RE: Out of trim trainer
Was I too succinct for comprehension?
Posted on: 11/21/2009 12:53 AM by Author "HighPlains" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=9269222

RE: Out of trim trainer
Speed sensitivity vs pitch is a trait of very nose heavy airplanes. Which is how almost all full size private airplanes are setup as well as most RC trainers. While dialing in downthrust will compensate for power changes somewhat during unloaded 1G flight, and changing incidence angles of the wing to tail can eleminate part of this, throttle management is the answer for the beginner. However, [b]to minimize the effect, move the balance of the airplane towards the back of the recommended CG range [/b](on some airplanes, you can even move it behind that). As you move it back, you can also remove some of the incidence. What this does is decrease the pitch response to speed changes. It will also increase the sensitivity of the elevator, make landings easier, and allow more advanced flight manouvers like spins and inverted flight. If you find the airplane still has too much lift and you want to do some interesting experiments. This will get you an idea of how more advanced airplanes with heavier wing loading will fly and land. You can add small spoilers to the top of the airfoil, starting with 3" strips taped about half way out on each wing panel. Out there is best since you avoid tripping the air that the tail flys in and you leave both wing tips flying. Start small, and work your way up to larger sizes.
Posted on: 11/20/2009 12:20 PM by Author "HighPlains" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=9267636

RE: GMS 47 = garbage
The trouble with threads like this is about an equal number of people have success with a product as the ones that don't. In 50 years of being around model stuff, I have yet to see an engine that was total crap, but most often it is the lack of experience of the operator. Some people can't even match socks, yet they expect to operate a device that requires some level of understanding. But let's not let the manufacturers off the hook either. Some of their marketing is a bit over the top, and what they recommend in the instructions can be misleading or less likely to give the best outcome.
Posted on: 11/20/2009 12:03 PM by Author "HighPlains" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=9267611

RE: How to internally clean a glow engine
Not a bad article, covers enough basics. I find that poor idle is often due to varnish. I also find that 50-50 mix of antifreeze and water in crookpot on low for 24 hours removes most of the varnish. Scotch bright works as well as steel wool. After crockpot, rise in cold water, varnish floats away. I use an ultra sonic cleaner with dishwasher soap and water to clean after the crockpot. This really cleans the pores of the metal and especially the bearings. After you are done with the water, place the parts in a warm oven at 250 degrees to drive out all mosture. When you remove parts from the oven (10-15 minutes) lightly oil all steel parts or moving parts. It is really best to use new cir-clips if you remove the wrist pin from the piston. Make sure the clip (the small music wire clip mentioned) is well seated in the groove, with an exacto knife tip pushing it around. If it comes out, the piston and sleeve will be destroyed. Reassemble engine, oil lightly, and go run. After the first run, check the torque of the head bolts, in fact do it for a couple runs. Don't go gorrilla on the bolts, just even torque on each.
Posted on: 11/20/2009 9:54 AM by Author "HighPlains" in the forum "Tips & Techniques"
http://www.rcuniverse.com/forum/fb.asp?m=9267318

RE: GMS 47 = garbage
I believe they are made by Sanye Machinery in Taiwan along with ASP, AP, Magnum, and SC. No doubt there are other house brands sold in other markets.
Posted on: 11/19/2009 7:18 PM by Author "HighPlains" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=9266058

RE: nemesis racer
Here is one, big at 42% http://www.hostetlersplans.com/nemesis.html
Posted on: 11/19/2009 5:55 PM by Author "HighPlains" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=9265875

RE: Sequence of shimming vs nitro
What kind of engine, exhaust and nitro content are you talking about.
Posted on: 11/19/2009 5:51 PM by Author "HighPlains" in the forum "Extreme Speed Prop Planes"
http://www.rcuniverse.com/forum/fb.asp?m=9265862

RE: nemesis racer
Which one do you want to build? Nemesis or the Nemesis NXT? Completely different designs.
Posted on: 11/19/2009 5:04 PM by Author "HighPlains" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=9265741

RE: Rudder area
Leave it as scale. Prop on a RC model is smaller diameter than scale, so it is not as destabilizing.
Posted on: 11/19/2009 4:46 PM by Author "HighPlains" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=9265697

What is hurting pylon
This pretty much sums it up. http://cohort11.americanobserver.net/latoyaegwuekwe/multimediafinal.html
Posted on: 11/19/2009 4:35 PM by Author "HighPlains" in the forum "General Racing Discussion"
http://www.rcuniverse.com/forum/fb.asp?m=9265670

RE: nemesis racer
That is not a picture of the Nemesis NXT.
Posted on: 11/19/2009 4:31 PM by Author "HighPlains" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=9265663

RE: OS 91 VRDF and 10 x 10 prop, Best airframe?
I don't always read these threads, but when I see something that is completely incorrect and spreading misconceptions then I respond: [quote]A 10X10 would require 21500 rpm to get 200mph of the back of the prop that might return 70% to max 80% of that speed say ~140mph to 160MPH and the prop would need more like 5 to 6 bhp to do those RPM(not counting air frame drag factors ) so is only likely to reach these RPM when unloaded in a steep dive and would expect more like 18K on the level and therefore slower speeds A 8X12( if you can get one made) prop at 23100 rpm would return 260mph of the back of the prop which might return ~180 to 200mph but the thrust from this prop would be very low at 200mph and unlikely to overcome the drag from the airframe so 180 would be more likely result except possibly in some down wind dives higher speeds might result[/quote] The poster has confused power tranfer efficiency with prop slipage. The amount of power a prop transfers depends upon a lot of things, but generally it is the 80 to 85% range. The so-call prop slipage is usually in the range of 10-15%, which means the prop is pushing air about 10% faster than the airplane flys. So when you are in the air, and the engine is unloaded, it takes an rpm and pitch for 220 mph to achieve 200. Where the power tranfer efficiency comes into play is figuring out how much faster you can go with more power, ie. bigger engine. It is also useful in figuring out how clean the airframe truly is, and what diving will add to top speed.
Posted on: 11/19/2009 12:53 PM by Author "HighPlains" in the forum "Extreme Speed Prop Planes"
http://www.rcuniverse.com/forum/fb.asp?m=9265262

RE: mini servos in .40 sized plane a no-no?
Well, I have used HS-80's and HS-81 with plastic gears and metal gears in the most intense enviorment possible - a Nelson powered Quickie 500 that flew well above 165 mph. I don't recommend this, because unless you really understand how to install the servos, they won't hold up. But in two different airplanes, I flew both for about 50 heats before each was lost to mid-air collisions. On the first, the wing survived, so I built another fuselage and sport flew it for about 10 more hours with a ST 40 and a Nelson pipe. Nice sport model, only about 140 mph. But I wanted to see how the servos held up. They worked fine but the outputs got real sloppy over time. The HS-85 has a BB output, so it would be much better. As far as vibration getting to the throttle servo, I use a mechanical filter to block the problem. What is the filter? I couple a short piece of 1/16" music wire to the throttle cable with a wheel collar. The mass of the wheel collar does the filtering function.
Posted on: 11/18/2009 5:17 PM by Author "HighPlains" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=9263490

RE: mini servos in .40 sized plane a no-no?
I would avoid the HS-81 servo in control surface applications. The reason is that they have no bearing on the output shaft, and will develop considerable slop after about 10 hours of use.
Posted on: 11/18/2009 10:29 AM by Author "HighPlains" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=9262594

RE: Planes with Props
The main thing for take-off of any airplane is that the controls are constantly used to make corrections as the take-off progress. The most demanding on the pilot are tail-draggers, though having the model properly set-up with regard to engine thrust line, main gear location (depending somewhat on type of runway - grass or pavement) and angle of attack make a big difference in difficulty. When first starting the take-off roll, more or less into the wind, you hold up elevator and right rudder as required to maintain directional control. As the model begins to roll, back pressure on the elevator is relaxed as the model picks up speed, all the while using the rudder as required. The goal is to get the tail of the airplane in the air (it's flying while the airplane is still on the ground). At this point, much of the rudder required initially has been relaxed, and the airplane steers on the ground about the same as if it had a nose wheel. Allow the airplane to continue to build speed until it achieves flight speed. Often, the model will just lift off, but you can also use a slight amount of elevator to increase the angle of attack on the wing and it will lift off. Making the take-off more difficult are cross winds, wind that does not align with the runway. This can cause problems through all phases of the take-off, since the model may want to weathervane into the wind, even to the point where you may even be using left rudder to hold the model on the correct heading. But be aware, the torque from the engine is very powerful, especially with larger low pitch props. So you can not freeze on the rudder, it takes a soft touch and constant adjustment. As far as use of the ailerons into the wind, you start off with full aileron at the beginning of the roll, but by the time you have reached flying speed, nearly all the aileron control input has been removed since the ailerons have much more effect as the speed builds. Master all these control inputs, by doing lots of take-offs in various conditions. But with some work at this, you will be amazed by your growing expertise, and will be ready for any model you want to fly.
Posted on: 11/18/2009 2:04 AM by Author "HighPlains" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=9262082

RE: .40 SIZED FLYING WING
[quote]Typically anything that departs for a circular or elliptical shape is not real good for airflow.[/quote] NACA ducts may void that observation. [quote]having the fin meltdown during a run would suck[/quote] The expansion of the gas cools it. ? is, does it expand enough 2B cool? I'm not sold on having an internal pipe*. What is the current thinking in CL speed? * Reason being the increase in surface area with airflow over the pipe and the inside and outside of the pipe cover being a lot of drag. Unless you restrict the airflow a lot.
Posted on: 11/17/2009 6:44 PM by Author "HighPlains" in the forum "Extreme Speed Prop Planes"
http://www.rcuniverse.com/forum/fb.asp?m=9261060

RE: How important is dihedral for a Low Wing?
[quote]The net effect was a visibly even roll rate [/quote] I'm not worthy. You are a tricky old Bast........ Thank god you chose pattern instead of pylon.
Posted on: 11/17/2009 10:40 AM by Author "HighPlains" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=9260022

RE: How important is dihedral for a Low Wing?
What I want to know is how many wings has Dick cut in half to correct the dihedral over the years? Or do you just build another and make the twick then? Myself, I discovered this phenomena about 30 years ago when I built a low wing stik for a wing that I had hanging around after a little stik was destroyed in a crash. The wing was originally for an Ace Super Pacer (low wing design) which I built without dihedral. But one day half way through the build, I realised that the wing fit perfectly on a Das Liddle Stik fuselage. I never finished the Super Pacer, and flew the Stik for a long time (as a poor college student). But after a very long time, the aileron servo quit while inverted at about 5 feet and the plane crashed. At home that summer, the low wing replacement stik was built. And although all the moments and incidences were maintained, it was a terrible plane to fly due to the adverse roll with rudder. It was a rookie, novice mistake I made then. And it took me a long time to find out why, since the net was long in the future. But over the years, I read a lot of articles in model magazines and slowly gleaned what the caused the unusual flight characteristics. BTW, it should have been more apparent, since the old Class II pattern airplanes that flew without ailerons behave the same way...when flying inverted. Since 90% (maybe 95%) of RC'ers have never heard of Class II, they were airplanes that flew with rudder, elevator, and throttle control only. Other than knife edge, they can fly almost all manouvers. But when flown inverted, left rudder still makes the airplane turn left, when looking at it you might think it should go right. Still, can you tell us number of wing sawed in half? The question for Hacksaw Hansen. Has a ring to it.[;)]
Posted on: 11/17/2009 10:32 AM by Author "HighPlains" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=9259998

RE: Long, but good reading:
Very interesting read. I think you could make the case for Don Mathis as the underlying genius behind much of the 60's era digital equipment. If I'm not mistaken, he also designed the W.S. Dean reed radio, the Digicon, Kraft (PCS, Heathkit), Micro-Avionics (Orbit), as well as the stuff he did while on the RCM staff. While not the only one doing early systems, his airborne units had 4 cell packs when most of the others were using 7 cells.
Posted on: 11/16/2009 6:39 PM by Author "HighPlains" in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=9258567

RE: .40 SIZED FLYING WING
Also noticed that the photo shows the covers and the reflection of the covers (bare AL), so the cover is half as big as it looks at first glance.
Posted on: 11/16/2009 3:53 PM by Author "HighPlains" in the forum "Extreme Speed Prop Planes"
http://www.rcuniverse.com/forum/fb.asp?m=9258190

RE: .40 SIZED FLYING WING
Most RV-4's are redlined to 210 mph. However Harmon took the basic design, put in an engine with 50% more displacement and called it the Harmon Rocket - good for about 230 mph. Van was not an outright supporter, though he did sell the majorty of the components for it. Along came Dave Anders. He took a basicly stock RV-4 and made very minor changes (basicly added a turtledeck to replace the bubble canopy. He built it as light as possible, lost a bunch of weight (helped the climb for CAFE scoring), and spent most of his effort around the engine. In light planes, a large portion of the total drag is from cooling the engine. Most light plane engine installations are about as bad as it gets in terms of drag. Big openings in the front, poor air management inside the cowl, and a few square corners to let the air out. Anyway, it can be as much as 15 to 20% of the total airplane drag. On top of that, he did the normal hotrodding things to the engine - higher compression, running at higher rpm than the standard 2700 for the Lycon 360, and special prop. Anyway, it was estimated to be pulling 225 to 230 hp instead of the standard 180 or 200 (depending on carb or fuel injection). Still, he should have been pretty slow compared to a Harmon Rocket with 270 to 300 HP. So with all the things he did, he ended up with a top speed of just over 250 mph. So he did a bunch of things right.
Posted on: 11/16/2009 3:48 PM by Author "HighPlains" in the forum "Extreme Speed Prop Planes"
http://www.rcuniverse.com/forum/fb.asp?m=9258181

RE: .40 SIZED FLYING WING
The covers on the RV-4 wing cover over the pivot points of the aileron hinges. So the front half is affixed to the wing, and the back half to the aileron surface. When the aileron moves the back half is moving inside the front half, with enough overlap that it is always covered at extreme movement of the surface. The photo on the right is the tailwheel assembly he used during his speed attempts. About the size of a roller skate wheel. The taper rod to the wheel is fairly aerodynamic due to its tilt relative to the air (gives an elliptical cross-section).
Posted on: 11/16/2009 3:04 PM by Author "HighPlains" in the forum "Extreme Speed Prop Planes"
http://www.rcuniverse.com/forum/fb.asp?m=9258088

RE: How important is dihedral for a Low Wing?
Sorry Jerry, but you don't understand the relationship of wing position with respect to the fuselage, vertical stabilizer and wing dihedral. When you flip the fuselage over and mount the wing on the bottom, then it is no longer an Ugly Stik. Perhaps you should do a few experiments and report back your findings. But instead of telling us what you don't know, perhaps you should listen to people that do know what they are talking about.
Posted on: 11/16/2009 2:41 PM by Author "HighPlains" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=9258033

RE: How important is dihedral for a Low Wing?
Nothing says novice more than the thought that dihedral is not an important design consideration. For very advanced aircraft with no roll coupling from rudder input, it's getting the proper amount of dihedral that does this. As Dick pointed out, putting the wing on the bottom without any dihedral to compensate for the wing position will make for a very poor flying airplane with adverse roll coupling. Right rudder will make the airplane roll left. A modest amount of dihedral would make it neutral, and more would make it roll to the right with right rudder. The first case makes for a terrible flight feel, the second case is what most strive for, and the third is closer to gentle sport types.
Posted on: 11/16/2009 11:40 AM by Author "HighPlains" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=9257629

RE: Rant about getting started
And the engine, radio, fuel, props...
Posted on: 11/16/2009 10:21 AM by Author "HighPlains" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=9257471

RE: Rant about getting started
I'd put the Devil himself on the box if he'd mow my yard.
Posted on: 11/16/2009 10:17 AM by Author "HighPlains" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=9257461

RE: .40 SIZED FLYING WING
You need "Canoe" covers. http://cafefoundation.org/v2/pdf_cafe_apr/RV-4.pdf 2nd page photo bottom of page. Good article on a fast homebuilt.
Posted on: 11/16/2009 1:59 AM by Author "HighPlains" in the forum "Extreme Speed Prop Planes"
http://www.rcuniverse.com/forum/fb.asp?m=9256954

RE: The Snaker
[quote]I wonder if "Fast Richard" is still around. I haven't seen much of him for several years.[/quote] He had a Free Fright design in MA back in Sept 2006
Posted on: 11/16/2009 1:21 AM by Author "HighPlains" in the forum "Q-500 Racing"
http://www.rcuniverse.com/forum/fb.asp?m=9256910

RE: .40 SIZED FLYING WING
18.87 gee's at the bottom of a knife edge loop! I don't think so.
Posted on: 11/15/2009 12:37 PM by Author "HighPlains" in the forum "Extreme Speed Prop Planes"
http://www.rcuniverse.com/forum/fb.asp?m=9255263

RE: question about going from 4 chan to 3?
If your transmitter will do it, I recommend mixing the rudder channel with the aileron channel. The reason is that you are used to using the rudder stick while on the ground for steering.
Posted on: 11/15/2009 10:07 AM by Author "HighPlains" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=9255003