RE: Ideas for illiminating tip stall, or undersireable wing drop upon stall.
Was the original wing built straight and symmetric. And the same questions for the extensions? Sounds basic but a lot of building surfaces aren't straight and people had no idea. Marble slabs and pool tables provide the best foundations for a good true wing build.
Posted on: 5/18/2013 11:34 PM by Author "dbsonic" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11515756

RE: C-ARF Ultra Flash build Thread + Video
I had not thought of it that way, but I think you guys are right about the CG affecting stall. The question is how much. Like if I have a fwd CG and it only takes say 6oz at the stab to balance.. then we are saying the wing is effectively loaded by an additional 6oz and the stall speed is now higher as a result. Correct? But 6oz on something like a Flash you are not going to notice any difference on landing stall speed IMO. How about 16oz.. still hardly noticable. Until you start adding several pounds will it really make a difference. Who has a CG that's so far out of whack, flies it, and finds it needs several pounds to balance? Usually its a few oz. Fwd CG airplanes usually run out of elev authority in my experience and simply land fast. I dont think I've ever had one stall and snap on flare.
Posted on: 5/15/2013 12:17 PM by Author "dbsonic" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11512421

RE: CO2 extinguishers
My understanding is for CO2 you need to get close to extinguish any fire. With Halon you can be a safe distance away, probably 10 or 20 feet and it will put out the fire effectively. For contained hot starts C02 is probably best. For a real serious fire, I would think you want the halon.
Posted on: 9/14/2012 8:05 AM by Author "dbsonic" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11228309

RE: 8FGS Dual Rates
I was able to program all the rates I needed last night based on that web page so thanks again. It was a piece of cake if you set the dual rate switch first, and understanding the on/off function and how to set it. Then go to setting the actual rates afterwards. In general my impressions of the 8FGS so far are: -Wonderful capability. I found it does trim mix also. That's great. That's why I go with Futaba. I once bought a "time to market" product from another vendor and it had too little functionality which was very disappointing. -Value. It's great this thing does 14 channels. -Dependability. These radios are rock solid. My 8UA still works from ~15 years ago. The bad. The user interface is just okay. It is sufficient but a little coarse. Once you get used to it, it's fine. And the manual needs work. It might be best to provide only a starter manual, and then a pointer to the web pages for detailed documentation like you provdied that can be updated and corrected easily. Take for example the Nexus 7 tablet - it doesnt even come with a printed manual, but is loaded with a pointer to the online version of the manual. Online manuals are easier to search as well.
Posted on: 9/6/2012 11:47 AM by Author "dbsonic" in the forum "Futaba Radios Direct support forum"
http://www.rcuniverse.com/forum/fb.asp?m=11219723

RE: 8FGS Dual Rates
Excellent. That's a good web page. In fact, it answers my next question about going to triple rates - since the switches are 3 position it seems natural to go that route. Thanks.
Posted on: 9/5/2012 2:05 PM by Author "dbsonic" in the forum "Futaba Radios Direct support forum"
http://www.rcuniverse.com/forum/fb.asp?m=11218606

RE: DS8511 oscilating
I've seen stuff like this and fixed it. It usually comes down to low voltage/poor signal situation and I have not seen the servo itself be the problem. The culprit often lies in the extension as mentioned by Dave and connectors! The connectors can become oxidized a bit and you get a little capacitance there. And if you are doing any fanout each connector adds its parasitcs as well. This can lead to the signal you send from the rx to deteriorate a bit by the time it gets to the servo. I would not fly your model again till you get it hashed out. I also like to use twisted extensions to get a little bit of extra shielding geometry(the presence of the ground already provides shielding but only in the plane of the ribbon cable).
Posted on: 9/5/2012 12:11 PM by Author "dbsonic" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11218473

8FGS Dual Rates
Anybody got a better explanation than the manual for dual rates? In general the 8FGS manual continually goes on and on about how to navigate through the menus(once you get the hang of it, it isnt too bad... not the greatest but not terrible) but does little to explain fundamental principles regarding the content. What is "alternate" regarding the dual rate switch assignments? This from a long time Futaba user. Need the info!!
Posted on: 9/5/2012 11:16 AM by Author "dbsonic" in the forum "Futaba Radios Direct support forum"
http://www.rcuniverse.com/forum/fb.asp?m=11218430

RE: WANTED BARF STAB
I'll bite. Can I ask what happened to your right stab?
Posted on: 8/22/2012 4:44 PM by Author "dbsonic" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11202607

RE: Ultra flash or Bandit
For my own edu. what will a brand new UF run you RTF (minus the turbine)?
Posted on: 8/17/2012 4:43 PM by Author "dbsonic" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11197278

RE: Futaba S-Bus system
I do agree that Futaba or perhaps Robbe need to be careful not to scare customers as this does look to be getting a bit more complex and expensive. Will the average modeler know when these sorts of components are necessary to use in their system? What are the guidelines? They may find customers will need a lot more consultation from tech support or reps as a result. My take is for the typical setup, none of this is needed. The initial Futaba presentations and docs mention none of this and you can distribute 2 or if necessary 3 (or more) batteries throughout the system given you have the spare ports(which you can even Y harness in if you like).
Posted on: 7/24/2012 5:50 PM by Author "dbsonic" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11167925

RE: Cali Sunday flying videos: SM Hawk 100, GJC MIG-15, FB Rafale
Awesome. The Mig looks great.
Posted on: 7/23/2012 11:38 AM by Author "dbsonic" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11165964

RE: paint gun recomendation
Ditto that on the HF gun. I figured it would be a one or 2 time use item and that something internal might rust after first couple of cleanings. But not so. Great gun for the price.
Posted on: 7/18/2012 10:46 AM by Author "dbsonic" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11160024

RE: Futaba S-Bus system
Back to the question about the sbus channel limitation. Is it that the typical Fut sbus rx provides 8 channels parallel and then a sbus port for another 10 giving a total of 18? 18 being the max?(nevermind how many proportional vs non). That would seem to fit with the 18ch system. presumably they used 4 bits for the sbus channel so I would think the max may actually be 16 sbus channels.
Posted on: 7/17/2012 2:26 PM by Author "dbsonic" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11158884

RE: Futaba S-Bus system
I once had an elevator pushrod fail on my JHH F86. Fortunately I was running dual elevator servos(one per elev surface) like most everyone these days. And so the other elev half saved the plane and it flies to this day. Again lessons from the full size. They do redundancy for a reason.
Posted on: 7/17/2012 12:09 PM by Author "dbsonic" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11158839

RE: Futaba S-Bus system
In full size aircraft are they not going this way also? You want to talk about a lot of wiring, check out airliners. They used to have a mile of wiring in those things. But to the point of redundancy, I would definitely consider a double RX(common with 30% and greater IMAC style aircraft) system with SBUS. That would work great and 2 separate SBUS systems for controlling left and right sides. And if they make a single RX with dual SBUS that would seem a fair way to go as well but I might prefer still the 2 receiver approach.
Posted on: 7/16/2012 12:27 PM by Author "dbsonic" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11157555

RE: JetCat Startmotor Specs
Had to make a lot of assumptions without a circuit diagram but if the ECU can really source 20A no problem and it truly was shorted, then there must be some evidence it was shorted somewhere. 20-100Amps racing to ground will make something toasty somehwere. I would worry about a collapsed rail but suppose it could be contained to the drive transistors. You should look for tarnished and sooty parts. If you find some then those components need replacing. Anyways if the components are still okay, Scott then you may be okay with even just 1ohm then. Assuming you drop all that across the resistor that's 16Amps. That's alot of current so get a beefy power rated resistor. But wasnt there already one originally? Or this is some kind of mod?
Posted on: 7/13/2012 12:34 PM by Author "dbsonic" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11154051

RE: JetCat Startmotor Specs
Its too bad they didnt tell you how much current the ECU could source but lets assume less than 1 amp. Start off by assuming you drop the entire voltage across that resistor (the motor a short). And size it accordingly. if you are really supplied by a 4s lipo then that is roughly 16volts so start off with 100ohm. So thats only 160mA and should do no harm and see if that spins your motor sufficiently. Then work down to a 50ohm and perhaps maybe as low as 10ohm. my 2 cents.
Posted on: 7/13/2012 10:09 AM by Author "dbsonic" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11153855

RE: FEJ F-14 servo rudder torq question
"mean three separate switches and regulators" What RX you using. With Futaba SBUS recievers like the 6208, you get an HV rx and regulators are not needed. I got the impression you plug in the battery anywhere and hubs/rx determine the distribution. BTW you can plug a battery into the SBD-1 cable and it will power the entire system as it if were plugged into the RX. Not saying you want to do that but is pretty cool. olnico, nice post about determining flight loads/linkage configuration using Rc calc.
Posted on: 6/29/2012 2:03 PM by Author "dbsonic" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11136923

RE: Lipo Fire in Workshop
One thing I have noticed is that sometimes I catch a wrong cell voltage on one of my older packs after plugging in the balance plug before the charge. It reads on the low side of reality which is bad. Good thing is my Ultima seems to catch it. It wont charge if it thinks the pack is so unbalanced. I plug it in again, check the voltage to make sure it reads similar to the other cells. I guess if I really do have a pack that is so far unbalanced, this charger will not accept it making it unusable. Maybe thats a good thing and time for the pack to be retired.
Posted on: 6/29/2012 1:54 PM by Author "dbsonic" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11136906

RE: Lipo Fire in Workshop
Dantley, that was terrible but glad you werent hurt. Didnt realize you were attempting storage mode which is the right thing to do. But I have to think that once in storage balanced state these Lipos are safe. Here is why I think that. Manufacturers and warehouses that sell these have literally thousand upon thousands of these. I have not heard about their factories and warehouses burning down(have they?) The probability that they have a "store state fire"(since that's the way they keep and ship them) is much greater than you are I given we have at most 100 of these(most have far fewer) and they store many more - any one of which could "go". Except their batteries are brand new and ours cycled and used. So its somewhere in the handling/discharge/charge cycle that they have the potential to bite and likely due to imbalance. If this is not the case and they can simply spontaneously combust anytime then we might as well forget this technology altogether(and eventually it will self destroy and we wont be able to obtain them anymore).
Posted on: 6/28/2012 3:40 PM by Author "dbsonic" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11135585

RE: Best way to locate dowels for hatch?
The way you do this is you make oversize holes first. Then make backing plates a bit larger than those oversize holes so you have some overlap. In the back plates, drill your hole for your dowel. Now assemble everything and tape/secure it all in place. Then slip those backing plates over the dowels sticking through your oversize holes and glue those backing plates in place. Your dowel holes are now in the perfect location.
Posted on: 6/26/2012 10:41 PM by Author "dbsonic" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11133397

RE: Pushrod Failer
"Unfortunately structural engineering is not the strong suite of many of the ARF providers" Exactly. My favorite was when Hangar 9 came out with the 1/4" thick aluminum landing gear that comes in 2 pieces and they have you bolt it to the 1/8 lite ply landing gear plate that is supposed to take all the moment loading from landing. ..But it packs nicely in a box. Which they have you keep for the pieces after the first hard landing. I guess they expected people to pitch it in favor of a one piece carbon/fiberglass gear.
Posted on: 6/26/2012 1:29 PM by Author "dbsonic" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11132782

RE: Lipo Fire in Garage
You could. The ammo box has the advantage of portability, but the cinder block has 2 or 3 compartments already and youtube vids show the idea of a ziploc bag of sand to snuff the fire. Works really well. credits to utahflyers. http://www.youtube.com/watch?v=ZNxLGDwGw-k
Posted on: 6/26/2012 12:53 PM by Author "dbsonic" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11132727

RE: Gear Doors, What is the best/easiest way to install??
Great tutorial. Thanks. Does everybody just use pneumatic actuators on nose gear doors or can the door be closed with rubber bands/springs sufficiently? My worry is if springs, with the added resistance, the nose gear may not extend all the way and result in nose skid landing.
Posted on: 6/26/2012 12:49 PM by Author "dbsonic" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11132714

RE: Lipo Fire in Garage
Good info, report says venting at 470F. So maybe the temp sensor setup to cutoff during charge is an effective way to go.
Posted on: 6/26/2012 11:44 AM by Author "dbsonic" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11132629

RE: Lipo Fire in Garage
+1 on clay pots and cinder blocks for storage. old Weber BBQs with vent holes too.
Posted on: 6/26/2012 11:37 AM by Author "dbsonic" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11132610

RE: Lipo Fire in Garage
I went ahead and got temp probes/sensors for my charger. I have no idea it they will work but I have the temp set pretty low and it should cutoff the charge if things get fairly warm.. but what I dont know is if this prevents the Lipo from going catastrophic(i.e chain reaction that once it starts to go that direction it will blow no matter what). Anybody know? I never tested it. OP. Thanks for the post. Its a reminder.
Posted on: 6/25/2012 4:06 PM by Author "dbsonic" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11131642

RE: Flying in adverse weather conditions
That's the tough part with RC. You dont know the indicated airspeed in high wind conditions(in contrast, is much easier to see and feel in calm conditions because it is effectively your ground speed, adjusted for altitude. Assuming no telemetry data usage here). General rule is use less flaps in windy conditions. Even though they lower your stall speed, the main concern is maneuverability/controllability/getting her down and not landing short. If you are talking 40mph crosswind though... better to fly another day.
Posted on: 6/25/2012 11:17 AM by Author "dbsonic" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11131265

RE: Flying in adverse weather conditions
Agree with HarryC. Laminar flow is not actually that big of an issue but in full size you want to watch the gradient so you carry extra indicated airspeed(as much as 1/2 the wind) expecting the wind velocity to decrease the closer you get to the ground(due to frictional losses with the terrain surface). Throw trees, buildings close to the runway and heat of summer thermals/t-storms in there and its a huge challenge. Do the best to keep the windward wing down and get her down in one piece.
Posted on: 6/22/2012 3:08 PM by Author "dbsonic" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11128117

RE: Are all RC forum's activity in decline?
I dont think it has to do with RCU technical issues. unpleasant but RCG works flawlessly and according to your numbers it is also seeing similar declines. FYI, Aviation in general is seeing decline whether it be RC or full size, hang gliding, you name it. Costs, economy, lack of flying sites and lack of airport upkeep are all detractors. And I'll just say it. 911 didnt help peoples' persception of flying either. Now its a hassle to fly on an airline. Meanwhile you have other new things (social media, gadgets, tons of online content)capturing peoples attention instead. And that's the way it is.
Posted on: 6/20/2012 12:27 PM by Author "dbsonic" in the forum "The Clubhouse"
http://www.rcuniverse.com/forum/fb.asp?m=11125502