RE: found this interesting discussion on Spiral Slipstream
Anybody that has used a propeller type mixer to mix paint has noticed that the paint will move in the direction dictated by the pitch of the propeller, but also spirals in the direction of the rotation. The same fluid dynamics applies to the airstream behind the propeller on an airplane.
Posted on: 9/8/2012 11:32 AM by Author "DwightMann" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=11221878

RE: found this interesting discussion on Spiral Slipstream
Anybody that has used a propeller type mixer to mix paint has noticed that the paint will move in the direction dictated by the pitch of the propeller, but also spirals in the direction of the rotation. The same fluid dynamics applies to the airstream behind the propeller on an airplane.
Posted on: 9/8/2012 11:31 AM by Author "DwightMann" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=11221875

RE: CAD motors, servos etc
[quote]ORIGINAL: Iron Dog My god, Chevelle, those are gorgeous!  [/quote] I agree. I am using TurboCad, and usually stop at drwaing a plan.
Posted on: 9/4/2012 2:52 PM by Author "DwightMann" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=11217447

RE: CAD motors, servos etc
That is where my problem lies. I am not sure which servos or motors I will use, but I know that they will not be something that I have. Most motors have specs regarding diameter ands length which is enough to start. Servo specs give overall height, but not distances abover and below the mount
Posted on: 9/3/2012 11:05 AM by Author "DwightMann" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=11215807

RE: CAD motors, servos etc
Maybe I need to be less lazy. Unless you are WAY faster then me, that engine must have taken awhile.
Posted on: 9/1/2012 7:56 PM by Author "DwightMann" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=11214037

CAD motors, servos etc
Is there any source for CAD drawings of servos or motors? The last thing that I want is to spend several hours designing and building aplane only to find out that I need to hack the cowl or that the servos don't fit. It would also allow me to make my servo and motor mounts before they are in the plane
Posted on: 9/1/2012 7:37 PM by Author "DwightMann" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=11214015

RE: NEW DLE 20cc Gasser! (Data & Links 1st Post)
I had a similar symptom caused by a loose wire in the battery connector. I finally noticed the " hot ignition" led was not lit.
Posted on: 7/19/2012 8:13 PM by Author "DwightMann" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11161955

RE: NEW DLE 20cc Gasser! (Data & Links 1st Post)
WWII planes had high horsepower and needed a lot of prop. Ground clearance was a problem. The Corsair went to a Gull Wing to help with ground clearance. Another issue is that a 9' diameter prop at 2500 rpm will have the tip exceeding the speed of sound. This would cause a lot of stress on the prop and loose efficiency. The multi blade props were used more as a sacrafice than to get more out of the engine, they just made a bigger engine to compensate
Posted on: 6/6/2012 4:08 PM by Author "DwightMann" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11109217

RE: NEW DLE 20cc Gasser! (Data & Links 1st Post)
A 15x7x3 may not be enough to load the engine. I had a 16x8x3 on an Aeroworks Extra 260 and was getting 8900 RPM
Posted on: 6/6/2012 7:32 AM by Author "DwightMann" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11108572

RE: NEW DLE 20cc Gasser! (Data & Links 1st Post)
[quote]ORIGINAL: ahicks [quote]ORIGINAL: av8tor1977 Any time an airfoil is stalled or nearly so, it is also creating [b]lots[/b] of drag. This loads the engine. As the airflow begins to go through the propellor as the airplane accelerates, the blades experience an effective reduction of angle of attack, unstall, and produce less drag. Hence the engine speeds up due to having less load on it. I have seen this on the ground while taching engines too. Point the airplane into the wind, and your tach reading at full throttle will increase. And of course I have experienced it as a pilot of full size airplanes as well. This is why a ''constant speed'' prop, which is cockpit adjustable, is very effective. You can flatten or lower, the pitch of the prop for takeoff, which makes the prop much more efficient starting from a stop and at low speeds. Then, when in cruise, you increase the pitch, making the prop more effective at that speed. The key is that the airflow through the prop changes the effective angle of attack of the blades. As far as the cooling angle, I understand your point. But even an uncowled sport airplane engine can get too warm with extended full throttle running on the ground. They need the added airflow from being in flight to be safe at extended full throttle usage. The center area of the prop makes a poor cooling fan. More on cooling here: http://www.rcuniverse.com/forum/m_11071695/tm.htm Hope this helps, AV8TOR [/quote] Ok, I was thinking ''stalled'' as in past tense - after it's stalled. I've got what you're saying now. Thanks [/quote] Compare a spin to a vertical dive. The plane is stalled during a spin and the speed is much slower than durin a dive which is not stalled
Posted on: 5/23/2012 3:41 PM by Author "DwightMann" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11092193

RE: NEW DLE 20cc Gasser! (Data & Links 1st Post)
[quote]ORIGINAL: av8tor1977 Cooling airflow isn't sufficient on the ground for most cowled airplanes for sustained full throttle runs. The aircraft really needs to be moving through the air to have sufficient cooling for sustained full throttle operation. I realize one would think the prop blast would be enough, but in many cases it's not.... AV8TOR [/quote] Equally important, the load on the engine will change.
Posted on: 5/21/2012 12:49 PM by Author "DwightMann" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11089111

RE: Non - airplane application for motor
Does not need to be brushless, I thought it would be simpler
Posted on: 2/17/2012 8:07 PM by Author "DwightMann" in the forum "Brushed/Brushless motors, speed controls, gear drives"
http://www.rcuniverse.com/forum/fb.asp?m=10964005

Non - airplane application for motor
I would like to use a brushed motor for a miniture merry-go-round type of application. I want to keep it simple, and hope that I don't need to use a Tx - Rx to control the motor. Can I use a variable resistor to control the speed and a switch to turn it on/ off? What is a good source for misc. gears to get it in the approximate speed range. I probably only want around 4 - 6 RPM on the final platform
Posted on: 2/16/2012 2:32 PM by Author "DwightMann" in the forum "Brushed/Brushless motors, speed controls, gear drives"
http://www.rcuniverse.com/forum/fb.asp?m=10962063

RE: mAh vs volts
[quote]ORIGINAL: Goldenduff Power is volts x amps do increasing either will increase power. Volts determines the revs per second (kv rating). [/quote] And the power needed to achieve those rpms will determine the current. In a car, the voltage will say how fast, going that speed uphill or down will dictate the current.
Posted on: 2/5/2012 12:43 PM by Author "DwightMann" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=10945321

RE: NEW DLE 20cc Gasser! (Data & Links 1st Post)
[quote]ORIGINAL: Estang Higher Octane does not give more power.  It will slow down the flame and give a more controlled burn. Some engines require the higher Octane, where as other will not bennifit from it. I am running Stihl oil with 91 octain pump guas in mine and it is still clean inside. I use to race Moto-x 2 strokes and ran H1R 2 cycle oil and it would actually clean the carbon off the top end. At $20 a liter it should have come with a new tool kit too :) [quote]ORIGINAL: woodbender Hello everyone, and thanks for all the great info. I'm definately a newbi with gas. Please pardon the question below if it's been covered already. A club member suggested using white gas Coleman fuel instead of gasoline from the pump. I tried it just for the heck of it and my elderly Zenoah 26 seems to like it just fine. Yes, it's expensive (but less than glow fuel), but my friend says it burns cleaner with less carbon build-up, etc. and offers a higher octane level (more power). I know just enough to be dangerous. Any thoughts, pro and/or con on running this fuel with my shiny new (and as yet unpackaged) DLE 20? [/quote] [/quote] Most high performance engines / race cars etc have high compression engines. The high compression requires a higher octane fuel. This may be why some associate high octane with more horsepower. Lead was added to fuel to increase the octane, but nothing about the lead will add horsepower.
Posted on: 1/6/2012 12:56 PM by Author "DwightMann" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=10895063

RE: NEW DLE 20cc Gasser! (Data & Links 1st Post)
[quote]ORIGINAL: Estang Seeing that the summer flying season is about over, and winter is soon upon us (dont shoot the messanger). I was wondering what is needed to make the DLE-20 winter flyable?. It can get kinda chilly up here in the Toronto area, but on nice days -9 Degs are tolerable. Would minor jetting be all that is needed? [/quote] I was wondering the same thing. There are some days when the temp never gets above 75. brrrrrrrr
Posted on: 10/13/2011 3:42 PM by Author "DwightMann" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=10763830

RE: NEW DLE 20cc Gasser! (Data & Links 1st Post)
RBean I have the same prop and exhaust in an Aeroworks Extra 260. I get 8,300 RPM. It is still trying to finish it's first gallon of fuel. I will switch to a better oil with the next gallon
Posted on: 10/12/2011 12:26 PM by Author "DwightMann" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=10761824

RE: NEW DLE 20cc Gasser! (Data & Links 1st Post)
I am very happy with the plane, it is well built and flies great. The template for the cutout in the firewall would not allow the carb to fit. The conversion kit that I received must have been different. I have a MAS 16-8 3 blade. I am thinking of trying a 17-6, what prop are you using?
Posted on: 10/8/2011 8:52 PM by Author "DwightMann" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=10755583

RE: NEW DLE 20cc Gasser! (Data & Links 1st Post)
I am very satisfied with mine as well. The fact that you did not use their conversion kit probably explains why you did not have any issues. And you saved a few $$.
Posted on: 10/7/2011 3:07 PM by Author "DwightMann" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=10753613

RE: NEW DLE 20cc Gasser! (Data & Links 1st Post)
I have an extra 260. I purchased the conversion kit from aeroworks. It has a few problems. Do not mount the throttle servo as they recommend. The servo arm will hit the wing tube. Place it further towards the rear and bend the pushrod to clear the tube or use a flex cable. If you install at the recommended distance between the firewall and spinner backplate, the mixture screws will be in within the thickness of the firewall. Lay everything out before you cut or glue. The conversion was not thought out very well. You may be better off building a new motor box
Posted on: 10/6/2011 10:21 AM by Author "DwightMann" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=10751459

RE: NEW DLE 20cc Gasser! (Data & Links 1st Post)
The octane rating of gasoline refers to the resistance of the fuel to preignition and has nothing to do with the energy of the fuel. High compression motors such as race cars are more prone to this which is why they need the higher octane. It doesn't hurt to use the higher octane, but if you car ( or plane ) doesn't "knock" with the 87 octane, anything higher is only a waste of money.
Posted on: 8/4/2011 11:57 AM by Author "DwightMann" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=10655244

RE: NEW DLE 20cc Gasser! (Data & Links 1st Post)
I am using a switch from Valley View that includes a fuel dot and two switches w/ charging ports. They also sell a similar product with a single switch
Posted on: 7/26/2011 3:58 PM by Author "DwightMann" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=10640220

RE: NEW DLE 20cc Gasser! (Data & Links 1st Post)
[quote]ORIGINAL: cerralvo78 [quote]ORIGINAL: DwightMann Any affect from higher heat or humidity ( or altitude) would make it necessary to lean the mixture. The warm air is less dense, so it would also need less fuel. [/quote] i try it today and i turn it clock wise to lean it and the engine die!!! So i move counter to rich it and it got better THEN I START GETTING BUBBLES in my gas line
Posted on: 7/26/2011 3:55 PM by Author "DwightMann" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=10640218

RE: NEW DLE 20cc Gasser! (Data & Links 1st Post)
Any affect from higher heat or humidity ( or altitude) would make it necessary to lean the mixture. The warm air is less dense, so it would also need less fuel.
Posted on: 7/25/2011 9:54 AM by Author "DwightMann" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=10638053

RE: Landing procedure
[quote]ORIGINAL: AA5BY Another concern is with the dreaded cross wind on the tail during base leg. That dreaded tail wind has gotten many of us who otherwise consider ourselves adequate pilots. Depending on the airframe, a number of designs will not be happy with the turn from base leg to final with a tail wind (cross wind in your face) and not putting extra speed on during such conditions can mean bad things in what some call coffin corner. Part of the problem is that the downwind leg... isn't downwind and we don't feel the plane the same as typical and we may slow up to get it to drop altitude... then when turning base leg we don't add throttle and the airspeed gets precariously low... then that final turn bites. [/quote] The plane doesn't care about the wind direction. By setting the trim for a particular speed, the visual componant is taken out and the pilot noot not worry about how fast the plane looks to be going
Posted on: 7/7/2011 3:59 PM by Author "DwightMann" in the forum "Tips & Techniques"
http://www.rcuniverse.com/forum/fb.asp?m=10610705

RE: 60-90 Extra 260 and 300 DLE 20 Installation
I have a few flights in now, this is an excellent combo. I am using a MAS 16-8 three blade prop. I went with the JTec Pitts style muffler. It would fit but a tight squeeze, so I shaved a little from the corner of the firewall and reinforced it from the inside. It came in quite a bit heavier than the 6 1/2 pounds that I'd seen advertised. At 8 lbs 2 oz, it has no bad habits and lands smoothly. I am still breaking in the motor, so I haven't tried any 3d, but the precision aerobatisc is great A couple clicks of down trim and it stays where it is pointed I mounted the engine more forward than the plans recommended to allow access to the carb adjustment, and I will relocate the throttle servo so that it clears the wing tube
Posted on: 7/6/2011 3:58 PM by Author "DwightMann" in the forum "Aero-Works Support"
http://www.rcuniverse.com/forum/fb.asp?m=10609023

Is the Rx-R Seawind any good
I would like to get my feet wet with something simple. I'm pretty good with land based planes, and would like something I can take to the river. The water is usually pretty flat in the mid week afternoons. I'm not looking for 3d, but would like to loop and roll. Is this plane/ combo a good candidate. Should I get the plane and another motor/ esc/ servos seperate or look aty another plane?
Posted on: 6/16/2011 4:13 PM by Author "DwightMann" in the forum "Seaplanes"
http://www.rcuniverse.com/forum/fb.asp?m=10577665

RE: NEW DLE 20cc Gasser! (Data & Links 1st Post)
Windgap, what does your 260 weigh?
Posted on: 6/15/2011 7:13 AM by Author "DwightMann" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=10575163

RE: NEW DLE 20cc Gasser! (Data & Links 1st Post)
Who checks for loose screws inside the carb or taken apart every servo and receiver? Am I the only one who just installs engines and radio equipment without disassembling and inspecting that all screws have loctite or the integrity of the solder connections? That is why the manufacturers have QC departments.
Posted on: 5/30/2011 11:53 AM by Author "DwightMann" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=10548444

RE: Extra 300 60-90 hardware
Same thing with my 260
Posted on: 5/20/2011 3:44 PM by Author "DwightMann" in the forum "Aero-Works Support"
http://www.rcuniverse.com/forum/fb.asp?m=10531678