RE: F89 Scorpian scratch build
WNY is probably the only location in the world that hasn't heard of digital video
Posted on: 11/16/2009 12:25 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9257720

RE: F89 Scorpian scratch build
For those of you who keep track of such minutia, my F89 has logged 54 flights as of this morning. She is a great flier.
Posted on: 11/13/2009 10:04 AM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9250718

RE: Wemotec Minifan Motors
I have been using the HET 3W motors (~$50) with the HET Tsunami 36 amp ESC's. A great combo with a 4S lipo. My avitar uses a pair of the MF480's and, while no speed demon, my F89 cruises easily for 4.5 minutes on a single 4Sx3300 lipo. This set up will develop 450~500 watts and with well designed nacelles, such as the A10, I would figure 52~55 oz. of static thrust with the above set-up. The motors drop right in to the shroud although they do require a single wrap of electrical tape to get a tight fit. You might want to ask this question at RCGroups, where some very knowledgeable EDF types hang out. Some of them have reported very good results with other, perhaps less expensive, motors.
Posted on: 10/15/2009 5:32 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9176091

RE: the best fans
You need to ask this question at RCGroups. That's where all the big EDF dogs play. I'm sure some of those guys have done the exact conversion you have in mind.
Posted on: 10/8/2009 7:02 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9157408

RE: GP Lear Jet conversion to EDF
At the weight you've mentioned, I would think a pair of 90mm fans are in order. 29 oz/sq.ft. wing loading is where the big dogs play. I'm partial to twin EDF's but I'm still mucking around with 68mm fans so I can't be much help. gunradd is correct. Head over to RCG's EDF forum. The very best of the EDF-ers hang out there and will point you in the right direction.
Posted on: 10/6/2009 7:45 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9152180

RE: House Of Balsa F-86 build.
I just looked at your post on "the other" forum. You now have some of the very best EDF guys in your corner.
Posted on: 10/3/2009 7:06 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9144183

RE: House Of Balsa F-86 build.
The air inlet of mine is sized for a 75 mm fan and measures ~2.75". My fan of choice is the 68 mm Wemotech MF480 and with these I aim for an inlet diameter of 2.4" and an outlet diameter of 2.14" Essentially the diameter of the air inlet should equal the "free swept area" of the fan. The FSA is the area of the shroud minus the area of the spinner. A good rule of thumb is the air outlet is ~85% of the inlet size. Ducting makes or breaks an EDF but the F86 is the easiest to duct as it is straight in - straight out. I try to maintain a constant cross sectional area inlet duct to minimize entrance losses. Any idea what the weight will be? Most of the F86's this size are flown on a 90mm fan but I'm able to use a smaller fan as the AUW is only 43 oz.
Posted on: 10/3/2009 1:50 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9143697

RE: Power supplys
Stan, A bad back does put the damper on a lot of activities, that's for sure. In your situation, I'd agree your solution is the best. Our flying field is "primitive" w/o electricity or running water so the DC battery is my only option.
Posted on: 10/3/2009 1:28 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9143658

RE: House Of Balsa F-86 build.
I just happen to come across this thread and decided to look into it as the F86 is a favorite of mine. Your F86 is is a great looking plane and should be good flier. But if it were mine and I didn't have much R/C plane experience in general and little or no EDF experience, I'd use some other plane for the learning curve. Dealing with EJF is a good plan as Robert Wagoner will not steer you in the wrong direction. What is the WS of the plane? Do you have a paved runway to fly from? Please keep RCU informed of your progress. There are a lot of readers who prefer ARFs but a few of us still build and will enjoy your thread. Here's my scratch built, 42" WS F86. She is pushed by a 75mm EDF, flies very well but needs a bungee launch. Our grass field is very rough and she doesn't develop enough thrust to push through the bumpy grass.
Posted on: 10/3/2009 1:18 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9143635

RE: F89 Scorpian scratch build
Tony A, Thanks. I put a second flight on the F89. Number two is always 1000% easier than the maiden as I know what to expect. This flight was much the same as the first except I did numerous low passes, each a little lower than the previous. When the timer went off at 4.5 minutes I set up for an uneventful landing. My only complaint is the grass clippings picked up by the air inlets. The F89, with its high, flat-bottom, Clark Y airfoil and straight LE, is aerodynamically related to a clipped wing Cub. I'm not sure if that is a good thing for a jet but her flight characteristics are very smooth and stable. For those of you who take interest in such things: The frontal area of the F89 is 113 sq.inches and my home grown spreadsheet predicts a Vmax= 62 mph. Adding the tip tanks increased the frontal area to 120 sq.inches. The additional drag resulted in a decreased Vmax=60 mph. The twin MF480/HET3W on 4S develop 800 watts @57 amps with 42 oz. static thrust.
Posted on: 9/30/2009 5:38 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9136621

RE: F89 Scorpian scratch build
b16a2sir Thanks but I don't know of anyone who has video capability. Added some tip tanks, seems to look better to my eye.
Posted on: 9/29/2009 6:09 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9133899

RE: Power supplys
The simplest solution would be to power the charger from your car's battery. For at-home use, I use a 12V automotive (or deep cycle marine) battery which I keep charged with a "wall-wart" trickle charger. If you feel the need, you can take your "at-home" battery to the field. A friend, who drives a pick up, carries a deep cycle in the bed. This battery is connected in parallel to the regular truck battery and is kept charged by the truck's alternator.
Posted on: 9/28/2009 8:17 AM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9129399

RE: F89 Scorpian scratch build
After a couple of weeks of various delays, some weather related , I finally was able to match my schedule to some half way decent flying conditions. This morning was cool, partly cloudy with light, variable winds. A range check revealed nothing amiss and a quick check of the balance indicated all was well. The bungee cord was stretched to about 20 lbs, the timer set for 5 minutes and with nothing left to do, I stepped on the pedal. I'm not exactly sure when I poured on the power but the launch was pretty much unremarkable and the F89 was off and flying. My first flights are always conservative affairs so after reaching a comfortable altitude I reduced the throttle to about the mid point. Wide left and right turns, a glide check (she's a floater), a stall check (benign, forward mush). A couple of clicks of right aileron, two or three down on the elevator and she was flying hands off. The balance point was 99% perfect. The timer went off and I set up for a landing. As soon as I was over the field I chopped the power and she came to an uneventful stop. The F89 presents herself very nicely and seems to be a rock solid flier. I had some concerns about the somewhat short tail moment but there was no evidence of any yawing As I was getting ready to change packs for another go, light rain began to fall so I packed up and called it a day. Life is good
Posted on: 9/26/2009 3:50 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9125691

RE: F89 Scorpian scratch build
The F89 is ready for its maiden flight. AUW is 68 oz, a bit heavier than planned. Still, with a w/l of 20.6 oz/sq.ft., she'll be a floater Now, just to get a decent weather morning...
Posted on: 8/27/2009 1:08 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9049529

RE: brushless motors
I believe your question is much too broad. Perhaps if you specified what wing span you are looking for then someone might be able to steer you to a possible vendor.
Posted on: 8/23/2009 2:22 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9038040

RE: 747-300 JAL
If you insist on using brushed motors at first, at least install the third motor wire. That way, when you do switch to the BL's, the proper wiring will already be in place and you might save your self the time and aggravation of adding a third wire
Posted on: 8/16/2009 8:37 AM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9019938

RE: electric conversion.
Fig, 2 results in 12S
Posted on: 8/15/2009 7:47 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9018990

RE: electric conversion.
If you wire them in series, the assembly will be 12Sx5000. At 25C, the maximum current will be 25 x5 = 125 amps Wire them in parallel, the assembly will be 6Sx10000. At 25C, the maximum current will be 25 x 10 = 250 amps I am using the Zippy packs and I think they are every bit as good as any of the higher priced packs.
Posted on: 8/15/2009 8:09 AM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9017901

RE: 747-300 JAL
Why bother with brushed motors? Seems like a shame to use them in a good looking plane as this.
Posted on: 8/15/2009 8:01 AM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9017891

RE: Where to put the weight???????
From what you have written, I'm under the impression your F9F is very nose heavy. The easiest fix is to move the battery packs aft but if that's not possible, then adding ballast is the only option. You might want to consider using rosin core solder that comes on a spool as it's very flexible and easily shaped to fit anywhere. The least noticeable location would be inside the duct, attached to the inner circumference, as far aft as possible.
Posted on: 8/14/2009 8:35 AM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9015569

RE: electric conversion.
"...a, I have a 60 amp esc and im not sure it would be enough (someone chime in here)..." You ESC will be worthless in your proposed setup. Think in terms of 100~110 amp capacity
Posted on: 8/13/2009 10:51 AM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9013099

RE: F89 Scorpian scratch build
Build up date. As shown, 60 oz. Expect final AUW ~ 66 oz. for a wing load of 20 oz./sq.ft.
Posted on: 8/10/2009 8:17 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9006063

RE: Questions about Kyosho T-33A
http://www.modelflight.com.au/accessories_covering_materials_for_models.htm
Posted on: 8/10/2009 8:14 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9006051

RE: F89 Scorpian scratch build
Mark, Thanks. Ribs were generated from Profili 2.0 and I drew the fuse fuse formers in CadStd. The cut files were then sent to the laser cutting service. No rib packs available
Posted on: 8/9/2009 7:52 AM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9001550

RE: F89 Scorpian scratch build
My F89 is almost finished, perhaps a week or two. All that is required is the canopy (pink foam), iron-on covering for the wing and the paint for the balance Weight as shown is 60 oz., expect AUW to be right at 66 oz for a wing load of 20 oz./sq.ft.
Posted on: 8/7/2009 6:54 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8998366

RE: Great Planes L-39/ParkZone F-27C
If you want speed and very easy hand launches, the Stryker is the way to go. It is very fast, very aerobatic, very easy to hand launch. Just an easy underhand toss sends it on its way. It will fly longer on a charge than the L39 The F27 will fly circles around the L39
Posted on: 8/4/2009 10:02 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8990680

RE: Ducted Fan/Motor Questions
If it were me, I would go to the local hobby shop and ask for their help in finding the correct screw size. Not ever having seen the fan in question, I can only guess the screw size. The 70mm Wemotech fans use 2.5 mm motor mount screws so I would think you will need at least that size for your larger fan. Another option is to post your question on the "other" forum http://www.rcgroups.com/electric-ducted-fan-jet-talk-12/
Posted on: 8/2/2009 11:48 AM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8983597

RE: 7800kv and 64mm EDF unit
I think you should spend $50 and buy a watt meter such as the "WattsUP". Foregoing that I would guess 2S is about the limit with a 7800 kV motor. The 54 amp ESC might be a bit on the small side. If you had a "wattsup" meter, you could measure the voltage from the battery as well as the voltage at the motor. The nominal rpm equals the kV times the motor voltage. The kV is a function of motor design
Posted on: 8/2/2009 11:40 AM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8983572

RE: EDF Jetliner Large scale??
If it were mine and I planned on selling it, I wouldn't assemble it as I think you will get a better price for it in NIB condition. Any individual who would seriously consider purchasing the BAE 146 will automatically assume they are a better builder than you. That may or may not be true but I would only consider buying the BAE 146 in the NIB condition. Plus it will be hard to ship to a new owner once assembled. The BAE 146 is not a plane for the inexperienced. The cost to power it properly will be in the neighborhood of $400 using the Robbe fans, $600 using the much better Wemotech fans. To that you need to add batteries for another $100~$150.
Posted on: 7/28/2009 9:29 PM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8972092

RE: Anyone else building eTurbinator ARF?
http://www.rcgroups.com/forums/showthread.php?t=921501
Posted on: 7/27/2009 8:04 AM by Author "Larry Dudeck" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8967172