ModelTech Sonic 500, need cg and surface travel info
 

Hi. Just started re-working my old Modeltech sonic 500. It has been around for a while and I owe it to the plane to put it back into the air. I built it about three years ago to be primarily a sport plane. I had put a new OS 40LA on it for power and Futaba 6DA radio and gear for control. It didn't take long for me to conclude that the OS 40LA was a total piece of crap. It was gutless and unreliable. After letting it hang around for about a year and a half I put it back into the air for a dozen or more flights trying to get the engine to at least work halfway right. No good. I put the LA onto an airboat and it still sucks. An OS 46AX now waits on the front of this thing just waiting for me to balance and reset the control throws. I did put in new radio equipment and the servos are now oriented in different positions too. Bad thing is I think my wife must have thrown out the old plans manual with the CG location and recommended control throws measurements. So if anyone has this info sitting around I would be very happy if you would share it with me. Thank you very much for any help. Has anyone here flown this aircraft with a 46 up front? The 40LA was a dog. I used to own a 25SX that had more get-up and go than that 40LA did. The 46AX seems to be light years away and definately feels like it will make that plane screem.


wes

RE: ModelTech Sonic 500, need cg and surface travel info
 

Hi!
It's strange that you didn't like the OS .40 LA ...it's one of the nicest engines around, not that powerful though, but fully capable of delivering good performance to a Sonic 500 airplane, at least at sea level. It's also very reliable.
Did you use 5% -10%, a 10x6 prop, preferable APC, and a good glowplug like OS 8 or Enya 3?

I have raced Q-500 pylon with the China-Clipper/Sonic 500 (same airplane different names) for at least 12 years and have had at least three of them and it's a very nice and easy airplane to fly. I have used Webra .40 GT and MVVS 6,5cc engines in my airplanes through the years, Webra being the most powerfull. Nearly everyone racing Q-500 pylon overhere uses one. The Webra .40 GT using the standard silencer turns a 10x6 prop at around 14000rpm on 80/20 fuel (Methanol and Castor oil) and speeds up even more in the air.

C of G on my airplane is 8cm from leading edge. weight is 1800g (as our Q-500 racing rules prescribe). elevator movement up, is 4-5mm. Siderudder is not important...mine is set at about 30 degrees deflection. Aileron is approximately 10mm up and the same down.

The tank space is rather cramped so a 6oz tank is all that's fits.
Best tank is of course the Tettra" Bubbleless" tank, but as our rules in Q-500 here in Sweden doesn't permit that tank to be used due to the high price, I use the next best...which is an ordinary tank with a "uniflow" setup (two clunks).
Here is some pictures of my China-Clipper/Sonic 500.

Regards!
Jan K
Sweden

RE: ModelTech Sonic 500, need cg and surface travel info
 

I have a tower 46 on mine with a 9x8 prop and that thing kicks @!! It's still not a Quicky 500 condender but it would easy do 110 straight and level. great stable ship at high speed. I'd love to see if the wing could hold onto a quicky Jett:D, don't think it would though. AFter you try a rossi or jett or nelson engine you'll have a hard time ever putting up with a crappy la engine ever again. get em for a trainer and maybe a scond sport plane but after that it's not enough:)

Anyway the elevator is lik3 3/8 up and down

rudder 3/4 either way

alilerons were like 3/16 up and down I set duel rates for alierons and elevator to 60% usually ran on low rates

RE: ModelTech Sonic 500, need cg and surface travel info
 

Jan K! That is a sweet looking plane dude. I dont plan to race mine. It is basicaly built for sport. My OS40LA has never been quite right from the factory I think. I run 10-15% nitro in my planes. The LA would fly the plane but it seemed sluggish on take-off especially as the airframe seems lightweight to me. Anyway it's on an airboat now. I did balance my plane earlier today. For some reason I thought my CG should be at 2 3/4 inch from the front of the leading edge. 10 cm back may be too touchy for me to handle. I'll try this at first as for the most part it will be a bit nose heavy at first which is ok for now. If needed I can adjust it quickly enough.

Thank you guys so much for your help!!!!!!

Wes

RE: ModelTech Sonic 500, need cg and surface travel info
 

Hi!
10cm is too far back! 8cm is what I have on my Sonic 500 and it is not sensitive in any way. I don't even use dual-rates when I fly, not on any of my pylonracers. You will notice if the plane is nose heavy if you turn sharply, say to the left, only using ailerons. If the nose drops... it is nose heavy! It should be able to do a nice aileron turn without dropping its nose.

Regards!
Jan K

RE: ModelTech Sonic 500, need cg and surface travel info
 

Hey Jan K,

I don't know why I was thinking 10cm. I was tired I guess. You are right 10 is way too far back. I actually set mine to balance around 2 3/4 inches which is just a tad over 7cm I think. Anyway my controls will be almost exactly the same as yours. I may have a touch more on the elevator and punch in some dual rate controls there as when I had the 40LA on it the factory elevator settings were fine but not enough for the way I launch and recover the plane. But like I said before...you have a fine looking plane man! You aren't afraid of crashing it in a race? I would hate to see such a fine plane destroyed!

Later,
Wes

RE: ModelTech Sonic 500, need cg and surface travel info
 

Hi Redfox435cat!

You are right dude! I was not impressed with the LA 40 I had at all. I have heard that some of the smaller LA engines are good but I don't know first hand. I have an old 40FP that is completely trashed with the sleeve lining coming off, but it still builds more power than that 40LA. It is just totally unreliable and the crankcase is badly corroded. I decommisioned it years back as it was my first engine and had been in numerous high impact crashes :D But that thing was like the little train that said 'I think I can'. Too bad OS did away with it. I thought it was the best inexpensive engine a person could buy back in the day. Anyway, I left that old thing under the storage building on an old model airboat and somehow had forgotten it. A few weeks ago I was cleaning up and seen it under there amongst the weeds and decidied to throw it away. Curiousity got the best of me as the engine was completely locked up! I wanted to see if the thing would still run. Anyway I tore it down and it was a little rusty on the inside but as there isn't any bearings in it I didn't think it would hurt to try and fire it up. I cleaned it up. Lubed it with corrosionX and put it back together. Installed an old worn out fox plug. Put the back plate and carb back on. The backplate gasket was gone and the carb o-ring cracked and broke off. Oh yea, one of the head bolts stripped out too. I primed it with fuel and hit it with the starter....it spun a few seconds as it blew out the lube and whammo bammo the thing sputtered to life!!! I let it sputter a bit and it went dead. I figured it was a touch rich so I turned back the needle a few clicks and tried again. It fired up again so I decided to open it up and the thing ran pretty good for the most part considering it was trashed in my book. But I could feel the power and the wind from the prop and I knew right away that it was stronger than its replacement design the 40LA. I won't put it back in the air but I did decide to keep it anyway. Just as a reminder that the 40LA sucks if nothing else and that some of the old engines were really good. Too bad OS got too cheap to keep making the FP engines and the original SX engines too. I had an os25sx and it was a great little noisemaker :D

As far as the Jetts and Nelsons I am completely ignorant of these engines. I do think I seen a jett fly once and if I remember right it was loud and obnoxious but hauled some major tail. I do remember a guy that flew a small Spitfire model with a YS45 2 stroke on it. I don't know much about those engines and I am not even sure YS makes it any more but it was the fastest thing I ever seen fly. I am not sure but did it have some kind of pump or super charger on it? If his little plane would go as fast and handle it I am sure the 500 could too. If I had a Jett engine I'd give it a go. It would make for great video whether it held up or not wouldn't you think:D?

Later,
Wes

RE: ModelTech Sonic 500, need cg and surface travel info
 

Wes, 2 3/4" will be fine for that plane. I flew one for years, the O.S. AX is a great engine, we use those up here locally for our NCPL 500 class.

Give an APC 10x7 Sport prop a try on that engine. May not give you the best TOP speed, but it will take off like a rocket and accelerate like crazy out of a hard turn.

I ran mine with 3/16" throw on ailerons and a hair more on elevator on Low rates, but bumped each up another 1/16" for landing on high rates.

One of my favorite handling Q500 type planes. More of a fast Sport Plane than a racing plane though.

RE: ModelTech Sonic 500, need cg and surface travel info
 

Hi Daven. I flew that thing today:D I have flown many flights on it with the 40LA but today it was a totally different animal. I was totally unprepared for it when I was taking off. It did torque hard left as soon as the wheels started getting light on the pavement. It was happening and excellerating so fast I knew I wasn't gonna have time to counter it so I just tried keeping the wings level to prevent it from stalling and looping and I fed in up elevator. As I did it went up like a rocket. No need to worrying about stalling on takeoof with it I guess, not moving as fast as it was. I knew right off it needed some trim adjustments so I brought it around backed off the throttle and got myself a safe distance from the ground. I haven't gotten used to the trim switches on my 7C yet, to me they aren't as quick and easy as manual trim levers. But I know it is a better radio than my manual 6 channel. A few clicks up and a few clicks right roll and it felt good. I didn't pay much attention to the rudder on the first flight as I didn't now what the burn rate on the 46 was gonna be. I could only get an 8 oz tank in it when I built it. I done a few laps. Pulled it into a vertical a few times. Made a few high speed diveing passes and made a couple of high low speed approaches to feel out its sink rate with the heavier setup. Good thing I did too. I haven't flown one out of fuel in a long time [8D] First I thought it just went dead from an engine problem as I only had less than 10 minutes in the air with it. But when I got it back on the ground the tank was dry. It made for a decent dead stick landing as I had plenty of altitude which I turned into speed and a good steady decent. Not a floater. Maybe it was too light with the LA in it. It never flew well with it. Today it was like it was on rails, or maybe more like a wire guided missile. I am only on the third tank of fuel through that engine so I was running it way rich and using a 10x6 MA prop to keep the revs down a touch. I think a few more tanks of fuel and an APC prop I'll see how fast it really can go then. I know it goes really fast now and thats with it tuned for break-in running. I wonder just how fast it was going. I only put one flight on it today. Don't think I could have stood it again. My knees where pure shaking. LOL, probably lost a little more of my hair today with that flight:) I'm sure glad to have it back in the air though.

Wes

RE: ModelTech Sonic 500, need cg and surface travel info
 

Hi!
Glad your first flight with the new OS was successful!
Put on a decent prop (MA are one of the worst) like APC or the black Graupner "Cam-prop" and you will see more speed. 10x6, 10x7 might be good for sport flying and 9x6,5, 9x7, 9x8 for speed.
If you want even more speed, get a tuned silencer (magic muffler) from Dave Shadel at Performance Specialties in Nevada.
Worried of destroying a plane??? Planes are supposed to fly and pylon racing is the ultimate thing in this hobby...And I have 4 more of those Tigers...!;)
Here is the one I won the last two races with. I have had it for 3 years now. The model is called "Ryggskott" in Swedish (Lumbago=backpain). It's a kit, made from the original Q-500 model in 1968. Engine is Webra .40 GT and prop is a Graupner 10x6 "Cam-prop". Speed is around 180-190 km/h.

RE: ModelTech Sonic 500, need cg and surface travel info
 

Hey Jan k that is another nice looking plane you have there. I am sure my flying skills aren't good enough for pylon racing but flying a fast plane sure is fun. I'll probably just keep things flying for sport fun now anyway. But who knows what may happen down the road. I'll just keep this one and consider it a first trial and error plane. I got it from a guy at work years ago. I think I paid 20 or 30 bucks for it. It was new in the box and was missing most of the small hardware. I put it together like the plans called to build a sport version. I had to build my own gear wires too. I think they are too weak or something as many times during landinds they will bend aft a little. But anyway it is a fun and fast airplane that I already want to make some improvements too. Yea the MA prop has got to go. I think it unloaded one time in a dive yesterday. It sounded really strange anyway. Kinda like and airborne version of a boat propellor cavitating. Not sure what it did really. But I have an APC handy that will go on there today. You dont think a 9 inch prop is too small for a 46? Anyway gotta go for now.

Wes

RE: ModelTech Sonic 500, need cg and surface travel info
 

A 9" prop would be fine on that engine. 9x7 or 9x8, I've tried them all on that engine and plane and definately like the 10x7 best for overall consistant speed and handling. That motor develops its best power between 14k and 14.5k. We use to bend the gear forward on those planes so that the center of the wheel was at the LE, it made for an easier plane to land. Also, it should float better than what you are saying, my guess is that you can move the C.G. back a hair.

RE: ModelTech Sonic 500, need cg and surface travel info
 

Well Dave I think it will float better than what I let it. I am just afraid to do it. I did let it float through one lap prior to landing it just didn't give any real warning signs of the impending stall. I'd rather keep the speed up and not chance it. I stalled it several times with the LA on it and it would drop whatever wing was on the opposite of the crosswind. It is a tough little airplane. The landing gear do seem tricky. I have to land on a really rough surface so it gets beat up. If it flames out I try to put it into the grass by the edge of the road. It always goes over on its nose if I put it into the grass. I am thinking of maybe moving it back like you say though. I looked at the websites you have linked. Some really good racing stuff posted there. I read your articles too[8D] When I decide to build a real quickie plane I will use that info and incorporate it into my construction. I've been out of r/c for a while and haven't heard of the tetra tanks before. Those are some really nice looking designs. I think they would be great for sport planes as well. Do they come in higher capacities than 6 oz?

RE: ModelTech Sonic 500, need cg and surface travel info
 

Hi!
Tettra tanks are very common in the racing world. There is many other dimensions.
Smallest is a 85cc (3 1/2 oz) and largest 500cc tank.
The China-Clipper tough to fly...?? No no. It's a sweet flying thing;)!
Al these sport Q-500 racers, if set up correctly, are as easy to fly as highwinged trainers and could be flown as slow as these too. Al my Q-500 airplanes could be flown to a nearly stand still in the air without stalling. Of course they are capable to stall but only when I want too, by giving full elevator and aileron (snap-roll).
Have you balanced yours laterally? Perhaps one wing is heavier than the other? I've always had to put a little lead in one wingtip on mine.
Also check final weight. 1800g is what my planes weigh (due to Swedish Q-500 rules) but American Q-500 rules allow even lighter airplanes at 1360g (3 1/2 pounds).
The landing gear on the Sonic 500 is not good, too soft! But bend them forward and landings will be easier.

Regards!
Jan K
Sweden

RE: ModelTech Sonic 500, need cg and surface travel info
 

I think you can slow it down more, these things should be very difficult to stall.

RE: ModelTech Sonic 500, need cg and surface travel info
 

Well to get it to balance with the 46AX I had to add 5oz of weight in the tail and 1/2oz more in the left wing. I know that is a lot of weight but the fuse is really tight and with my pushrods iside the tail boom there was no way to get my battery pack back far enough to do any good. I have an aluminum engine mount up front like the Nexstar uses. Maybe I could do better if I try and find a lighter mount. The plane really flies with authority now though with the AX up front. Flies like it is on rails too. I guess I have just gotten used to landing my planes at a faster speed that feels more responsive and safe when the wind is blowing. I land them in the road by a big corn field in front of my house. Very little traffic during my flight times and my son spots and watches for me. The road is narrow and the wind seems to always be blowing in south Alabama. Only in the dead of summer when it is 100 degrees outside does the wind not blow. Anyway I have to navigate 2 power lines, 3 street signs, potholes and patches in the road. But I am not complaining though. I really have it made compared to folks who have to drive many miles to fly. The nearest club to me is over an hour away. Nearest that I am aware of anyway. I work shift work so I only get to see my wife and son on the weekends. I don't want to drive off and miss them on the weekends. So I grab my son and we head to the road:D Well, he is almost 15 so I don't just grab him up any more! Soon as I get a good feel for flying back I am gonna teach him to fly if he wants. He's gonna be getting a neat toy for Christmas this year and it will kinda let me know pretty quick if he likes r/c hobbies:D But don't tell anyone.

Wes

Hi someone has the sonic or plan or any scheme,in my city try to make a category with this model i am in charge of drawingup plans and build a prototype thanks in advance .
Saludos from Maracaibo Venezuela

Hi Guys,
Cleaning house (plane reduction) and came across a box labeled "sonic 500". It's the remains of my last one including the manual. However I created plans, profile drawings, wing profiles and templates to cut one piece foam wing cores. Never built a replacement, so its destine to the recycle bin. That being said, if I can be of assistance to help out, let me know. Canopy could be cut from a sig canopy and a built up turtle deck.
Got2retire, (actually did now)