RE: What batteries for 5
LiPo's measure 4.2v when fully charged. A 10S pack, hot off the charger, will measure 42v, still within the motor's limits.
Posted on: 1/1/2012 10:42 AM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10886131

RE: What batteries for 5
Not knowing anything about the 5" fan you have, I'll take a stab at this. Just guessing 25000 rpm with a kV=700 motor: 25000/700 = 35.7 v @3.7 v/cell LiPo, 35.7/3.7 = 9.6 or 10S Limiting current to 100 amps, power would be 10*3.7*100 = 3700 watts, bare minimum If it were mine, I'd consider two 5S x 5000 mAhr packs wired in series. These would have to be good quality packs rated at 40C. Not ever flown anything larger than 70mm, I might be way off in my guesstimate.
Posted on: 12/31/2011 5:28 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10885199

RE: Hobby King Gulfstream G-500
Huge improvement on the windows. What are you going to power her with?
Posted on: 12/18/2011 1:22 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10865322

RE: Scratchbuild.....90mm jet
You are to be commended. In this day and age of cra##y ARF's and other assorted, imported junk, they are very few of us around who will attempt to build from scratch. And before fans of ARF's jump all over me, remember this. Tomorrow's ARF is today's scratch build. Go for it, angelrcdesign
Posted on: 11/17/2011 6:13 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10817277

RE: EDF help please
"...Weight 8.5 lbs. Wingspan 34" Length 46.5 " ... 8.5 lbs? What's it made of? Concrete?
Posted on: 11/16/2011 6:11 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10815619

RE: Thunderbolt A-10
Jeanskydive, Thanks for the video link. Up till now I have steered very clear of ARFs in general but this one seems to have a lot of potential. What is the fuse/wing covered with?
Posted on: 11/6/2011 8:18 AM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10799242

RE: Thunderbolt A-10
What are the materials of construction? I just lost my 52" WS A10 and have a pair of 70mm fans, motors, ESC's, etc., etc. just looking for a home. I would consider this air frame only, as long as it is not foam.
Posted on: 11/4/2011 11:17 AM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10796721

RE: Thunderbolt A-10
Did you purchase just the airframe? Never mind, found what I needed to know.
Posted on: 11/3/2011 3:58 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10795488

RE: RClander T33 for 90 or 120mm edf
What are the materials of construction? Any U.S. dealers? If not, what are the shipping costs from China?
Posted on: 9/21/2011 6:25 AM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10727120

RE: Why doesn't Parkzone have scale military edf's?
There are two primary reasons why any vendor does not offer a particular product; First, the marketing arm of the company does not see a viable market for the product. Secondly the potential product is in development and is soon to be released. I'm guessing the later.
Posted on: 9/5/2011 10:32 AM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10702628

RE: When will EDF jets surpass wet turbine Jets?
I don't think the turbines will go away altogether but I do think the EDF's will be the plane of choice, primarily because of the fewer and fewer flying sites that allow turbines. My club's field does not allow turbines as their use results in too much burned grass (no paved runway). For those who have a lot of disposable income and are willing to part with it, BVM and TAMJETS are two of numerous vendors that sell high end EDF's. Their products are capable of 150+ mph, have good flight duration, excellent flight characteristics and are beautifully scaled as well.
Posted on: 9/5/2011 8:45 AM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10702423

RE: ASM Mig 15
http://www.rcgroups.com/forums/showthread.php?t=1402800&highlight=asm+mig+15 Perhaps you can contact this guy...
Posted on: 4/4/2011 7:15 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10443415

RE: mig 29 BH Help.
one elevator servo or two?
Posted on: 4/3/2011 11:49 AM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10440236

RE: 120 mm shulman fans
"...I've tried the same batts and speed controllers on another 120 fan and I'm getting 3600 watts and 85 amps, which is where the two fans should be...". Which leaves either the fan itself or the motor. Is there any possibility of installing the impellor backwards? Is there any possiblity of the motor running in the wrong direction? Is there any possibility of the wrong impeller? What kind of clearance is there between the impellor and the shroud? If the impellor is correct then the problem must lie in the motor. Good luck in finding the solution, sounds like expensive equipment to me.
Posted on: 3/29/2011 6:15 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10431266

RE: help with the electrics!
"can i connect more than 1 servo in 1ch in the receiver? " Yes. Typically both aileron servos will plug into ch. 1, using a "Y" wire harness. The same is true for two ESC's (if twin motors) both connected to ch. 3, again using a "Y" wire harness. The rudder servo and nose wheel servo also will plug into the same channel, again using a "Y" harness "the motor i'm interesting in is working with 22.2v battery but everything else with 7.2v, what i can do to combine them?? is it possible?? " Yes, it is possible to use a 6S (22.2 v) battery for the motor. But you will have to power the receiver separately. You can do this by using a separate voltage regulator, sometimes referred to as a UBEC (universal battery eliminator circuit) which takes power from the 6S flight battery and regulates that voltage to a level suitable for the receiver. Or you can power the receiver with its own small battery. "why the ESC is needed?" The ESC is used to convert the battery supplied DC voltage and current to a form that can be used by the motor as well as control the motor's speed. If the motor in question is of the brushless design, the ESC must be designed for that application and will have three wires going to the motor. If the motor in question is of the brushed variety, the ESC will have only two wires going to the motor. If the motor is a brushed type, you could connect the battery directly to the motor but you would not have any control over the speed at which the motors shaft turns. The ESC must be designed to handle the voltage in question as well as the maximum amperage the motor is expected to draw.
Posted on: 3/20/2011 10:06 AM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10411547

RE: How to determine EDF
Start by deciding what you want the plane to be capable of. Will it be bungee launched, hand launched or use landing gear. Once you've decided on that, make an estimate of the ready to fly weight, including the fan and battery. Then decide if you want vertical performance. If so, the thrust must be greater than the weight of the plane. So if the AUW of your plane is 5 lbs and you want true vertical performance then the fan must produce at least 5.5 lbs of thrust. With that value in mind, your next task is to find a suitable fan/motor/ESC/battery combination Or you can take the easy way out and use watts/lb. For good "jet" like performance figure on 175 watts.lb. While the resulting power/weight ratio may not permit true vertical, it will provide ample power to take off from a smooth runway.
Posted on: 3/11/2011 10:26 AM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10393421

RE: Sebastiano Silvestri hovering an *EDF* 3D Mig 29
Doesn't make any difference if it is foam, composite or concrete. The hoverability of this plane has all to do with piloting skills than the model itself
Posted on: 3/7/2011 2:52 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10385108

RE: Berkeleys Skyray - Old Kit
Can't tell what the wing span is or how it is to be powered. Any more info?
Posted on: 2/24/2011 11:49 AM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10360732

RE: will this work ........
You need to determine the power developed by the motor/fan with an 8S pack. Stumax should have that answer Once you know the power, you can calculate amps.
Posted on: 2/19/2011 4:34 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10348659

RE: EDF Size?
Decide on what the "mission" is to be. Landing gear, hand launch, bungee???? Aerobatic, vertical or just lazy cruising? Construction method - balsa with iron-on, solid foam, FG over foam??? Once you have an idea of what you want, you can then look at thrust vs weight. For true vertical, the t/w > 1 Once you have an idea of the weight you can start looking at fans, motors and packs. Many decisions to be made, no silver bullet...
Posted on: 2/19/2011 4:32 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10348654

RE: EDF INLET LIP
A well designed inlet ring cross-section will resemble a flat bottom air foil, similar to a Clark Y. Something like this.
Posted on: 2/18/2011 1:52 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10346085

RE: will this work ........
Nominal voltage of an 8S pack is 8*3.7=29.6 v At 5000 W, current will be (5000/29.6 v)=168 amps At 4000 W, current will be (4000/29.6)= 135 amps Don't think a 100 amp ESC will do the job....
Posted on: 2/18/2011 1:46 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10346067

RE: battery switch=reprog esc?
Any ESC worthy of the name will automatically sense the number of cells and adjust itself accordingly, unless the number of cells you are using exceeds the capacity of the ESC. The loose magnet is the cause of your problems. I have been known to purchase very inexpensive ESC's, so inexpensive they did not even have a brand name on them. They were so inexpensive the arrived with no instructions or documentation what so ever. Even when controlling two motors, these cheap ESC's had no problems going from 4S to 3S
Posted on: 2/5/2011 3:15 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10315070

RE: kyosho t33
The Ky T33 is a great first EDF, even with the stock motor. The balance point, as noted above, is at the finger holes. It will hand launch easily. Mine was subject to glitching and I always believed it was arcing in the AP29L motor that was the cause. After my T33 was long gone, the salvaged fan, now powered by an HET 2W motor and a 2S lipo pushed my F9F around for 300+ flights. Alas, the F9F is now longer but the tip tanks from the T33 are in use on my F89. Good luck with your T33 and enjoy.
Posted on: 2/5/2011 6:29 AM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10313991

RE: Kress Jets HE-162 Salamander
Interesting build. I don't know anything about Kress fans so I can't comment. You might want to pose the question at RCGroups, EDF forum. If it were mine, I'd forget the Kress fan and buy a current design fan with the appropriate motor and ECS. "...I don't like hand launching much, or using a catapult of some type. This model will not have landing gear. Would a dolly that drops during take-off be feasable? ..." Launch dollies are tough to do right, at least for me. If the dollie relies on the plane for motive power, the fan may or may not produce enough thrust to achieve take off velocity. Assuming the dollie/plane system will reach TO velocity, you then have the problem of keeping the plane on the dollie until it is ready to launch. If the plane leaves the dollie before stall speed is exceeded, it will merely roll to one side and crash. So you need a mechanism of some sort to insure the plane remains firmly attached to the dollie during the TO run. This becomes even a greater issue if you are trying to launch from grass. The dollie will require its own battery, receiver and steering servo. I have seen a powered launch dollie based on the chassis of an R/C truck, which you probably have. This option will insure TO velocity is reached and is steerable. The problem of keeping the plane on the dollie is the same as the un-powered version. Consider using an dollie mounted electro-magnet to keep the plane on the cart. You could control the magnet current from an unused channel of your radio. After all is said and done, I think a bungee is the easiest with the best chance of a successful launch.
Posted on: 1/15/2011 6:16 AM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10264918

RE: Günter Bäumker avro rj 100 rc model
The Avro looks very much like the BAE 146. Every now and again an ARF (foam) shows up on EBay. Try RCGroups and do a search on the BAE 146. There were a couple of build threads on this model which might be of some help.
Posted on: 1/11/2011 7:18 AM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10255025

RE: WM400 mk2 on 4s
"...I was also looking into dual esc and batteries..." Dual ESC's, single battery to ESC connection
Posted on: 1/9/2011 3:26 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10251118

RE: WM400 mk2 on 4s
My A10 uses a pair of WM400 fans driven by HET 3W motors powered by a single 4Sx3300 LiPO. At full throttle the motors draw 33 amps each at 420 watts for a combined power of 840 watts. Static thrust (measured) was 52 ounces total, Top speed calculates at 72 mph.
Posted on: 1/5/2011 4:36 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10242199

RE: WHAT TYPE OF UNIT SHOULD i USE ON A 30 LB f-86?
Two suggestions Contact Robert Wagoner at the Electric Jet factory (www.ejf.com) or look at Bob Violet Models (www.bvmjets.com) As an EDF you are looking at serious dollars, similar to a turbine. Forget glow engines for this plane.
Posted on: 12/24/2010 7:26 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10216627

RE: ME262 Fan Jet Engines
Try this electric motor calculator http://brantuas.com/ezcalc/dma1.asp
Posted on: 12/7/2010 6:38 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10183325