RE: Skymaster F-16 rudder flutter fix
Thanks for the post, Jack. I'm building this jet right now and have been going back and forth on whether to use the stock setup or do the BVM-recommended modification. I'm installing the same engine you used (or the equivalent): a JetCat P160-SX. My biggest qualm is that Bob and Dustin strongly recommend the external linkage, and I have the utmost respect for both of them. What did you mean by "Wrap a 1/4" by 1/4" piece of aluminum tape around the rudder steel torque rod?" Where did you place the tape?
Posted on: 11/19/2009 11:22 PM by Author "Jeffpro" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9266673

RE: suggestions for a sports jet for a p70
Bandit!!!
Posted on: 10/29/2009 4:28 PM by Author "Jeffpro" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9212862

RE: has anyone built a thrust reverser yet ?
Thrust reversers are somewhat discouraged by the AMA. Here's a quote from the AMA turbine safety regs: [i]Other special controls such as water injection, thrust reversers, variable nozzles, etc. are acceptable only if engine manufacturer provided and supported by development testing and user training.[/i] They're not forbidden, just not quite approved, either.
Posted on: 10/29/2009 4:25 PM by Author "Jeffpro" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9212857

RE: QPoxy
It's good stuff (I used some last week after picking up a couple of tubes at Super Jet South), but it runs a lot more than AeroPoxy and VPoxy. Aeropoxy is still the right stuff for creating nice fillets and such. QPoxy will be nice, I think, for field repairs, and for applications where you WANT an adhesive to run so it can ooze into gaps.
Posted on: 10/29/2009 11:49 AM by Author "Jeffpro" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9212181

RE: Reason for Engine Shutdown Identified?
Black magic is right!
Posted on: 10/23/2009 1:57 PM by Author "Jeffpro" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9196268

Tailpipe Alignment
How perfectly does a turbine nozzle need to be centered in the tailpipe? Is 1/8" misalignment (offset from center) too much?
Posted on: 10/23/2009 11:08 AM by Author "Jeffpro" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9195891

RE: Reason for Engine Shutdown Identified?
I should have included a link to the previous thread because it answers many of your questions: [link]http://www.rcuniverse.com/forum/m_9189256/tm.htm[/link] Many have told me that a static discharge can indeed cause the ECU to report a power failure, although not everyone agrees. I didn't notice any of the receivers blinking, but to be honest, I might have overlooked it. I don't mount the satellite receiver directly on top of the bypass cover; it's on a mount that's glued to the cover. I'm going back to that configuration because the engine seems to run equally well with or without the cover. Thanks for your help, BTW!
Posted on: 10/22/2009 11:13 PM by Author "Jeffpro" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9194977

Reason for Engine Shutdown Identified?
We had a great discussion the past couple of days in another thread about why the engine shut down on my Bandit earlier this week. The evidence (a power-fail report from the ECU) pointed to either an intermittent battery connection or possibly a static discharge. I thought of something this afternoon that might explain what happened. Just before the flight in which the engine shut down, I had the jet upside-down while I attached the wings. When I turned it back upright, one of the satellite receivers had fallen out. I replaced the receiver, finished my prep work, and took off. Normally, the satellite receiver that fell out sits on top of my turbine bypass. Because I've made the last few flights without the lid on the bypass (I installed a new FOD screen and wanted to make sure it didn't restrict airflow around the turbine), I attached the satellite receiver to the inside of the fuse next to the turbine. When I did, I draped the lead connecting the satellite receiver to the main receiver over one of the wing tanks. If static electricity was generated by fuel sloshing in the tank, it had a direct conduit to the receiver through the satellite lead. In most of the flights prior to this one, the lead sat on top of the turbine bypass and never touched the tank. We'll never know for sure, but a static discharge from the tank to the receiver through the satellite lead seems like a possibility. In the future, I will be a LOT more careful how I route my satellite leads...just in case.
Posted on: 10/22/2009 8:48 PM by Author "Jeffpro" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9194598

RE: What do you think of Century Jets
It's just one data point, but check out my experience in this thread: [link=http://www.rcuniverse.com/forum/m_4412764/anchors_4412764/mpage_1/key_jeffpro/anchor/tm.htm#4412764]Fix for Century Jet Design Flaw[/link]
Posted on: 10/22/2009 2:07 PM by Author "Jeffpro" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9193725

RE: Bandit ARF...Any bad points.
Out of curiosity, how many of you who have a 120 or higher in your Bandit use a speed sensor to limit the speed? I have a JetCat speed sensor in mine but have thought about removing it and just making sure that I manage the throttle well enough to stay in control.
Posted on: 10/21/2009 2:19 PM by Author "Jeffpro" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9191113

RE: First Flame-Out
Thanks, Matt! Extremely helpful. I'm increasing the concentration of anti-static additive in my fuel just in case it was a static electricity discharge that shut down my turbine yesterday. Furthermore, am looking at ways to add redundancy to my power system. I already have a JR PowerSafe system to install in the F-16 I'm building, and I plan to look at alternatives such as SmartFly as well.
Posted on: 10/21/2009 12:45 PM by Author "Jeffpro" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9190874

RE: First Flame-Out
Unfortunately, I don't have an empty receiver channel to plug into. But having two connections rather than one makes sense. Maybe it's time for a 12X. [;)]
Posted on: 10/21/2009 9:39 AM by Author "Jeffpro" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9190497

RE: Bandit ARF...Any bad points.
[quote]ORIGINAL: readyturn Question to the group.... I have a BARF, which I have not flown yet, as I am not sure of the distances needed for takeoff and landing. My club field is 500 ft x 35 ft, which works fine for tthree of us flying Boomerangs. What are your thougts as to the field for flying the BARF off of??????????? Thanks Rick [/quote] The more runway, the better. My Bandit is heavier than most because of the 120 in it and the extra fuel weight, but I wouldn't even think about flying it on some of the shorter runways that I fly my BobCat off of. A Bandit can be landed in 500 feet, but I don't think I'd maiden it there if it was my first Bandit flight.
Posted on: 10/21/2009 9:37 AM by Author "Jeffpro" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9190495

RE: Bandit ARF...Any bad points.
I've had no steering problems with the stock gear, and I've even gotten used to assembling it at the field. At first I thought assembly was a pain, but after lots of practice I can have it assembled and ready to fly in 10 minutes. The one caveat I would add about a Bandit is that you CANNOT let the nose gear come down too hard or, heaven forbid, let the nose gear touch first on landing. If you do, you'll get into the dreaded "Bandit bounce." It won't happen if you manage the landing properly, but none of us are perfect every time. If it starts bouncing and the amplitude of the bounces are increasing, throw the power to it and come around for another try!
Posted on: 10/21/2009 8:21 AM by Author "Jeffpro" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9190356

RE: First Flame-Out
[quote]ORIGINAL: digitech Static discharge happens mostly on the ground (taking off) and not while flying.. i also suffered a few of these myself with a jetcat P-160 (powerfail) are you using both ECU cables? or just trim function (1 cable)? eather way it is even best to connect the secondary cable also to the ecu even when its not used. a powerfailure can come also from a signal or power-cut to the ecu throttle cable. also dont use a switch between the Lipo and ECU , these also can cause problems to the ECU. [/quote] I don't have a switch between the battery and ECU. It's a direct connection. I use the single-cable setup (trim lever arms the ECU). I'm curious about connecting a second lead even when it's not used. I don't have an empty receiver channel to plug it into, so it would just be dangling off the ECU. Are you thinking that that might prevent a static discharge between pins?
Posted on: 10/21/2009 8:04 AM by Author "Jeffpro" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9190335

RE: First Flame-Out
[quote]ORIGINAL: SinCityJets The problem is the re-boot lasts just long enough to for the ECu not to get a good signal, making it think there was a power failure. I have seen it here to on a lightning. Most likely culprit on this one was static build up in a near-empty tank. Chad [/quote] I was 3 to 4 minutes into the flight, so I don't think it was that. At that point in the flight, my wing tanks are normally 1/3 to 1/2 full and my header tank is of course completely full. I do most of my flying at Georgia Jets and some of the members there have had problems with static discharges in their Ultra Bandits. Interestingly enough, week before last at Georgia Jets, I touched the turbine while fueling and got a static discharge. I waited a few seconds, touched it again, and got another discharge. Once I finished fueling, touching the turbine produced no discharges. Today, before the flight, I touched the turbine a couple of times during fueling just to see if I might be building up a static charge. Nothing!
Posted on: 10/20/2009 11:43 PM by Author "Jeffpro" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9189851

RE: First Flame-Out
[quote]ORIGINAL: mr_matt Hi jeffpro, We need to concentrate on the most_likely_issue versus any_possible_issue. Call me at 805 907 4462 to discuss if you have the time. Regards, [/quote] I'll give you a ring tomorrow.
Posted on: 10/20/2009 11:36 PM by Author "Jeffpro" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9189834

RE: First Flame-Out
[quote]ORIGINAL: SinCityJets Might also be a static issue. Are you using any kind of anti-static spray or additive? Chad [/quote] I do use anti-static additive in my fuel. In fact, I was running a fresh batch of fuel with a fresh capful of anti-static liquid.
Posted on: 10/20/2009 11:35 PM by Author "Jeffpro" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9189831

First Flame-Out
I experienced my first flame-out today. I was flying my BVM Bandit equipped with a JetCat P120-SX at a local airport and lost the engine on the downwind leg of the pattern. Landing was no problem because I was flying off a 4,000-foot taxiway. I turned back to the runway, dropped the gear and the flaps, and landed the jet right in front of me. I'd love to know why the engine quit. There was no puff of smoke like you often see when there's a bubble in the fuel line. I plugged in the GSU after the flight and it told me I suffered a power failure. The ECU battery (a 7.4V Duralite) was fine; it read 8.2V under no load and 7.8 volts under a 1A load. I unplugged and replugged all the battery connections and then flew again without incident. This was approx. the 30th flight for this turbine and it has always performed flawlessly. I'm thinking that maybe I had some dirt or corrosion on a battery contact and that it resulted in a power glitch. The GSU reported 0 fail-safes, so I assume that it wasn't a receiver problem. Is there anything else I should look at?
Posted on: 10/20/2009 8:10 PM by Author "Jeffpro" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9189256

RE: Question for Skymaster 1:6 F-16 Owners
[quote]ORIGINAL: AndyAndrews I used the mod after losing 1/2 of my stab in flight. The mod (no external linkage) is rock solid without any problems. Andy [/quote] What do you mean by "mod (no external linkage)?" Are you still using the rudder post?
Posted on: 10/20/2009 11:21 AM by Author "Jeffpro" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9187974

RE: Question for Skymaster 1:6 F-16 Owners
Excellent first-hand info, icepilot. Thanks for sharing! I like your videos, BTW. I'm ditching the post and going with the external linkage.
Posted on: 10/20/2009 9:46 AM by Author "Jeffpro" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9187787

RE: Question for Skymaster 1:6 F-16 Owners
I'm not sure the default setup is subject to flutter if properly installed. That's what I'm interested in knowing. It's the engineer in me. [:D]
Posted on: 10/20/2009 8:26 AM by Author "Jeffpro" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9187624

Question for Skymaster 1:6 F-16 Owners
I'm building a Skymaster 1:6 F-16 and wondered how many others who have done the same used the internal rudder linkage, and how successful they've been at doing it. Here's the skinny. The Skymaster build manual has you use an internal post to drive the rudder. The post goes up through the fuselage, and a fork at the top engages a horizontal bar in the bottom of the rudder. At least one F-16 that I'm aware of has gone down due to this linkage. BVM now recommends that you forego this linkage altogether and install a servo in the rudder with an external linkage and a control horn. Many people are saying that the default linkage is prone to flutter. Here's my dilemma. The seat in the fork at the top of the rudder post is angled about 20 degrees. If you get the post backwards, you're definitely going to have trouble because the rudder will be forced upward as it turns. The manual is far from clear on this. I suspect that people who have lost F-16s to rudder flutter and tail separation may have installed the post backwards. If the post is installed correctly, it seems as if it should work because it provides a positive, slop-free linkage. So, how many of you who fly Skymaster F-16s have SUCCESSFULLY ued the internal rudder linkage, and how many have gone with an external linkage?
Posted on: 10/20/2009 8:07 AM by Author "Jeffpro" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9187592

RE: Worlds Best RC Jet Pilot
Two names I haven't seen in this thread are Dustin Buescher of BVM and David Payne of Horizon Hobby. Both are top-notch. I once saw David do rolling circles two feet off the ground with a 40%er!
Posted on: 9/27/2009 8:14 AM by Author "Jeffpro" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9126939

RE: Wren or Jet Cat? Cant decide..
[quote]ORIGINAL: SKYPILOT WOW, Nice shilling Harley,[:D] Wrens are also sold and serviced here in the US in Indiana and you know it!! Here are some Wren facts as compaired to the Jetcat. 160 to 160 Wren, Lighter, Cheaper, faster spool times, 3 year waranty Both are great engines, both make great choices, I own the Wren 160, i bought it from Ron Ballard at Wren turbines USA. Ron is a COMPLETELY trained and fully autherized Wren dealer and service agent and has the fastest turnaround time in the industry. Ron is very laid back, friendly and easy going on the phone. [/quote] Spools faster than a P160-SX??? I'd need to see perf data to believe that. A P160, yes. A P160-SX... I own a P160-SX that hasn't flown yet, so I can't tell you exactly how fast it spools. But there's no comparison between my P120-SX and an old P120.
Posted on: 9/22/2009 10:53 PM by Author "Jeffpro" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9116796

RE: Is the Rookie a good first jet?
BobCat all the way. You will love the quality as well as the handling.
Posted on: 9/16/2009 12:11 AM by Author "Jeffpro" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9099416

RE: Extra Long Servo Leads
This may be a dumb question, but do you need twisted wire when you're using 2.4 GHz radio equipment?
Posted on: 9/1/2009 3:28 PM by Author "Jeffpro" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9062162

Extra Long Servo Leads
Anybody know a source for long servo leads, as in 6'-8' long? 22 gauge is OK, but 20 gauge is even better, and the higher the quality of the connectors, the better. Need 'em for my Skymaster 1:6 F-16.
Posted on: 9/1/2009 1:13 PM by Author "Jeffpro" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9061833

RE: Are today's Kero-start turbines better than propane start?
[quote]ORIGINAL: BaldEagel The JetCat early ignitors seem to have had a problem with life expectancy, but the latest Mk 2 seem to last indefinatly, compared to the glow plugs needed for propane start they are far superiour and give a more consistant start up, the more up to date major manufacturers are now making turbines with internal Kero start ignitors which shows their faith in the system, my JetCat 120SX takes a little longer to start than my P80 with an external Kero start, but it has never failed to start and runs wonderully, I will never go back to a gas start and have made this a major factor when looking for a new turbine. Mike [/quote] Love my 120SX, too, and just bought a 160SX to go with it. Neither has been flown enough to judge the long-term durability of the internal ignitors, but I do love kero-start and am hopeful that the SX ignition system will prove out in the long run.
Posted on: 8/31/2009 7:55 AM by Author "Jeffpro" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9058268

RE: Skymaster F-16 1:6 150 flights!
I'm building the same jet right now. You've inspired me! What a beautiful bird.
Posted on: 8/24/2009 5:02 PM by Author "Jeffpro" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9041227