60" Molded racers for MoM

[Konrad]

Got out in the afternoon and test flew at Mussel Rock an ancient 60" moldie called the "Flash II", sold by North East Sailplanes 20 years ago. Ran into a fellow sloper who goes by the handle funkyfreestyler. He was helping me read the slope. I think out of frustration with me not following his instructions, he broke out his 60" (RCRCM SunBird) and proceeded to show me how the slope was flown and more to the point the landing pattern. This was an eye opener not only as to how much better funkyfreestyler is as a pilot but also how much faster the modern 60" moldie is. Things have progressed in the last 20 years.

This thread isn't to show how out of date I am but rather to ask what it the state of the 60" moldie. Looking at Aloft Hobbie's site I don't see any 60" molded racers. Looking at Soaring USA (I have $100 gift certificate from working the ISR) I see that there is a long list of out of stock 60" ships. Has the heyday of the 60" come and gone? What is the current hot MoM 60" molded glider? I know it isn't the "Flash II"!

TIA,
Konrad

P.S.
Ok, I found this
https://alofthobbies.com/mibo-mini-terminator-1.html

 

[thenated0g]

Not trying to sidetrack your post but i almost made a new thread yesterday as i found this guys channel with a ton of great foamboard gliders and most all his videos are at Mussel Rock. I added it to my google maps wishlist. Looks like a great long cliff side. How is recovery?

 

[Konrad]

At that spot the landing is as if you were at a "powered field". Come way back from the lip and fly her in. There is no rotor issue. Sometimes the wind stops and the lift quits on final, but that is slope flying. There is another spot (a little to the left) where if you go down give up all hope. It is known as the death bowl. Not so much as it kills planes but rather pilots and hikers! A little further south is a nice ridge but has the classic lip turbulence when landing.

 

[Wayne]

60" racers - Sunbird is pretty popular, that is what Miguel was flying with you. (He is a darn good pilot, but don't tell him, it might go to his head.) Hammond is working on a new 60" racers for us, hope to have it soon. We used to sell the Protege, I think it was the all out best 60" of all time. Very fast, very tough, very expensive. They seemed to have gone out of business though. We have another 60" in stock, the Dart III from Mibo. While an older plane, it has a very nice HN airfoil and performs very nicely. I think we have one or two in stock, just not up on the site yet.

 

[Konrad]

Dart III looks nice but I don't like the ailerons out to the tip. In the air these have given me problems with flutter at high speeds and at low speed seem to help induce a tip stall. Then there the real reason I don't like ailerons out to the tip. On my cart wheel landing they get torn off!

Nobody has any Sunbirds in stock. You going to cary any RCrCM for the entry level crowd?

Come on DOC.!

 

[Konrad]

Miguel seemed to have a level head on his shoulders. Rather than talking to me until he was blue in the face, he risked his moldie to show me how the slope was flown.

Doing a little more looking around, I see that 60" racing seems to be more of a fun class rather than a rabid all out racing class. I may not be coming to this class of racing with the right attitude. I gather that the fear, fun and excitement of M.O.M. racing is the possibility of there being contact. With that being a concern/possibility the use of high dollar molded 60" gliders doesn't look practical. With most 60" moldies costing $300 to $400 plus a midair would quickly suck the fun out of the class.

Today the only moldie I see as having a chance is the $250 Destiny, but it is a bit too small at 54".
https://www.soaringusa.com/Destiny-Sailplane-w-Ballast-Tube.html

The RCRCM Sunbird looks like it is just at the upper price limit for a MOM 60" racer.
https://www.soaringusa.com/Sunbird-Glass.html

Now I don't know but I'd think that the use of these Blejzyk ships might be more practical. I'm thinking of making the wings one piece with 3 or four layers of glass over the center section like a leaf spring. And a layer of 2 oz glass over the rest of the wings.
https://alofthobbies.com/spin-1-5m-slope-sailplane.html
https://alofthobbies.com/elf-1-5m-slope-sailplane.html

Is there a weight or wing loading limit of the NCSS MoM 60" class of racer? I would think this would define what is needed in the way of reinforcing the wings.

Before I get any more committed to the 60" MoM racing I think I'll try to attend the July 1st race at the slot. Can anybody give me some contact info. I don't do Facebook for privacy issues, or RCGoofs as I've been banned for questioning their motivation and policies.

 

[Konrad]

Had a great day flying at Mussel Rock! In fact it was my best day ever slope flying! Heck, I could fly Half Pikes to the moon and back. Not too surprising as you could fly a bowling ball the lift was so strong!

Learning from Miguel, I now have the Flash 2 rolling as fast as I want. I also found the missing speed, I added 200 grams of ballast. The Flash 2 looks to have about 20% more wing area than the RCRCM Sunbird. By upping the wing loading has allowed the Flash 2 to actually fly faster than the Sunbird. As I have snap flaps I was able to get the Flash 2 to come around in a turn faster than the Sungbird. I need to be clear that Miguel has his Songbird set up as an aerobatic ship not a racer. I'm sure with some simple trimming the Sungbird could go a lot fast than it did today.

I did learn that the V tail rudders on the Flash are rather week compared to the cruciform tail of the Sunbird. I'll see if I can rig some more throw out of them without loosing too much elevator resolution. Again I think far too many designer are fixated on the Beechcraft 110° V tail angle rather than developing a good setup for rudder authority.

 

[Wayne]

Sweet!

I will suggest you stay far away from the Destiny. They are horrible little planes. Other than a low price, that plane has nothing going for it. Tail area is lacking, it is also set at the wrong angle. The wing is a nightmare that loves to tip stall. Chris has one and we have modified the heck out of it at the iSR event just to try and keep it in the air. It still throws the occasional tip stall all the way to the ground.

 

[Konrad]

Destiny- That was the name of that plane. Thanks for the heads up!

 

[Konrad]

The July 1st 60" MoM race was canceled, with only 7 folks it would have been more work than fun to have held the race. There were some world class pilots that did show up! But I still had a great time sport flying the "Slot".

Bruce Tebo showed us what speed was all about! He spent most of the day coach us on how to DS. I really learned a lot just listening to him. Thanks Bruce for coming up to the bay area for this race.

The lift was fantastic with the wind speeds being 30mph to over 40mph. This was the first time I've sloped "inland sites". I'm fortunate to fly where the wind is coming off a large body of water. What I noticed is that the inland air is much dirtier (turbulent), not surprising. But what surprised me was how poorly the V tails handled this turbulence. My Flash 2, and the other V-tail Darts, flittered around when flying in the turbulence while cruciform models like the Sunbird flew with much more grace.

I found landing at the slot wasn't too bad. The top of the hill is nice and flat with tall grass as a cushion. Now there is a killer rotor on the back side, so just stay out of it! 3 of my 4 landing looked good I noticed that with the ground speed being zero the resultant 40 mph airspeed meant that it was best to land with the rate switch set low.

On my 4th landing I made too wide a turn and got caught in that killer rotor. I had noticed that my aileron response was odd. I had attributed it to the turbulent wind. But after retrieving my model I'm thinking that one of my aileron servos had let go from the wing skin. That's my story and I'm sticking with it, as to why I made such a wide turn into the rotor! OK, I can't say definitively as my landing on the back face of the hill did hit the ground hard, enough to jettison my battery and ballast, all 300 grams of it. I also damaged the wing near the root, I will post how I repair a glass and rohacell foam structure in the glider section.
https://forum.alofthobbies.com/inde...olded-models-60-glass-and-rohacell-racer.367/

What I'm getting at is that I think I used the wrong adhesive gluing in the wing servos. I think I should have used Beacon's "Foam-Tac". I was using Bob Smith Industries "Foam-Cure". These are not the same compounds. While the Foam-Cure never gets real hard it isn't near as flexible as the Foam-Tac nor does it have the tenacious grip of Foam-Tac. I like Foam-Cure for the repair of foam (EPS & EPO) as it flexes with the foam and seems hard enough to allow some sanding of the glue joint. I like Foam-Tac as it holds fast to more rigid materials (read servos).

I'd really like to see a servo tray for these servos PDI-0903MG, but I'm sure they would have close to the same price as the servo. So sales probably wouldn't support a servo tray/frame.
https://alofthobbies.com/jx-pdi-0902mg-servo-19kg-264-oz-in-10sec-94-grams.html
Might be a good reason to look into a 3D printer!

 

[Wayne]

You should ask Chris to make some of those trays up for you. We can then sell them in the site.

 

[Konrad]

Chris is the low volume production run expert ( 3D printing)?

 

[Wayne]

Yep.

 

[Konrad]

Inadequate documentation is the bane of our existence!

I got a good price from Aloft Hobbies on this dated Mibo Dart III. I got this largely on the hope of adding a rudder to compete with the RCRCM Sunbird. Here is an excerpt from the sales page.

"We recommend using flat wing servos for the ailerons and flaps. Many builders opt for elevator control only (using 13 mm servo with metal gears), but if you want a full rudder function, it is easy to cut rudder and make it functional. Live hinge is already laminated in rudder skin so you need to add another rudder servo similar size as elevator.
The HN airfoil is awesome for high speed and the wing is equipped with flaps and ailerons not only allowing full trailing edge cambering. This plane is designed to go fast, handle crisply and land slowly. The plane can be ready for flight in one evening of work. Just install the radio gear and you are ready to go.”

Well, I’m here to say this model does NOT have any Kevlar in the layup to act as a live hinge! I can also say there is no hinge material on the port side of the rudder! There may be some mylar on the starboard side but it isn’t clear! I etched the port side on my fin to score a line to flex the hinge and cut through the starboard side to allow the rudder free movement. You guessed it, the rudder came off in my hand as I flexed the nonexistent “live hinge”!

If there is only a live hinge on one side of the fin lay up it should be mentioned by the OEM! Now after the fact I now see 3 faint hash marks on the starboard side that might be trying to indicate that there is a mylar insert on the starboard side of the fin. These hash marks actually look like stray carbon fibers that may have gotten caught in the lay up. Again there is no mention of how to interpret these marks, if they are in fact indication of mylar in the lay up.

The fin skin on the starboard side does measure on average 0.08mm thicker than the port side skin. This indicated that there was something on the starboard side. Or that the lay up just was a bit heavier on the starboard side.

Piss poor documentation by Mibo!

It looks like I’ll now need to fabricate a hidden center hinge arrangement for the rudder. Just what I don’t want to do with an obsolete design.

 

[Doc James Hammond]

How about this?

Note in the first 4-view the top (plan) view tailplane is the wrong size.

 

[Konrad]

So what am I looking at?

I'm liking the long nose and the wing tips.

 

[Doc James Hammond]

So what am I looking at?

I'm liking the long nose and the wing tips.

Konrad, don't you recognise a Firebird when you see one...but...hold on...No, I didn't make that one yet!

But look here: Could it be close?

Cheers,

Doc.

 

[purview]

too cl ose and the dust gets sniffed,
yeah looks beautiful without carbon clothes
dihedral effect is the same as on the autodesk Picture. the height of the middle part (where the drill is) is compared to the left wing tip, as it is, quite amazing James

it is not a classical straight fuselage
more like your design lines

 

[Wayne]

We have been after a good 60" for a while now.

Konrad - Sorry about the missing hinge! Mibo told us it was there... Seems they must have changed their minds and didn't tell anyone.

We finally got our shipment of Aeromod gliders in, they have the flat out fastest 60" I have ever seen, but it comes with a very high price tag. I doubt anyone would want to put one up in a MOM (man on man) race for fear of a mid air. I debated it at one time, but then someone talked me out of mine and I let them buy it. Many years later and we finally got another shipment of these little jewels and I'm keeping one for myself.

-Wayne

 

[Konrad]

I think the mylar is there but on the starboard side. I like to have my rudder "pull" for a right hand turn. This is a habit left over from my 3 pylon racing days. Besides it looks better not looking at the hinge gap as one launches the ship (I'm right handed). I think I had a 50/50 chance and lost. Again piss poor documentation from Mibo!

I think I'm recovering from this fiasco. I have used 2 Robart hinge pins. Waiting for the glue to cure. Then it looks like this will give me a chance to develop my skills at making epoxy wipers.

If all goes well this might be a blessing in disguise!