RE: AkroMaster CL-20
Man, that wing extension looks like a great idea. Flaps sounds even better. Together would make a really decent airplane.
Posted on: 11/19/2009 10:21 PM by Author "da Rock" in the forum "Control Lines"
http://www.rcuniverse.com/forum/fb.asp?m=9266536

RE: H9 Spitfire Build
The Slimline Pitts muffler does fit inside that cowl with the OS61-OS91s. But all will have the head showing. I've considered retrofitting a replacement cowl on my Spit. I've got a H9 Warhawk that'll get that treatment when it's assembled. The stock muffler, even flat black, is quite a bit more "model stuff" than just a head sticking out.
Posted on: 11/19/2009 7:00 PM by Author "da Rock" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=9266024

RE: H9 Spitfire Build
[quote]ORIGINAL: jim pettis I'm slowly coming to that realization. The only mufflers for the OS 2 strokes seem to exhaust to the side, unless you mount the engine sideways, which I'm pretty sure means the piston head sticking out of the cowl. There is this kit that says you can exhaust your Pitts anywhere... http://www.wholesaletrains.com/Detailair.asp?ID=200403174 but I have no clue how it works with the Pitts muffler, and I'm pretty sure I don't want to buy all the parts only to find it really doesn't work in this set up. Lets face it, I've waded through this post for the 3rd time, and have seen no one really using a 2 stroke in the plane. I'm sure there are people out there that do, but until I can see the finished results, I guess I'm going to have to cough up the extra money, and get me 1st 4 stroke. I know for sure they make a very nice Slimline inverted muffler for the 1.00. At least I hope it fits the ''new'' 1.00 FA-AAC..... Anyone confirm this? [/quote] I'm using an OS91FX with stock muffler in mine. It's awesome with a 3Blade Master Airscrew on it. I studied how to enclose everything in that narrow nose. Studied the problem for almost a year after seeing how good the Corsair and P47 worked with Pitts mufflers. Well, it's a problem of that narrow beak on the bird. There are mufflers made that have the expansion chamber right up against the exhaust outlet. Their pipes stick straight out the top of the chamber. So if you mount the engine straight down, the pipes stick straight down. I passed on that because with that pinched cowl, there wouldn't be any cowl on the left side. I also passed on mounting the engine at 9 o'clock and using a regular pitts for the same reasons everyone has. I've got a 40size Warhawk. P40s have the same problem Spits have. Funny, they both used the same engines at times back then. I also scratch built a bunch of models with narrow noses back in the day and needed to completely enclose as much as possible. It wasn't possible to do better than having the engine's standard muffler sticking out the left side. So I painted the suckers flat black. That's how my Spit flies today. Even when doing low passes right to left, it's doesn't really stand out. It's there, but almost any other solution isn't much better.
Posted on: 11/19/2009 6:50 PM by Author "da Rock" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=9265999

RE: KARBONITE GEARS
That's interesting. So I looked up the list of Hitecs at Tower to see how many larger than standard servos they sell with Karbonite gears. All I could find was the HS-755HB for Giant Scale. They have a bunch of High Performance and Premium Digitals but only two of about 30+ of those have KG and they're both standards. So the HS-755HB is the one Hitec to avoid for bigger models that're going to be flown in the winter. They've got a ton of standards with KG. I've got a bunch (a BUNCH) of models 9lbs and under that get flown all winter. Since moving back south from Minnesnowta, I don't do below zero flying anymore. Heck, we don't get those temps. They do get used under freezing. Never had anything I would call a brittle failure. Fact is, never had anything I'd call a wear problem. So I'm guessing the warning applies to flying Up Nawth mostly.
Posted on: 11/19/2009 6:37 PM by Author "da Rock" in the forum "Questions and Answers"
http://www.rcuniverse.com/forum/fb.asp?m=9265959

RE: AkroMaster CL-20
[quote]ORIGINAL: scott17 Hey, the guy asked a question and needed some info, so I gave him the BEST answer I knew. There are literally volumes of info on this exact subject at those sites and I did not have the time or inclination to write them all here. So what should we do, not give the guy help because it exists on another stunt specific forum so we please you, or should we help the guy out if he needs it? These forums are great and I have gotten and given much info here, but to be honest, the best and most control line flyers frequent those 2 forums and a control line hopeful could learn anything and everything they ever wondered about there. Lets not let politics stand in the way of a guy getting some good info. [/quote] No problem. You did what you had time and inclination to do. And it's a good link. On the other hand, my explaining the situation that existed after you answer was to keep the help coming. And that's what I do, try to pump up the value of this place. It's got nothing to do with politics. It's all about making this place a good one to come for information.
Posted on: 11/19/2009 6:14 PM by Author "da Rock" in the forum "Control Lines"
http://www.rcuniverse.com/forum/fb.asp?m=9265914

RE: Balsa grain direction
It's basically impossible to run grain parallel to 3 different lines. So I assume you're thinking to sheet from the LE back with some, from the TE forward with some and possibly some down the middle. Trust me, it's been done. That extra work might be worthwhile to some, but in fact balsa differs enough that it's really not worth the effort. What is worth the effort is to sort all the sheets by weight and strength. Use the strongest where it'll be down the spar and forward to the LE. Throw out the weakest and find better. If you're sheeting foam, it's not so important. The foam provides the same support that webbing provides spars, only it does the support everywhere.
Posted on: 11/19/2009 7:40 AM by Author "da Rock" in the forum "Questions and Answers"
http://www.rcuniverse.com/forum/fb.asp?m=9264709

RE: Time to make the switch!!
[quote]ORIGINAL: sunnybreeze Contuining with this thread I found a thread on beginner R/C Radio. I now understand the bulk of it including mixing. Can someone tell me what DSM2 means?? [/quote] DSM2 is an enhanced DSM. DSM is based on DSSS. DSSS appears to be: [quote]DSSS systems transmit on a single selected frequency but on a very wide band. Only a small portion of that band is used for specially encoded information. In addition, DSSS offers an increase of processing gain for significant improvements in range. With years of development and testing, the DSSS modulation scheme was optimized for RC car and airplane use, and Spektrum´s DSM 2.4GHz Spread Spectrum Technology was born.[/quote] So it sounds like all those are names that cover a 2.4 protocol that uses a wide band to enhance the security of the signal that uses just a small portion of the band to exchange our command information. Bottom line, it's JR/Spektrum's method of 2.4
Posted on: 11/19/2009 7:26 AM by Author "da Rock" in the forum "RC Gliders, Sailplanes and Slope Soaring"
http://www.rcuniverse.com/forum/fb.asp?m=9264696

RE: AkroMaster CL-20
Gee Scott, with help like that, this forum won't ever need much space, will it. Anybody want to offer help here? Or is RCU wasting their time with this forum?
Posted on: 11/19/2009 7:07 AM by Author "da Rock" in the forum "Control Lines"
http://www.rcuniverse.com/forum/fb.asp?m=9264671

RE: help with non-planing shapes
[quote]ORIGINAL: soarrich [quote]ORIGINAL: da Rock The planform shape of each blade really isn't going to matter much at the terribly low Reynolds numbers they're seeing. There really aren't much ''aerodynamics'' in play there. [/quote] I think there's more than you imagine. 3D foamies are like a fly swimming in molasses, the Reynolds numbers are low
Posted on: 11/18/2009 3:06 PM by Author "da Rock" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=9263152

RE: help with non-planing shapes
to get rid of that is to remove them. [quote] da rock, yes several manufactures have played
Posted on: 11/18/2009 8:56 AM by Author "da Rock" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=9262424

RE: Throttle Servo Setup
[quote]ORIGINAL: Abv0377 How do i go about setting up a throttle servo so that it gives me the ability to set trim for correct idle on my nitro engine? Today I was trying to increase the idle on the engine and noticed I had the trim on the transmitter at max. What is the proper proceedure to set throttle servos on a nitro/gas engine? thanks for your time and help. -ABV [/quote] A really short answer that covers linkages for all functions is that it's always a good idea to adjust the airplane to remove TX trim found during the model's initial flights. Adjust the linkage in the same manner it was adjusted while assembling the model.
Posted on: 11/18/2009 6:55 AM by Author "da Rock" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=9262258

RE: help with non-planing shapes
Think about the actual environment the magic blades are going to be working in. Your arrow may accelerate quickly in an archery frame of reference, but it starts out a zero and is pretty slow while the magic is supposed to be keeping those blades from planing. How long does it take for the fletching to stabilize the shaft, and how much does the shaft flex. The magnitude of the flex is going to be displacing the blades. In fact, they're going to be yawing probably faster than they'll be going in the first feet. Has anyone made blades that "screw around" the point to match the "screwing around" of the fletching? That might be worth an experiment. The blades actually resist the rotation caused by the fletching. They're going to do it more the faster the rotation. So there should be an enhancement downrange no matter what happens immediately at release. What might be beneficial at release would be the new shape of those helical blades offering less resistance to being driven side against the air. They will now offer a curved side instead of a flat one. But just brainstorming.......... and trying to cause some thought a bit off the usual path............. BTW, there might also be an enhanced penetration from them as well. Since lots of hits are through-and-through, the real benefit if there is easier penetration would be from a reduction of blade area. good luck with your quest..........
Posted on: 11/17/2009 10:36 PM by Author "da Rock" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=9261708

RE: help with non-planing shapes
OK, you got a couple of aerodynamic problems. The chord of an arrowhead's blades is very short. And it's speed is very slow. So the Reynold's numbers are small. So small that the blades really aren't working like an airplane wing, even an average size model airplane. Your blades might be working like park flyer wings do. About any planform wing works for them and about any airfoil. I'd suggest the blades that're advertised to be non-planing got that way from cut/try engineering. If they actually do anything at all unique, that is.
Posted on: 11/17/2009 10:19 PM by Author "da Rock" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=9261665

RE: help with non-planing shapes
Would you be so kind as to provide the bowhunting definition of "planing" or "non-planing". It might help those of us who aren't familiar with bow hunting terminology.
Posted on: 11/17/2009 9:07 PM by Author "da Rock" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=9261455

RE: H9 Spitfire Build
[quote]ORIGINAL: k lupold Hey, In your Vid, i see you have the flaps Down on takeoff I will try it! I heard some people use them but I never see anybody! she looks like she jumps right up! in the sky! thanks for the Video ken [/quote] I tried using half-flaps for takeoff and didn't see the value. Mine will come off the ground anytime after it rotates, and it'll rotate too soon as it is. It looks good for those observers that might notice, however. But I've got to keep mine down if the flaps are down.
Posted on: 11/17/2009 1:31 PM by Author "da Rock" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=9260348

RE: Any decent .46 size Biplanes?
Hey Scar, I think someone awhile back said he thought the WM Ultimate30 was actually the Ultimate40 with a new name. It hadn't sold as a 30, and they decided to change the name to suit the market better. I'm not sure he matched up the specifications, but truth is, the WM-U-40 would fly well with a decent 30 on it.
Posted on: 11/17/2009 1:28 PM by Author "da Rock" in the forum "Questions and Answers"
http://www.rcuniverse.com/forum/fb.asp?m=9260338

RE: Larger Revolver
This bigger Revolver really looks like it'll fill a niche. There aren't many tapered wing sport planes that size. It looks like it'd be suitable to learn precision aero and IMAC maneuvers. Especially for those of us who like to do maneuvers but aren't planning to go competitive. It doesn't have the 3D size ailerons that're found on the small IMAC stuff. hhhhhhhmmmmmmmmmmmm I got a spare OS91FX on the shelf. mmmmmm anybody put one in the air yet?
Posted on: 11/17/2009 9:59 AM by Author "da Rock" in the forum "ARF or RTF"
http://www.rcuniverse.com/forum/fb.asp?m=9259931

RE: Any decent .46 size Biplanes?
My WM Ultimate 40 is excellent. It's advertised to take a 46 and that'll most certainly be enough power. It is NOT a docile bird. The SkyBolt is a good choice if you're looking to just bore holes and want them to look like = instead of - but the Ultimate does biplane stuff really good.
Posted on: 11/17/2009 5:44 AM by Author "da Rock" in the forum "Questions and Answers"
http://www.rcuniverse.com/forum/fb.asp?m=9259655

RE: Engine Only Starts UPSIDE-DOWN???
move the tank side mount the engine adjust the low speed needle
Posted on: 11/17/2009 5:38 AM by Author "da Rock" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=9259650

RE: How important is dihedral for a Low Wing?
Actually the original poster asked about dihedral in his subject line. So the question actually is about what dihedral might do to the flight of his bashed model, that happens to be a Stick. He's gotten a bunch of advice that all goes pretty much toward what he's wanting to do. Plus he's getting info about how important dihedral is for a low wing.
Posted on: 11/16/2009 6:17 PM by Author "da Rock" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=9258519

RE: How important is dihedral for a Low Wing?
[quote]ORIGINAL: hugger-4641 Agreed, dihedral works on Tigers, 4stars, Escapades, Caps, whatever. But he's not building one of these, he's building a Stick, I haven't seen any Sticks with dihedral. Doesn't mean some one hasn't done it, but I believe the Stick was designed without dihedral to achieve the flight characteristics you get by not having it. But I agree, if he wants to go thru the trouble of putting some in, it might handle a little better in normal flying. I still don't think it will be a drastic difference, but it would be fun to find out.[;)] [/quote] What a Stick has is dihedral effect. A high wing, even if it's a straight wing, will show dihedral effects simply from having the wing above midwing. So Sticks have "dihedral", like it or not. Placing the wing low without compensation is creating an airplane that does not mimic a Stick. So he's going to create something that isn't a Stick at all.
Posted on: 11/16/2009 2:47 PM by Author "da Rock" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=9258055

RE: How important is dihedral for a Low Wing?
I'm voting with Dick. On a couple of issues. Go ahead and try it. The completed one in the attachments looks really kewl. I wish I'd done the same to mine back when I had it. And the dihedral would be worthwhile. Look at the Tigers and 4stars for how much works. OK, I'm going to vote twice............. Do it! No lie, it'll be unique and unique is good, really good. (we do this for fun, right)
Posted on: 11/16/2009 9:24 AM by Author "da Rock" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=9257352

RE: Hangar 9 60 size corsair arf
[quote]ORIGINAL: skillet92 And guys I do know that this has been over time and time again, but would you tell me where your CG's are set. I have mine at 4 and 3/4 and yes I am doing well but it still seem very pitch sensitive and I do wonder if I am Tail heavy?? [/quote] The safe range is 4.25"-5.5" Yours is decent. By pitch sensitive, if you mean it's got a sensitive elevator, then reduce it's throw.
Posted on: 11/15/2009 10:52 PM by Author "da Rock" in the forum "ARF or RTF"
http://www.rcuniverse.com/forum/fb.asp?m=9256632

RE: Seagull Yak?
Our club raffled off the Yak I built. I discussed the CG with the guy who won it and told him to check this thread to see what others had discovered about the mfg's recommendation. I just now noticed how long it is, so decided to plug in what geistware.com computed for the bird. 5.5" to 6.8" is a safe range to be in for the maiden. If you've not flown a tapered wing model before, no matter where you've got the CG, keep in mind tapered wing birds will drop a wing when pushed no matter what the CG. All the CG does in those situations is determine how much or little elevator throw does the deed. 5.5" is about as far forward as you'd need to go. It can be back as far as 6.8" and still be safe, although you'd expect that to give you very effective elevator. Five and a half would certainly keep the elevator throws from scaring you. Move back to 6.8" and you'll probably need to reduce the elevator throws. With a tapered wing, the max elevator throw is usually reduced from mfg's recommendation for more accurate control. With tapered wings, you very often want to do that no matter where the CG winds up.
Posted on: 11/15/2009 6:58 AM by Author "da Rock" in the forum "ARF or RTF"
http://www.rcuniverse.com/forum/fb.asp?m=9254763

RE: Balance Lanier P47???????
The safest, surest, most dependable way to deal with an unknown CG on a model is: http://www.geistware.com/rcmodeling/cg_super_calc.htm You make 9 measurements of the model, plug them into the application and run it twice, with 5% and 15% static margin. That gives you a reliable CG range for the model in question. It considers the things that're important to pitch stability, like the tail volume. I use it with models that have known manufacturers recommended CGs just to check. Have found a significant number that're wrong, just plain wrong. With today's asian arfs, it's worthwhile to do that, but it also very safely provides a reliable answer when no CG is known.
Posted on: 11/13/2009 6:48 AM by Author "da Rock" in the forum "Questions and Answers"
http://www.rcuniverse.com/forum/fb.asp?m=9250410

RE: Pull Pull servo placement
A question often asked about pull/pull..................... Since both the servo arms and the horns rotate, why would ackerman be needed? As long as the distance from the center of rotation to the connect points for both the servo arms and horns are equal, ackerman isn't needed is the answer usually given.
Posted on: 11/4/2009 8:57 AM by Author "da Rock" in the forum "Questions and Answers"
http://www.rcuniverse.com/forum/fb.asp?m=9227281

RE: LHS Have no stock
[quote]ORIGINAL: gsoav8r My favorite hobby shop and the one that gets the majority of my business is about an hour away so I normally call them and get the goodies sent to my door. The nice thing is that they stock a lot of RC stuff but if they dont have it they can normally get in a few days. Shipping from them to my door is one day if I call before noon-ish. Oh, and theyve always beat the mail order places on things like kits, engines, radios... Cheers. [/quote] Sounds like KC They're also a great place to go hang out. Always have something you didn't think about hanging on the racks.
Posted on: 11/4/2009 5:17 AM by Author "da Rock" in the forum "Questions and Answers"
http://www.rcuniverse.com/forum/fb.asp?m=9227069

RE: Real Flight G5...
[quote]ORIGINAL: cappaj1 [quote]ORIGINAL: da Rock And that $80 is Tower's price, which will wind up actually costing me $65 to include the sucker in my next order. [/quote] How do you manage that? I only have codes for $15 off $100 order? Just wondering if there's a deal I can take advantage of I'm not aware of. Probably ordering with other stuff, right? Thanks. [/quote] Right
Posted on: 11/3/2009 10:23 PM by Author "da Rock" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=9226552

RE: OS46ax
What you've just seen is why you should try more than one prop. Best thing to do with a new airplane is to figure on testing at least 3 props before picking one. Start with what you see at the field on your engine. Get that size and one the next diameter up. It's often worthwhile to get the same dia/pitch but in a different brand, especially if it looks a lot different. Different blade area can do wonders. Different tip shape is worth trying. Say your engine is on a couple of models at your field, one turning an 11x6 and one a 12x5. Look at the planes those engines are on. Figure to try the prop that's on the model most like yours. Say it's the 11x6. When you're getting your 11x6, look at the 12" props and pickup a 12x5 or 12x6. If there aren't any, get a 10x8 or 11x7. Or just get another brand of 11x6. See the plan? Try something, anything, that's close to what looks to be the best match.
Posted on: 11/3/2009 4:06 PM by Author "da Rock" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=9225619

RE: OS46ax
You've just seen your first example of how undependable the propeller identification system is for model propellers. Both a 10x6 and 10x7 turning the same revs, right. In fact the id system is not to blame. Our belief that it's perfect is. The blade area and airfoil have a lot to do with how they work. The id system just suggests what to expect, nothing much better can be counted on.
Posted on: 11/3/2009 3:53 PM by Author "da Rock" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=9225586