socket head screws and I am going to have to use an allen wrench to get the screws out 1/1000 of a turn at a time! I am going to box the cutout in with 1/16 ply to stiffen up the mounting area and hopefully minimize flexing in the fin. I did not get as much last night as I had hoped but I want to take this part slow. We will see how it goes today.

Chris

Ok, this is going to work fine, I boxed in the servo bay with 1/16th ply and interlocked the servo mount with the bottom wall. I then applied aeropoxy to everything I could reach. The fin is now very solid in this area, I will tweak on it a little harder after all of the glue cures and see how it is going to hold up. If you use this method keep fitting the servo cover as you make the walls in the bay, it did not take much deformation of the glass to make the cover fit less than flush. More pics to come!

Another

OK, I think I have this thing figured out now. The fin is very stiff where the servo is installed. I am still going to put the stock servo mount in as it looks like it is a key structural member, I am going to lighten it up some before I glue it all in. Now it is on to mounting the fin to the fuselage and then when that is done I get to do it all over again for the right side! Tell me what you guys think.

Chris

"Coincidentally, I'm working on the stingray rudders right now too. I'm concerned about cutting a big square hole in the side, reducing the structural integrity of the fin. I'll probably try it as they recommend at first and see how it goes. If I need to patch a hole later, so be it I guess... "


Kelly W.

Just food for thought...when I was cutting out the servo cover on the second fin I noticed that it was rather flimsy after I had been messing with the other fin after it was completed. Mounting the servo up in the fin really made a difference in the rigidness of the fin with the servo being boxed in with the 1/16th ply. Thought I would pass it on just in case you cared!

Chris

Yur' right Chris,

The box section will definitely help restore the fin's rigidity, acting like a series of shear webs. Thanks for testing it and giving us your opinion. I have lots of time before I install the servo because I'm still capping the control surfaces, drilling hinge locations, and working in the fuselage. Plenty of time to make up my mind here.

Switching gears for a second, on my hotspot I really like the fact that the rudder servo is readily serviceable and the control linkage is direct and short. Although it sounds like it would work fine, I don't really like the Stingray's recommended control linkage as I feels its a bit long and not normal to the axis of rudder rotation. Your system wins hands down, so long as the rigidity is maintained in the modified skin.

I've just re-read you posts and have a question about post #83/84. The servo mount looks like it's 1-piece and permanently bonded in place. If so, how are you going to going to reach the fasteners? That looks like it could be a pretty steep angle, even for a ball-end Allen key. Had you stayed with the servo in its downward facing orientation, the fasteners could be accessed through the bottom of the fin. When I made the mounts for my hotspot wings, I bonded in a set of laminated plywood mounting blocks, then used a set of machined aluminum brackets to make the servo mount to a face parallel to the wing skin. I'll post a pick later, after my PC decides to get up on the right side of the bed... If I follow your lead, I'll probably use the same method here.

Hey, I just noticed you're in Spokane! We'll need to do some formation flying at Whidbey! I'm ~2hrs north from Whidbey Island.

KW

The servo mount is hard mounted. I used the #2 socket head sheet metal screws. The top screws can be accessed with a ball driver and the lower ones have to be removed with a modified allen wrench, actually the forward one can just be loosened and the aft one has to be removed. It is a tight fit and the screws are hard to get too but I think that it was worth it overall. I would suggest that you open up the bay a little more for easier access to the screws. Let me know if you want dimensions on where to start cutting. Also be sure to check how far the rib is inside the fin on BOTH fins before you start cutting because mine were at different measurements!, I got lucky though and everything worked out ok. I will finish the second fin today and then go for mounting them to the fuse. Formation flying would be really cool, I hope to make it to Whidbey this year, but I am pretty sure that with the current situation with Saddam Insane I am pretty sure that I will be deployed for yet another summer! This will be the third summer in four years that I have been gone, I always leave right before the first event and get back after the last one, I am usually gone about 100 days at a time, but if a war starts the 100 day thing flies out the window and we stay gone for as long as it takes!!!

Chris

Hey,

The rudder pushrod lengths and angles apparently worked well enough for a successful test-flight series, but I think the geometry just isn't ideal. The mod that Stratotanker did is great. Short, and at 90s.

Guys, I have to come clean. I have been taking all the credit for the rudder servo mod, when actually it was my daughter Emma. Here she is hard at work putting the finishing touches on! Can't wait till she is big enough to fly! She sure can tear up some realflight though!

As you can see, she is the brains behind the operation. Here she is putting the preliminary adjustment on the rudder linkage for me. What would I do with out these mad skills???

Chris

What a cutie!

Thanks, she is one crazy kid!

Chris

I started mounting the fins to the fuselage. After the glue cures on the spar mount I will install the original servo mount for strength and reinforce everything with aeropoxy and then it is on with the canopy This thing is starting to look like a plane! A question for you experienced guys out there, if you were going to mount an additional speed brake on the bottom how many sq. in. would you make it?

the spar ready for gluing

coming together

another

dear paul,

mark leavesley here just a quick note to ask if theres any problem with the air brake on the stingray when opened in flight,
as we have heard its makes the model roll badly.

Shaun, Strato, whoever: what torque do you think is a minimum required on these rudders? I am considering the Hitec digital 5125 (the skinny wing mount servo). It is listed as 49 oz-in at 6 volts. Thanks.

Woketman,

I used these servos on my HotSpot on the rudders in conjuction with a JR 460 gyro and they are great!!! Zero slop and fantastic holding power. Plus, they come with those good aluminum servo arms. The way that the servo is mounted offers zero deflection too.

Kevin