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RE: Batteries for TJ100 and a TJ120
Drain rate (amps) & desired flight time. Also if your model has enuf wing area to carry the weight. Phil
Posted on: 11/16/2010 12:40 PM by Author "PhilLin"
in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10139025
RE: Turnigy Lipos
Hi, Aces! Sorry to hear your pack puffed with a short life. Can't determine from your pix which type you have. The gold letter seems to come with nanotechs, but the rest of the label don't quite match. Pls confirm? My 6s5000's nantechs seem to be holding so far (fingers crossed); but our outdoor e-flight season is pretty much over. These were on ly lukewarm after flights draining to 500ma of rating at up to 22C rate, so did not bother to check temp with IR gauge (I have not drained my packs this low before. Usually only to 80% capacity). So will be watching for more feedbacks. Phil
Posted on: 11/16/2010 12:34 PM by Author "PhilLin"
in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10139012
RE: Turnigy Lipos
I'm new to using Turnigy cells. Have 2 x 6s5000 nanoTechs (25c/50c) since summer. Have over a dozen flights on them & found they have boosted wattage from 4kW to 4.5kWs as they maintain higher volts. Does not seem to want to balance w/ my TP210v, which does not light up initially when hooked up. I'm sample size of one, so eager to hear other inputs. Phil
Posted on: 10/29/2010 8:18 PM by Author "PhilLin"
in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10103247
RE: Elan flying in HD
Nice flying, Stobe! Where is Vantaa in Finland? I've been to Jyvaskyla & of course, Helsinki; & even played a round of midnight golf. Here's another vid of a Boomer I took to learn HD video shooting: ... www.youtube.com/watch?v=akPEgxJdYHQ [:D] Phil
Posted on: 10/29/2010 10:56 AM by Author "PhilLin"
in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10102143
RE: Warbirds & Classics over the Midwest
Thx, Carl! Changed again since last I checked. Heard also of some great sponsors, including: Air Age, Balsa USA, Futaba, Great Planes, Promark, RcLightMaster, Sig among others plus local businesses! Phil
Posted on: 7/27/2010 12:19 AM by Author "PhilLin"
in the forum "Events, Shows and Fun Fly's - Airplanes"
http://www.rcuniverse.com/forum/fb.asp?m=9890882
RE: Warbirds & Classics over the Midwest
Wow!! 80+ pre-registered pilots, & the event is only some 3-weeks away! This annual event is developing into a real regional fly-in. Aircraft types include giant scale war birds & classics. Out-of-state pre-registered pilots so far represent Ontario, Canada (3); IN (4); MN (12); OH (2); IL (12); MI (2); & AZ, IA, FL (1/ea) so far. FL & AZ? Those are a long ways away. I heard notable fliers such as Dennis Crooks, & Carl Bachuber of the giant 4-engine fame, are to be repeat attendees. If you have not firmed up your plan to fly at the meet, there is still time. Earlier bugs to the club & event web sites have been cleared up quite a while ago. Please visit these for more info. Phil
Posted on: 7/26/2010 5:17 PM by Author "PhilLin"
in the forum "Events, Shows and Fun Fly's - Airplanes"
http://www.rcuniverse.com/forum/fb.asp?m=9889870
RE: EasyTiger Models Tigerline X-29 Build
Jury has yet to come back with their verdict. I believe mine is next on the tee & might be able to maiden next week. (refer to Bruff thread in RCGroups/forums)[:D] Phil
Posted on: 7/5/2009 10:48 PM by Author "PhilLin"
in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8909423
RE: EasyTiger Models Tigerline X-29 Build
[quote]ORIGINAL: angelrcdesign Did the real have a 2+ deg. on the conard? [/quote] Don't know about the full scale. But if you look at mpope1's sideview pix, there seem to be some positive incidence on the foreplane. I like your bottom note about "try & try again", but to the Irish tune: ........Oh Donnie boy, the packs the packs are costly, ........The radio too, they certainly are not cheap..... Cheers, Phil
Posted on: 4/23/2009 10:12 AM by Author "PhilLin"
in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8708288
RE: EasyTiger Models Tigerline X-29 Build
bruff, that's what Arbo told me in the first place. But I also remember he did not have too much luck with his smaller x-29 last time around. At any rate wish you luck. I must have misplaced & forgot about the folder with my X-29 Nitro & Hasegawa manuals at our last club meeting. Hope someone decide to return it.[:(] Phil
Posted on: 4/22/2009 5:57 PM by Author "PhilLin"
in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8706153
RE: EasyTiger Models Tigerline X-29 Build
Nick, I sent you PMs via RCGroup in response to your quiz re inlet efficiency. Too long to post here. Just a heads up in case you don't visit that forum too often or notice the PM alert. Just go to the personal mail near top right hand corner then click on the PMs. Your latest hanging thrust measurement shows a thrust to weight of about 56%. Hope the ram air effect moves that ratio up near 80% or it will fly like an airliner[:o] If you need a quick & economical way to fab a rounded inlet ring, I posted my method c/w photos in www.rcgroups.com/forums/showthread.php?t=963957. Bruff indicated that using a round lip ring cut down his entry losses to provide significant free increase in static thrust.[:D] Waiting to hear about your maiden. Hope the weather cooperate. Phil
Posted on: 4/18/2009 1:06 PM by Author "PhilLin"
in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8692964
RE: Another JMP F-4 Phantom Conversion
Nice job, Ron! You've got a keeper. That Rhino sure flies with lots more perforamnce than the IC fan version. Thanks for posting. Now lets see Paul put up his with twin JMP fans driven by the big Lil' Screamer motors. Phil
Posted on: 4/15/2009 6:26 PM by Author "PhilLin"
in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8684844
RE: EasyTiger Models Tigerline X-29 Build
Hi, Nick! In case you did not receive an alert, Bruff posted on his RCGroup X-29 thread that his install is having less entry loss most probably due to having a round lip ring in front of the fan. Don't know if you agree that without an rounded lip ring, airflow into fan will form an eddy which restricts total or mass flow, resulting in less static thrust & lower watts than your rpm wud otherwise consume. Don't know if you wud want to try a rounded lip ring? Maybe I was not totally getting the jest of your question above; thus my response may not be totally satisfactory. What I found from much static testing show that watts-in is more directly reflecting actual work your fan is doing. AS can be observed in my charts above, the watts vs thrust curves for different fans, motor, packs configs all tract close together with small differences.; generally the larger diameter fans showing a bit more than the smaller ones. Hope this helps. Happy Easter. Phil
Posted on: 4/10/2009 11:40 AM by Author "PhilLin"
in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8667674
RE: EasyTiger Models Tigerline X-29 Build
Hi, Nick! I did not mean to complicate things. You can just use the graphics & not bother with the math, since the equations is merely a curve fitted thru the discrete test points. So for example for your 1690watts reading, change it to Kilowatts to avoid dealing with a lot of zeroes, so 1.7Kilowatts. For the graphic method that is 3 & half divisions between 1.0 & 2.0 on the x-axis. Go vertically up from there to intersect the pink curve & read the thrust off the y-axis; which is about a quarter of the division between 6.0 & 8.0 or 6.5-lbs. Close enuf since this curve is for a Haoye 4" (or 102mm) instead of say a HiMax 96mm. Have fun, Phil
Posted on: 4/9/2009 10:46 AM by Author "PhilLin"
in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8664372
RE: EasyTiger Models Tigerline X-29 Build
You can use better laser tacks and do as Bruff. I measured mine using the frequency counter function on a $25 multitester. WW had data showing it gives about same ballpark rpm as Bruff's method, without risk of disturbing airflow or being sucked in by the big vacuum cleaner[:D] Phil
Posted on: 4/8/2009 9:55 PM by Author "PhilLin"
in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8663080
RE: EasyTiger Models Tigerline X-29 Build
[quote]ORIGINAL: frisconick ..................... Phil, Sorry, but I must be dense today. I still don't get what "x" is and the other magic numbers?? With all the different motors available with different KV ratings and different sweep areas and pitches, I still don't get how one can extrapolate the thrust without more info, or am I still missing something basic? Nick [/quote] Nick, the X is the x-axis variable, which is Kwatts-in, as I tried to note in the text portion of the post. As I also stated, the outputs from the "balck=box" is slightly affected by the variables mentioned; e.g. motor effcy changes can raise or lower the curv a bit, & 40C packs will have lower internal resistance, decreasing pack loss slightly; but 40C packs will have bigger effect in raising max end performance due to higher voltage under load. Have fun. Phil
Posted on: 4/8/2009 9:50 PM by Author "PhilLin"
in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8663060
RE: EasyTiger Models Tigerline X-29 Build
You're right on about calculating fan or prop performance from scratch, Nick. I'm not an expert on fans, so I take a "black Box" approach to it; as has a few folks, notably Carl Rich & Whistling watts. We kind of test a fan/motor/pack/Esc system on the bench, measuring the amps,volts,watts-in fed into the black-box, while at the same time take measurements of the static thrust, fan rpm & sometimes exhaust velocity, to try quantify the performance of the black-box. Some will argue static testing is almost irrelevant while emphasizing inflight measurements. Note also that the block-box results areaffected by factors inherent, such as use of rounded intake lip or proper exhaust pipe, motor or ESC efficiencys, & yes even pack internal resistance. I don't want here to get into fan loading in flight, etc.; but I find good static test data very useful for picking suitable motor & packs for my EDF apps, for instance, by using charted data to predict the outcome. Carl Rich has published various tabulated data including the HiMax 96mm fan in his threads on the RCGroup forum. I've tested a Haoye 4" fan up to 26550rpm (12s 20C packs, 66.1amps, 8.31-Lbs S-thrust). & I'll attach the chart below; as it shud give very close figures for other 4" fans: Note the Formula in chart: ...Haoye4 = -0.0675(Kw-in)^2+3.7887Kw-in+0.2335 has kilowatt unit for watts in. ... Chart shows one can get almost 1.5-lb S-thrust diff between a 90mm fan vs a 120mm fan at ca2.3kw Cheers, Phil ps: edit to correct amps & thrust figures due reading cross lines in spreadsheet
Posted on: 4/8/2009 9:37 PM by Author "PhilLin"
in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8661591
RE: EasyTiger Models Tigerline X-29 Build
Sorry about the size of chart in above post. I'll try again as I cud not find way to delet the previous one. Okay! Much better.
Posted on: 4/8/2009 2:30 PM by Author "PhilLin"
in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8661661
RE: EasyTiger Models Tigerline X-29 Build
I was side tracked a bit in my above reply to FriscoNick's post#69; sorry! I meant to say that at ca1700watts for a 4" fan, you can expect about 6.5-Lbs of static thrust. Since you're getting ca3.5-Lbs, allowing for wheel loss, you're netting about 54%, or 46% loss[8|][:(] My twin 90mm F-4 with 34" long area ruled fullducting had less than 5% loss, or almost undetectable with a fish scale. So IMHO it is worthwhile to see if this loss can be minimized for this X-29 model. Also, I wud be very interested to hear if you see some improvement when the model gets in motion. Cheers Phil
Posted on: 4/8/2009 11:01 AM by Author "PhilLin"
in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8661041
RE: EasyTiger Models Tigerline X-29 Build
Thanks for the weight data, Nick! 3Lb2oz static thrust is a bit on the anemic side for that AUW though. I measured the rolling resistance before on my Ke-E-Cat conversion, which came to about 0.5ozs/lb. I'm guessing you are losing a lot of thrust due no inlet ducting. If you decide to try measuring static thrust by hanging your model on the fish scale, just make sure there is a stop on a wingtip opposite the fan rotation to counter torque twist. I'm thinking of doing a couple of things to study the effect of no such ducting for this model (: - First, I'm going to try "S" shape opposite hand inside flat walls (as previously mentioned), which are attached flush to the inside straight part of the inlet openings. These wud also act as aft end battery box support; but wud mainly act as inlet air flow open guides based on Coanda principle. I've been granted 2 patents (one for a passive & another for an active devices ) in industrial apps. I'm sharing this one pro gratis as I don't think there is enuf money in this hobby to pay for a patent[:D] I'm curious how such a simplified flow guid compare vs. -Second, a regular ducting merged from 2 inlet branches c/w extended median wall downstream of the merge.
Posted on: 4/8/2009 12:40 AM by Author "PhilLin"
in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8660076
RE: EasyTiger Models Tigerline X-29 Build
Hi, Nick! Looking good. Hope the weather clears up soon so you can maiden. If you got a chance, can you please post your AUW? TIA! Phil
Posted on: 4/5/2009 10:17 PM by Author "PhilLin"
in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8652526
RE: EasyTiger Models Tigerline X-29 Build
Hi, Nick! I agree the CG can never be aft of the main wheel ground contact point. It won't just be funny but most probably fatal to the model. I flipped the fuse upside down, which allowed much easier pin pointing of said CG per the manual. 290mm aft of the canard L/E puts CG about qtr inch ahead of the wing L/E crooks. Setting CG 0.5 to 1.0-ins fwd of this point for first flight attempt shud be prudent, so long as you have long enuf runway to abort in case of no rotation. I'm thinking of fashioning a pack tray with opposite hand flat S shaped vertical walls in front of the fan; which shud also act as inside portion of temporary air intake guides from the 2 side inlets. Let us know what size of packs you are using & share details how you finalize their position for CG. All of us behind you can then follow your lead[:D] Good luck with your upcoming maiden flight! Phil ps: One might be able to reverse the main gear wires by adding small hardwood blocks under the fwd end of the external wire grooves, shud one needs to move the gear back a tad. Just a thought.
Posted on: 3/31/2009 8:03 PM by Author "PhilLin"
in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8636178
RE: EasyTiger Models Tigerline X-29 Build
[:D]Nick, my apologies for creating a confusion when I just assumed that the Nitro X-29 is the same as the EZ Tiger X-29[:(]. What they say about assuming? I went & reread the Nitro manual re CG, after your above comments & found I may have been a bit confused about what it said (mea culpa). The section of the manual consists of a paragraph of text & a pix with the CG dimension drawn in. Don't know if it is the same as in your manual? So I thought it best to put the text here & describe the pix: ["The ideal CG Position is 90mm (3.5-in.) behind the leading edge measured at the centerline on the wing (at the top). In order to obtain the proper C.G., add weight to the fuselage or move the battery position. Always check that the C.G. is properly positioned before flying. Failure to use the proper center of gravity is likely to result in a crash." The picture is a side view of the modewl. It dimensions the CG as located [color=#0033CC]290MM[/color] behind a reference I take as the air intake opening (or is it shown from the leading edge of the canard at the fuse intersection?.] You can see from the quoted manual that there is more than one way to interpret. So I went back & checked my drawing & found that the "3.5-in" distance puts the CG just 0.2" behind my 25% of MAC, when measured from the fuse intersection of the wing L/E!. Taking a conservative approch of a 10%-15% stability margin (or 15% to 10%mac) wud put the CG where my calc placed it at 0.5" to 1.0" behind the crank of the wing L/E, for a first flight! The pix reference still confuses me, so I'll go check after this post. Hope this excercise did not cause you too much inconvenience. It sure cleared up mind![:)][:D] Phil
Posted on: 3/30/2009 6:40 PM by Author "PhilLin"
in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8632329
RE: EasyTiger Models Tigerline X-29 Build
Hi, Arbo! Thx for your feedback! Hope the CG can be cleared once a brave soul makes the first flight. I did some rough tape measures & plotted the wing planform. I found the wings almost to 1:8 scale. Incidentally, the fuse has been foreshortened quite a bit from scale??[:(] Your CG location is close to manual recommended. My calc showed CG range about half each aft of the wing L/E crank joints to 1-inch back. Of course it is prudent to test the fwd position first & adjust backwards in steps. This is about 5" aft of the manual[8|][:o]. One can expect no harm trying the fwd positions, just expect to find it difficult to rotate the nose up for lift-off. But to far aft is usually fatal. Just to clarify the PS in my above post, which seem unclear in retro, my wing planform has a wide "W" shape at the leading edge all the way at fuse centerline; & MAC calc with whole wing planform, but not including the lifting body contribution of the fuselage. Cheers! Phil
Posted on: 3/30/2009 5:47 PM by Author "PhilLin"
in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8630821
RE: EasyTiger Models Tigerline X-29 Build
Ron Sweeney flew one in GDF successfully for years but lost it after conversion to turbine due to insufficient stiffness of the f/g work for higher speeds. As you said, I've not seen a vid of the Nitro version in flight either. Perhaps the Savage brothers (in the other forum) can help out, but don't think they visit this side regularly. Unlesss I'm mistaken, the method for determining CG is the same for canard vs convention tail aft config. The mean aerodynamic chord I got was 10.63". Placing CG at 5% of MAC (for 20% margin) wud really force the canards to carry quite a bit of up load, since it is forward of the wings & very short coupled. The rear stab of conventional configs wud have to carry a down force with tail moment determining the amount to balance. Maybe Bruff won't mind taking a stab at it? Phil Ps: I did not include the lifting contribution of the fuselage, which is significant for modern jets. It wud move the CG point forward in most cases.
Posted on: 3/29/2009 10:54 PM by Author "PhilLin"
in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8629785
RE: EasyTiger Models Tigerline X-29 Build
I hate to second guess the kit designer's recommendation on CG location; especially if it was thoroughly tested in real world. And there is nothing worse than a tail heavy model. But I did make a rough calc of the CG for the Nitro X-29, & am very puzzled that my location is quite a bit rearward of the manual[:o]; & this is allowing for a 20% stability margin. Don't take my result as correct since I have not test flown it to confirm. I'd like to ask others to take a stab at it & compare. Nice catch on the fan axis, Nick! Now I'll go quietly follow this thread. Phil
Posted on: 3/29/2009 10:01 PM by Author "PhilLin"
in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8629615
RE: Another JMP F-4 Phantom Conversion
A belated congratulations for your successful F-4 re-maiden! I was away for a while & got behind my e-mails. Sorry. I'm glad you solved the mystery of the sensitive stabilator! I cud not come up with other aerodynamic reason why it wud behave different from when it was an DF at same CG location. It will be helpful to others to know you are flying with CG 1.5-inch forward of plan. I also felt F-4s fly rock solid with fwd CG. Having also heard of unusual expo signage used by JR, I've been checking assideously control surface movements against stick position on any new radio install I've had to confirm its expo action. This consist of standing a steel tape vertical next to the control surface (lower edge for up movement, & visce versa). Have fun with your reborn Rhino! Phil ps: The vids show your converted F-4 performing with much more authority while the DF version seemed to lug around a bit. Same.
Posted on: 3/25/2009 11:33 AM by Author "PhilLin"
in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8615026
RE: Another JMP F-4 Phantom Conversion
Ron, IIRC the JMP dwg I used to CAD the inlet ducts showed a CG location just aft of the former where wing spar joiners are mounted. On my smaller JHH F-4 where the gear location is suppose to be nearly scale, I measured the down force at the stabilator pivot, using a fish scale, and found the force was nearly equal that when lifting at the nose gear, while at the flying weight config; i.e. about 2-lbs (for a 12.3-lbs AUW). Having moved your main gear ground pivot forward, your stab force required to rotate is of course much lower, but once off the ground, stab force will be relative to the moment around the CG. My F-4 needed about 1-3/8" (max deflections 1-7/8 in) L/E down on the Stab to maintain landing attitude with the flaperon deployed. This much deflection is obviously different from the JMP version, which is seems to me to have CG designated much closer to the CP? Phil ps: corrected AUW above, & stab deflections. Memory not reliable.
Posted on: 2/11/2009 5:01 PM by Author "PhilLin"
in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8456524
RE: Another JMP F-4 Phantom Conversion
Hi, Ron! Before I make a wild guess, I'd be interested to know which turbine (I assume a single?) you intend to use in your F-4, & what total fuel tank capacities in the model in DF & turbine configs? Wonder if the fuel slushing in the tanks is enough to upset the actual CG? In A. Sheldon's case, his incident occured right after take-off, so fuel caused shift probably not a factor. Unless his max deflection was too small to correct for an aft CG situation? I have first hand & sad experience with rearward CG shift on my F-4. Phil
Posted on: 2/10/2009 5:36 PM by Author "PhilLin"
in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8462177
RE: Easy Tiger 101mm F-86 w/ pics!
Does the kit come with inlet ducting? TIA! Phil
Posted on: 2/7/2009 11:32 AM by Author "PhilLin"
in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8448739
RE: Another JMP F-4 Phantom Conversion
I did lift the thrust line slightly for Paul's JMP conversion above to allow better spar connection with removable wing panels & wing load transfer. I based it on my twin fan JHH F-4 which had about 5deg of nose down thrust, & did not seem to have any problem with trim change re throttle. The full scale F-4 also had this feature, from what I can deduce. My smaller F-4 did hav a significant nose down from deploying flaps at final; so may even neutralize any pitch up from closing of throttle when landing. I was able to catch Paul just before his leaving for a family vacation in Jamaica. He liked Ron's feature of removing only the wing outer panels. The CG discussion should be helpful for Paul when the time comes. I will be checking my CG position ( as a % of chord) for comparison between similar planforms. Ron, you may beat Paul to the remaiden, as our spring can be expected much later than the earlier & balmy ones you get across the pond. Phil
Posted on: 2/5/2009 8:05 PM by Author "PhilLin"
in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8443017
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