Ringmaster Juniorish

More "take apart" work with the core and the centre rib,

I cut out the lower fuselage piece first which was a mistake as I needed to get the rib central before I cut out the upper slot. So I had to tape it back together.



I added the ribs that support the central sheeting to the centre rib.




Luckily, I got everything to line up.

Ian, one thing I found with all Rings are that the nose breaks off very easily. While I admire your take apart effort, they usually take themselves apart. While this is a scratch build, the stock Rings never offered enough doubler material and it stopped directly behind the leading edge. Being a take apart now, it looks like you have A lot of motor mount area and no support holding it together. I'm not a electric flyer and this appears to be nitro power, even though it's small, the top motor mount appears to extend very far back and the bottom has very little behind it now.

Ken, you are perfectly correct. This is what it would look like with an OS 15



I definitely wouldn't be comfortable with this but that will not be the power plant. It will be and OS motor - OMA-3810-1050 - and that won't fit between the bearers. I will show the mounting when I have finished it.

Here it is ready to take the mounting,



I was a lttle concerned after cutting out the wing hole and removing the wing bottom from the fuselage how narrow the upper spin was. However, because of the plywood core epoxied between balsa - it is incredibly strong. It will take some force to break it.

I keep looking for weak points have seen so many of these slab things break aound the wing area - front and back.

One of he strongest slabs I have seen is constructed with the engine bearers running the entire length of the fuselage with the wing inbetween the bearers.

.

It was time to set the centre rib today. Luckily, on this wing the spars were a nice press fit so I could assemble it without any glue.

I made sure that the rib was square to the spars in both axes.





Then inserted the wing in the fuselage for a double check against the fuselage.







Then the dodgy bit. I tacked it with thin CA very carefully or I could have glue the wing in place prematurely.

Quick visual and then the wing back to the bench to complete the build.

It’s looking nice and straight, can wait to see it finished! Any ides as to how much the electric gear weighs?

Looking good Ian !

Agreed. Looking great!

The engine mount, 4 layers of 3 ply laminated , now just needs the corners rounding off.



This will be mounted using gussets at the back and front, top and bottom.

The motor weighs 5.4 oz



but with the ESC and timer - that gets pushed up to 7.5 oz compared to 6 oz for an OS 15



On Ron's hotel build of the Junior Ringmaster - i noticed concern over the weight of the engine and the model ending up nose heavy. On this I am clueless.

The motor is about 3/16" further back than the plan shows the IC engine and the ESC and timer will be mounted behind the motor.

The real killer is the battery. The battery projected for this weighs 6 oz but that can be shunted backwards and forwards to assist with the C of G. The battery projection is from one of the calculators and based on a 9x6 propeller.

The other thing to bear in mind is that the fuselage is 1/2 oz heavier that plan because of the ply core and epoxy for the lamination. The fin is also ply and so there will be a rearward shift with this. Who knows!

I also remebered Ron forgetting to put in any tip weight. On this I will miss out the tip weight. The propeller is a pusher and so will spin clockwise.

Nothing ventured, nothing gained.

The wings are ready for a final sand and a trial fit.

Ian, I have never seen Eric Rule's Junion up close. The standard Ring Junior by Sterling was not all that favorable. The problem lies with the wing loading. The lighter engines like a OK .14 and a Fox .15 suited these models. The Fox had more power than the OK but it weighed a touch more. The Junior Ring like almost EVERY Sterling profile is designed nose heavy. The Junior's wingspan was too narrow and too thin therefore the engine you show in the picture is oz's heavier. ANY modern .15 on a Junior is a very bad choice. It will fly fast in level flight but it will not perform throughout the maneuvers well. When the power cuts it lands like a meteor.

In theory as I'm quite certain others have used would be a Cox .09 Medallion or TD. The lightweight and power available would be quite beneficial. I had a K&B Torp.09 on one but it had to fly on shorter lines than I preferred but it did fly it quite well. Adding tail weight as I discovered on the Junior didn't make too much difference. While it assisted the turn, it certainly didn't benefit in the glide. I even went as far to extend the fuse a additional 2" and also made a brass tail wheel. It's a fun plane to fly unfortunately it's not the same as it's big brother. The electric on the nose could be a big game changer here as the powerband is consistent throughout. I never flew electric nor have a desire. Almost all of are club members are switching over. Bob Hunt flew his newest electric Sweet Sweep at our vintage combat last weekend and I will say it was incredibly impressive. I would certainly like to hear back on your results using electric on this plane. I truly feel it's a solution to a old design. Ken

Thanks Ken. I don't expect miracles from my builds but it does help to be aware of potential problems.

I have not yet seen electric c\l combat models but have a couple of park flyer flying wings. They are foamies and fly well in mild weather but ......... eat propellers. You can get IC enginesto stop with the propeller horizontal but the elctric motor allows the propeller to turn. The elctric propellers I use are quite brittle and break easily. I wonder how those on a combat model fare on landing.

Combat flying is brutal on models and the results of a punctured battery is not something you want to see at close quarters,



I keep putting off building one of these because of the prop issue.

https://www.stevensaero.com/product/scram-control-line-combat-model/

I do think though that it would be an ideal candidate for a Bee.

Ian, funny you showed the video in regards to the battery. Bob Hunt had 3 people with him to assist him in flying. The one fellow William built a beautiful plane. If you've ever seen the Teosaki, this looked like a smaller version as it had a geodetic wing. It had a oversize motor and battery. Our vintage combat has changed a bit as the guys who build them don't want to fly them in a combat match. I do, but that's me. They have one event to see how fast you can fly and another where you fly the PAMPA stunt pattern as fast as you can. William was flying for speed and the plane got way ahead of him. Over the top and into the ground resulting in a fire and a meltdown. I'm thinking in my mind there goes several hundred up in smoke.

Hi Ian, It will be exciting for me, to witness the maiden-flight of this/your model. You may or may not know that I have an original kit-built Sterling S5 Junior Ringmaster that's been "ARF" status for decades.



I have a few glow-engines that would be well-suited to fly the airplane.. but I also have parts for an electrickery-installation at my disposal.. (less a timer)..

I'm not sure this is supposed to be a vote, but in case it is, I vote glow.

Myself I would go glow.  Top Fuel for me.  Having said that, a pistol car transmitter with a leckie might be interesting for a local park where no one would notice you or grumble.  I think an OS .10 or TD .09 would be ideal on .012" 52 ft. lines.  I don't have a Ringmaster but will go out and maybe fly someones next week. I seem to be a pilot [bleep].  I was watching a normal size Ringmaster fly and it seemed quite a good flyer.  The tail was lengthened and elevator enlarged. Anyway, it looks like this one should be ready for next weekend? (edit) The weight would be a wash with the .15. There would be a bit extra weight with the tank to bring the total up to maybe the same. Then again there is the firewall with the blind nuts which might be offset if the nose is shortened if needed for balance.

No glow chaps. Don't want to invoke the noise police and want to fly this locally.

Seeing Roddies Ringmaster Jr reminded me of Ken's recommendation to use ceconite/koverall for cloth hinges. I really like the strengthe and longevity of cloth hinges and the speed of fitting but they are not pretty,



No matter how neatly you apply them, they stand proud and are not disguised by finishing.



I should have ironed those before applying them!

So for the Junior, I tried Ken's recommendation. I had to take 6 photos and keep changing amgles before I could show them!



They were applied using dope and cut using a raser blade. They are strong.

They work great, look great. The Koverall also accepts paint without making them bind and get stiff.

A one week gap and back to it.

I glued the tail plane on and it was easy to line up as the plywood fin is integral to the fuselage. I spent quite a while assembling the electrickery , drilling the mounting holes, bending the undercarriage and making the reinforcing gussets for the motor mount.





After looking at the model and realising there was a distinct nose heaviness, I put balsa either side of the fin mow ready for sanding. This actually mad quite a difference to the C of G and brought it to only slightly nose heavy.



I think it will look better but not sure where the C of G will end up after finishing.

Having the wing removable has definitely made wing fitting easier and more precise.




The bottom fuselage piece is now permenantly glued on and there is a good fit at the top of the wing. I will cover the wing before finalising that joint but it will only be a few swipes of sandpaper.

I used an RC pushrod for the elevator.



and here is the wing being pulled off





A nice tight fit and now the wing is ready for covering

Engine mount now gussetted



Fin shaping started

Progressing nicely Ian.  I like your new hinge system, big improvement over cloth which I used for years.  But I tend to stick with pin hinges, I love the freedom of movement but they have to be added after everything else is completed or they get contaminated.

After cleaning the castor goo off two Ringmaster Jrs. yesterday and removing and cleaning the engines I can appreciate the convenience of electric.

The "Happy number" - Bob

She is looking good Ian !! Want bee long now till in the air .

After getting sidetracked on numerous other projects finally finished it




No longer take apart but glued together after painting.