---------------------------------------------------------- TeamGrumman-List Digest Archive --- Total Messages Posted Tue 07/03/12: 9 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 11:55 AM - Cowling size (Gary Vogt) 2. 11:57 AM - What's new (Gary Vogt) 3. 12:07 PM - Question (Gary Vogt) 4. 02:12 PM - Re: Question (FLYaDIVE) 5. 07:57 PM - Re: Question (Gary Vogt) 6. 08:36 PM - AG5B upper cowling (Gary Vogt) 7. 08:59 PM - Grumman airfoil (Gary Vogt) 8. 09:54 PM - Re: Question (n76lima@mindspring.com) 9. 10:19 PM - Re: Grumman airfoil (n76lima@mindspring.com) ________________________________ Message 1 _____________________________________ Time: 11:55:34 AM PST US From: Gary Vogt Subject: TeamGrumman-List: Cowling size A while back, I mentions that Brooks-"I grew up with a 4 foot Starrett ru ler in my hand"-Margolien had said the Jaguar cowling was too wide and th at he was 'trimming' them to fit. -Over the weekend I had the opportunity to compare an AG5B cowling to a Jaguar cowling. -You can see from the pi cs they are EXACTLY the same size. -Not almost, but exactly.=0A=0AI had t hought about moving the joggle on the cowling to make it narrower after Bro oks said my cowling was 1/4 inch wider than the aluminum cowling and that h e had to make them fit. -I think I'll leave the Jaguar cowling alone. ________________________________ Message 2 _____________________________________ Time: 11:57:43 AM PST US From: Gary Vogt Subject: TeamGrumman-List: What's new Last week, Bruce asked if I had any stories. -Just one.=0A=0AI did an ann ual on a Tiger a couple of weeks ago. -Someone had RTVd the intake duct t o the engine mount. -Now, you may not know this, but, RTV will cause rust anywhere it touches steel, paint or no paint. -=0A=0APlease keep it off the engine mount.- ________________________________ Message 3 _____________________________________ Time: 12:07:18 PM PST US From: Gary Vogt Subject: TeamGrumman-List: Question Barry, this one is for you because you have so much more trivia knowledge a bout electronics than most. =C2-If anyone else knows the answer, be answe r also.=0A=0AI was thinking about the electronic ignition system I installe d on both Dean's and Larry's planes a few months back. =C2-Both of them w ould have benefitted from having separate toggle switches for each mag. =C2 -That would make the mag checks a little simpler. =C2-=0A=0AAnd, then t he trusty Avionics Master. =C2-I think making a single point failure in a plane is stupid, but, what do I know. =C2-=0A=0ASo, I got to thinking (h ere we go again), on a cars ignition switch,=C2-=0A=0A=A2 the first position turns on the battery. =C2-( listen to the radio etc.)=0A =A2 the second position turns on the alternator and the rest of the electri cal system.=0A=A2 the third position starts the car. =C2-During the start, the radios are dropped off-line to prevent damage to the radios.=0A =0AMy questions are:=0A=0A(Q1) Why not incorporate separate toggles for the mags and an ignition switch that behaves just like a cars ignition switch? =0A=0AThat would simplify the entire process.=0A=0A(Q2) Is there a switch t hat would work that is easy to convert to a planes requirements? ________________________________ Message 4 _____________________________________ Time: 02:12:55 PM PST US Subject: Re: TeamGrumman-List: Question From: FLYaDIVE Hello Gary: That is exactly what I fly in the RV6. Toggle Master - Toggle ALT - Toggle L Mag - Toggle R Mag (Electronic Ignition) Now, I went a little out there with the switches. I used Heavy Duty DPST (Double Poll Single Throw) switches. Heavy duty so they would have a nice solid SNAP when they are turned on and off and would not move without noticing (works great with a gloved hand). These are the large size switch that require about a 3/8" hole for mounting and has a very high Amperage rating 15 to 20 Amps. The DP so there is a huge amount of internal redundancy in the contact ability. I just tied each of the sides of the switch together. As well as having Silver Contacts. I know, way over kill, since all they do is short out the Mag to ground and turn relays On & Off. And rubber boots are also available. Lots of advantages - And SIMPLE. Your question 2 "(Q2) Is there a switch that would work that is easy to convert to a planes requirements?" I gather that you want it just like a cars switch system (OFF - Master ON- Alt ON - Radios ON)? But you are NOT going to connect the MAGS to the same switch, is that correct? Then what if you want to have the RADIOS ON with the ALT OFF? <-- As in a ALT failure and Radios still functioning (Running off Battery Power)? The next thing that comes to mind is ALL the Repetitive Training we have all gone through over the years. We have certain things infused into our brains. The pilots would have to relearn things that are a bit different than our norm and what has become almost a muscle response. If you interested in this type of switch I will search one out for you. It would more than likely be a ROTARY switch with an enclosure. Would you want it Key Activated? Barry On Tue, Jul 3, 2012 at 3:06 PM, Gary Vogt wrote: > Barry, this one is for you because you have so much more trivia knowledge > about electronics than most. If anyone else knows the answer, be answer > also. > > I was thinking about the electronic ignition system I installed on both > Dean's and Larry's planes a few months back. Both of them would have > benefitted from having separate toggle switches for each mag. That would > make the mag checks a little simpler. > > And, then the trusty Avionics Master. I think making a single point > failure in a plane is stupid, but, what do I know. > > So, I got to thinking (here we go again), on a cars ignition switch, > > - the first position turns on the battery. ( listen to the radio etc.) > - the second position turns on the alternator and the rest of the > electrical system. > - the third position starts the car. During the start, the radios are > dropped off-line to prevent damage to the radios. > > My questions are: > > (Q1) Why not incorporate separate toggles for the mags and an ignition > switch that behaves just like a cars ignition switch? > > That would simplify the entire process. > > (Q2) Is there a switch that would work that is easy to convert to a plane s > requirements? > > * > =========== =========== =========== =========== > * > > ________________________________ Message 5 _____________________________________ Time: 07:57:44 PM PST US From: Gary Vogt Subject: Re: TeamGrumman-List: Question Barry,=C2-=0A=0ALet me write it out again. =C2-Maybe you read it so fas t the first time that you missed the details.=0A=0A=A2 the first posi tion turns on the battery. =C2-( listen to the radio etc.)=0A=A2 th e second position turns on the alternator and the rest of the electrical sy stem.=0A=A2 the third position starts the car. =C2-During the start , the radios are dropped off-line to prevent damage to the radios.=0A=0AThe mags do not need to be a part of the switch. =C2-The mags would then be just two separate toggles.=0A=0AJust as in a car, the radios can come on wi th the first position. =C2-Alternator with the second. =C2-So, you can turn on the radios just like you would with a split master without turning on the whole system. =C2-If an old GM ignition switch would work, then I' ll look for that. =C2-It needs to be keyed. =C2-The key, then, is requi red to turn on the radio. =C2-Just like your car.=0A=0AGary=0APS, the ALT side of the Master switch is nothing more than adding power to the field c ircuit. =C2-In case of an alternator failure, turn the key to the first d etent; =C2-i.e., radios. =C2-If you wanted to change the emergency proc edure, just pull the field breaker. =C2-=0A=0A=0A________________________ ________=0A From: FLYaDIVE =0ATo: teamgrumman-list@matr onics.com =0ASent: Tuesday, July 3, 2012 2:11 PM=0ASubject: Re: TeamGrumman -List: Question=0A =0A=0AHello Gary:=0A=0AThat is=C2-exactly=C2-what I fly in the RV6. =C2-=0AToggle Master - Toggle ALT - Toggle L Mag - Toggle R Mag (Electronic=C2-Ignition)=0ANow, I went a little out there with the switches. =C2-=0AI used Heavy Duty DPST (Double Poll Single Throw) switc hes.=0AHeavy duty so they would have a nice solid SNAP when they are turned on and off and would not move without noticing (works great with a gloved hand). =C2-=0AThese are the large size switch that require about a 3/8" h ole for mounting and has a very high Amperage rating 15 to 20 Amps.=0AThe D P so there is a huge amount of internal=C2-redundancy=C2-in the contact ability.=C2-=0AI just tied each of the sides of the switch=C2-together .=0AAs well as having Silver Contacts.=0AI know, way over kill, since all t hey do is short out the Mag to ground and turn relays On & Off. =C2-And r ubber boots are also=C2-available.=0ALots of advantages - And SIMPLE.=0A =0AYour question 2 "(Q2) Is there a switch that would work that is easy to convert to a planes requirements?"=0AI gather that you want it just like a cars switch system (OFF - Master ON- Alt ON - Radios ON)? =C2-But you are NOT going to connect the MAGS to the same switch, is that correct?=0AThen what if you want to have the RADIOS ON with the ALT OFF? <-- As in a ALT fa ilure and Radios still functioning (Running off Battery Power)?=0AThe next thing that comes to mind is ALL the=C2-Repetitive=C2-Training we have a ll gone through over the years. =C2-We have=C2-certain=C2-things infu sed into our brains. =C2-The pilots would have to relearn things that are a bit different than our norm and what has become almost a muscle=C2-res ponse. =C2-=0A=0AIf you interested in this type of switch I will search o ne out for you. =C2-It would more than likely be a=C2-ROTARY=C2-switc h with an=C2-enclosure. =C2-Would you want it Key=C2-Activated?=0A=0A =0ABarry=0A=0A=0A=C2-=C2-=0A=0A=0AOn Tue, Jul 3, 2012 at 3:06 PM, Gary Vogt wrote:=0A=0ABarry, this one is for you because you have so much more trivia knowledge about electronics than most. =C2- If anyone else knows the answer, be answer also.=0A>=0A>=0A>I was thinking about the electronic ignition system I installed on both Dean's and Larry's planes a few months back. =C2-Both of them would have benefitted from ha ving separate toggle switches for each mag. =C2-That would make the mag c hecks a little simpler. =C2-=0A>=0A>=0A>And, then the trusty Avionics Mas ter. =C2-I think making a single point failure in a plane is stupid, but, what do I know. =C2-=0A>=0A>=0A>So, I got to thinking (here we go again) , on a cars ignition switch,=C2-=0A>=0A>=0A>=A2 the first position turns on the battery. =C2-( listen to the radio etc.)=0A>=A2 the se cond position turns on the alternator and the rest of the electrical system .=0A>=A2 the third position starts the car. =C2-During the start, t he radios are dropped off-line to prevent damage to the radios.=0A>=0A>=0A> My questions are:=0A>=0A>=0A>(Q1) Why not incorporate separate toggles for the mags and an ignition switch that behaves just like a cars ignition swit ch?=0A>=0A>=0A>That would simplify the entire process.=0A>=0A>=0A>(Q2) Is t here a switch that would work that is easy to convert to a planes requireme nts?=0A>st" target="_blank">http://www.matronics.com/Navigator?TeamGrumma n-List=0Atp://forums.matronics.com=0A_blank">http://www.matronics.com/contr ======================= ________________________________ Message 6 _____________________________________ Time: 08:36:15 PM PST US From: Gary Vogt Subject: TeamGrumman-List: AG5B upper cowling I have two AG5B upper cowlings.=0A=0AOne was a prototype and is made of fib erglass. -The other is a production carbon fiber part.=0A=0AIf you need o ne or want one as a spare, I'll sell both for $1000 or any reasonable offer . -=0A=0AGary ________________________________ Message 7 _____________________________________ Time: 08:59:46 PM PST US From: Gary Vogt Subject: TeamGrumman-List: Grumman airfoil Under the heading of way too much time on my hands and a curiosity that won 't let me leave this topic alone, I've been converting to CAD the dimension s of several NACA airfoils and matching them to the Grumman airfoil. -Goi ng on the premiss that the original AA1 had a 64-415 airfoil, I laid out a drawing to match it as close as possible. -=0A=0AThe original AA1 airfoil is close to the 64-415, but it isn't really a 64-415. -Using that same a irfoil, and drooping the nose so that the nose was parallel to the "0" wate rline and then extending that line to the spar, well, let's just say, it's an interesting airfoil, but nothing close to a 64-415.=0A=0A=0AThen, adding the flaps and ailerons from a Tiger and you have a completely new airfoil. -It's skinnier than a 64-415 and fatter than a 64-412. -So, I algebrai cally added the points of both the 64-415 and 64-412 airfoils and divided b y 2. -In theory, a 64-413.5. -This airfoil is damn close to the Grumman airfoil with the exception of the flat bottom from the nose to the spar. -However, the spar location makes it a 63.5-413.5 or something similar. =0A=0AThat's why I wanted some good locations. -I still need them if you have the time and patience.=0A=0AFrom the looks of it, the Grumman airfoil actually a pretty decent airfoil. -Much thinner than the -415 and a longe r upper surface with a nice gentle curve. -The -415 has a rather steep cu rve past the 40% chord peak. -=0A=0AComparing it to a Clark-Y one needs t o begin making assumptions on installed incident angles and the fact that t he -Y is flatter on the bottom.=0A=0AInteresting. -=0A=0AFeedback appreci ated. ________________________________ Message 8 _____________________________________ Time: 09:54:00 PM PST US From: n76lima@mindspring.com Subject: Re: TeamGrumman-List: Question Yeah, no reason that can't work. At least on an experimental. Bet you have trouble getting the FAA to approve an antique GM ignition switch. And the key on the Master, Alternator and Starter isn't as effective at theft prevention as on the mags. One could flip the mag switches on and hand prop it, fly away with a handheld radio. Granted, one could open the cowl and pop the P-leads and then flip the Master on and hit the Start button on a Grumman... --Bob Steward the first position turns on the battery. ( listen to the radio etc.) the second position turns on the alternator and the rest of the electrical system. the third position starts the car. During the start, the radios are dropped off-line to prevent damage to the radios. The mags do not need to be a part of the switch. The mags would then be just two separate toggles. Just as in a car, the radios can come on with the first position. Alternator with the second. So, you can turn on the radios just like you would with a split master without turning on the whole system. If an old GM ignition switch would work, then I'll look for that. It needs to be keyed. The key, then, is required to turn on the radio. Just like your car. Gary ________________________________ Message 9 _____________________________________ Time: 10:19:41 PM PST US From: n76lima@mindspring.com Subject: Re: TeamGrumman-List: Grumman airfoil You don't mention changing the radius of the leading edge on the AA-1A and later airfoil in your description of your efforts to lay out the unique Grumman airfoil. It seems quite a bit larger radius than the AA-1 nee 64-415 airfoil. Harry Riblett did some work on the NACA data and found issues with a wave or ripple in the upper surface based on the published tables. This inconsistency causes flow disruptions (loss of laminar flow earlier than expected and other issues with Stall and the Hysteresis loop of air attachment after stall. The first paragraph of this paper gives a brief description of what aerodynamic hysteresis is and what it does. http://www.public.iastate.edu/~huhui/paper/2008/AIAA-2008-0315.pdf It is a near certainty that the AA-1 airfoil has that same inconsistency, and since the AA-1A was done "on the hangar floor" from the AA-1 profiles, it seems likely that it has the same issues that the donor airfoil had. Harry's book "GA Airfoils" is very interesting reading for those that are wanting to understand airfoil design. Highly recommended. http://www.aircraftspruce.com/catalog/bvpages/ga_airfoils.php Gary, you got access to one of the CFD programs to "blow" on your reconstructed airfoil? There are a number of questions that need to be answered, mostly revolving around the slope of the forward camber and how it feeds into the large radius nose. This paper is offered for those that don't know what we are talking about, and how Eppler and CFD have changed the entire concept of airfoil design from carving models and blowing on them, to designing the flow and pressure distribution you want, and then calculating the shape that would MAKE that happen. http://www.airfoils.com/design.pdf --Bob Steward [Gary] Under the heading of way too much time on my hands and a curiosity that won't let me leave this topic alone, I've been converting to CAD the dimensions of several NACA airfoils and matching them to the Grumman airfoil. Going on the premiss that the original AA1 had a 64-415 airfoil, I laid out a drawing to match it as close as possible. The original AA1 airfoil is close to the 64-415, but it isn't really a 64-415. Using that same airfoil, and drooping the nose so that the nose was parallel to the "0" waterline and then extending that line to the spar, well, let's just say, it's an interesting airfoil, but nothing close to a 64-415. Then, adding the flaps and ailerons from a Tiger and you have a completely new airfoil. It's skinnier than a 64-415 and fatter than a 64-412. So, I algebraically added the points of both the 64-415 and 64-412 airfoils and divided by 2. In theory, a 64-413.5. This airfoil is damn close to the Grumman airfoil with the exception of the flat bottom from the nose to the spar. However, the spar location makes it a 63.5-413.5 or something similar. That's why I wanted some good locations. I still need them if you have the time and patience. >From the looks of it, the Grumman airfoil actually a pretty decent airfoil. Much thinner than the -415 and a longer upper surface with a nice gentle curve. The -415 has a rather steep curve past the 40% chord peak. Comparing it to a Clark-Y one needs to begin making assumptions on installed incident angles and the fact that the -Y is flatter on the bottom. Interesting. Feedback appreciated. ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message teamgrumman-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/TeamGrumman-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/teamgrumman-list Browse Digests http://www.matronics.com/digest/teamgrumman-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.