RE: Buil a mini F3A / practice machine. Need input from scratch builders.
Here are more detailed pics.
Posted on: 10/29/2009 7:09 PM by Author "dolanosa" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=9213327

RE: Buil a mini F3A / practice machine. Need input from scratch builders.
So here's the first of the second set of pics. In this one, I have cut the fuse lengthwise and made some formers. These are actually the formers I used to create the fuse in the firset place. It starts at the firewall and goes to the tail. You should be able to see the canopy section as well as the doubler that runs from the firewall to the wing trailing edge. There are more formers than needed so please tell me what I need to delete. I friend of mine says to take out the three that are in front of the vertical stab which is what I'm planning to do. As far as the verticaln stab is concerned, I will change the leading edge of the rudder to be correct and have a bevel. I will also add some wood to go around the horizontal stab. Of course, if the vertical stab will be made from foam, I can change that as easily enough I think. Speaking of foam, I can just take out most of the top formers and make templates for a foam-based top. In which case, I might as well do the bottom formers in foam as well. I'll upload more detailed pics in a few minutes. Thanks for the help.
Posted on: 10/29/2009 6:52 PM by Author "dolanosa" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=9213275

RE: Scratch Builidng a Plane
Brad, Go to some of the websites that have free plans...there's a sticky on this forum. Look at their layouts, materials used, where all the parts are supposed to be and go with it. Even better, build a kit or two to appreciate the complexity, or lack thereof, of building a plane. Also, I don't know whether or not you have access to CAD software but I'm assuming no. In this case, you can go the old fashioned way by enlarging a tree-view drawing it to the size you want by using a projector. Once you do that, you can easily trace over the plane and make your plane from that. When it comes to fiberglassing, that's a completely different animal and you will need different materials and tools. When you see planes made in fiberglass in Youtube or somewhere, they're not showing you 90%...this includes the materials, measuring and pre cutting, and finally the years of accumulated knowledge these guys have. The best thing for you to do is to find your local RC club and see if anyone of them builds from kits or from scratch. They're getting harder to find. It's even harder to find someone who is very good at making molds and laying up fiberglass. Learn from them everything they know and you'll have a leg up on this obsession.
Posted on: 10/25/2009 5:46 PM by Author "dolanosa" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=9201233

RE: Buil a mini F3A / practice machine. Need input from scratch builders.
Bruce and CP. I can't wait to get back to the workstation to keep at this model. The way I was thinking about this since it's getting colder in Chicago was to follow the construction techniques of several of the 2M planes like the Black Magic series or my old Typhoon 2000. It's basically a box with the top and bottom shape either built up or a foam shell. The main box will have a doubler up to the wing's trailing edge, traditional construction so far. If I do the foam top and bottom, I may just make the wings foam as well. That may not lower the weight but at least it will be done relatively quickly. As for the design of the model, I have moved the wing about 3/4" up and will most likely create a "false" dihedral by making a flat top and a dihedral bottom, kinda like the Ultra Sports series. Also, I'm really thinking about adding an anhedral to the horizontal stab. (Maybe that will also help with the low wing or maybe because I think anhedrals just look especially cool.) As for the nose being short, I followed the very simple 1/3 rule for building the plane. The CG is 1/3 distance from the tip of the nose and 2/3 distance between the horizontal stab MAC. Actually, the distance between the CG and the stab MAC is a little longer to have more moment. I wanted to keep the nose moment short enough so there is "less" torque acting on the plane but still within reasonable limits. It also looks short because the canopy is closer than the wing. Back to construction. I do have a lot of 2.7oz glass cloth since I making some molded parts a while back. If I use that as the outside skin, do you guys think that I will still need reinforcement inside the fuse around the less stressed areas of the fuse? Maybe an outside skin and internal reinforcement around the high stress areas such as the firewall or and the landing gear? I do like the idea of just painting the model and not applying covering unless necessary. I don't have any covering material and they can get expensive...plus I'm not really great at applying them. I also have some CF that I can use for the LG plate and will be making a CF-1/8"ply-CF sandwich for the firewall as well. Anyway, this winter will be very busy for me with these planes since I'm planning to build three pattern planes to compete in sportsman next year. I will have this plane as a winter practice plane and two primary planes, a Silent ST that I never finished building and a Hydeout, (if that's the name of the 120 sized plane. If not, it's the Hydeaway.) I still need to buy decent servos, rebuild the YS 120 for the SIlent, get an OS 160 for the Hydeout, make some Hyde mounts, etc. It's gonna be a lot of time spent in the basement during midnight hours, but I really hope to compete in some local events. I just hope I get some good deals at some swap meets and such. I will also need to get another vacuum pump as my old one finally bit the dust. Thanks for your input, guys. I really appreciate this little round table. Butch
Posted on: 10/25/2009 5:29 PM by Author "dolanosa" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=9201201

RE: Buil a mini F3A / practice machine. Need input from scratch builders.
Well put, combatpigg. I will go with tried and true techniques and think you're right about the latest techniques. I was pricing some wood and the waste after all the cutting and the lightening holes will be quite a lot. Maybe once the plane is flight tested and found to be true, I can invest more into making a lighter aircraft. Right now, I'm thinking 1/8" sheet sides with 1/4" triangle sticks for the main box with 1/8" sheets for the formers. That sounds about right.
Posted on: 10/24/2009 3:59 PM by Author "dolanosa" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=9198797

RE: Buil a mini F3A / practice machine. Need input from scratch builders.
combatpigg, Interesting...I'll take a look at a couple of my Q500 planes lurking around the basement. That kind of construction is very easy. I will just have to add the top and bottom formers to make the other shapes. I'm out of town at the moment and I should be back next week to work on the design again. I was already doing something like that with a doubler from the firewall to the wing TE. I'll upload a pic once I get back. Thanks. Butch
Posted on: 10/23/2009 10:32 PM by Author "dolanosa" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=9197361

RE: Buil a mini F3A / practice machine. Need input from scratch builders.
Here is the basic plane. It's a solid so I can cut it up to make the parts.
Posted on: 10/23/2009 6:58 PM by Author "dolanosa" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=9196904

RE: Buil a mini F3A / practice machine. Need input from scratch builders.
ok, I have the initial drawings. I don't see upload image at all.
Posted on: 10/14/2009 2:43 AM by Author "dolanosa" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=9171857

RE: FREE Laser Cutting!!! Yes FREE!!!
Mate, Once I have finished the plans for the little F3A plane I'm making, I'll send you the DXF. You then will have to be the lab rat to try it out. It will be a 40 sized pattern plane. Right now I'm trying to get help from other RCU members on the best way to build this. Once a consensus comes in, the plan will be sent to you. Cheers! Butch
Posted on: 10/13/2009 5:12 PM by Author "dolanosa" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=9170439

Buil a mini F3A / practice machine. Need input from scratch builders.
Hello everyone, As winter is coming upon us early this year (Chicago is freezing right now), I'm thinking of building my own Mini F3A pattern plane to build along with my full on pattern aircraft. I have scratch built airplanes a long time ago and I'm planning to get back into the hobby. There are several planes out there right noe that meet the criteria for mini-F3A but I want to build my own for several reasons. I currently have the plane in 3D CAD format, the way I want it to look as well as the technical, aerodynamic aspects. Unfortunately, the end product actually looks like a smaller version of the new F3A designs out there, wide body, deep fuselage, thick trailing edges, etc. I'll post some pictures later as I go. So let's say the actual fuse, wings, stabs, etc are all planned out. I want to build it out of wood as light as possible and possibly getting the second "kit" laser cut once the first one is flight tested and deemed neutral in all aspects of flight. Here is my dilema and I have to balance weight, strength (not meant to survive a crash but able to withstand snaps), and budget. As you guys well know, there are several ways to make built up planes. There is the 'normal' pattern plane method of building a box and gluing formers where needed, then sheeting the plane with 1/16" balsa. I have built planes this way before and it has served me. I believe this is an evolution to the old pattern 'slab' method where 1/4" slabs of balsa were used to make the sides and carved blocks to make the irregular shapes such as the nose or the leading edges of the vertical stab. There is also the tried and true stringer and former (bulkhead) method that is an older technique but make make for a heavier plane. I think that this may be cheaper too since I don't have to buy a ton of thin balsa sheets but thicker sheets that I can make stringers. Now, as you guys also know, with the advent of 3D (flying) design, many things have changed. I have seen several models that have a very open box structure without sheeting. I was looking at my buddy's 40% and it was very open barely any sheeting except to make the upper deck shape. Other than that and the part in front of the cockpit, no sheeting. I have also seen examples of this in the smaller 3D aircraft. This looks promising as it will help by having less weight, I guess. Ok. This is where you guys can help me a lot as many of you are avid builders. What are the pros and cons for each design? Please note that this plane will not be designed for 3D or very high G maneuvers like blenders and such. It's meant to perform its best in pattern maneuvers so lighter will be better and will help in downline maneuvers as well. I want to keep the weight as light as possible to maximize the available engine power. I also want to embrace the latest building techniques to advance my knowledge. Most of all, I want to save money since that's the resource that's very limited right now. What about built up wing vs foam with balsa sheet? What about a 1 or 2 piece wing? Here are some design specs: Screen shots by tonight. Motor to use: Non-piped Rossi 40 Span: 56" Length: 58" Width: 4 - 4.5" Total height: 12" (canopy height is around 8") Weight: As low as I can get. Thank you very much for your help. I really appreciate this. butch
Posted on: 10/13/2009 3:24 PM by Author "dolanosa" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=9170163

RE: Looking for a DXF of Desperado 60
Sent you a PM
Posted on: 9/26/2009 2:06 PM by Author "dolanosa" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=9125528

RE: ID please
Yep, that is an exhaust outlet, kinda like one of the Kaos planes. I think there were a few of that design a whlie back. I miss that plane though. I think I had a Rossi 60 F.I.R.E. on it. I remember it was kind of heavy but the paint was very thick and I believe it had clearcoat so when you get a crack on it, it would spider out. It also needs retracts and was very fast, just like it's supposed to be.
Posted on: 9/21/2009 5:55 PM by Author "dolanosa" in the forum "Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=9113149

RE: ID please
I used to have one of those which I got from a trade. I forgot the name...something like starhawk or some sort. I think it had the name inside the fuse where the serial or model number is located.
Posted on: 9/16/2009 8:58 PM by Author "dolanosa" in the forum "Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=9101731

RE: Bending fuselage in catia assembly
Ben, I'm not an expert on Catia by any means but I used it a very long time ago, almost in another life. Is it possible for you to go back to the original 3D part and make the braces that will make the shape of the aft of the fuse? You can most probably just use transform or join the vertices. I don't think you need to go hard core FEA on this part since that's just going to measure stress using certain params. Did you use extrude on the geometry? You should be able to add more control points, or resolution. You can use that to join the different parts. Another thing you may be able to do is to create a 3D spline that is "pre-bent" in 3D space. I think you should be able to extrude that in normal so it follows the curve correctly. PM me since I may have some tutorials that I found when reading about how much this and other applications changed. I was using Acad 3 or 4 all the way to 10 and I just downloaded the trial from Autodesk....I can't even begin to find out how to do this anymore. What happened to the command lines?!?
Posted on: 8/18/2009 9:49 PM by Author "dolanosa" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=9026867

RE: Looking for a cad guy for hire
Stealth AssassinSeems that you don't need any 3D work. From the original post, you just needed 2D CAD files to laser cut. In that case, I don't understand why it's so difficult about it? ...or am I completely missing the point? This should not be difficult at all if the prelim. drawing is complete with all the dimensions. Or did you want a 3D model that can be used to make a mold? What I mean is a 3D surface so you can put it on a CNC machine to shape out the master so you can make a mold. This will require different skills altogether. I used to do CAD/CAM as a mold maker in Michigan and received 2D files from clients all the time. Making 3D parts and a mold (plastic injection) is so different from the original parts since there are many more variables required such as plastic shrinkage, where the injectors will be, vents, coolant lines, etc. Then, when I started doing this as my own business, you have to have post-processors for each type of controller, Fanuc, Bridgeport, etc. Then the test run to make sure that the machine doesn't crash, cutting out the prototype, you get the drift.So basically, did you want 2D drawings of the parts or 3D surface drawings. And did you want them with tool paths for the laser and/or router? What is the timeframe to get this done? How much time do you think it will take for a competent CAD guy to finish this? (how long do you think you can finish the CAD drawing?) Have you looked at the commercial CAD guys out there? I know they're expensive but that's their job so they do that all day and are very good but every change you make is billed. Most of the guys who do CAD here don't do this for a living with some exceptions. I've been out of the business for a while now but I still do some CAD work now and again although the software is not as expensive (free) and they are rather antiquated (the free version of ProgeCAD 2000) but that does most of what I need. I used to work on ProEngineer, AutoCAD, CADKEY, CATIA, and EZ-CAM. THer are guys here that probably buy(?) their high-priced software but that's definitely not needed. I'm starting to get back into it since I'm building a CNC router. This will help in making some planes that's been sitting around in my head and notebooks. Let me know exactly what you need and let's see what we can do. If it's just 2D work, it should be relatively easy.
Posted on: 6/30/2009 9:57 AM by Author "dolanosa" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=8894324

RE: engine and servo 3-views
pm me. I have some in dxf files.
Posted on: 6/30/2009 9:14 AM by Author "dolanosa" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=8894217

RE: OS 50 SX fuel problem. Please help.
I will disassemble the needle valve assembly and seal it again. I just can't believe that I've had this motor for years and I haven't been able to break it in. Will let you know the outcome by this week. Thank you. Butch
Posted on: 6/29/2009 12:12 AM by Author "dolanosa" in the forum "O.S. Engines Support"
http://www.rcuniverse.com/forum/fb.asp?m=8889657

OS 50 SX fuel problem. Please help.
Hello there. I have been flying for many years but stopped a while back. The last motor I bought was the 50 SX which has always given me problems. All my other OS motors do not have the separate high speed needle and they work flawlessly. This one always goes lean and quits. The problem it seems is that there are air bubbles coming from the needle valve nipple where I can see it go through the fuel line to the carb. The symptoms do not seem to go away. These are the things I have done to try to alleviate the problem. By the way, the engine was broken in as well as it could. I was breaking it in when I noticed the problem and even after all of this, it still runs lean. 1. Replace the fuel tubing between the needle valve and the carb. That didn't work. 2. Checked that the fuel tank was not producing too much vacuum since the motor seems to drink more fuel than the tank can supply. For this I checked the lines and the metal tubing in the tank. They were clean. 3. Replaced the tank metal tubing and fuel lines with larger sizes. Still did not work. 4. Disassembled the motor and checked for cleanliness and dirt particles. I used the antifreeze method (without the rubber parts)to get rid of the carbon buildup and used an ultrasonic cleaner to make sure the engine was completely clean. Nothing. 5. Replaced all the gaskets on the motor as well as the gaskets on the entire needle valve holder assembly. 6. Replaced all the O rings. 7. Tried the old trick of putting a fuel filter between the needle and the carb. Also tried putting it right before the fuel inlet. It seems that the nipple angle is wrong and the fuel line will not fit properly, thus introducing air into the fuel line at high vacuum levels (full throttle). I have gone as far as opening the needle valve until it almost falls out and that doesn't work as well. PLEASE HELP! I really want to go flying this year with this motor. Thank you. Butch P.S. There the fuel does not have any issues with vibration so there are no bubbles coming out of the tank.
Posted on: 6/23/2009 10:18 PM by Author "dolanosa" in the forum "O.S. Engines Support"
http://www.rcuniverse.com/forum/fb.asp?m=8875610

RE: Pen Plotters
I [i]currently[/i] use a Houston Instruments DMP 162 plotter and I love it. Wouldn't trade it for the world.. The only thing that it won't print is and raster images and yes, that includes some parts of PDF files. My pens are loaded up so outlines and important lines are 0.5mm, center lines, hidden lines, etc are .35mm (different colors) text is .25. I have used the Ricoh, Summa as well as the HP-GL/2 drivers. Each have their quirks but you get used to it.
Posted on: 5/1/2009 10:46 PM by Author "dolanosa" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=8733187

RE: The end for LIPO's
*lol*
Posted on: 4/1/2009 9:12 AM by Author "dolanosa" in the forum "Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=8637893

RE: Fat or Skinny wings?
Still too many variables. How high do you want to fly? Must have the right airfoil. Duration? How long do you want to stay up at what power settings? Airspeed envelope? Landing speed, cruising speed that you want. Total estimated weight? How much do you want to lift with the wings? Rocket to be used? If you don't want to make your own motors, you can at least maximize your fuel burn here. etc...etc. By the way. is there a reason you're using a wedge shape? I assume that you want to go pretty fast with the rockets but the shape will probably slow you down. For cool factor, I pick #3
Posted on: 3/5/2009 6:11 PM by Author "dolanosa" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=8547555

RE: CAD drawn plans, how long?
Just finished "designing" a stick. True, it's an easy design based on a proven plane but I made some fundamental changes sich as a stick-built side instead of slabs, etc. It took about 40 hours om the computer since I was also making new groups and assembly drawings.
Posted on: 2/20/2009 7:14 PM by Author "dolanosa" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=8499469

RE: Loaded Question: Why is it that rc pilots ignore flight physics?
Here's a simple one, basically using the original poster and many other people who decide to learn by themselves for one reason or another. Let's say some guy decides that rc airplanes are fun and he should give it a try. $500 dollars later, he has the plane, radio, and starting equipment. All he knows at this point is how the control surfaces should move is the sticks are pushed or pulled which is basically all they give you in kit or ARF building manuals. After reading the engine manual, he finally is able to start the engine reliably. Butterflies in stomach, he throttles up...and the plane noses over...several times. He finally gets the plane to go straight and pulls on the elevator. The plane goes up nearly vertical. In a panic, he puts the engine to idle. You can guess what happens. If he knew just a little bit, like stalls, and MCA, he would be fighting the plane correctly. Here's another one for the same people who are building their airplanes...large hinge gaps. You see them at least several times a summer. They decide that it's ok as long as the control surface moves and nothing happened the last 10 times they flew their airplanes. They take off, decide to do a high speed run. You hear a buzz and the plane re-kitss itself in midair sans the box it came in. A little knowledge on airflow would make him at least close that gap. And another...beginners who don't understand CG placement will blame the plane for erratic behavior resulting in a crash, "I think it was my batteries died when the plane went vertical." Another...non-beginners but semi-noobs with fighter planes suddenly see their planes drop a wing when coming in for a landing. "I grease in my trainer all the time, what happened?" A little knowledge on wing loading. Another...powered airplane pilots trying to land a high performance glider. The glider stays at 1 foot above the runway...never landing until it crunches tall grass or something harder at the end of the field. Ground effect, anyone? You also get the guy who already knows how to fly and loves to firewall his engine. His planes hold up, thankfully but he doesn't know why his planes' tails move from side to side. He thinks it's a servo but no. He can't fix it so he just says jokingly that his plane is wagging its tail to make it go faster. What could it be, hmmmm? You also get the guys who is trying their hand in extreme aerobatics. They have their own signature crazy tumble that they practiced over and over to perfection during the fall and the spring. Summer rolls around and it's hot and humid. All his fair-weather friends want to see him do this incredible maneuver but he can't seem to do it for the life of him? Hasty retreat to the shade, tail between his legs. What happened? One more...the designer. We all know one of these lads. These are the guys that never seem to get a break when they design their own airplane. They come to the field with 5 or 7 new airplane designs and one after another, they fly like they hate the air. Some crash, tearing HS-55 servo gears and bending expensive LiPo batteries, sending sheets of tattered blue foam all over the field. Notice that the planes they made that are copies of successful designs actually fly a little better that their own creations? They need to at least understand basic design principles. These examples are all real and if you've been doing this for a while, you see this pattern every summer. It's easy to say that they need a tutor to help them fly. What if they don't have one or can't afford another $200 for a video game? This is where learning just the basics of the physics of flight will help immensely after shelling out half a thousand dollars of hard-earned money.
Posted on: 2/16/2009 2:58 PM by Author "dolanosa" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=8483206

RE: Loaded Question: Why is it that rc pilots ignore flight physics?
Even though I know HOW and WHY planes fly, I still crash. Knowing the physics behind flight dynamics does not make one a better pilot. BUT, it does give you a different insight as to why you crashed. Most importantly, it gives you an insight if you are building something new. I'm not talking about a kit, or from plans. I'm talking about things that have not been tried before. For example, a tailless aircraft. If you haven't seen a B2 or some of the new RCAS, how would you control it? How about a VERY small airplane, or an ornithopter. THIS is why people learn flight dynamics. "Designing" and building your own plane, following known criteria is not designing anything new. It's just another plane like the rest of them. Learning the physics of flight will help you if you are delving into the unknown. Now, if you're learning to fly, that's a little bit of a different story. I half-agree with Dick about theory means nothing when teaching someone to fly. Dick goes by the tried and true method of having so much experience, he's probably forgotten more that I know. Our models are severely overpowered so as long as the throttle stick is somewhere above high idle, the engine is pulling with authority . Flight theories play a role when the ENVIRONMENT starts taking over. Fly just above stall speed for a while, if you don't know at least some of the HOW airplanes fly, you won't know WHY your airplane is behaving the way it is. The brain is a most amazing thing. You see people pushing sticks around, making planes dance on command. They may not know how airplanes fly but how did they get there? Two big parts are experience, (muscle memory) and eye-hand coordination. The third part is subconscious when the mind is doing thousands of calculation per second looking at the plane angles, velocity, etc. Aero-engineers make these subconscious calculations into something visual on the chalkboard and these formulas and others make up the theories behind the physics of flight. Knowing this, they "why" of flight becomes difficult to answer because of the number of variables involved within that snapshot of time. There are generalizations that are accepted. A plane stalls because it loses lift abruptly in both slow and high speeds, leaving you with a re-kitted airplane. Sure, people will tell you your plane stalled. How do they know this? Oh yeah, you don't need to know any flight theory. The plane stalled because it wants to.
Posted on: 2/10/2009 12:43 AM by Author "dolanosa" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=8459873

RE: Loaded Question: Why is it that rc pilots ignore flight physics?
[quote]ORIGINAL: apwachholz Having been involved in radio control airplanes for a relatively short period of time (as compared to most), one of the most common oversights I've seen when learning (or for that matter teaching someone) how to fly is understanding physics of flight. Now I'm not talking super details such as load, wing chords, thrust lines, etc. What I'm talking about are the [b]basics[/b] of flight, like how an aircraft even stays in the air (lift) or what it takes to avoid, or for that matter recover from, a stall. When I ventured into rc I did what most do and learned by trial and error. However, after having gone through my paces I began to investigate and found two major gaps in the learning process presented to anyone new: 1) lack of explaining why you should know these physics, and 2) lack of this information (geared towards rc'ers) existing in general. Am I missing something here? Shouldn't understanding how a plane flies and how you should fly it (aside from the control sticks) be the most important bit of information presented to a beginner (or for that matter an experienced pilot) from the start? To me it's similar to learning how to drive a car...if you just jump right in and press the gas - odds are not in your favor you or your car will survive your first experience. Just curious to see what others have to say...[/font] [/quote] Hmmm...who taught you? I have to agree that there should be a BASIC understanding as to how planes fly...or why they behave the way they do. Maybe your instructor (1) Thought that you already know the basics of flight or (2)didn't care. Then again, you said that you learned through trial and error...implying that you are learning by yourself which is not a good idea in the first place. Just my $.02
Posted on: 2/9/2009 9:13 PM by Author "dolanosa" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=8458951

RE: wood used in ARFs
Obechi?
Posted on: 2/5/2009 9:52 PM by Author "dolanosa" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=8443506

RE: autoCAD 2009
[quote]ORIGINAL: Lafayette Well, I am currently evaluatingturboCAD pro 15. And I have to say, that it dominates my interest. AutoCAD is very hard to learn and you have to type in commands and stuff, turboCAD is easier and cheaper. So I will go with it. Hey, how do youc reate laser cutting sheets with it? [/quote] In this hobby, you will never use 100% of what ACAD can do. You don't need to. You will use basic drafting techniques, layering, using libraries, making groups, blocks, etc. BUT, in ACAD's defense, if you learn it, you can learn ways to make yourself more productive than with lesser applications. Drafting is drafting is drafting. How you use it to your advantage is the key. As far as laser shhets I think the best way is to do most of the work for the machinists. Make a layer with the sheet you will use and, in my case, I have a 2-3mm border inside so if the wood is warped a little, there will be no problem. The next layer will be your parts. Layout your parts to maximize the space usage on the wood. Some companies will ask to have one color for cutting and one for engraving. Send them the file with sheet thickness and materials as a DXF or even possibly DWG. They should then make the correct toolpaths based on your specifications. If you have a CNC, that's a different story. You can do whatever you want. A CNC application is not much harder to learn but there are concepts that become more important since you are starting to make a real object and not just an idea. You will need to know safety, feeds and speeds, the correct way to set up toolpaths, and possibly some G codes if you need to edit on the fly. I haven't worked with ACAD for a long time now. I see that they have a 30 day eval for ACAD 2k9. Looks interesting.
Posted on: 1/30/2009 12:10 PM by Author "dolanosa" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=8419416

RE: Predicting airflow pattern over a body
Lafayette, Have to agree with BMathews. If you're playing with a new design with many unknown variables. There is no accurate mathematical way you can predict air movement within a three-dimensional space without spending a LOT of money. Think of it, even aircraft companies, Formula one racing teams, and car companies STILL use wind tunnels. Even they need help from a physical model. Not only do you have to solve for R, surface finish, etc, you will also need to solve for airflow that goes around the object at all angles since you don't have an infinitely long ramp, sideslip, airflow around the base where the ramp, etc. ...and that's just the beginning of your problems. Now solve for 3 dimensions. One 'cheat' would be to use something like XFOIL or a really old version of SNACK. Pick a likely airfoil candidate and look for separation. Now make a model and test it on a wind or water tunnel. Or, you can plow through 1000 pages of calc and trig. I did. BTW, on your other post with the picture of the formulas, if the formula is for this particular problem, it's the wrong one.
Posted on: 1/21/2009 7:01 PM by Author "dolanosa" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=8385239

RE: anyone built a balsa strip cutter
http://www.gryffinaero.com/models/ffpages/tools/balsastrip/balsastrip.html http://www.windandwavemodels.com/BalsaS.html Hope these help
Posted on: 1/8/2009 5:37 PM by Author "dolanosa" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=8335395

RE: What should I do?
consider yourself lucky that she just didn't sell it to buy party food.
Posted on: 12/31/2008 5:52 PM by Author "dolanosa" in the forum "Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=8303301