hey,


I need some advice about the Great Planes Extra 300s 40 ARF

I've wanted to step up to an aerobatic plane because flying a SuperStar Inverted dosent work to well.(though I havent had a major crash yet)

I want to know what to expect when I fly this thing.

A guy that fly's at the field has one ,he said it fly's like a great plane should...from what I seen it does.....JW

Loved mine with an OS .61FX until I had a switch failure and it made hole in mother earth. Tracks straigtht and true with no bad habits. It's second only to my 1/4 scale H9 Cap 232. I liked it so well I have a new one in the box ready to assembly. It does need more power than .40 or .46 in my opinion.

Its on its way from towerhobbies. Im hoping to get it airborne by the end of this week


Thanks

I have the kit. I have a .46 fx on it. It is a bit underpowered, but since it is a kit, my .46 is my most reliable engine. Anyway, the kit flies like a dream. Throw the thing on high rates and there's not a whole lot you can't do. Move the CG foreward and flying inverted is no problem.

I just picked one up at the LHS. Going thru it now and so far looks good. One question though, looks like a pitts style muffler would fit good in the cowl with a 46fx? Anybody have that set up?

MLC

I have two of them, they are sweet flyers!!

One has an OS 91 surpass four stroke with 14 X 6 APC and flies great.
The other has a Saito 100 four stroke... WOW, unlimited vertical at 3/4 throttle!!!

I wish there cowlings and wheel pants were of better quality, mine are already cracking.

Do yourself a favor and glass the inside of the cowl before you mount it, you will be gla you did.
Also reinforce the wheel pants too. The parts look really good but won't last very long without the reinforcement.

And last but not least, prepare yourself for a thrill with the sticks!! And when you land, be sure not to try and slow it down too much, the wings are fully symetrical and will land a little faster than you may be used to. These extras fly straight and true and will track like they are on rails.

Good luck and have fun, they are great planes (note the pun)

MR G

This is my favorite model by far. Mine is powered by a 91 Surpass. It fly's like its on rails. Point it where you want to go and it's there. It's easy to wheel land or three point. It will knife-edge all day. I installed a high torque servo on the rudder and it made a big difference. I moved the gear forward about a half an inch. My cg is about 1/4 inch behind the recommended rear cg. I did this to help it flat spin. Gap seal all the hinges. I have flown one with a 70 Surpass and I think it flew better than mine.

Takeoffs require little rudder if you go easy on the throttle. I am onto my second cowl. The first cracked after two seasons. The wheel pants are long gone. I fly off grass and they split within a month.

This plane will make you look a better pilot than you are. Enjoy it.

If you want an Extra that is more suited to a 40-sized engine, you might want to look at the World Model Extra Sports 30 - with a hot 40 (or 46 ) up front it cranks along. The finish on this ARF is superb with a fully glassed cowl and canopy. Having a short fuselage, it tends to be a bit squirelly on take-off, and will snap if you're a bit quick on the elevator, but apart from that it flies beautifully.

Russell.

I've got the ARF with an OS .46 FX. It flies great. Not over powered, but sufficient. It is not a "3-D" plane, does standard acrobatic maneuvers well.

Carl

My son flies one with a Saito .91 4-stroke and a 14x8 APC prop ... it flies like it's on rails and has unlimited (and fast) vertical ... nothing prettier that a huge, really huge, loop with snaps at the 90 degree points of the circle! Does it all yet lands pretty tame unless you get stupid slow. Some club members have ones with OS .46FX's and theirs flies great, too. But the larger Saito turns it into a real pilot and crowd pleaser! This plane just says take me vertical with rolls and a snap on the way up and then 4 point rolls all the way down! Or, take it high and spin it down for almost instant, thumbs-off recovery. A dandy plane.

Great plane. Mine has a Saito 91 on it turning a 13x8 APC. I think it is powered just right for the altitude I live at. I'd like to see what it would do at lower altitudes. It is a capable airplane. With a 91 it will easily hold knife edge and perform a one roll circle. It has enough authority to do a slow roll right after takeoff. Just watch out for the nasty tip stall. It does a great snap roll and will snap with too much elevator input. So, watch the low altitude manuevers.

I also added flying wires to the tail after hearing about some horizontal stab failures.

I was once at a fly-in and got a chance to fly someone elses 300 with the 61 FX on it. The plane with the Saito 91 was a little more alive and the throttle more responsive.

Flying Characteristics:-

Being an Extra, it flies pretty straight and true, but can snap in a tight loop, or when recovering from a fast downline, if you have the CG too far back and / or have too much elevator movement.

Don't yank it into the air, unless you have a lot of power on board. Make sure it has enough airspeed on takeoff before leaving the ground.

Landing needs a little throttle management. That is, dont' come in too slow (or too fast! but hotter is a better mistake than too slow!). Have a tiny bit of throttle as you approach, and don't make the landing flight path too flat. Only chop the throttle completely at the very last stage.

Other than that, a great plane to fly, that is very forgiving.

Watch the snap though!

-David C.

I finished my Extra 300s 40 about a week ago and have already put around 30 flights on it. I love this airplane. I went from a trainer to this plane (despite recommendations to the contrary from folks at my field), and I don't really see myself ever returning to the trainer. The Extra takes a bit of getting used to the first few flights, but once you get used to using more rudder on takeoffs and the required landing speed, it's a joy to fly.

My only problem is that I underpowered my plane. I read posts about the 46FX being a bit underpowered so I opted to use an OS 50SX. Although this engine puts out 20% more HP than the 46FX (according to OS), I still feel underpowered. The plane definitely does not have unlimited vertical performance with this powerplant. Yesterday, I spent some time making thrust measurements with various props. My plane weighs in at 6lbs 10oz, and the most thrust I was able to achieve was just under 4lbs. I am thinking seriously about buying a 4-stroke 91 to replace the 50SX engine. Based on the comments in this thread, it sounds like the 91 will be just the ticket to provide unlimited vertical.

Quick question, how well does the 91 (OS or Saito) fit under the cowl?

BTW, my wheel pants are already beginning to crack from a couple of semi-hard landings. I found a guy on the web that makes custom fiberglass wheel pants and cowls for this ARF (and a number of other ARFs too). I imagine I'll be ordering them soon.

Dave

I have a Saito 72 in mine and that seems to be very compatible with ample power. The Saito also slots into the space left by an OS 46FX.

-David C.

Thanks for the quick reply David. Does your Saito 72 provide unlimited vertical? I am not necessarily looking to hover the plane at 3/4 throttle, but I do want it to head straight upwards without stalling when I bury the throttle. As it stands, my 50SX has trouble providing the power for large loops (which may have been a blessing since I am very new to flying this type of airplane).

Thanks again.

Dave

Got a Mag 91 four stroke in mine with a 14X6 prop... What a blast to fly... tracks like it is on rails... plenty of verticle..One of my favorite planes.. I did glass the inside of the cowl and the wheel pants before installing the however...

I ordered a Saito 91 4-stroke from Horizon, and it is supposed to arrive in the mail tomorrow.

I'm curious, did you guys who used a similar engine do anything special when mounting it? I am a little concerned with the vibrations that a large 4-stroke will produce, and I'm thinking of using a Du-Bro motor mount with the little rubber grommets to absorb vibrations. Of course, this motor mount will not work with the existing mounting holes. In order to use the Du-Bro mount, I'll either have to drill new holes (and somehow install the blind nuts in the existing firewall) or perhaps install a 'sub-firewall' to mount to the existing firewall (at the expense of extra weight of course).

Perhaps I'm being too paranoid with regard to engine vibrations. Did you guys just use a regular glass-filled mount for the 91 4-stroke or did you do something more extravagant?

Thanks in advance,

Dave

I used the supplied motor mounts on mine... I did however drill a couple of 1/8 inch holes on each side of the fusalage and use 1/8 inch dowls to pin the firewall to the fusalage.. This however is SOP for me on ARF's... As near as I can figure the weakest link is the horizontal stab... I ended up sheeting mine with 1/16th balsa to reinforce it.. With the extra weight of the Mag 4 stroke the balance worked out pretty good...

It turns out that the Du-Bro mount doesn't allow enough clearance for the cowl so I guess I'll be using the supplied Great Planes mount as well. I think I'll beef up the firewall a bit too as you did. Thanks again for the advice; I can't wait to see how this plane flies with the added power.

Cheers,

Dave

Sounds good.. Let us know how it works out...
It is a great flying plane..

Not sure anyone cares but...

After spending some time with the Saito 91, I realized that it really didn't quite fit the airplane. It would have stuck out of the front of the cowl by a centimeter or more, and although workable, it bothered me a bit. As a result, I ended up buying a Saito 72, which fit perfectly under the cowl (with a couple of small holes for the rocker arm covers). Although I broke the engine in with a 14x6 prop, it seemed to be a bit much for the engine at the field. For my initial flight, the plane seemed quite sluggish. I replaced the 14x6 prop with a 13x6, and the engine ran much better. I have a good deal of vertical pull now, but it still isn't quite unlimited. In any case, it's definitely a lot more fun to fly now, and you got to love that 4-stroke sound!

I am currently running 10% nitro fuel. I plan to try 15% nitro and install that 14x6 prop again or perhaps I'll try a 14x5 prop instead. In any case, I am much happier with the new engine. I'm not sure if I'll return the 91 yet or not. I have 30 days to return it (provided I don't actually use it first). I am thinking of keeping it around and perhaps installing it on the Extra without the cowl for those days when I want that extra umph!!

BTW, I just read that Saito is coming out with an 82 engine that has the same footprint of the 72 with 20% more horsepower. Ah well... if only I'd known that sooner.

Thanks again for the help.

Dave

Sounds like your having fun with it... It's a heavy ARF.. That's why I chopped the cowl and put the .91 in it.
I have a couple of the Saito .72's and am running APC 13X6's on them .. I think I could get better pull with
them if I used like a 14X4 but I don't have the ground clearance to do it.... From what I read on the Horizon
site the 65,80 and 91 all use the same case... You might still have the length problem with the 80..

Sorry for all the posts... my wife is sick of listening to me talk about R/C airplanes...

Anyway, I've come full circle on this airplane with regard to the engine. After installing the Saito 72, I took it out to the field for some flight testing. Unfortunately, the plane didn't perform nearly as well as I hoped with this new powerplant. Uplines ran out of steam very quickly; the plane became mushy at the top of loops; etc. I tried using 15% nitro fuel and various props (even an APC 14x4W) with very limited improvements on vertical performance. I did some additional thrust measurements at home and found that the best thrust I could achieve was around 4lbs 10oz with a 14x6 prop. Although the FA-72 managed more thrust than the OS 50SX, it was far from providing the power needed to push around a 6lb 12oz plane.

So... I went back to the Saito 91 (after considering the new Saito 82a and an OS 61FX). I must say that I wish I had used the 91 in the beginning. Because I had to mount the engine as far back as possible, the CG on the plane actually moved aft, thereby allowing me to remove ~1/2 ounce of lead from the tail. The net result is that even though the FA-91 is 1 3/4 ounces heavier than the 72, my plane only weights about 1 1/4 ounce more. A quick measurement shows that I now get about 6lbs 10oz of thrust spinning a 14x6 prop... so I gain 2lbs of thrust while barely adding weight to the plane at all. One downside is that the 91 really sucks the fuel down so the little 10oz fuel tank only provides about 6-7 minutes of flight time.

A guy at the flight field told me to try 30% nitro in the Saito. He says he always uses 30% in Saitos and gains around 400-500 RPMs at the top end. I did some checking on the net and found that Saito says 30% is fine. Unfortunately, I also discovered that 30% nitro heli fuel is twice as expensive as the 15% stuff (almost $30/gallon for Coolpower). I might try it, but I imagine I'll stick to 15%.

Anyway, I can't flight test the plane until tomorrow because my club is hosting a helicopter fun-fly competition this weekend which is using the airplane runway. I can't wait to see how it performs tomorrow.

Dave

djwalker what prop are you running on your sx 50 ? I have one on my DP ultimate 40 and with a 12x6 apc I'm pulling a little over 6 lbs. of thrust with 15% nitro coolpower. It gives good vertical although not quite unlimited. I also have a Thundertiger g 51 on the gp 300s wunning an 11x6 apc it pulls about 5.5 pounds of thrust. the plane with everything waighs out at 6 lbs. 2oz and I had to add just a little tail waight. I was thinking about the saito 82a also but am still undecided if you know somebody who has one let me know how they like it. thanks