From: owner-krnet-l-digest@teleport.com[SMTP:owner-krnet-l-digest@teleport.com] Sent: Wednesday, July 08, 1998 7:44 PM To: krnet-l-digest@teleport.com Subject: krnet-l-digest V2 #113 krnet-l-digest Wednesday, July 8 1998 Volume 02 : Number 113 ---------------------------------------------------------------------- Date: Wed, 08 Jul 1998 11:29:06 -0700 From: Micheal Mims Subject: Re: KR: Stabilizer enlargement/washout Tom Andersen wrote: > > Mike, > What I like about the strakes is that they produce very little bending moment on the stab spars. Adding span to the stab adds many times more force compared to an equivalent amount on root ribs and strakes.>>> Bending moment on the horizontal stab is very small (go jiggle your favorite spam can tail and watch it oil can!), in fact it should be a negative force and not one of very much significance. I cut my horizontal spars so that they only tapered to 1.5 inches at the tips rather than 5/8. I don't think the amount of drag this will produce is worth worrying about. I guess we will see! I prefer to have a more ridged tail for higher speeds to help counter possible flutter issues. I also used two layers of 8oz cloth instead of one on the stab, the elevator is stock. I read somewhere that strakes are actually provide more effect per square than regular flying surfaces. But know one will say how much more. ------------------------------ Date: Wed, 08 Jul 1998 11:33:18 -0700 From: Micheal Mims Subject: Re: KR: Compu-Fire Sites Tom Andersen wrote: > > Ross, > Does Compu-fire make a dizzy for the Soob EA-81? I could go for a > lower-profile unit for my DDTS. > -Tom > I doubt it, that was one of the things that discouraged me from pursuing the Subaru option was the lack of HP or after-market parts. Almost everything must be built up at home or pay the so called aircraft engine converters big $$$ for parts that should be dirt cheep. Did you happen to get one of the distributor conversion kits that was offered on the Soob List? - -- zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz Micheal Mims SP290,.. Filling and sanding now! mailto:mikemims@pacbell.net http://www.geocities.com/CapeCanaveral/Hangar/4136/ Irvine Ca Fax 949.856.9417 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ------------------------------ Date: Wed, 08 Jul 1998 15:19:33 -0400 From: Tom Andersen Subject: Re: KR: Stabilizer enlargement/strakes/mount Mike, GO FOR THE STRAKES. No increase in frontal area, minimal weight, cool looks. It's practically free stability. It's the next best thing to a longer tail. Maybe they'll even reduce the polywog appearance. When I saw the 1/4 scale model with just the the enlarged stab on it and my cut-down elevators, I was scared to fly it. With the large strakes and regular elevators, it should be ok. The KR-2S tail reminds me of the race planes of the 30's. They are all cut down to go fast, but they are compromised in stability. I'm adding your drawing to my web page next to mine. I've got 3.5 megs to go. Woo Hoo! BTW I'm not going to rip apart my upper motor mount to install the doubler. Since I'm building the engine's mount to attach to the corners of the firewall, and I'm going with the steel webbed brackets behind the firewall right at those points, I don't see the purpose of the doubler in my case, except for additional glue surface at the ends. The steel brackets tying to the sides more than make up for that. Maybe the weight of the brackets is the same as the doubler (especially with lots of liquid weight smeared all over it.) I like your idea to fill the areas up there with 5/8" stock. I'll pull my upper web off and reglue it on without the 5/8" fillers to make it "box". I want that web ON the longerons, nothing in between. - -Tom Micheal Mims wrote: > At 10:12 PM 7/7/98 -0400, you wrote: > I'm going with 8" increased span(total), a longer nose rib, and great big > strakes. http://home.att.net/~tomkr2s/index.htm >>> > > Man those top view shots of the KR2S really show what wrong eh? Just look > at that picture on the left! Your headed in the right direction Tom. > > FYI While I was running the data for a stock KR2S through the spreadsheets > from Roncz I found the horizontal tail needed to be 2.5 square feet larger > at a minimum. Mine is right at 2.5 square feet larger and like you, I may > install strakes to add a few more. > zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz > Micheal Mims > SP290,.. Filling and sanding now! > mailto:mikemims@pacbell.net > http://www.geocities.com/CapeCanaveral/Hangar/4136/ > Irvine Ca > Fax 949.856.9417 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ------------------------------ Date: Wed, 08 Jul 1998 15:36:47 -0400 From: Tom Andersen Subject: Re: KR: Stabilizer enlargement/spar length Mike, Maybe the fence effect of the fuse on one side increases the effectiveness of the area. Yea, that's a good idea to go with two layers of cloth at the stab extensions. I'm thinking of recutting stab spars 10" longer and 1/2" thicker at the tips to accomodate an airfoil out there. I've glued the front spar in, but it's not too late by any means. The elevator spar will be usable with tapered additions at the tips. I like the cut-down elevator span. Troy Petteway has cut even further. That really says something about the elevator size. It's waaay too effective. - -Tom Micheal Mims wrote: > Tom Andersen wrote: > > > > Mike, > > What I like about the strakes is that they produce very little bending moment on the stab spars. Adding span to the stab adds many times more force compared to an equivalent amount on root ribs and strakes.>>> > > Bending moment on the horizontal stab is very small (go jiggle your > favorite spam can tail and watch it oil can!), in fact it should be a > negative force and not one of very much significance. > > I cut my horizontal spars so that they only tapered to 1.5 inches at the > tips rather than 5/8. I don't think the amount of drag this will > produce is worth worrying about. I guess we will see! I prefer to have > a more ridged tail for higher speeds to help counter possible flutter > issues. I also used two layers of 8oz cloth instead of one on the stab, > the elevator is stock. > > I read somewhere that strakes are actually provide more effect per > square than regular flying surfaces. But know one will say how much > more. ------------------------------ Date: Wed, 08 Jul 1998 15:44:05 -0400 From: Tom Andersen Subject: Re: KR: Compu-Fire Sites Mike, I haven't got the dizzy conversion kit yet. One of the things I like about the Soob though, is the utter integrity and strength of the basic core engine. A modest DDTS converter shared upclose pics of his intake manifold, which you form from the same materials as the exhaust manifold, which only has two runners as well. In fact, I can do a basic T shape up there, with the turbo it's never a problem as long as your T is centered. BTW, Is your 0-290 a 0-290G? I hear these were dirt cheap, uncertified versions used in ground power units with a huge bell housing on one side which was cut down for aircraft use. They worked as well as the 0-290 for only a few hundred dollars. - -Tom Micheal Mims wrote: > Tom Andersen wrote: > > > > Ross, > > Does Compu-fire make a dizzy for the Soob EA-81? I could go for a > > lower-profile unit for my DDTS. > > -Tom > > > > I doubt it, that was one of the things that discouraged me from pursuing > the Subaru option was the lack of HP or after-market parts. Almost > everything must be built up at home or pay the so called aircraft engine > converters big $$$ for parts that should be dirt cheep. Did you happen > to get one of the distributor conversion kits that was offered on the > Soob List? > > -- > zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz > Micheal Mims > SP290,.. Filling and sanding now! > mailto:mikemims@pacbell.net > http://www.geocities.com/CapeCanaveral/Hangar/4136/ > Irvine Ca > Fax 949.856.9417 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ------------------------------ Date: Wed, 08 Jul 1998 12:56:11 -0700 From: Micheal Mims Subject: KR: RC Servo trim motor Hey maybe one of you RCers can help out here. I have a ton of old RC servo motors from my RC days. What would one do to drop the voltage to the right amount and how would you control the motor from the cockpit? Rocker switch? What was the typical voltage for a Kraft or Futaba servo? How would you wire it? zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz Micheal Mims SP290,.. Filling and sanding now! mailto:mikemims@pacbell.net http://www.geocities.com/CapeCanaveral/Hangar/4136/ Irvine Ca Fax 949.856.9417 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ------------------------------ Date: Wed, 8 Jul 1998 15:19:24 -0500 (CDT) From: Steven A Eberhart Subject: Re: KR: RC Servo trim motor On Wed, 8 Jul 1998, Micheal Mims wrote: > Hey maybe one of you RCers can help out here. I have a ton of old RC servo > motors from my RC days. What would one do to drop the voltage to the right > amount and how would you control the motor from the cockpit? Rocker switch? > What was the typical voltage for a Kraft or Futaba servo? How would you > wire it? The really older servos used center tapped 4.8v battery packs so the motor only saw 2.4v + or - depending on the direction. The later ones, last 10 or 15 years used a bridge circuit to drive the motor so they saw the full 4.8v, actually a pulse train of 4.8v pulses. With the price of servos so cheap today I would probably buy a new servo for $20 to $40. You can either use a unit that directly drives the servos directly so that the position is proportional to the control or remove the servo amplifier and use limit switches at the ends of the travel to interrupt the current to the motor. In the first instance your trim tab position would be directly proportional to the trim lever in the cockpit, just move it to the desired deflection. In the second case you would hold the trim switch down until you got the desired amount of trim travel as senced by the seat of your pants. I would probably favor the first option. The aircraft voltage could be dropped to the 5v needed for the servo and controller using a simple 3 terminal voltage regulator from Radio Shack. A few capacitors and resistors to filter the supply voltage and you would be in business. I will dig out my R/C catalogs tonight and see what looks reasonable. Any other R/C'ers feel free to jump in here. I think we have the makings of another development project that can be used by many KR builders. Steve Eberhart - ------------------------------------- http://www.newtech.com/nlf One test is worth a thousand expert opinions but a thousand opinions are easier to get. When once you have tasted flight you will always walk with your eyes turned skyward, for there you have been and there you will always be. --Leonardo da Vinci ------------------------------ Date: Wed, 8 Jul 1998 15:37:13 -0500 (CDT) From: Steven A Eberhart Subject: Re: KR: RC Servo trim motor On Wed, 8 Jul 1998, Steven A Eberhart wrote: > On Wed, 8 Jul 1998, Micheal Mims wrote: > > > Hey maybe one of you RCers can help out here. I have a ton of old RC servo > > motors from my RC days. What would one do to drop the voltage to the right > > amount and how would you control the motor from the cockpit? Rocker switch? > > What was the typical voltage for a Kraft or Futaba servo? How would you > > wire it? > > The really older servos used center tapped 4.8v battery packs so the > motor only saw 2.4v + or - depending on the direction. The later ones, > last 10 or 15 years used a bridge circuit to drive the motor so they saw > the full 4.8v, actually a pulse train of 4.8v pulses. With the price of > servos so cheap today I would probably buy a new servo for $20 to $40. > > You can either use a unit that directly drives the servos directly so > that the position is proportional to the control or remove the servo > amplifier and use limit switches at the ends of the travel to interrupt > the current to the motor. In the first instance your trim tab position > would be directly proportional to the trim lever in the cockpit, just > move it to the desired deflection. In the second case you would hold the > trim switch down until you got the desired amount of trim travel as > senced by the seat of your pants. > > I would probably favor the first option. The aircraft voltage could be > dropped to the 5v needed for the servo and controller using a simple 3 > terminal voltage regulator from Radio Shack. A few capacitors and > resistors to filter the supply voltage and you would be in business. > > I will dig out my R/C catalogs tonight and see what looks reasonable. > Any other R/C'ers feel free to jump in here. I think we have the makings > of another development project that can be used by many KR builders. > After a little more thought we might want to use fiber optics from the cockpit back to the trim tab. Use a high intensity LED at the controller to drive a plastic fiber optic cable with a photo diode at the servo end to recover the pulse train that drives the servo. We could stand the high loses from the plastic cable since the run would not be that far. THis would practically eliminate noise as a concerne. Steve - ------------------------------------- http://www.newtech.com/nlf One test is worth a thousand expert opinions but a thousand opinions are easier to get. When once you have tasted flight you will always walk with your eyes turned skyward, for there you have been and there you will always be. --Leonardo da Vinci ------------------------------ Date: Wed, 08 Jul 1998 16:38:52 -0400 From: Tom Andersen Subject: Re: KR: Stabilizer enlargement/washout Mike, I was thinking of bending force rather than twisting force. Bending force tries to bend it down at both tips as in an overspeed pull-out. The max stress would be the amount that drag would create, plus the amount you apply via the elevator controls. Maybe since the elevator controls don't go all the way to the tips, this worst case would produce no more stress than the stock elevator/ stab setup because the fixed stab extensions don't produce an increased elevator load, right? - -Tom Micheal Mims wrote: > Tom Andersen wrote: > > > > Mike, > > What I like about the strakes is that they produce very little bending moment on the stab spars. Adding span to the stab adds many times more force compared to an equivalent amount on root ribs and strakes.>>> > > Bending moment on the horizontal stab is very small (go jiggle your > favorite spam can tail and watch it oil can!), in fact it should be a > negative force and not one of very much significance. > > I cut my horizontal spars so that they only tapered to 1.5 inches at the > tips rather than 5/8. I don't think the amount of drag this will > produce is worth worrying about. I guess we will see! I prefer to have > a more ridged tail for higher speeds to help counter possible flutter > issues. I also used two layers of 8oz cloth instead of one on the stab, > the elevator is stock. > > I read somewhere that strakes are actually provide more effect per > square than regular flying surfaces. But know one will say how much > more. ------------------------------ Date: Wed, 08 Jul 1998 16:44:14 -0400 From: Tom Andersen Subject: Re: KR: RC Servo trim motor Steve, Have you seen the TMI servo drivers for sale now for only $24? See RCM from last month. It's basically a rheostat knob with a pulse width driver to command the servo. Perhaps with a shield over the wires it could be used to drive the trim servo, which I think is a great idea and plan to use as well. - -Tom Steven A Eberhart wrote: > On Wed, 8 Jul 1998, Steven A Eberhart wrote: > > > On Wed, 8 Jul 1998, Micheal Mims wrote: > > > > > Hey maybe one of you RCers can help out here. I have a ton of old RC servo > > > motors from my RC days. What would one do to drop the voltage to the right > > > amount and how would you control the motor from the cockpit? Rocker switch? > > > What was the typical voltage for a Kraft or Futaba servo? How would you > > > wire it? > > > > The really older servos used center tapped 4.8v battery packs so the > > motor only saw 2.4v + or - depending on the direction. The later ones, > > last 10 or 15 years used a bridge circuit to drive the motor so they saw > > the full 4.8v, actually a pulse train of 4.8v pulses. With the price of > > servos so cheap today I would probably buy a new servo for $20 to $40. > > > > You can either use a unit that directly drives the servos directly so > > that the position is proportional to the control or remove the servo > > amplifier and use limit switches at the ends of the travel to interrupt > > the current to the motor. In the first instance your trim tab position > > would be directly proportional to the trim lever in the cockpit, just > > move it to the desired deflection. In the second case you would hold the > > trim switch down until you got the desired amount of trim travel as > > senced by the seat of your pants. > > > > I would probably favor the first option. The aircraft voltage could be > > dropped to the 5v needed for the servo and controller using a simple 3 > > terminal voltage regulator from Radio Shack. A few capacitors and > > resistors to filter the supply voltage and you would be in business. > > > > I will dig out my R/C catalogs tonight and see what looks reasonable. > > Any other R/C'ers feel free to jump in here. I think we have the makings > > of another development project that can be used by many KR builders. > > > > After a little more thought we might want to use fiber optics from the > cockpit back to the trim tab. Use a high intensity LED at the controller > to drive a plastic fiber optic cable with a photo diode at the servo end > to recover the pulse train that drives the servo. We could stand the > high loses from the plastic cable since the run would not be that far. > THis would practically eliminate noise as a concerne. > > Steve > > ------------------------------------- > http://www.newtech.com/nlf > > One test is worth a thousand expert opinions but a thousand opinions are > easier to get. > > When once you have tasted flight you will always walk with your eyes > turned skyward, for there you have been and there you will always be. > --Leonardo da Vinci ------------------------------ Date: Wed, 08 Jul 1998 13:46:59 -0700 From: Ross Youngblood Subject: KR: Amazing website (not for archive) I was looking for someone at work on the internal phone directory, and stumbled across this web link. As I am often concerned about bad weather flying in the winter here in Oregon, it was nice to stumble across a place where they can only build roads when it is -20 below. http://www.geocities.com/TheTropics/Shores/1100/prudhoe.html - -- Ross Youngblood Pager: (800)SKY-PAGE PIN#895-9073 Staff Technical Specialist voicemail: (800)538-6838 x 1632 Schlumberger SABER Bus Line: (541)714-1754 Corvallis,Oregon mailto:rossy@San-Jose.tt.slb.com ------------------------------ Date: Wed, 08 Jul 1998 15:03:41 -0700 From: Ross Youngblood Subject: Re: KR: Bummer... 1/2 Compu-Fire dead Adrian, I swapped HT leads... for a electronic ignition module like the COMPU-FIRE, it's not recommended to do the spark test. My timing light with the inductive pickup worked well enough. It detected sparks on the two fwd cylinders but not aft. Swapping wires was no help. With this ignition, there is no coil, only the module itself with a fwd and aft cylinder "coil" which is actualy some nifty electronics that can fire a large > 50KV pulse. The pulses fire twice every revolution per cylinder (don't ask me why, but they do), and they are triggered by a cap that replaces the normal distributor cap. The compu-fire is split into two modules, the top one in my case is blown. John mentioned one thing that could blow an electronic module would be an open HT lead. I don't think this is why COMPU-FIRE doesn't recommend the spark test, I think they are afraid of someone becoming a ground path for 50KV. -- Ross Adrian Carter wrote: > Hi Ross and KRnetters, > On your ignition system, check all you HT leads or you can use the plugs > by removing each one and letting them lie on the heads and see if you > get a spark. Make sure there is no fuel around. If no response with > spark try and get your coil with HT leads bench tested rather than > buying a whole new set. It's a lot of bucks - this can be a learning > process which is invaluabel in itself. Good Luck!!!!! > -- > Adrian VE6AFY > Mailto:cartera@cuug.ab.ca > http://www.cuug.ab.ca/~cartera ------------------------------ Date: Wed, 08 Jul 1998 15:04:54 -0700 From: Ross Youngblood Subject: Re: KR: Compu-Fire Sites I don't know, the trick would be a modified hall-effect switch & rotor to replace the distributor cap. You might find other aftermarket CDI ignitions that would work well too. - -- Ross Tom Andersen wrote: > Ross, > Does Compu-fire make a dizzy for the Soob EA-81? I could go for a > lower-profile unit for my DDTS. > -Tom > > Ross Youngblood wrote: > > > I discovered Steve Bennetts New GPASC site http://www.greatplainsas.com > > while > > looking for Compu-Fire on the net. Nifty Site! Check it out if like > > me... you haven't > > been looking at engine stuff for a while. > > > > COMPU-FIRE has a website at http://www.compufire.com, but it's currently > > under > > construction... > > > > -- Regards > > Ross ------------------------------ Date: Wed, 08 Jul 1998 15:13:39 -0700 From: Ross Youngblood Subject: KR: Compu-Fire Hope I just got off the phone with Mary-Jo at Compu-Fire, and got an RMA#... if I can find my reciept for the unit, it may still be under warrenty! I paid by credit card to some VW mail order outfit, If I could only remember when, it's been some time. At any rate, I am going to ship the unit out to see if they can fix me up. I will keep you posted. -- Regards Ross ------------------------------ Date: Wed, 08 Jul 1998 17:42:28 PDT From: "Richard Parker" Subject: KR: Re: car pool from nashville anyone who wants to carpool, I'm arriving at 1:55pm on friday, and leaving at 3:55 pm sunday. I can get a company govt rate with unlimited mileage. E-mail me at any of the addresses below if you want to carpool we can set up a meeting location and method Rich Parker richontheroad@hotmail.com theparkers@monad.net help@pneutronics.com >Anybody flying into Nashville at 2:00 or 3:00 Friday the 24th? Mark >Lougheed is flying in from Seattle and will need a ride from the airport to >Columbia, about an hour long trip at most. He'd like to bum a ride with >somebody. Anybody else arriving at Nashville at about the same time? > >Thanks, > >Mark Langford, Huntsville, Alabama >mailto:langford@hiwaay.net >see KR2S N56ML at http://home.hiwaay.net/~langford/kr2s.html > > Richard E. Parker Jaffrey, NH richontheroad@hotmail.com http://top.monad.net/~theparkers/kr.htm ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com ------------------------------ Date: Wed, 08 Jul 1998 20:10:06 -0500 From: Bobby Muse Subject: Re: KR: N541RY Progress report At 06:20 PM 7/5/98 -0700, you wrote: >Here are things I have to check: > >1 ) TIMING > I dumped Bob Hoover's "Finding TDC" sermon on the web from > the KRNET VW link. This will allow me to verify TDC. I also > made a XEROX of the timing wheel in the Great Planes manual > and hope to validate that I have some good static timing this >evening. > > -- Regards > Ross > > Ross, Where did you find Bob Hoover's "finding TDC"? Bobby Muse(N122B) mailto:bmuse@mindspring.com Wimberly, TX ------------------------------ Date: Wed, 08 Jul 1998 21:08:11 -0400 From: Tom Andersen Subject: Re: KR: RC Servo trim motor Mike, I uploaded two ads to my web site http://home.att.net/~tomkr2s/index.htm for R/C servo motor controllers that would be perfect for this application. One even comes in kit form, allowing the creative homebuilder to put it right in the panel or handgrip. I like the KMI version myself, although the Mallory looks a little bit sturdier. As far as servos, you can pick up the Mega 1/4 servo from Hitec for about $35 which has 249in/oz of torque, larger gears and output shaft, and 2x thick servo arms. I use one on my radio control lawnmower for steering the front wheel. (Pics for sure someday). - -Tom Micheal Mims wrote: > Hey maybe one of you RCers can help out here. I have a ton of old RC servo > motors from my RC days. What would one do to drop the voltage to the right > amount and how would you control the motor from the cockpit? Rocker switch? > What was the typical voltage for a Kraft or Futaba servo? How would you > wire it? > zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz > Micheal Mims > SP290,.. Filling and sanding now! > mailto:mikemims@pacbell.net > http://www.geocities.com/CapeCanaveral/Hangar/4136/ > Irvine Ca > Fax 949.856.9417 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ------------------------------ Date: Wed, 08 Jul 1998 20:13:48 -0500 From: Bobby Muse Subject: Re: KR: more good reading At 07:01 PM 7/7/98 -0700, you wrote: >go to: > >http://www.ellison-fluid-systems.com/article/fuelsystemsforhomebuilts/fuelsy >stems.htm >zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz >Micheal Mims >SP290,.. Filling and sanding now! >mailto:mikemims@pacbell.net >http://www.geocities.com/CapeCanaveral/Hangar/4136/ >Irvine Ca >Fax 949.856.9417 >^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > Why? Bobby Muse(N122B) mailto:bmuse@mindspring.com Wimberly, TX ------------------------------ Date: Wed, 8 Jul 1998 21:13:02 EDT From: HAshraf@aol.com Subject: Re: KR: Stabilizer enlargement In a message dated 98-07-08 03:31:34 EDT, you write: << FYI While I was running the data for a stock KR2S through the spreadsheets from Roncz I found the horizontal tail needed to be 2.5 square feet larger at a minimum >> Are these spreadsheets you used public domain? I would like to have a look at them. Haris ------------------------------ Date: Wed, 08 Jul 1998 21:14:38 -0400 From: Tom Andersen Subject: Re: KR: Re: car pool from nashville/me too I offer the same thing to folks arriving later. I'll be getting a rental at Nashville airport arriving 7:50am Saturday morning, departing 11:35am Sunday. - -Tom Richard Parker wrote: > anyone who wants to carpool, > I'm arriving at 1:55pm on friday, and leaving at 3:55 pm sunday. I can > get a company govt rate with unlimited mileage. > E-mail me at any of the addresses below if you want to carpool we can > set up a meeting location and method > > Rich Parker > richontheroad@hotmail.com > theparkers@monad.net > help@pneutronics.com > > > >Anybody flying into Nashville at 2:00 or 3:00 Friday the 24th? Mark > >Lougheed is flying in from Seattle and will need a ride from the > airport to > >Columbia, about an hour long trip at most. He'd like to bum a ride > with > >somebody. Anybody else arriving at Nashville at about the same time? > > > >Thanks, > > > >Mark Langford, Huntsville, Alabama > >mailto:langford@hiwaay.net > >see KR2S N56ML at http://home.hiwaay.net/~langford/kr2s.html > > > > > > Richard E. Parker > Jaffrey, NH > richontheroad@hotmail.com > http://top.monad.net/~theparkers/kr.htm > ______________________________________________________ > Get Your Private, Free Email at http://www.hotmail.com ------------------------------ Date: Wed, 8 Jul 1998 21:27:40 EDT From: HAshraf@aol.com Subject: Re: KR: RC Servo trim motor In a message dated 98-07-08 16:20:25 EDT, you write: << > Hey maybe one of you RCers can help out here. I have a ton of old RC servo > motors from my RC days. What would one do to drop the voltage to the right > amount and how would you control the motor from the cockpit? Rocker switch? > What was the typical voltage for a Kraft or Futaba servo? How would you > wire it >> Mike, The servos should work fine with 5-9 volts. A linear regulator suggested is a good idea. If you plan to have no proportional control, take the control electronics out and wire a Dual Pole Dual Throw (DPDT) switch directly to the motor. This way you can run the servo in both direction. A simple circuit could be made to read the potentiometer directly to indicate position. The problem with RC servos is that they are too fast compared to say a MAC servo. If you want I could make a drawing and e-mail it to you. Haris Ashraf ------------------------------ Date: Wed, 08 Jul 1998 20:41:30 -0500 From: Bobby Muse Subject: Re: KR: Pan Head Screws At 10:34 PM 7/7/98, you wrote: >At 08:17 PM 7~1~98 -0700, you wrote: >>Aileron Heads, the manual says to use 8/32 pan head screws every 6 inches. >>I wanted to use MS 35190 screws (page 86 on AS&S cat) with skin washers >>A3235-017-935 (page 91). Any thought out there on this? >> >>Micheal Mims > >=========================================================================== > >I think I used the 100 degree flathead (MS24694) . The tensil strength >appears to be more than double the MS35190. How would you get >10 degrees down aileron with pan head screw holding the hinges >in place? Yes, the text says panhead screws but the picture in drawing >number 71 shows flathead screws. Flatheads seemed the way to go. > >Larry Flesner > > > I used Pan head screws. I also drilled a correspondinf hole in the opposite hinge-half to accept the screw head and staggered the screws fore and aft. Bobby Muse(N122B) mailto:bmuse@mindspring.com Wimberly, TX ------------------------------ Date: Wed, 08 Jul 1998 20:43:26 -0700 From: Shannan Rheude Subject: Re: KR: when do you? Micheal Mims wrote: > > Ross Youngblood wrote: > > > Fingerprints contaminating the wood? I think epoxy would bond into > > the wood joint > > over a fingerprint, and be stronger than the same joint, if it was > > previously coated with > > epoxy. > > FYI, I used an electric palm sander with very light sand paper and hit > all the interior surfaces before I painted on a coat of epoxy. This to > remove any oil and sweat from my hands. I also thinned the epoxy with > alcohol and it worked GREAT! Mike, How much alcohol did you use per ??? Is it better if you just drink it before you start? Ron Rheude KR-2 in work! srheude@erols.com ------------------------------ Date: Wed, 08 Jul 1998 20:58:04 -0500 From: Bobby Muse Subject: Re: KR: Front Deck Questions At 02:34 AM 7/8/98 EDT, you wrote: >>My forward deck is the top of my tank - it's all one piece. By making >>a >>separate tank and deck cover you will add weight, allow for less fuel >>and >>add complexity to the KR. >> >>KISS > >If you need to get the front deck off and the tank is full, how many fuel >lines do you have to disconnect, and how heavy is the thing to pick up? >Or do you have to drain the tank before you can do anything? > >Mike Taglieri > > I always drain the tank thru the carburator fuel supply line. I have 10 gals in the tank, it takes about 30 - 40 minutes. I pull two piano-hinge pins and disconnect the fuel line just after the fuel shut-off valve at the bottom of the tank. I remove the slight/fuel gauge lines and vent line. After draining the tank it takes about five minutes to remove the tank/top. The same for replacing the tank/deck. I only remove the tank/deck during annuals or when I may want to add/delete a radio or instrument. It makes it real easy. Bobby Muse(N122B) mailto:bmuse@mindspring.com Wimberly, TX ------------------------------ Date: Wed, 08 Jul 1998 21:10:51 -0500 From: Bobby Muse Subject: Re: KR: Re: Bummer... 1/2 Compu-Fire dead At 11:35 AM 7/8/98 -0400, you wrote: >Email (repy) to cary@storm.ca > or ve3ev@rac.ca >Web page http://www.storm.ca/~cary/ >KR2 area http://www.storm.ca/~cary/kr2.shtml > >---------- >> From: Ross Youngblood >> Well, I'm bummed. >> >> The good news is this explains why my two cylinders seemed to be running >> cold, and why it >> was so hard to start. Maybe I can sell the Compu-Fire unit to someone >> with a 1/2 VW engine :). >> It ran really good with only two cylinders but it's probably not the >> best way to begin the break-in >> cycle. > >You could have come to a bad end. A real bummer there. > >Sorry: I couldn't resist. > >Perhaps you can shed some light for me on the engine response when checking >left then right ignition. I use "Bendix" mags. When I check the left or >right mag, the engine shakes like Model 'T' on a cordoroy road. I know my 6 >cyl Continental shakes a bit, but thought the Revmaster might have been >protesting too much. All CHT and EGT readings are close to each other and >well within the green. The rpm's drop about the same for each. Just how >much of a St. Vitus dance should I expect? > >- Cary - > >(BTW, great for making milkshakes) > Cary, I have a 2100d Revmaster and I when which from Right to Left, I can barely tell a difference and I'm idling at about 600rpm. Maybe you're idling too slow? or have bad plugs or ignition wires? Check wire routing. I have all my left mag wires going to the top plugs and the right mag wires ging to the bottom plugs. Bobby Muse(N122B) mailto:bmuse@mindspring.com Wimberly, TX ------------------------------ Date: Wed, 08 Jul 1998 20:07:07 -0600 From: Ron Lee Subject: KR: Selling my VW engine. This from the VW list. Ron Lee At 04:30 PM 7/8/98 -0400, you wrote: >To all on the VW list, thanks for all your help. Unfortunately, I've been >brainwashed by the Other Side and find myself a Soob convert. Fortunately, I >don't have to shave my head or anything, but I do want to sell my VW. It's an >1835 cc VW engine, converted for aircraft use. >You can see it at http://home.att.net/~tomkr2s/index.htm. It runs great, in >fact I ran it last weekend just to keep it fresh inside. >-Tom >unsubscribe (Did I do that right?) > > > ------------------------------ Date: Wed, 08 Jul 1998 20:11:05 -0600 From: Ron Lee Subject: Re: KR: The Wind TUnnel test results Steve. Thanks for the post. However, some of us (maybe just me) are not very bright when it comes to the info on that site. Can you or someone provide a comparison between the new airfoils and RAF48 such as TBD more lift at TBD less drag. TBD stall speed. yada, yada, yada Ron Lee PS. I did notice the fact that the 18% airfoil might not be the best for the whole wing due to some airflow separartion at the trailing edge. Did I read that correctly? At 11:32 AM 7/8/98 -0500, you wrote: > >THe following message was just received from Ashok. He has the wind >tunnel test results for the new AS5045 and AS5048 on his web page. We all >owe Ashok a lot for all of his efforts in helping to take the KR into the >21st Century. > >Thanks Ashok, we look forward to a lot of planes flying around with your >airfoils. > >Steve Eberhart > >---------- Forwarded message ---------- >Hi folks, > >It is finally ready! >http://amber.aae.uiuc.edu/~ashok/kr2/airfoils/tests/ > >I do appreciate your patience. > >Thanks, >Ashok > > ------------------------------ Date: Wed, 08 Jul 1998 22:43:40 -0400 From: Tom Andersen Subject: Re: KR: more good reading/long Mike pointed out the following site http://www.ellison-fluid-systems.com/article/fuelsystemsforhomebuilts/fuelsystems.htm and probably meant it to be a checklist for fuel system design and execution. Here's an excerpt I thought was good: (maximize your window it's indented a bit) Fuel system accidents include not only outright failures of devices in the system, but things we rarely think about, such as: Not knowing how much fuel you can put into a tank because of attitude sensitivity or venting. Small vent tubes easily obstructed by a single drop of water or an insect. High pressure boost pumps cavitating with interruption or surge in flow. Fuel selector valves sticking or not having clearly defined detent positions. A leaking gascolator gasket admitting air bubbles into the system, yet leaks little or no fuel. Vibration-induced cracking and leakage of spare fuel tanks. Split flares in metal tubes producing leaks, or inlet of air into system. Inadvertent flap valves in fuel hoses produced by improper insertion of connectors. Foreign bodies in the tank jamming boost pump piston or breaking carbon vanes of high pressure pumps. Inadequate sized elbows or other fittings in the system producing bubbles in the flow of fuel. Foreign bodies obstructing finger screens, gascolator screens or filters that are too small. Leaky carburetor floats. Leaky fuel injector servo diaphragm (beware of the shelf life). Leaks in diaphragms and edges of diaphragm in engine driven pumps. An unsupported vibrating fuel hose that partially obstructs flow. Worn or grooved connector fittings that leak air or fuel. High pressure systems (fuel injection) are considerably more critical with respect to leaks and obstructions than low pressure systems, for obvious reasons, and experience bears this out. Also fire hazards are greater with high pressure systems due not only to the higher pressure but because of the increased footage of plumbing and larger number of connections in the engine compartment. Boost pump failures and pump priming failures are also more prevalent here. Gravity fuel systems, while seemingly simple and reliable, are plagued by very small supply pressures and ease of interruption. For instance, the minimum pressure required by most current carburetors is 1/2 lb./sq. in. This requires a gravity column of 18 inches -not counting any losses for tubes, filters, valves, elbows, connectors, etc. - or the occasional sticking of a float needle valve. For small engine applications only, where small flow requirements prevail. Air being sucked into the flow of fuel can be as obstructive as vapor lock bubbles. This is another reason to have little or no suction component to the fuel system. Fuel leaks are much easier to find than air leaks because air leaks don't always leak fuel. At the Ellison site, of course, all roads lead to OZ. (An EFS-unit). But they play devil's advocate fairly well and make you think twice about what you've planned as far a fuel system. The rest of their dissertation on fuel systems is even better! Following is an outline-type summary of fuel system items to observe when designing or building your fuel system. Fuel Tanks Into which a known amount of fuel can be put each and every time (not attitude, tilt or vent sensitive). Of reliable mechanical construction, unlikely to develop leaks with time and vibration and unlikely to present an unusual hazard in a crash landing. This requires substantial resistance to rupture on impact or deformation. Must not have low spots behind baffles and in comers for collection of water. Vibration is worse in 4-cylinder airplanes than others, and must receive generous respect as a destroyer of structures and producer of leaks. Fuel Tank Caps Must not leak fuel, air or water. Expensive, but available and necessary. Look at those caps - take them apart and examine them. Small details are important here. Sump Adequate depth and size, with screen and drain valve as necessary. Do not tolerate a main tank without a real sump. Auxiliary tanks, with good lowpoint drains and a "no take-off" restriction 0. K. without sump. Unporting Protection Prevention of fuel being thrown away from sump outlet by uncoordinated flight or turn just before take off, by use of slosh gates or check valves and baffles in tank. Necessary. Vents 3/8" tubes or larger to prevent a frozen drop of water from obstructing. As short a run as possible, especially if horizontal (because of water droplet precipitation), with non-icing opening (any one of several types). Backup second vent highly desirable. Valves As simple a system as possible with all on or off if possible. An amazing number of accidents occur from pilot misplacement of valve handle or valve sticking, even from handles breaking off. Also even when properly changed, a long interval is required before engine starts. Selector valves are inherently dangerous and should be recognized as such. One alternative is a separate ball-type valve for each tank, arranged so that the handle position is obvious. Also these valves are more reliable and don't stick. Boost Pump Must be inside sump or have short gravity-fed inlet, otherwise very often will not reprime if run dry, especially fuel injection boost pumps. Do not try to suck fuel uphill or forward. It pulls bubbles into the fuel inviting cavitation. Acceleration occurs forward and upward on take-off and climb for a sustained period of time and fuel moves backward and down, and that's where the inlet of the boost pump should be if it is not in the sump. Protect inlet of pump with screen or filter adequate to protect the pump from jamming due to foreign body. Such filter must be inspectable and cleanable. These are often provided in the pump body by the manufacturer. Fuel Routing Should be direct from boost pump through filter to carburetor or fuel injector servo. Have engine driven pump plumbed in parallel, not series, so that possible vapor lock in engine driven pump will be bypassed. A check valve may be necessary, depending on pump type. Engine Driven Pump Requires shroud for positive-pressure ventilation to cool it, thus minimize fuel boiling (due to accessory case and oil temperatures which heat it). Fuel Lines and Devices Should not be exposed to heat anywhere, for two reasons: 1.To prevent vapor lock (bubbles whose surface tension make them resistant to going through small holes). 2.To prevent fire in case of accident, or fuel leak in flight Particularly avoid proximity of fuel lines or carburetors to exhaust pipes radiated heat is more intense than most people imagine. This heat acts as an ignition source in case of accident, or a fuel leak, or a crack in an exhaust pipe in flight. Metal heat shields are often necessary because most heat transfer in cowling is by radiation, not convection or conduction. Examples are the metal shields between an exhaust pipe and adjacent hoses or wires seen in many factory airplanes. Fuel Lines Should be of well engineered type and size and protected by fire-sleeve in engine compartment. Fuel Filters Gascolators are not sacred devices, not even very efficient ones. They were really designed for use with fuel tanks without sumps or sump drains. With sump drains they become unnecessary, or at best supplementary. Often they are sources of fuel leaks and air leaks into fuel systems. Also they are sometimes vulnerable to rupture in case of accident. Where tank sump drains are provided, good fuel filters of several types are better than gascolators and are safer, less prone to leaks and damage. Must be of adequate size and accessible to inspection, draining, cleaning or replacement. Beware of very small automotive filters which could obstruct in flight from a slug of dirt in the fuel. I am using a FRAM HPG-1 fuel filter in my Glasair. It is commonly used in racing cars and boats, has an excellent service experience. It has a 13 ounce capacity, a steel case into which you can put a drain valve. Expensive and bulky, but a good example of what is needed. Water Detectors Two brands are currently available (Wag-Aero; A.I.R. Corp., Oakland). A very good idea - either in sump or filter can. Gauges Reliable, backup simple mechanical type gauge or sight-tube gauge advisable for last few gallons in addition to standard gauges. Float switch with warning light is another good alternative (Aircraft Spruce). Fuel gauges are justifiably mistrusted, but they are also usually of low quality. Reliable separate gauging of the last 1/10 or so of fuel can be very accurate. Flow meters and totalizers are not a substitute for fuel gauging because they are so dependent on accurate knowledge of how much you start with. Be sure to have some back-up gauging or warning system beyond standard gauge system, or a reliable spare tank. Spare fuel Tanks, Header Tanks, Etc All have definite problems, including selector valve hazard, but they are a reasonable alternative it designed well. Using a vibrating firewall as one wall of header tank is a questionable practice unless it is specially reinforced and stiffened. (Touch that firewall in flight sometime.) Again think of a survivable crash landing or an in-flight fire. A VW-like standpipe in the main tank is one alternative to a spare fuel tank - or a separate tank within the main tank that fills automatically -or a spare tank that transfers into the main tank. Outer wing panels are the best location for spare tanks, for structural as well as safety reasons. Air Inlet System To Carburetor or Fuel Injector Servo Must be of adequate size and especially not obstructed by a too-small air filter. Better no filter than an obstructive one, because the obstructive one can seriously disturb fuel mixture and produce erratic throttle-mixture correspondence. Air filters are highly desirable but must receive the same design consideration as any other system and not simply yield to what is convenient (frequently seen in homebuilts). Be sure filter will also act as flame arrestor in case of start-up backfire - it can save your whole airplane. This is done by containing the filter in a blow-out and suck-in proof container. A curved elbow type of air entry into a carburetor is poor practice because of inertial lamination of airflow into the carburetor. A plenum, horn or diffuser entry is much better, and removes those dead spots at some throttle settings also higher power. Overflow Drains From engine pump, inlet spider, inlet plenum boxes as well as drains from filters and gascolators, must be overboarded in a safe place away from exhaust. A manifold collector and single drain often useful here. Carburetor Heat Source Standard and necessary. Can be easily combined with cabin heat. Pulling carb heat cable turns off cabin heat with two-way flap valve. Be sure to overboard any unused carb or cabin heat so there's a constant airflow over shrouded exhaust pipe. Otherwise that segment of pipe will bum through and become an early carbon monoxide and/or fire hazard. Belly Protection In case of gear-up landing, or gearcollapse accident in fixed gear aircraft. Any exposed or vulnerable fuel-containing structures such as sump, filters, drains, gascolators, etc., should have mechanical protection. No drain valve or such structure should project where it can be easily broken off in a belly landing. Longeron-like braces in belly pan is an example of a mechanical protective structure. A strong belly plate under this area is another. Fueling Putting fuel into aircraft tanks deserves some thought. The flow of fuel through a hose and nozzle creates static electricity, and a discharge arc sometimes occurs to the filler neck of the airplane - explosion. So, in fiberglass or other composite airplanes, it is desirable to ground the metal fuel filler cap ring. This is true because any mass of metal plus adjacent semi-conductor fluid (gasoline with some moisture in it) has some capacitance. As such, it becomes the target for a static electric arc from the fuel hose nozzle (which may or may not be grounded) or the pouring spout of a jerry can. This filler-neck grounding should be done with a wire (18 gauge or so is enough) attached with a good AN plated bolt and washer through the ,aluminum ring to a good plated crimpon fitting. These details are to minimize dielectric corrosion of the dissimilar metals. Aluminum bolt or rivet and wire could also be used. However, the experience with aluminum wires and connectors in the presence of moisture is poor. The wire should be mechanically supported properly into the cabin area where it is attached to the ground buss through a resistor (approx. 1 meg OHM 1 watt). This resistor limits the power of any static discharge. What it actually does is spread out the time of the discharge from instantaneous to several micro seconds. This then replaces the arc with a corona-like discharge which is probably below ignition temperature for gas fumes. In any case, when fueling, it is good practice to keep the nozzle in contact with the filler neck. If both the filler neck and the nozzle are grounded, there should be no problem. But you can't be too sure about some gas hoses and nozzles or ground connectors to airplane from the truck or pump. Finger screen in sump should be grounded - by grounding aluminum line or connector. Fueling from plastic (polyethylene) cans should never be done because these materials have a very high static electric generation potential when gasoline flows over its surface, or it is rubbed against another material. Metal cans are much safer. The preflight ceremony of draining sumps and other fuel devices should be taken seriously because it is here that you can best prevent the most terrifying of aircraft accidents - the engine stopping on take-off or initial climb. Water is the chief enemy, foreign bodies of all kinds, second. Always use a cup or container to drain fuel, so that you can am any water or debris that you drain. If you can't see it, you don't ever know how much to drain, and every once in a while it takes a lot. Fueling from some places can produce very large amounts of water and debris - much more than a cupful - even gallons. Old buried tanks with doubtful maintenance are guilty here, even some trucks have pro: produced such events. I know first-hand of several such events. Cessna's experience in rocking wings and tail to dislodge water from wrinkled bladder tanks should be remembered - it was successful. This applies to other airplanes, too, such as taildraggers where low spots due to attitude become pockets for water -or nose draggers with multiple baffles. Water droplets on the floor of a gas tank seem reluctant to move toward the low spot (sump) unless agitated, especially with minimal dihedral wing tanks, apparently due to surface tension. Water is soluble in gasoline to a limited extent, and this is particularly important in winter (see article by Niel Petersen Sport Aviation, December 1986). As fuel cools in the tanks overnight, some water precipitates out as droplets. This accounts for some of the .moisture of condensation' even when the tanks are full. Also if it is cold enough, these droplets can form ice crystals or slush, which can obstruct fuel outlet screens, even to the point of collapsing them in flight In the cold winter areas this can be important not only as a pre-flight consideration, but on long flights at altitude, where the fuel has time to become cold. Jet-powered aircraft use fuel heaters or water-dissolving additives ("Prist") in their fuel for this reason. However, their fuel has a greater solubility for water, and their flight altitudes are higher - but the problem is essentially the same. Conclusion This list is, of course, incomplete. My emphasis has been on those items which seem to me to be most important from a safe-design standpoint. Homebuilders suffer from "ran out of room" problems just when something like a fuel filter or an air filter demands a place, then compromise occurs, and the last items on the list get the poorest design. Don't yield to this - be willing to go back and rebuild or rearrange things so that fuel priority is properly respected. One last thing. If; you must put fuel system components in the engine compartment (where all the heat and ignition sources are), group them together and build a good metal, positively ventilated, box around them. Place the vent exit as far away from the exhaust pipe as possible. In fuel systems, the enemies are heat, water, leaks, foreign bodies, static electricity and devices that invite human error. ABOUT THE AUTHOR Lyle S. Powell, Jr., EAA 38012, has been flying for 23 years (Commercial, Mulfi. Instr., 3300 hrs.). Lyle has owned several factory-built airplanes, built and rebuilt a VariEze, a Glasair (with 750 hrs. on it) and is now building a Glasair III. He offers thanks to Andy Marshall of Marshall Consulting, George Periera (designer of the Osprey and G.P.-4) and Jim Horn (Voyager engine instrument design consultant) for their help and advice on this article. Yea, it's a lot of bandwidth, but it's so chock full of good info it's worth more than a bunch of replies to the group such as "Yes, I'll be at my mother's house in Timbuktu, how about U?" - -Tom ------------------------------ End of krnet-l-digest V2 #113 *****************************