I agree Chad RTF WEIGHT then it is fair for everyone. After all what is the point in having a 5kg dry weight limit for a glow plane when its flight weight is well over 5kg.

But just like you stated Chad I personally have no problem with the rules as they are now, as my electric plane are under the weight limit as are many others, however I think they should be review to be fair to everone, because they are not fair currently.

If I remember correctly the old rule was : weight of the airplane after the flight.


Mark

I was going to suggest this, as it is used in virtually all forms of motorsports as the baseline. Still not fair to electrics, however. The new technology is just different and doesn't fit the same framework we are used to. As pointed out, though, it is currently possible to make the limit with electrics. But at significant expense. But then, what doesn't cost $$$ in any form of competition that involves equipment and technology?

Here is a question that I have never heard the answer to - what was the purpose to the 5kg limit in the first place? Since the engine displacement limits were removed, it seems to me that eliminating the weight restriction and simply limiting the envelope dimensions to dictate model size would make the most sense. It might make a 2M plane more affordable by allowing people to build slightly heavier aircraft that still fly well But past history in pretty much any form of competition says that this generally doesn't work as intended. I am not trying to get people going about previous battles relating to the weight/engine/cost issues, just wondering what the intent of the original 5kg limit was?

Mark

Does the 5kg limit not come from the pre 2X2m days when models could be any size and it was an effort to limit the size?

They are talking about abandoning the weight limit to speed up processing at Worlds and Euros, don't know what the outcome was though. You could probably find out if you looked at some of the past CIAM minutes.

A

no weight limit = 7kg bipes with bigger engines and a whole lot more cost.

In that case with a 42V limit on electrics they would be no longer powerful enough.

Is the 42 volt limit on the battery (Loaded or unloaded?) or the voltage to the motor? Or on any voltage in the airplane?
We have ways....
Jim O

Changing a rule will likely change the planes we fly one more time. As mentioned biplanes would be much more feasable. Will a 2 M biplane fly better than a 2 M monoplane? I don't know. Biplanes never impressed me in the past when flown against a standard pattern plane, but they always had a smaller wingspan. Now they could be the same size if the weight limit was removed.. Each size/or engine limit change has lead to a change in the planes that we fly. Generally getting bigger each time. Would a widebody 2 M pattern plane fly well on a OS Hanno special

Yes it is harder to make the weight limit with an electric but that is becoming easier as battery technology advances. Will we get smaller cells from where we are now? If so then changing the limits for todays equipment will have more profound effect in the future.

I was around when the first people tried 4 cycle 120's instead of a piped 60 when the 4 cycle displacement limit was raised. Interesting but I wouldn't waste my money. Technology improves and YS 120's clearly outperform the best of the piped 60's. Now a rule change made to equalize the 2 technologies allows a swing to the favor of the one that was being helped by the rule change in the first place.

So yes it may be more difficult to make weight with an electric but I say leave it as it is or else a new can of worms will be opened

Stuart

Open circuit voltage of the batteries....or at least thats how they were being tested. I am not sure if the rules explicity state that though.

It will take years and a lot of convincing to change it....from the discussions I have seen of the CIAM sub-committee the issue of higher battery voltage is rather divisive at the moment, so I would not expect to see it change in this decade.

They were very diligent about checking every electric model for voltage prior to every flight in France and they weighed every model after every flight as well.

Stuart, I agree

Back to the Pinnacle

Indeed Chad, indeed. As my brother said, there will always be someone will just go that step too far. He instanced a DA 150 in a plane that is not 2m squared but 2m cubed!

My personal opinion is raise it to 6kg. Would make it easier for fatter lekkies to make weight limit, would allow the use of Ni-Cd/Ni-Mh packs instead of Li-pos as someone pointed out and it would also allow petrols to make the weight limit much more easily. In the UK we have also had peoples scores not counting as they were a smidge over 5kg. I know rules are rules and all that but I think it is ashame that these pilots make all the effort to go to an event, practice etc etc just to have their scores discounted as they were an ounce over the limit or so. 6kg limit seems like the sensible option to me.

A

Let's get back to the build. This week I received most of the stuff I will need to finish the plane. I am still waiting for a piece of carbon sheet for the motor mount and a piece of carbon nomex for the servo tray. I have been pretty busy at work but I finally had a chance to do a little work last night and today.

I decided to tackle the aileron servo mountings. This is one spot that I will admit to being a bit disappointed with the plane. The aileron servo opening is rather large at just under 2.5 by 1.25 inches. I choose to use JR 9411SA servos which are quite a bit smaller than the opening. The lips on the servo bay are not very stiff nor long enough to mount this servo. Adding ply servo rails above the fiberglass lips and glued to the sides of the bay would have worked but the servo would have ended up too far out of the wing for my taste. I decide to make a small tray from .125 fiberglass covered end grain balsa. I really like this stuff for its low weight and strength. Luckily I had a few pieces left over from the center of a few formers that I made to build a plane back in 1991 I made a paper template as shown and then cut the fiberglass balsa composite to match. I added a light balsa rail to the edges that will glue to the turned in sides of the servo bay. The completed tray weighed 4.6 gms before gluing in place. I think Oxai could have put in a piece of nomex sheet in this spot that could be cut out for your servo choice. The only thing else needed would be something to screw into. This would be minimum work on there part as they make the composite wing. It took me several hours to get it done.

For connections I choose CHP control horns, Hanger 9 ball links and titanium pro links. A thin piece of lite ply is embedded in the aileron and just wide enough to mount the CHP control horns. The outline of the lite ply can be made out in the picture. The ply seems pretty soft when drilling through it but the screws seem to hold well enough.

The servo is mounted into the fiberglass balsa composite tray using small pieces of nyrod to hold the screws. This is an idea just posted by Matt13 in the share your light building secrets thread. It sounded good so I thought I would try it. I first tested it on a scrap piece of fiberglass balsa composite and it seems to hold very well. The screw themeslves held in the balsa fiberglass composite but the nyrod makes it that much stronger. 1/4 inch pieces are used.

Now if I could just match the pink paint for the tray it would look just fine

Nice stuff, just a small lip to hold the tray. I guess they size for the big Futaba Servo. This makes sense, pick the worst case and then other servos can be modified in place.

I've been doing some research also on wing weights.


This is from the TS Composite Oxalys thread.
"Hello Rune
Weigth of finished wing without servo is 850 g. Total weight estimated of wing is about 950 g without wing tube. Plane already to flight without fuel is about 4700 g (Yamada engine).
Claude "

This is 33oz converted. 16.5 oz per panel. Composite Molded wing. Model total 4700g or 10.4lbs

Then a Bob Pastorello experiment the Tojerio these are film covered, 15.8oz and 16.4oz per panel, with Petrol he is 11lbs plus a smidgen depending on the right engine combo.

Local buddy got a Brio kit last fall. He is at 14.5oz per panel with no covering yet. My guess is Ultracote will add 2oz per panel. He is working on it now. Should be a few weeks and will know the wing weights.

I see this 15.5oz per panel in a painted wing as a huge bonus guys. It may not be like Dave's Supreme for weight but man alive its not heavy in the spectrum of what else is out there.

By the way Stu, I like all the photos you have taken. Looks good.

I see Central and OXAI USA are offering the Beryll and have prices up now. Talked to Mr Johnson and they have Pinnacle, E-Pinnacle and Beryll models coming in June.

I may just have to spring for one of these bad boys. If they fly 1/2 as well as they look then we got something. Come on lets see it get done man.

Allen

One thing about the composite wings that I think outweighs any weight consideration is that
they are absolutely straight, no warps, waves, dips, kinks or any other irregularities. The hinge line
on my OTOP is absolutely straight with zero, none, no gap at all. Both panels weigh exactly the same
total weight and if you support one end and weigh the other they are exactly the same weight at the
tip or at the root. The airfoil shape is exactly the same on either panel at any point on the wing. The wing
tips are shaped exactly the same on both panels. The ailerons are exactly the same shape and weight. I've
seen some very good builders and have a couple of friends that can build some unbelievably nice airplanes but
this level of exactness would be hard if not impossible to duplicate on a foam and balsa wing. My wing panels
weigh 17.9 ozs each with 8411sa servos, arms, extensions, linkage, screws, graphics, and servo mounts and they
are plenty light enough for me. If money were not an issue for me I would have my order in for one of the
OXAI models today !
Back to the subject of this thread---Very nice airplane !!!!!!

tommy s

A word of caution there----I've seen similar setups fail----sometimes not straight away---vibration perhaps?
Cyano in the screw holes to harden them helps, or perhaps your nyrods? The nyrod thing works well long term for me.

Straightness in a composite wing, stab or fuse for that matter is totally dependant on the mold which is dependent on the original form for the mold. But yes if it is straight then all of the pieces taken from the mold should be straight. A frequent complaint of one of the other composite planes is the same aileron trim being required to fly level. I would suspect a slight twist in one of the molds that is being used. It is one of the reasons that I took it off my list of planes to consider.

I will be weighing up all of the servos, motor, spinner etc to see how much room there is to play for installations etc. I will post it as soon as I get it added up. I also just received my carbon fiber plate and carbon covered honeycomb material to be used fro motor mounting and servo/battery monting respectively. The honyecomb material could easily have substituted for the fiberglass covered balsa that I used for the aileron servo moiunts. But you may only save a gram or two.
One place I could reduce weight a bit is to change the steel screws used for axels and for mounting the landing gear to aluminum. You could probably lose 1/2 an ounce or so just with that. Anyone know a source for aluminum screws where you do not have to buy a box of 50

Hopefully I will get a bit more construction done today and tomorrow.

Stuart

I have weighed up all of the components. (Let me know if I forgot anything.) The weights are listed in the chart below. I estimated for elevator and rudder pushrods and cables.
I still have to add motor mount, battery tray and elevator servo tray, and the glue to install them.

So far I am at 10 pounds 1.5 oz. An ounce and a half can be lost by changing to a 900 mah battery pack instead of the listed 2400 Li ion pack listed. The weights of the fuse and wing panels are now pretty accurate as they have been weiged with a digital scale that seems pretty accurate instead of the spring scale used earlier.

In regards to wing weight as discussed earlier. It could definitely be done lighter with foam/balsa and film covering. For my comparison I weighed one of my Desire panels, a little smaller but with a retract and wheel as well. It only weighed 14.5 oz (411 gms) They were done as light as I could have with honeycombed cores etc.

Stuart

Wow,

good weights. We all know that the models will fly well on e-power at the weight limit. Tony F's Partner discussed here first was at the limit according to the threads, Jason's NATS winning Impact was there, Quique's NATS winning Brio was there, I spoke to Chip last year about the Scandle thingy and he told me it was within grams of 5kg, this placed 4th at the worlds.

Looks like Stuart you are going to have a good shot at 10.5lbs. Just keep watching the grams.

There are those that can and do and then there are those that tell us all how its suppose to be done.

Good show,
Allen

The rudder servo and horn were next. The rudder servo was mounted in the existing tray made from a honeycomb fiberglass composite. Gold Nyrod pieces were used for screw mounting as before. In order to figure out where to drill the rudder horn screw hole, the servo with ball links was put in place to measure down to the center of the links. This measurment was transfered to the outside of the fuse on both sides. A long straight edge was run from this mark, through the precut cable hole and a mark made on the rudder over the ply plate. The mark ended up in the lower third of the ply plate on each side. Once satisfied that the marks are in the right place and set back from the leading edge of the rudder an equal amount (double check by measuring from the trailing edge of the rudder in case the angle sanded into the rudder leading edges are unequal) a hole is drilled part way through from each side for a 30 mm bolt. The rudder horn is made up from 2 med MK horns. The center bolt is a 3x30 mm bolt with the head cut off. The bolt is just long enough but could be longer if you can find a slightly longer 3mm threaded piece.

Hey Stu,
Why are you using those expensive MK horns on an arf?....
Greg Grigsby

Funny how this is only my second real ARF

Unfortunately the geometry of the rudder cable exit guides to the rudder horn only really allow for crossed cables. I am not sure if there is really a downside to them but I have always preferrred and used uncrossed cables in the past.

The rudder horns were screwed on with a little silicone rubber on each base to fill in the rear gap under the horn due to the rudder taper, and to help prevent loosening, Loctite was also used on the screw. I used Hanger 9 ball links on the servo wheel and MK links on the rudder end. For cable I have always liked Berkley Steelon fishing leader. It is a plastic coated wire. The wire is soldered into Dubro threaded couplers. The cable is stripped and bent back on itself and held in place with solder. The wire does not accept solder but the solder locks it in place.

Right now I have a 35 mm JR large output wheel. This is not quite enough throw and will need to be changed.

Stuart

What are you going to use for elev. control, DEPS, PULL PULL?

Sorry for the delay in continuing but I have had some time limitations again this week. Not sure how I will get the time to fly it as I can't even find the time to finish it

As far as Elevator control right now I am planning on using a carbon fiber pushrod like the deps system only .125 diam. I will use several guides rather than a full legnth sleeve. I have a bit of a hangup about using the .07 rod although obviously many are using it without issue.

Stuart

Hi,

My Pinnacle is very close to being ready to fly. I received it about a year ago, so talk about slow building...

Well anyway, it is Hacker (14XL) powered, and I will be using my trusty 5300mAh TP Pro-Lites to feed the Hacker with electrons. The weight is very close to the 5 kg limit, and I'm still missing a few Depron air-guides etc., but hope to keep it under the limit!

The weights are:

Fuselage: 2881 grams
Left wing: 443 grams
Right wing: 448 grams
Wing tube: 94 grams
TP 5300mAh Pro-Lite: 1100 grams

Total: 4966 grams


I started out with a raw kit weight of 2280 grams, so nothing wrong with that, however it all adds up in the end. I have put on an APC 21x13WE, and it is a very heavy prop, so I might save a little by going with the Mejzlik 20x12WE I have, but I'm not sure if it will load the Hacker properly. I guess time will tell...

I have attached a few pics for your information. The rest are available on my web-site: [link=http://morten.laugesen.nu/]http://morten.laugesen.nu/[/link]

Thanks for the pictures. I actually have checked your site several times looking to see if there was an update to the plane. I also studied your initial pictures carefully when deciding whether to buy this plane or not.
Let us know how it flies

Stuart

I finally have hads a few hours here and there to get a few things done.
First I wanted to revisit the aileron linkage. I was not real happy with the connection on the control horn side. The CHP control horns are nice and the clevis fits very well. Probably too well as it doesn't tolorate side to side movement very well. I could feel it binding with extremes of servo throw.
I substituted a Hanger 9 2 mm Ball link screwed into the control horn. It fit well and did the trick. You can see what I mean as far as the angles in the last exagerated servo throw picture. The first picture is the original linkage (on the other wing).

Stuart