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RE: DX7 problem
Sounds like something just went bad. Sounds like more of a receiver issue than transmitter. Hopefully you sent the receiver in also. I usually will "fly" a plane on the ground with a brand new receiver working the controls for a couple of flights worth of time since many times if a piece of electronic gear is going to go bad it will be in the first hour of its use.
Posted on: 6/9/2010 8:10 PM by Author "RCHubbub"
in the forum "3D Flying!"
http://www.rcuniverse.com/forum/fb.asp?m=9792763
RE: Well there goes an $8 glow plug...
An F plug is also longer than many two stroke plugs and the element will sit closer to the combustion chamber which may cause issues with plug longevity depending on the two stroke engine.
Posted on: 6/8/2010 6:10 PM by Author "RCHubbub"
in the forum "Questions and Answers"
http://www.rcuniverse.com/forum/fb.asp?m=9790328
RE: Spektrum DX7 reciever feedback
[quote]ORIGINAL: gramps70 Has anyone had any problems with Signal feedback using the DX7 reciever? I have a KMP P47, 71inch span, useing a RCGF 26cc gas engine and electronic ignition. At full power on the ground the ailerons and or flaps will jump like they are getting a bad signal. The flaps do have a reversing y harness installed to make the go the same way. [/quote] Amplified reversing Y? This might apply. http://www.spektrumrc.com/Articles/Article.aspx?ArticleID=1797
Posted on: 5/3/2010 11:24 AM by Author "RCHubbub"
in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=9706816
RE: Tell me again about Rx batteries...
[quote]ORIGINAL: abufletcher Well, all the numbers just aren't adding up. Today I flew my Kyosho Me109 ARF powered by a fully charged 4.8 volt 700mAh battery (Sanyo, purchased about a year ago, no problems). When I took it off the Hanger9 SureCycle it was reading 5.8V. That's the reading I ALWAYS get on all my 4.8V batteries on this charger. Could this be related to the fact that in Japan household current is 110V but 50 cycles? I did three flights (with a LOT of aerobatics) for a total of about 40 minutes of airtime. After each flight, I checked the power level with my Hanger9 voltmeter. After the first two flights, the pack was reading a bit over 5.1V or so and 4.9V under load (at the 1A setting). After the third flight, it read 5.1V but dropped to 4.7V under load. I figured better safe than sorry so I packed up and came home. At home I put the pack back on the Hanger9 charger and ran the discharge function to see how many amps were ''left.'' To my very great surprise, when I checked a couple hours later, the display read 704mah! What's up with that??? [sm=confused.gif] BTW, I'm assuming that 1A on the voltmeter stands for a load of 1000ma (2A=2000mah and .5A=500). This is a six servo model (T, R, E, 2x A, Retracts) so is the 1A setting ok? [/quote] Not sure. You've had a battery that was essentially dead with 18 mAh left but was still flying, and you've had a battery that was essentially still fully charged with 704 mAh after 40 minutes of hard flight. So hard to draw any useful conclusions. I would take the fully charged battery and while it is discharging, record periodically the voltage and amount of discharge to help become familiar with the relationship between those two numbers. Yes. 1A = 1000mA. A 1000mA current draw at one hour would be 1000mAh. Don't know about the 50Hz line frequency, but I don't think it would cause an issue. It's going to be converted to DC voltage anyway for the charger. 1A test load is fine for the battery and what you are doing. The only real reason for testing a battery with some small load is to discharge the surface voltage on the battery's plates so that the battery's density voltage can be measured. Any larger test loads are useful to stress test a battery that might be used in high current applications such as a motor battery or a battery powering a very large aerobatic systems for example.
Posted on: 4/7/2010 10:24 AM by Author "RCHubbub"
in the forum "RC Scale Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=9643770
RE: Tell me again about Rx batteries...
[quote]ORIGINAL: abufletcher [quote]ORIGINAL: RCHubbub When you said it reads only 18 mAh I presume you mean you went home and discharged it and measured it with only 18 mAh left in the battery before the low voltage cutoff was reached on the discharge cycle. If so, then honestly that doesn't make sense, but there are too many variables here. [/quote] Yeah, it read 18mAh after I got home
Posted on: 4/4/2010 10:22 PM by Author "RCHubbub"
in the forum "RC Scale Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=9637648
RE: Tell me again about Rx batteries...
[quote]ORIGINAL: abufletcher Maybe I just need to stop trying to understand. [:'(] Just tell me what battery and charger combinations you all use and I'll buy that! Only once in 6 years have I ever lost a model to a dead Rx battery and that was because as I was charging the packing in the model through I had left the switch on so it wasn't really charging. But I can't help feeling that I've just been lucky. The night before I go to the field, I plug in the battery pack. The next day I fly for 30-60 minutes. I go home. That's all there is to my battery ''technique.'' [/quote] I think it's really just too open ended to answer your question. I think you are almost there. You are doing the right things. You are measuring how much the battery discharges in mAh and how much it takes to fully charge back up. You are measuring voltage without a load and with a load and seeing how much of a voltage drop you are getting. Doing the discharge cycle you can watch how the battery voltage drops and how it really drops down in the last 10% of the battery's capacity. Understanding these relationships will help you to make the right choice in battery size and understanding its reliabiltiy/dependabiliity during the life of the battery. Hopes this help some.
Posted on: 4/4/2010 9:35 PM by Author "RCHubbub"
in the forum "RC Scale Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=9637531
RE: Tell me again about Rx batteries...
[quote]ORIGINAL: abufletcher [quote]ORIGINAL: BobH Just remember this.. You can get lots of volts from a decent sized battery. The smaller the battery the less available. A decent volt meter (plug in type) is sufficient. It'll tell you how much you have remaining in the battery. If its suspect (below the recommend level) you dont fly. Pretty simple. [/quote] I must not be understanding the basic relationship between volts and mAh. I have a plug-in volt meter (from Hanger9). When I plug it in, it tells me the pack's voltage pre-load and under load. If the battery falls below 4.8 (under load) then it isn't safe to fly. It doesn't tell me anything about mAh. Are volts and mAh just flip sides of each other, i.e. less volts remaining means less mAh? If so, why do we need to care about mAh? Seriously, this makes absolutely no sense to me. So given two packs, one 4.8V 600mAh and the other 4.8V 1200mAh, the second pack should allow me to fly for twice as long, right? [/quote] The relationship between volts (potential) and mAh (capacity) is this. For NiCd and NiMH chemistries, as the capacity drops so does the voltage. So unless you have a watt or amp meter hooked up during flight which I know you don't, the only way to have an idea through measurement of how much capacity you have left is by measuring the voltage. Though it is not really standadized, the nominal voltage of a cell is the cell at approxiametly 30 to 60% of its capacity depending on the manufacturer and marketing hype. That is why a fully charged battery measures above its nominal voltage and as capacity is depleted, voltage drops. Now many will use the nominal voltage as a no fly point since just to be safe as there will be a point in time as lower capacities are reached, that the cell begins to die off very fast and could do so in mid flight. Now there are some chemistries such as A123 and other Li variants that maintain a very constant voltage through most of its capacity discharge especially after the first 10 to 20% is used. Since voltages changes very little during the discharge, it is usually not safe to rely on voltage to estimate how much capacity is left, but it is much more important to "know" the battery in use and its application to know when you need to stop flying with it. To generally answer your last question. Yes, double the mAh rating (capacity) of the battery doubles the flying time
Posted on: 4/4/2010 9:24 PM by Author "RCHubbub"
in the forum "RC Scale Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=9637501
RE: Tell me again about Rx batteries...
[quote]ORIGINAL: abufletcher Yikes! The Sanwa 4.8/700mAh pack, which was reading 635 after the last recycle (and then had a 14 hour charge cycle), reads just 18mAh after just three 10 minutes flights on a 6 servo ARF (Aileron x 2, E, R, T, retract servo). Does that mean I absolutely would have crashed on the next flight...or for that matter just dodged the bullet on the third flight? That seems like a pretty heavy use for just three flights!!! [:o] I was flying fast and hard with a lot of maneuvers, but still....just three short flights??? My voltmeter reads it as having 5.32V and 4.08 under load (1A). I would never in a million years have guessed that it was that low. BTW, I don't get the voltmeter. I mean what's the point of knowing that the battery is putting out X amount of voltage, if you don't know how long it will continue to put out that amount. Seems sort of like a gas gauge that only tells you the amount of octane is the remaining gas but not how much actual gas is left. I feel like I'm back to square one. [/quote] i'll try to help with my opinions. When you said it reads only 18 mAh I presume you mean you went home and discharged it and measured it with only 18 mAh left in the battery before the low voltage cutoff was reached on the discharge cycle. If so, then honestly that doesn't make sense, but there are too many variables here. Have I seen a six servo setup use 200 mAh per flight? Yep. But that doesn't seem normal for this setup for you. Could you have left the receiver on when you packed up and went home? Was the retract servo binding some? Don't know. But with only 18 mAh left in the battery, that is a dead battery. To me, anything less than 15% capacity is a dead battery. If this is the same battery that was discussed before, then I still don't trust the battery as I think it has too much voltage drop under load. I'll be more bold and say the battery is bad. You have a dying cell in that battery. You can tell since the pack only reads 4.08 volts under load (well under nominal voltage of 4.8 unless that was a typo on you part).
Posted on: 4/4/2010 9:12 PM by Author "RCHubbub"
in the forum "RC Scale Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=9637467
RE: Tell me again about Rx batteries...
Though they don't focus on RC specifically, Battery University is an excellent source of information. http://www.batteryuniversity.com/index.htm
Posted on: 4/1/2010 8:30 AM by Author "RCHubbub"
in the forum "RC Scale Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=9629212
RE: Tell me again about Rx batteries...
[quote]ORIGINAL: abufletcher I've got a HiTec 4.8V / 600mAh 4-cell NiCd battery that when discharged on my Hanger9 Sure Cycle charger reads 478 and 5.8V. It was reading fewer mAh but after a few discharge/charge cycles it got up to 478. On my Hanger9 digital variable load voltmeter (set at 1A) it reads 5.55V and 4.82V under load (i.e. with the load button pushed). What does that all mean? Is this battery good? [/quote] It's a matter of opinion. I would not trust it as it appears that there is a weak or dying cell in the pack that could drop out unexpectantly to the point that you lose your receiver especially if there is a lot of servo action going on which only hastens the voltage drop. Not knowing the history of the battery or even if it's brand new, typically I stop trusting a battery when it won't hold 80% of its rated capacity, or if I have a voltage drop of more than 0.3vdc between no load and a reasonable load. Your battery fails both those parameters for me personally to think of using it.
Posted on: 3/30/2010 11:22 AM by Author "RCHubbub"
in the forum "RC Scale Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=9624061
RE: World Models Sky Raider Mach 1 -Balance ?
CG is relative. You can move CG it to any point on the wing you want though the plane might or might not fly the way you want it too. And whether the relationship is valid or coincidental, for our model planes and how they are constructed, a neutral flying plane will usually have the CG balance point relatively close to the spar as to any other component on the wing.
Posted on: 2/16/2010 11:37 AM by Author "RCHubbub"
in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=9509216
RE: World Models Sky Raider Mach 1 -Balance ?
[quote]ORIGINAL: bsumrell Have a new World Models Sky Raider Mach 1 trainer arf. Pretty decent plane, went together pretty well, but the balance point is not making sense. The balance point they have listed is 80mm(3 1/8'') from the LE although the spar in the wing is about 3 3/4 from the LE. No major bashing, put the plane together pretty much as per instructions with the exceptions of 30 min epoxy being used on the tail feathers. Have all items(battery,receiver,servos etc.) placed per instructions. If I hold the plane at their recommended CG point, the plane is tail heavy. If I hold the plane at the spar like normal, the plane is balanced perfectly and sits level. It has been my little experience that most simple high wing planes such as this one should have the CG located at the spar. Am I missing something here? Do I balance at the spar or at their suggested location? Thanks for any advice. Bryan [/quote] Balancing it at 3 1/8 has the effect of making it more nose heavy in relation to a CG at 3 3/4. For trainer planes it is normal to move the CG more forward and usually ahead of the spar. The plane is tail heavy at 3 1/8 because you haven't added nose weight or moved components forward to bring it into balance at that point. Once you've balanced it at the recommended 3 1/8, if you check it again at 3 3/4 at the spar, the plane will appear nose heavy now.
Posted on: 2/16/2010 9:41 AM by Author "RCHubbub"
in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=9508916
RE: A STARlet is born...
[quote]ORIGINAL: Daniel-EL Just looked at Hobby People's site and the Corby is now $250![:@] [link=http://tinyurl.com/y8nnnwg]38.5% Corby Starlet[/link] [/quote] Ask them to price match their lower price for you. Not sure about Hobby People, but I know Tower has done that in the past for people. They don't usually want their customers to feel screwed just because an item went on sale a couple weeks after they bought it.
Posted on: 1/19/2010 11:44 AM by Author "RCHubbub"
in the forum "RC Scale Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=9429264
RE: Saito FG-20
[quote]ORIGINAL: modelflyer5 Is it my imagination. They have raised the minimum octane rating to 91 octane. I thought that they said that 87 was OK. I did not see any other changes from the revised version that they issued. They did not mention having the fuel tank in the glow position. The Mustang that I have my engine in is still flying nicely. I have gone a click leaner a couple of times since I got the engine back from Horizon. It still is breaking in though. I noticed that the black suit is starting to clear up. It is now just putting out a blue colored oil out the vent line. [/quote] I think they do in a roundabout way on page 13. "It is not designed as a fuel pump to draw fuel from a tank mounted in the middle of your airplane. The fuel tank needs to be mounted as close to the centerline of the Carb assembly as possible; the same as we have had to do for all these years with our glow engine installations."
Posted on: 1/4/2010 1:09 AM by Author "RCHubbub"
in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=9385129
RE: 2.4 Spektrum won't work with a gas engine
[quote]ORIGINAL: Matt Is there a website on there or a document, with ALL the rules for setting up a gas engine in an airplane by any chance? I have one gas airplane and knew really nothing about it. I figured i would just set it up like i do any other glow model. (i soon found out a truck load of information of what NOT to do when you have a gasser -AFTER- i flew it...lol) But I've had it for a season now and have no problems with it. And i'm flying on 72mhz with a pcm reciever. ** one more question, what do you guys think about using 'Y' extentions in gas airplanes? Do they put your plane at risk for interference issues?? thank you so much, and sorry for butting in like this... [/quote] Good info here. http://www.rcuniverse.com/forum/m_8673009/anchors_8674981/mpage_1/key_newbie%252Cgas/anchor/tm.htm#
Posted on: 1/3/2010 9:52 PM by Author "RCHubbub"
in the forum "Tips & Techniques"
http://www.rcuniverse.com/forum/fb.asp?m=9384645
RE: NEW DLE30!
I've noticed a couple of people mentioning a Walbro carb, and I thought mine was going to come with one but instead it came with a Tillotson carb. Is that normal?
Posted on: 10/30/2009 12:11 AM by Author "RCHubbub"
in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=9214151
RE: NEW DLE30!
I can't express how disgusted I am reading all of this. If I had started to check into this engine two weeks after I did, it would have been about the time all of this crapola started and would have definitely bypassed this engine. Whatever it is, it is obviously a manufacturer defect that is relatively easy to replicate. The issue of puddling would seem to have to impact virtually every DLE-30 at one time or another regardless of the engine mounting orientation. I can only conclude it's another example of the manufacturer using the end user as a beta tester which happens way too often, and leaves the end user scrambling for a solution. So unless I miraculously don't have this issue, and have no reason to believe that I won't, I'm left with an engine that I won't trust in a plane (which I have already spent several hours converting over) and is nothing more than a paperweight to me. I bought mine from TBM so I don't really know what to expect from them if I also have this issue. But more than likely it's going to become a wait and see if DL acknowledges the issue and offers a fix or try one of the homemade fixes that will probably void the warranty. The more I think about it the angrier I get. At least I didn't buy a Saito FG-20 as you should see the problems those guys are having. Beta testers should get paid or receive a significant discount off the engine price for finding these issues and determining solutions. [:@] rant over
Posted on: 10/28/2009 11:38 PM by Author "RCHubbub"
in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=9211227
RE: NEW DLE30!
In three weeks the feedback on this engine has gone from pretty much fantastic to they all seem to have some built-in low idle/tilt/flooding issue that you have to use some kind of workaround or modification to overcome. [:@] I really don't know much about engines, but can someone explain why a pooling issue that requires some method to either induce draining of the pool or run the engine at a higher idle to prevent the pooling is not a carb issue? Do most engine manufactures create weeping channels to prevent such pooling that DLE overlooked? And why can't the carb be adjusted to prevent excess fuel from pooling in the first place?
Posted on: 10/26/2009 11:20 AM by Author "RCHubbub"
in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=9203030
RE: NEW DLE30!
I saw it somewhere, but can't seem to find it now. What is the correct spark plug gap for the CM6? And what is that three hole, fiberglass looking gasket item used for that came with the engine?
Posted on: 10/20/2009 8:30 AM by Author "RCHubbub"
in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=9187633
RE: NEW DLE30!
The DLE-30 is my first gasser that I'm trying to get going and I have a few questions if you all could help me out. 1) On rotating the carb 180, there is a gasket on the carb, a spacer, and a gasket on the engine side. The engine side gasket and rubber spacer are shaped for one orientation on the engine and to align with the small hole in the engine, not sure what that small hole is. The carb and gasket seem to have mirrored holes opposite of each other with one of the hole aligning with the hole in the engine and the other hole seeming to be blocked off. So when I rotated the carb, I kept the engine side gasket and rubber spacer in the same position and rotated the carb and carb side gasket 180. Is this all I have to do? 2) After rotating the carb, do I need to make any changes to the initial H/L needle settings before starting the engine? 3) This plane doesn't have an engine box and I may have to mount the ignition unit inside the cowl on the other side of the firewall. Any heat/cooling issues with this? Does the ignition unit need air passing over it for cooling purposes? 4) If I want to have 10-15 minute flight times plus the before and after ground running time and have about 20% fuel reserve, what size tank would be appropriate? I get the impression from reading other posts that a 10oz tank might be all I need. 5) Has anyone tried the J-Tec wrap around Pitts muffler they have listed on their website? 6) Does anyone know the ignition's full throttle current draw?
Posted on: 10/19/2009 12:23 AM by Author "RCHubbub"
in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=9184304
RE: NEW DLE30!
[quote]ORIGINAL: Ken Cz Has anyone used the Dubro pourous metal ( sintered -cast- metal) clunks and do they help reduce bubbles getting to the engine? See link below. http://www3.towerhobbies.com/cgi-bin/WTI0001P?I=LXD741&P=8 [/quote] I'm just getting into gas engines so I don't have any actual experience, but I did ask a knowledgable gas guy about this exact clunk. He said you can use it, but if you have any concerns about bubbles, it is not the best choice. He thinks the felt clunks are the best because they get saturated with fuel so if the tank gets low and starts coming out of the fuel, the saturated felt will help prevent bubbles. But with the metal sintered clunk, it doesn't get saturated like the felt and with its large surface area may even increase the chance of bubbles, so he thinks if a felt-like clunk was not going to be used, a standard clunk would be the next best choice.
Posted on: 10/17/2009 10:18 AM by Author "RCHubbub"
in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=9180155
RE: Minimum Specktrum Radio for Buddy Box
[quote]ORIGINAL: jollycub I have a DX7 transmitter and want to buy a used radio to buddy box with. What is the minimum radio I can buddy box with? Is it the DX6i, a DX5E or what? What was the transmitter that came with the Blade 400? Would that work? [/quote] The minimum standard JR buddybox to me was the S400, but that won't work with the Spektrum. They seen to only work with a digital/computer type radio as a buddybox. The lowest end radio I've seen work as a buddybox and it not being another Spektrum is a JR SX600, but JR doesn't make that anymore though there are some still for sale out there.
Posted on: 9/4/2009 3:55 AM by Author "RCHubbub"
in the forum "JR Radio & Spektrum Radios"
http://www.rcuniverse.com/forum/fb.asp?m=9068857
RE: Aerovate Engines
[quote]ORIGINAL: Piston Hey Bob NO worries at all... We each confirmed each others positive actions!!! I was tickled that both of us were thinking along the EXACT same lines and providing the same valid advice. I know that I had the same problem of having mufflers loosen up and it was sage advice like this that saved me from going nuts trying to figure it out. Great minds......Now if only I could fly like you... [:D] Cheers Henry [/quote] You and Bob do seem to contradict on the red loctite part. Bob says to use it, but in your linked loctite article you say to NEVER use red loctite unless for a specific reason. Is this one of those times?
Posted on: 8/27/2009 9:02 AM by Author "RCHubbub"
in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=9049007
RE: Hangar 9 60 size corsair arf
[quote]ORIGINAL: leedees [quote]ORIGINAL: jim pettis Pit, I had my 1st pair set up exactly like you do now, however, I had maybe a 1/8-3/16'' gap between the retract and the strut. We have narrow grass runways, and generally my bends occured when I would go off into the taller stuff. (I know, I need to practice my landings...) Wasn't that big of a deal, as I had spare wires with me, and I was actually glad for the bend instead of a rip out. However, it would be nice if the retracts would accept 3/16 wire instead of the 5/32. I'm hoping the spring turn cuts down on the issue, as I'm getting worried that at some point I'm going to strip out the set screws on the retracts if I keep reefing on them to tighten down on the latest replacement wire. That last picture is actually one of my new set up in its unfinished stage.... [/quote] The Lado retracts are available (sort of available anyway) with a 3/16'' wire setup. I ordered some ten days ago and the website showed them in stock but nothing yet. On second thought I may be wrong about this as you have a Corsair and I plan to fit the 3/16 size to H9 P-47. [/quote] How did you order them? Are you talking about the 60-2 for the H9 Corsair? I've been checking almost everyday and they've always shown out of stock, and Doug Lado's email last week indicated they still weren't done filling the 60-2 back orders.
Posted on: 8/20/2009 3:54 PM by Author "RCHubbub"
in the forum "ARF or RTF"
http://www.rcuniverse.com/forum/fb.asp?m=9031490
RE: Glow Powered Foam Flycat Build!
[quote]ORIGINAL: brett65 I read about a guy who put a glow engine on a parkzone trojan once, it was on rcgroups. [/quote] Here is one of our club members with his glow engine parkzone trojan. http://www.youtube.com/watch?v=zoD0mONqpV8
Posted on: 8/12/2009 12:58 PM by Author "RCHubbub"
in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=9010576
RE: New 81
[quote]ORIGINAL: kochj this thread is dying... anyone building one?? I will be clearing the bench soon for this one.. [/quote] Typically happens when they don't make the plane anymore, and that's going on almost a year and a half now. I've got more than 200 flight on mine (yep, I count my flights :)) with a 120 AX and have thoroughly enjoyed the plane.
Posted on: 8/12/2009 9:00 AM by Author "RCHubbub"
in the forum "ARF or RTF"
http://www.rcuniverse.com/forum/fb.asp?m=9010076
RE: Saito FG-20
[quote]ORIGINAL: mike early But when speaking of gasoline quantities, does anyone ever use weights? Only volumes, right? [/quote] Typically yes, but if you are going to change tank sizes or move the tank around in relation to CG, then one might find it useful to think in weight. For example, if you buy a plane with a stock 22 fluid oz tank intended for glow fuel but want to convert the plane to a heavier gasser and go to an 11 fluid oz tank, one might think they would be reducing fuel weight by 11 oz. But 22 fl oz of methanol would weigh about 17.6 oz, and 11 oz of gasoline would weigh about 8.25 oz, so the saving in fuel weight is not 11 oz but more along 9.4 oz. So this all boils down to that a fluid oz and a weight oz are only equivalent when dealing with water.
Posted on: 8/4/2009 9:08 AM by Author "RCHubbub"
in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8988764
RE: Saito FG-20
[quote]ORIGINAL: mike early I've been a little confused but didn't try to think about it. But I need to get this straight: We are talking about fluid ounces. 16 ounce fuel tank can hold 16 ounces of water but only 12 ounces of gasoline? By the very definition, when you fill that fuel tank up, you will have 16 ounces of gasoline. Now I realize that a weight ounce is an entirely different animal. One good thing about the metric system is milliliters is always milliliters.... 470 ml of water will fit inside and 470 ml of gas will fit inside. [/quote] Same situation whether it's metric or not. It comes down to density. It depends on the blend, but gasoline typically has a specific density of 0.7 which mean that for the same given volume, gasoline will only weigh 0.7 or 70% of what water would weigh. I'm rounding for simplicity, but a 16 fluid oz container will hold 16 fluid oz of water which will weigh 16oz, but that same container holding 16 fluid oz of gas will only weigh 11 oz. And in the metric system, a container that can hold 470 ml of water will weigh 470 grams, but if it held 470 ml of gas, it would only weigh 329 grams.
Posted on: 8/4/2009 8:22 AM by Author "RCHubbub"
in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8988683
RE: RCGF Engines
[quote]ORIGINAL: Tseres [quote]ORIGINAL: RCHubbub [quote]ORIGINAL: Tseres Connery I have used grade 8 bolts with 60mm of thread. Used red locktite,tightened with a wrench and used a cutoff wheel on cutting the head off. I did this to be able to use the true turn aluminum spinners that I had laying around. I think that this will work for me. If I didn't already have some expensive spinners
Posted on: 7/24/2009 8:01 AM by Author "RCHubbub"
in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8959895
RE: RCGF Engines
[quote]ORIGINAL: Tseres Connery I have used grade 8 bolts with 60mm of thread. Used red locktite,tightened with a wrench and used a cutoff wheel on cutting the head off. I did this to be able to use the true turn aluminum spinners that I had laying around. I think that this will work for me. If I didn't already have some expensive spinners laying around, I would not have dun this. Henry knows more then I do so head his advise. [/quote] Was that the 20cc? So not possible to use a true turn spinner without doing such a modification? Annoyingly stupid things like this are what can turn me off a product regardless of the other attributes.
Posted on: 7/23/2009 11:58 PM by Author "RCHubbub"
in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8959399
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