RE: New! On board fire extinguisher for jets
Below is the body of an email previously sent to a customer describing methods of operation. Hope it is helpful. Bill As discussed, Flame Out is activated by pilot control at the transmitter. 1. The most common turbine fires are wet starts on the flight line. The operator or pilot has immediate control, saving 20 to 30 seconds necessary to find and use a conventional fire extinguisher. 2. A second common problem is an airframe equipment or engine malfunction in the air. The pilot operates Flame Out in case of an air emergency. Flame Out will shutdown a full throttle turbine and cool the engine prior to the cornfield crash. Even if fuel tanks break on impact, a cool engine is not likely to ignite raw fuel. Best-case scenario is no fire. Worst-case scenario an extra 3 minutes to arrive at the crash scene with additional equipment. 3. Occasionally a visible fire is observed in the air that can be extinguished under pilot control. The flight controls are not set to fail-safe and often a relatively safe power off landing can be made in a confined area or runway. 4. Since Flame Out is servo activated, fail-safe can also be used. Impact or trigger on impact is an additional possibility. Flame Out will trip if seriously shocked or dropped hard.
Posted on: 10/14/2009 12:07 PM by Author "BillS" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=9172586

RE: A123 for rx pack, regulator required?
[quote]I have one plane that uses 500 to600 mah's for 4 twelve minute flights and another that only uses 300 to 400 with the same amount of flight time. That's running 2 2300 packs in each plane. [/quote] After putting an amp meter on several servos in a few airplanes I was surprised at the difference in amp draw when a servo has binding that is not noticeable otherwise. Bill
Posted on: 8/22/2009 11:20 PM by Author "BillS" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=9036844

RE: TH 75 vibration problems ?
[quote]ORIGINAL: MOTORMAN37 [quote]ORIGINAL: BillS My TH 75 engine was very tight and I preheated it before starting it on the bench. I also relieved the cylinder to piston clearance before running the engine. Will do it again if an engine will not turn over to my satisfaction when cold. Long time mechanic and Mechanical Engineer. Bill [/quote] I understand the preheating you did, but why
Posted on: 8/22/2009 11:05 PM by Author "BillS" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=9036815

RE: TH 75 vibration problems ?
My TH 75 engine was very tight and I preheated it before starting it on the bench. I also relieved the cylinder to piston clearance before running the engine. Will do it again if an engine will not turn over to my satisfaction when cold. Long time mechanic and Mechanical Engineer. Bill
Posted on: 8/21/2009 11:35 PM by Author "BillS" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=9034878

RE: Pusher Muffler
Some of those flying Bob Cat’s are using the following method. Post # 3375 http://www.rcuniverse.com/forum/m_4588799/mpage_135/key_/tm.htm Bill
Posted on: 8/8/2009 10:26 PM by Author "BillS" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=9000915

RE: Why No Choice of Receivers with 10cg???
I have an 8U radio but at least half the flying fleet or 20 or so are flying with only 4 channels. None are park fliers. There is a substantial difference in cost of 8 channel, 7 channel and 4 channel receivers. It also appears that some versions of 8-channel equipment are being discontinued. The marketing seems to obscure what works with what rather than explain. Maybe someday it will all become clear. Bill
Posted on: 8/1/2009 12:07 PM by Author "BillS" in the forum "RC Radios, Transmitters, Receivers, Servos, gyros"
http://www.rcuniverse.com/forum/fb.asp?m=8981342

RE: cooling a pusher
[quote]ORIGINAL: James c harrell I need some ideas on cooling a pusher type engine. Had one and if it idled any length of time it would overheat. I thought of a bigger head like a heli head but are they available for most engines or are they different. Just don't know but I am sure someone out there has the answer [/quote] I have experienced the problem with a number of different engines on a Bob Cat. The lack of pusher prop sizes makes the problem bigger than it should be. Running a smaller pusher prop than tractor seems to help some. Using a larger engine than would normally be necessary seems to help some. Going to the end of the runway and crank and go seems to help, i.e. no taxi time and no run up. However the engine in pusher configuration often simply runs different in the air and I have not found a solution. Bill
Posted on: 7/29/2009 12:00 PM by Author "BillS" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8973651

RE: Muffler pressure - yes or no
[quote]ORIGINAL: hueyman How would you keep fuel from spilling out the tank vent if not attached to muffler pressure? [/quote] On the one engine I run without muffler pressure I put a “T� in the muffler line about 1� from the muffler. One side of the “T� is not connected to anything. Fuel does not leak from the open T. It looks like a normal setup and works well. I guess there could be a miniscule amount of pressure at high throttle. Bill
Posted on: 7/12/2009 12:36 AM by Author "BillS" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=8925607

RE: Header Tank / CG
[quote]ORIGINAL: captinjohn Sounds like maybe you fly pattern style....and I guess some up-lines can be long or several seconds.  I am kinda a guy that likes to fly smooth & all of a sudden throw in some mean snap rolls and spins.  I enjoy landing and go around if my last landing of the day does not look like a #10!!!!!   Capt,n<[/quote] I am a casual flyer who likes to experiment. However running out of fuel on the up line is undesirable. Header tank was only 1oz or 10% of total fuel. The purpose of the reversed main tank was to uncover the clunk so the fuel draw would be from a much shorter distance and the main tank could be further away without concern about starving the engine. Bill Slips. I know better.
Posted on: 6/8/2009 10:42 AM by Author "BillS" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8835089

RE: Nitro models pusher Bobcat?
From a design standpoint I have always thought the mains were too far back on the Bob Cat. Sitting on the wheels on the bench it takes a lot of weight on the stabilizer for the Bob Cat to rotate. I use fixed gear and moved the mains forward so I can’t give you a comparison weight. I located the mains about 2 1/2� behind the CG. I also fly Kougars and they stick like glue on landing. The Kougars are all set up with a negative AOA with mains 3� or so behind the CG. Bill
Posted on: 6/4/2009 10:36 AM by Author "BillS" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8824938

RE: Muffler pressure - yes or no
I have one engine that runs better without muffler pressure. Had a number of dead sticks on the first 20 or so flights in a different airplane. While running on the bench I noticed that pulling the pressure line while at 8,500 rpm resulted in cleaner running. The engine is an early 90’s two stroke. Thirty-five more flights have been made without muffler pressure and without any problem or dead stick. Bill
Posted on: 6/1/2009 11:39 PM by Author "BillS" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=8818397

RE: Header Tank / CG
[quote]ORIGINAL: captinjohn Bills, this is something I am going to try.  Negitive pressure should not happen (my guess) the pump should keep the level in hopper tank the same I hope.  That should alow the engine to have the same mixture and not go lean.  I am going to set this all up on a very big stand so I can see what is happening. In a plane the system would be hard to see whats going on.Â
Posted on: 6/1/2009 10:19 AM by Author "BillS" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8816049

RE: Header Tank / CG
"Or how you will break the flow from the main tank so that the header tank is not getting negitive pressure from the main tank. "In the installation that I described the main tank clunk is not under water (fuel) on the up line but is under water on the horizontal. Horizontal attitude draws fuel from the main tank. Vertical does not draw fuel from the main tank. The set up that I flew and tested had a break over attitude at 38* with a full load of fuel.Header Tank: 1 oz. with 2 lines plumbed normally.Main Tank: 11,3 oz. with two lines. Stiff clunk that did not ‘U.’ Muffler pressure to main tank only. Main tank reversed so clunk was towards the engine.Vent line on main was adjusted to allow about 9 1/2 oz. total fuel for header tank and main tank.There were a number of successful flights and the fuel system performed as anticipated.Bill
Posted on: 5/30/2009 11:39 PM by Author "BillS" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8812635

RE: Wife bothered by epoxy glue. Alternate solution?
Maybe a new girlfriend would help set the priorities.Bill
Posted on: 5/30/2009 12:34 AM by Author "BillS" in the forum "Tips & Techniques"
http://www.rcuniverse.com/forum/fb.asp?m=8810535

RE: Header Tank / CG
[quote]ORIGINAL: Sport_Pilot [quote]ORIGINAL: BillS Might want to rethink the issue. No fuel is drawn from main when vertical. Fuel is drawn from main when horizontal.Bill [/quote] Well there you go if fuel is not drawn then the engine will quit. However I think you mean that fuel is not drawn from the tank. This doesn't matter its the elevation of the clunk to engine that counts
Posted on: 5/30/2009 12:28 AM by Author "BillS" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8810526

RE: Nitro models pusher Bobcat?
The main wheels were changed from 3� dia. to 2 5/16� which will probably represent 1/2� or so AOA change. With the TH .75 there seems to be plenty of reserve power at lift off so I should be OK. I will use about 1/32� aileron down and some down elevator trim on the initial flights. ‘Leap off ground’ cannot possibility be worse. After the last series of big bounces I decide to stop repairing the fuselage. Either learn how to fly it or destroy it.Bill
Posted on: 5/30/2009 12:23 AM by Author "BillS" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8810513

RE: Nitro models pusher Bobcat?
“known good� set up is a questionable statement.Weight 8 pounds without fuel.AOA = zero degrees when sitting on the ground.GC is approximately 10 1/8�.Engine TH .75Prop 11 X 8 pusher13,000 max rpm.I find that ailerons down less than 1/16� makes a difference during take off. Aileron must be adjusted to neutral after take off for airplane to fly level at speed. Leap off ground seems worse when ailerons are neutral. Down ailerons push the nose down. Seems backwards.I have landed with more than 1/8� up aileron reflex but it was with a smaller engine and probably does not apply to the current .75 engine, which has a higher pitch prop.Idle speed of 3500 rpm is likely to produce a bounce. At 3000 rpm landings are generally without bounce. The airplane flies very flat with a dead engine. It has never bounced when the engine was dead but lands long.Ground run time and taxi time makes a difference in how the engine runs. Will test with slight positive AOA soon to determine if ‘leap of ground’ is reduced.Bill
Posted on: 5/29/2009 9:45 AM by Author "BillS" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8808496

RE: Header Tank / CG
Might want to rethink the issue. No fuel is drawn from main when vertical. Fuel is drawn from main when horizontal.Bill
Posted on: 5/29/2009 9:32 AM by Author "BillS" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8808455

RE: Header Tank / CG
The main tank clunk line does not U and the clunk is uncovered on the up line. Draw is only from the header on up line.Bill
Posted on: 5/28/2009 10:31 AM by Author "BillS" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8805690

RE: Header Tank / CG
A header and main tank concept that is a little too complex for most and is therefore not recommended I have used the concept and it works.But if the main tank is reversed front to back and the clunk is at the front (with stiff fuel tubing) the fuel raw height can be controlled. I used a bigger main tank than normal and then short filled the tank controlled by the height of the fill vent line.At vertical attitude the draw is only from the header tank but with full muffler pressure. At horizontal attitude the fuel raw is from both header and main tank with full muffler pressure but with zero draw height. I used 38* as the break over from main to header only fuel feed. I sized the header to provide fuel for the longest up line expected. The parameters can easily be change to suit your circumstances.As with all system fuel draw height varies some as the fuel is depleted. Think about it. Good luck.Bill
Posted on: 5/27/2009 8:38 PM by Author "BillS" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8804147

RE: Header Tank / CG
Joe,Have you experimented with a header tank? The main tank can be a small distance from the header as you begin to experiment and can be moved further back if the results are favorable. You may not have enough room for a main tank at the CG.Bill
Posted on: 5/27/2009 12:34 PM by Author "BillS" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8802837

RE: Header Tank / CG
I believe there is little flight performance to be gained by moving the tank to the CG. However there are a lot of troubles to be found with the tank far from the firewall. A few calculations of CG change on a 120-size airplane might be important in your evaluation.I have used header tanks numerous times with good success. At full throttle muffler pressure is greater than 9 inches of water. The last header tank installation used a main tank with the clunk to the front of the airplane. The forward clunk allowed fuel draw from the header tank only on the up line and on angles of attack greater than 38*.A main tank sitting on the ground can be sucked dry at idle. It takes only a few minutes to try the experiment with no changes to the airplane.Bill
Posted on: 5/26/2009 12:12 PM by Author "BillS" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8799714

RE: Nitro models pusher Bobcat?
but too much positive angle of attack will turn a hot landing, or even a normal not stalled landing into a bouncing tip stalling unhappy time. I have had a few of the “bouncing tip stalling unhappy time� landings. Idle speed too high seems to aggravate the bounce even with zero AOA. It is difficult to get a 75 engine with 11 x 8 pusher to slow to landing speed. Incidentally my airplane flies very flat and lands long when the engine has quit. With smaller engines (had three) on the airplane it lands much better. However the take off with smaller engines was always without enough reserve power and sometimes scary.In addition aileron down by less than 1/16 inch has a big effect on the take off. Aileron reflex down pushes the nose down. The most successful flights have been with slight aileron reflex down for take off and to adjust to neutral flight when in the air.There seems to be a very delicate balance between engine size, prop size, AOA, CG, and aileron reflex without much margin of error.Bill
Posted on: 5/26/2009 11:26 AM by Author "BillS" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8799601

RE: Non-pumped 2-stroke with tank at CG?
I believe there is little flight performance to be gained by moving the tank to the CG. However there are a lot of troubles to be found with the tank far from the firewall. A few calculations of CG change on a 120-size airplane might be important in your evaluation. Bill
Posted on: 5/13/2009 8:56 PM by Author "BillS" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8766877

RE: Tower .75 2 stroke issue HELP !!!
[quote]ORIGINAL: RCPAUL Usually, you increase the compression ratio to use low-nitro fuels! [i]the extremely tight bore taper prevents removing a gasket [/i] - why? Paul [/quote] Good question. After looking inside the engine again the conclusion has to be incorrect. Must have been too many Coors. Bill
Posted on: 5/11/2009 11:52 AM by Author "BillS" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8759493

RE: Tower .75 2 stroke issue HELP !!!
[quote]ORIGINAL: Charley [quote]ORIGINAL: BillS My engine had two head gaskets and was sensitive to head bolt torque. Never did understand the two head gaskets but it runs fine now. Bill [/quote] The two head gaskets were in there probably because the engine was designed to run on no-nitro fuel. They were lowering the CR for us nitro freaks. [:D] CR [/quote] Sounds logical and you may be correct
Posted on: 5/10/2009 10:04 AM by Author "BillS" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8756425

RE: Tower .75 2 stroke issue HELP !!!
My TH .75 was also very tight and I took it apart and fitted it to my liking. Since I put it back tight I also heated the engine before starting it for the first few tanks. The cylinder appeared to have burrs at the top of the cyliner possibly caused by the final tumbling operation. Also the break in procedure should be different than your description. My engine had two head gaskets and was sensitive to head bolt torque. Never did understand the two head gaskets but it runs fine now. Bill
Posted on: 5/9/2009 7:24 PM by Author "BillS" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8755038

RE: Nitro models pusher Bobcat?
[quote]ORIGINAL: CrashPro And the winner of the 'Ugliest Bobcat' contest is.............. [/quote] CrashPro, The pictures look like many of my airplanes and I love it. Often the plain Janes provide remarkably more pleasure than their prissy counterparts. Performance is important. Bill
Posted on: 5/8/2009 9:37 PM by Author "BillS" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8753023

RE: Fuel Tank in a pusher prop Jet
Like others have said the tank spout is towards the front and the clunk is towards the rear. It is a little tight but not difficult to make room. Villa is absolutely correct about engines running different in pusher configuration. Some engines are more difficult to tune in pusher configuration than others. One minute from engine starting is a good rule of thumb. I found it necessary to use smaller props when in pusher configuration. The all up weight of the airplane is likely to be 7 pounds and an OS .50 was too small in addition to tuning difficulty as a pusher. Bill
Posted on: 4/27/2009 12:02 PM by Author "BillS" in the forum "Questions and Answers"
http://www.rcuniverse.com/forum/fb.asp?m=8719264

RE: .....sig king kobra
Never ha a hinge problem of any kind on a Kougar or King Kobra … except in a crash. However the rudder is usually connected to the front wheel steering, which receives a lot of shock load. Bill
Posted on: 4/26/2009 10:02 PM by Author "BillS" in the forum "Kit Building"
http://www.rcuniverse.com/forum/fb.asp?m=8717698