krnet-l-digest Friday, April 25 1997 Volume 01 : Number 002 ---------------------------------------------------------------------- Date: Thu, 24 Apr 1997 06:36:03 -0500 From: Bobby Muse Subject: Re: KR: wing flaps and ailerons At 12:54 PM 4/22/97 -0600, you wrote: >At 10:59 97/4/22 -0700, you wrote: >> >>The KR has always had a reputation for being a very fast performing aircraft >>both in pitch and roll. The pitch, because of being short coupled, the 2s >>should fix that. >>But the roll? I've heard it said you think about turning this way or that >>and the KR goes. Could it be that the aileron could be shortened? there by >>allowing for a larger flap? > >SNIP > >> David Moore >> > >Maybe a better KR pilot will comment on this but my short ride in Troy's >KR-2 gave me the impression of very nice roll control. Not only that, but >there did not appear to be a need to use rudders during a roll. I think it >is designed that way but other than a difference in deflection of opposing >ailerons, I cannot accurately state why that is. So my guess is that you >would not need to change the ailerons. > >Realize that my time in a KR is limited so take my comments accordingly. > >Ron Lee > > Ron, I don't believe it could be said any better. The differential ailerons is the reason the KR has the ability to perform turns using only the ailerons. Bobby Muse bmuse@mindspring.com ------------------------------ Date: Thu, 24 Apr 1997 06:46:34 -0500 From: Bobby Muse Subject: Re: KR: pulleys At 11:30 PM 4/22/97 -0400, you wrote: >I just made my fittings for my pulleys, put the pulleys and gave it a >"test run". It appears that the pulley is rubbing on the bracket. Is it >ok, or is it recommended to put washers on the bolt, between the puley >and bracket, to give it more clearance so as not to rub? > > David > Yes. Bobby Muse bmuse@mindspring.com ------------------------------ Date: Thu, 24 Apr 1997 07:20:19 -0500 From: Bobby Muse Subject: Re: KR: Fuselage: Covering with 1.45 oz deck cloth At 12:03 AM 4/23/97 -0400, you wrote: >In a message dated 97-04-22 22:34:40 EDT, Steve Horn wrote: > >My reasons for covering the fuselage are two-fold; one is for durability, the >other is for aesthetics. I don't intend for the covering to be structural. > I primarily want to protect the wood stucture from the elements and >contaminants (oil, fuel, hydraulic fluid, etc.), and personally will feel >more comfortable with the "boat" sealed with a skin of fiberglass. I know we >could get the same effect from many coats of a good finish, but I like the >idea of a more-or-less impervious cocoon of glass. I haven't calculated the >added weight, but with 1.45 oz. cloth it will be relatively little. In my >mind the benefits outweigh the negatives. > >BTW, Tony Bingelis recommends this technique on page 156 of "The Sportplane >Builder" (I just looked it up). Regarding the added weight, he says you can >estimate about 1 ounce of resin per square foot, plus the weight of the >cloth. >Rick Junkin >EagleGator@aol.com > > > The one ounce of resin per square foot of fiberglass is based upon a thicker/heavier glass. At 1.45 oz. cloth, the amount of resin would be less. Bobby Muse bmuse@mindspring.com ------------------------------ Date: Thu, 24 Apr 1997 07:20:20 -0500 From: Bobby Muse Subject: Re: KR: Nomex Flight Suit? At 09:29 PM 4/22/97 -0700, you wrote: I was looking for a VW oil cooler on the Web, and >found the Nomex racing suits instead. > >-- >Ross Youngblood I purchased the oil cooler that I have been flying with for almost 4 years was purchased from a J.C. Whitley automotive catalog. The oil cooler is mounted on the firewall, using a ram air tude/shroud. Bobby Muse bmuse@mindspring.com ------------------------------ Date: Thu, 24 Apr 1997 07:15:53 -0700 From: MARVIN MCCOY Subject: Re: KR: Fuselage: Covering with 1.45 oz deck cloth Bobby Muse wrote: > > At 12:03 AM 4/23/97 -0400, you wrote: > >In a message dated 97-04-22 22:34:40 EDT, Steve Horn wrote: > > > >My reasons for covering the fuselage are two-fold; one is for durability, the > >other is for aesthetics. I don't intend for the covering to be structural. > > I primarily want to protect the wood stucture from the elements and > >contaminants (oil, fuel, hydraulic fluid, etc.), and personally will feel > >more comfortable with the "boat" sealed with a skin of fiberglass. I know we > >could get the same effect from many coats of a good finish, but I like the > >idea of a more-or-less impervious cocoon of glass. I haven't calculated the > >added weight, but with 1.45 oz. cloth it will be relatively little. In my > >mind the benefits outweigh the negatives. > > > >BTW, Tony Bingelis recommends this technique on page 156 of "The Sportplane > >Builder" (I just looked it up). Regarding the added weight, he says you can > >estimate about 1 ounce of resin per square foot, plus the weight of the > >cloth. > >Rick Junkin > >EagleGator@aol.com > > > > > > > > The one ounce of resin per square foot of fiberglass is based upon a thicker/heavier glass. At 1.45 oz. cloth, the amount of resin would be less. > > Bobby Muse > bmuse@mindspring.com - --------------------------- For what its worth... I would agree. A closer estimate would be to just double the weight of the glass you are putting on. If you are putting on ten yards of two oz per yard cloth the weight would be about 20 oz of cloth and about 20 oz of resin. This is an estimate. Keep in mind that the only thing the cloth is doing is keeping the amount of resin the same thickness on the wood and also the glass helps keep the wood from checking by stabilizing the movement of the wood from temperature and humidity changes. That way your finish and the wood under it lasts longer and you have less maintance. Paint and primer by itself will not do this. Marvin McCoy Mr.Marvin@worldnet.att.net - ------------------------------ ------------------------------ Date: Thu, 24 Apr 1997 10:41:53 -0700 From: "David M. Gargasz" Subject: Re: KR: KR sides RDefrain@aol.com wrote: > > Just finished reading my e-mail from the list and got to pondering something. > Would it be possible to construct the sides of a thin (1/4" or so) foam and > cover it with a thin layer of glass on both sides. > > ? #1 would it be strong enough. > > ? #2 would it bond properly to the wood airframe. > > Just thought I'd throw out some horse feed. > > Ralph D hi Ralph, All early boats by Glastron were built with wood frames incased in fibreglass that were smooth on the outside with the glass covered frame exposed on the inside. My idea [pioneering] was to use 1/2" urethane board between all the kr framing members instead of plywd. rounding the wood slightly for good adhesion and showing the framing slightly on the inside, The last time I thought about using the system I new the kr boat would be stronger more sound proof would accomodate up to 200hp, but the exposed inspections mandatory before closure, quality control of layups and higher cost than plwd. the lightest kr built ever Gene Gargasz % dave@erienet.net ------------------------------ Date: Thu, 24 Apr 1997 08:42:58 -0600 (MDT) From: Ron Lee Subject: Re: KR: KR sides At 02:21 97/4/24 -0400, you wrote: >Just finished reading my e-mail from the list and got to pondering something. >Would it be possible to construct the sides of a thin (1/4" or so) foam and >cover it with a thin layer of glass on both sides. > >? #1 would it be strong enough. > >? #2 would it bond properly to the wood airframe. > >Just thought I'd throw out some horse feed. > >Ralph D > This is the sort of structural change that has to be tackled by someone with more structural knowledge than myself. It is one thing to delete the thin glass layer on the sides. Reportedly, that glass is not for structure but a method to protect the plywood and perhaps also to get a nice smooth surface. If a person knows that ther can achieve those two goals without the glass.... great, go for it. But I am assuming that the plywood is an essential structural element. Changing it requires knowing how to replace it to get the proper structural end result. Note that many planes are made with all composite bodies. However, even the long-ez class planes have wooden longerons. and the glass layup is more than one layer of 1.5 oz glass plus the foam is a heavier foam compared to urethane or the hot wirable foam. As far as glass bonding to wood, my experience is that that is a good match, compared to glass to metal which bonds poorly. Ron Lee > ------------------------------ Date: Thu, 24 Apr 1997 01:02:56 -0700 From: Donald Reid Subject: Re: KR: KR sides RDefrain@aol.com wrote: > > Just finished reading my e-mail from the list and got to pondering something. > Would it be possible to construct the sides of a thin (1/4" or so) foam and > cover it with a thin layer of glass on both sides. > > ? #1 would it be strong enough. > > ? #2 would it bond properly to the wood airframe. > > Just thought I'd throw out some horse feed. > > Ralph D The spruce framework carries the tensile (pulling) and compressive (pushing) stress in the fuselage. The plywood carries the shear stress. That is the force that tries to change the angle of diagonal between the members. (Visualize a square being forced to a parallelogram). The highest stress fuselage bays have a diagonal piece of spruce that does the same thing. Even with the diagonal spruce member, there are still shear stresses that must be carried by some portion of the structure. According to ANC-18, "Design Of Wooden Aircraft Structures", 3/32" mahogany plywood has an ultimate strength in shear of between 1700 to 3010 pounds per square inch, depending upon the grain orientation to the forces. Bidirectional fiberglass will carry approximately 30,000 pounds per square inch. Using the lowest strength value, a 1 inch wide piece of one thickness of the 3/32" plywood can carry 159 pounds in shear. (1700 #/in2 * 3/32 in). A typical fiberglass ply is 0.01 inches thick. A one inch wide piece of glass will then carry approximately 300 pounds. The Aircraft Spruce catalog lists a strength of between 200 and 250 pounds per inch for the 6 oz glass cloth. When you compare only the strengths, one ply of glass would be strong enough to replace the 3/32 inch plywood. This would not give any allowance for partially sanding through the glass during the finish, puncture resistance, etc. Two plys would probably work fine. If there is any question, build a few test pieces and load them to destruction. Don Reid donreid@erols.com ------------------------------ Date: Thu, 24 Apr 1997 23:41:51 -0400 (EDT) From: DAmbrose12@aol.com Subject: KR: Fuel Filters Hi: I was looking at the new J.C. Penny catalog tonite and I see they have glass fuel filters in there for $5.99 and they also sell the replacement filters. They call it an aircraft style and say it filters down to 40 microns! Their number is 1-800-553-1872 if you want a catalog. It has lots of stuff in it! Regards Dennis. ------------------------------ Date: Thu, 24 Apr 1997 23:25:22 -0700 From: Ross Youngblood Subject: Re: KR: Wood Repair (not a keeper for Archives) Austin Clark wrote: > > At 23:53 4/23/97 -0700, you wrote: > >RDefrain@aol.com wrote: > >> > >> Another suggestion I would consider is to make the repair as Ross stated > (the > >> slope method) and try to locate it where the double longerons are. > >> > >> Ralph D > > > >I second that idea. I'd make my scarf joint there as well. > > -- Ross > > > > > Thanks for all the comments. Since this piece has not been installed > (glued) yet, I will make the scarf joint. It will be located in a straight > section of the fuselage. If I had this damage at a stage of construction > like Jim mentioned, I would feel comfortable with injecting epoxy into the > crack. > > Austin Clark I think the injecting epoxy idea is a sound one too. I'm not too sure about super glue, as it doesn't fill gaps as good as epoxy, but given a fresh break, clamping should fill all the gaps. Modern adhesives are wonderful. -- Ross ------------------------------ Date: Thu, 24 Apr 1997 23:34:54 -0700 From: Ross Youngblood Subject: Re: KR: wing flaps and ailerons Bobby Muse wrote: > Ron, I don't believe it could be said any better. The differential ailerons is the reason the KR has the ability to perform turns using only the ailerons. An old newsletter had an article by Steve Robinson of the original Ken Rand & Steve Robinson duo. He indicated that the differential aileron design & aileron gap, was done purposely to counter adverse yaw. I thought it was a nice touch. -- Ross ------------------------------ Date: Thu, 24 Apr 1997 23:38:37 -0700 From: Ross Youngblood Subject: Re: KR: Oil Coolers Bobby Muse wrote: > I purchased the oil cooler that I have been flying with for almost 4 years was purchased from a J.C. Whitley automotive catalog. > > The oil cooler is mounted on the firewall, using a ram air tude/shroud. > > Bobby Muse > bmuse@mindspring.com I like that idea. I can get the $70-80 stock flipped VW cooler from Great Plains, or similarly priced locally, or go with a cheaper $35-45 firewall mount system. I was up at Columbia aeromotive in Troutdale Oregon where I stop in to buy bolts when I'm in Portland, they have what looks like the coolest oil cooler so far (pun intended). It's by far the lightest thing I've seen, but it's $78 bucks. I think it is used for Continental/Lycoming engines, but it looks rather small. I don't recall the name but it is made in Sweeden, I found that interesting. -- Regards Ross ------------------------------ Date: Thu, 24 Apr 1997 23:42:01 -0700 From: Ross Youngblood Subject: Re: KR: Fuselage: Covering with 1.45 oz deck cloth MARVIN MCCOY wrote: > Keep in mind that the only thing the cloth is doing is keeping > the amount of resin the same thickness on the wood and also the glass > helps keep the wood from checking by stabilizing the movement of the > wood from temperature and humidity changes. That way your finish and > the wood under it lasts longer and you have less maintance. Paint and > primer by itself will not do this. > > Marvin McCoy > Mr.Marvin@worldnet.att.netMarvin, Thanks, This and the Tony Bengilis reference are sound arguments for the use of deck cloth on the fuselage. I sit corrected. -- Ross ------------------------------ Date: Thu, 24 Apr 1997 23:56:53 -0700 From: Ross Youngblood Subject: KR: New Member posting This is a multi-part message in MIME format. - --------------464161C8FEF Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit The following is a terrific posting from a new KRNET member Don Blankenship. He is commenting on the not yet dead horse issue of incidence... Content-Type: message/rfc822 Content-Transfer-Encoding: 7bit Content-Disposition: inline Ross, I enjoyed reading your article on building your KR more than any other similar material. It was informative and educational and greatly appreciated. As an educational project, I have analyzed most aspects of the plane and am building one myself. I was amazed that your in-depth study of the aircraft has produced several nearly identical results as my own. In particular, I widened my horizontal stabilizer 6 inches on each side and kept the elevator sizing the same. That should produce longitudinal stability characteristics close to those of a Lear jet. I did use horizontal tail spars 1/8 inch thicker than plans to maintain the stiffness of the h.t. for flutter resistance. Widening the horiz tail from 71 inches to 83 inches is better than stretching the fuselage, because it produces the same pitch stability as lengthening the fuselage 18 inches or more without adding the weight and wetted area (drag) of a fuselage stretch. Also, stretching the fuselage does nothing for you in terms of vertical tail control, because at the same time you lengthen the moment arm of the tail, you add fuselage area which counts against you in a cross-wind landing. There is, however, a serious error you should correct in your articles on the KR aircraft. You have mistakenly recommended changing the wing incidence angle to 1.0 degrees instead of the 3.5 degrees at wing root called out by the designer's plans. You observed that KRs seem to be nose down low to the ground. That is because just above the ground the aircraft are (1) in ground effect where they are getting more lift than they need and (2) may have flaps down which also points the nose down some. Both things will give a false indication of a desirable wing incidence angle. At cruise in steady level flight, the KR-2 needs slightly more wing incidence relative to the top longerons than the original prototype KR-2 needed. Look at any published picture of KRs in flight and you will see they are almost always nose up in level cruise (smiley picture-taking attitude). That is because most KR-2 aircraft are heavier than the original 480-pound aircraft and therefore need to fly at slightly greater angles of attack for any given airspeed. This is most apparent on approach before entering ground effect. At slower speeds, the required angle of attack is in the neighborhood of 10 degrees, and to get there you have recommended taking off another 2.5 full degrees from the over-the-nose visibility of the aircraft by reducing the incidence angle from 3.5 degrees to 1.0 degrees. At any airspeed at or below trim cruise, such an airplane is going to fly with its longerons canted upward unnecessarily. I personally installed my wing at 4.5 degrees incidence for over-the-nose visibility, but that was not necessary. The 3.5 degrees called out by plans is fine for any KR-2 that is not particularly slow at cruise. Considering wing twist, the actual net incidence angle of the whole wing is less than 3.0 degrees anyway. Your article was very authoritative and most of it appears well thought out and informed. Many people, including myself, will use it in their quests for better aircraft designs. There is really no way not to sound condescending or even nasty when pointing out a well-meaning person's errors, but people will depend on the veracity of your advice for their lives. If you would like to talk about modifications to make aircraft safer, I can be reached at (937) 859-8581 after 5:00p Ohio time or by e-mail reply. There are modifications that can be made to aircraft such as NASA anti-stall/spin leading edges, seat belt attachments, and others. I am carefully trying to learn about such modications but have not tested them in my unfinished aircraft. There is one more noteworthy aspect of aircraft that is gaining great negative publicity for experimentals as well as large general aviation aircraft. The 737 that crashed last year was suspected of rudder control reversal. That is, the pilot pushed on one rudder pedal but the opposite was deflected. Witnesses said the plane just seamed to roll over and dive at the ground inverted. At least twice in separate fatal incidents, witnesses have said the same about KRs. In both those crashes, the pilots were low and slow over a potential landing area and likely cross controlled the aircraft in an improper manner. It is highly likely that the pilots did not properly put in ailerons to roll in the direction they needed to go to line up with the runway and did not follow with opposite rudder as they should have. Instead, they apparently stomped the rudder the direction they wanted to go then countered aerodynamic forces with opposite aileron. That incorrect cross-controlling produces what is termed an "under-the- bottom" stall in which witnesses say 'the plane just seemed to roll completely over for no apparent reason.' The AOPA has a video tape that demonstrates the phenomenon in flight testing. It has to do with fuselage / wing interactions in a side slip. Low wings and high wings both do it, but they roll over in opposite directions given identical improper cross-controlling. Hope to discuss more later. DON BLANKENSHIP ------------------------------ Date: Fri, 25 Apr 1997 00:02:41 -0700 From: Ross Youngblood Subject: Re: KR: Fuel Filters Dennis, Cool.. I've got two glass filters already, one for each wing tank. they are the ACS type, but turn out to be FRAM auto filters. I wonder if the J.C. (Penny or was it Whitney) catalog flavor is the same. I may order some filter elements to see. Thanks for the Phone # I've got a catalog. It's hard to tell what you get from JC, unless you buy it and check it out. Not as much risk buying from ACS or Wicks. -- Ross DAmbrose12@aol.com wrote: > > Hi: > > I was looking at the new J.C. Penny catalog tonite and I see they have > glass fuel filters in there for $5.99 and they also sell the replacement > filters. They call it an aircraft style and say it filters down to 40 > microns! > Their number is 1-800-553-1872 if you want a catalog. It has lots of > stuff in it! > > Regards Dennis. - -- Ross Youngblood KRNET-L administrator mailto:rossy@teleport.com http://www.teleport.com/~rossy/N541RY.htm ------------------------------ Date: Fri, 25 Apr 1997 00:26:54 -0700 (PDT) From: owner-krnet-l@teleport.com Subject: [none] Teleport set me up with a KRNET digest list. I haven't had time to do anyting with this yet, but the system spit out a digest anyway. For those who are wondering what this is, the digest list "krnet-l-digest" will monitor all KRNET traffic for you and when the file reaches a maximum size, or so many days have elapsed, you get ONE email with all KRNET stuff over that time period. Sender: owner-krnet-l@lists.teleport.com Precedence: bulk Reply-To: krnet-l Now, before you get too excited, your KRNET admin (thats me), is busy sanding and painting his KR. This means that the digest list is just as recieved from TELEPORT (the host for this list). I haven't checked to see how many days of activity are in the digest, this could be daily. I just got my first digest mailed to me today. To join the digest, AND unsubscribe from KRNET-L in one fell swoop send an email to: mailto:majordomo@teleport.com with the body text: subscribe KRNET-L-DIGEST your_email_address unsubscribe KRNET-L your_email_address end Be sure to use YOUR correct email address otherwise... nothing happens. For those who are swamped by the email to KRNET, and just want to keep up with the email, you might want to join the digest. However currently if you unsubscribe to KRNET-L, you will no longer be able to post to KRNET. I would recommend that users try the digest first for a couple of days/weeks before unsubscribing to krnet-l. Please email me directly with any comments/suggestsions to keep email traffic down. Thanks! -- Ross Ross Youngblood KRNET-L administrator mailto:rossy@teleport.com http://www.teleport.com/~rossy/N541RY.htm ------------------------------ Date: Fri, 25 Apr 1997 00:29:57 -0700 (PDT) From: owner-krnet-l@teleport.com Subject: [none] Teleport set me up with a KRNET digest list. I haven't had time to do anyting with this yet, but the system spit out a digest anyway. For those who are wondering what this is, the digest list "krnet-l-digest" will monitor all KRNET traffic for you and when the file reaches a maximum size, or so many days have elapsed, you get ONE email with all KRNET stuff over that time period. Sender: owner-krnet-l@lists.teleport.com Precedence: bulk Reply-To: krnet-l Now, before you get too excited, your KRNET admin (thats me), is busy sanding and painting his KR. This means that the digest list is just as recieved from TELEPORT (the host for this list). I haven't checked to see how many days of activity are in the digest, this could be daily. I just got my first digest mailed to me today. To join the digest, AND unsubscribe from KRNET-L in one fell swoop send an email to: mailto:majordomo@teleport.com with the body text: subscribe KRNET-L-DIGEST your_email_address unsubscribe KRNET-L your_email_address end Be sure to use YOUR correct email address otherwise... nothing happens. For those who are swamped by the email to KRNET, and just want to keep up with the email, you might want to join the digest. However currently if you unsubscribe to KRNET-L, you will no longer be able to post to KRNET. I would recommend that users try the digest first for a couple of days/weeks before unsubscribing to krnet-l. Please email me directly with any comments/suggestsions to keep email traffic down. Thanks! -- Ross - -- Ross Youngblood KRNET-L administrator mailto:rossy@teleport.com http://www.teleport.com/~rossy/N541RY.htm ------------------------------ Date: Fri, 25 Apr 1997 00:34:40 -0700 From: Ross Youngblood Subject: KR: KRNET-L-DIGEST Teleport set me up with a KRNET digest list. I haven't had time to do anyting with this yet, but the system spit out a digest anyway. For those who are wondering what this is, the digest list "krnet-l-digest" will monitor all KRNET traffic for you and when the file reaches a maximum size, or so many days have elapsed, you get ONE email with all KRNET stuff over that time period. Sender: owner-krnet-l@lists.teleport.com Precedence: bulk Reply-To: krnet-l Now, before you get too excited, your KRNET admin (thats me), is busy sanding and painting his KR. This means that the digest list is just as recieved from TELEPORT (the host for this list). I haven't checked to see how many days of activity are in the digest, this could be daily. I just got my first digest mailed to me today. To join the digest, AND unsubscribe from KRNET-L in one fell swoop send an email to: mailto:majordomo@teleport.com with the body text: subscribe KRNET-L-DIGEST your_email_address unsubscribe KRNET-L your_email_address end Be sure to use YOUR correct email address otherwise... nothing happens. For those who are swamped by the email to KRNET, and just want to keep up with the email, you might want to join the digest. However currently if you unsubscribe to KRNET-L, you will no longer be able to post to KRNET. I would recommend that users try the digest first for a couple of days/weeks before unsubscribing to krnet-l. Please email me directly with any comments/suggestsions to keep email traffic down. Thanks! -- Ross - -- Ross Youngblood KRNET-L administrator mailto:rossy@teleport.com http://www.teleport.com/~rossy/N541RY.htm ------------------------------ Date: Fri, 25 Apr 1997 06:34:57 -0400 (EDT) From: Baleco@aol.com Subject: Re: KR: Fuel Filters In a message dated 97-04-24 23:45:26 EDT, you write: << I was looking at the new J.C. Penny catalog tonite and I see they have glass fuel filters in there for $5.99 and they also sell the replacement filters. They call it an aircraft style and say it filters down to 40 microns! >> Hummn, wonder what a good filtration level is for fuel? Typical oil filter paper is good down to 10 micron. A stainless mesh like an Oberg is good down to 3. Haven't I seen the flat Oberg element adapted to a fuel filter for racing? These units are of very high quality. I had one as an oil filter on my Maule. Did an excellent job. Marty ------------------------------ Date: Fri, 25 Apr 1997 06:29:58 -0500 From: ejanssen@chipsnet.com (Janssen Craig) Subject: Re: KR: New Member posting At 11:56 PM 4/24/97 -0700, you wrote: >The following is a terrific posting from a new KRNET member >Don Blankenship. >He is commenting on the not yet dead horse issue of incidence... > > There is, however, a serious error you should correct in your articles > on the KR aircraft. You have mistakenly recommended changing the wing > incidence angle to 1.0 degrees instead of the 3.5 degrees at wing root > called out by the designer's plans. > > You observed that KRs seem to be nose down low to the ground. That is > because just above the ground the aircraft are (1) in ground effect > where they are getting more lift than they need and (2) may have flaps > down which also points the nose down some. Both things will give a > false indication of a desirable wing incidence angle. > Don, How do you explain the nose down attitude at cruise, say at 1500 feet, without flaps - which is what most of us are referring to? Ed Janssen ------------------------------ Date: Fri, 25 Apr 1997 09:37:53 -0700 From: Owen Davies Subject: Re: KR: Wood Repair That idea of using cyanoacrylate to repair a longeron crack really worries me. Great glues in the short term, but I've always understood that they are likely to let go after a few years. Anyone else know more about this? Owen Davies ------------------------------ Date: Fri, 25 Apr 1997 08:58:22 -0500 (CDT) From: Steven A Eberhart Subject: Re: KR: Possible builder...(NOT FOR ARCHIVE) On Wed, 23 Apr 1997, Tom Crawford wrote: [big editorial snip] > This is not counting about the same > number of hours standing there with a dumb look on my face, scratching my > head trying to figure out how to do something that is not made clear in the > construction manual. > Construction manual? Construction Manual? you got a construction manual? I got a notebook that meticulously described how to make the retractable gear that nobody is using, some notes on construction methods and some notes and drawings. After you take out the retract section and the construction methods sections there is very little left filling up the book. Compare that with what you get for a Cozy IV and it makes you wonder. You can even make a phone call and talk to someone who has built and flown a Cozy - curious marketing strategy ;-) Oh well, as I have said before, I am keeping the design for the drink holder and scrapping most everything else - guess I didn't need a manual after all ;-) Steve Eberhart newtech@newtech.com ------------------------------ Date: Fri, 25 Apr 1997 07:28:59 -0700 From: Micheal Mims Subject: Re: KR: Wood Repair (not a keeper for Archives) At 11:25 PM 4/24/97 -0700, you wrote: >I think the injecting epoxy idea is a sound one too. I'm not too sure >about super glue, as it doesn't fill gaps as good as epoxy, but given >a fresh break, clamping should fill all the gaps. Modern adhesives >are wonderful. > > -- Ross YES the modern adhesives are great! If it was cost effective it would be cool to build your KR using Zap or Hot stuff, they make about three different thicknesses (one that is gap filling and used on plywood) and an accelerator. IF anyone out there has built a wooden RC model in the last 5 years you know what I am talking about. This stuff penetrates the wood far better than any epoxy I have ever used and it is just as strong if not stronger (in RC applications)!! If this stuff could be used your drying times for parts would go from 48 hours to about 30 seconds! _______________________ ~~~~~~~~~~~~~~~~~~~~~~ Micheal Mims Just Plane Nutts mailto:mimsmand@ix.netcom.com http://www.netcom.com/~mimsmand ------------------------------ Date: Fri, 25 Apr 1997 12:02:00 -0500 From: "Tim \"KitaruSapien\" Tracey" Subject: Re: KR: Wood Repair At 09:37 AM 4/25/97 -0700, you wrote: >That idea of using cyanoacrylate to repair a longeron crack >really worries me. Great glues in the short term, but I've >always understood that they are likely to let go after a >few years. Anyone else know more about this? > >Owen Davies > The thinner the cyano, the brittler the glue & the tighter the bond between surfaces that is needed(to my experiences). Some cyano gels have additional components to lend a epoxy-like life to cyano's & reduce brittlness, but invariably they fail before most of the quality epoxies set under proper conditions. The real benefit of super-thin cyano's is their penetrating abilities in soft woods; a tight bond here will almost always rip the wood regardless of it's quality rather than the glue(perhaps common knowledge). ------------------------------ Date: Fri, 25 Apr 1997 13:10:17 -0400 From: Vince Bozik Subject: Re: KR: Wood Repair (not archivable:) > YES the modern adhesives are great! If it was cost effective it would be > cool to build your KR using Zap or Hot stuff, they make about three > different thicknesses (one that is gap filling and used on plywood) and an > accelerator. IF anyone out there has built a wooden RC model in the last 5 > years you know what I am talking about. This stuff penetrates the wood far > better than any epoxy I have ever used and it is just as strong if not > stronger (in RC applications)!! If this stuff could be used your drying > times for parts would go from 48 hours to about 30 seconds! Yea, I know what you mean. The penetration is great, and good joints are as solid as any I have done with epoxy. The only downside is that you had better had that joint right, or else you'll have a mess! The key to the hot stuff and other cycasdfjasdf(sp???) seems to be pressure on the joint; and once the pressure is obtained, it's locked! The stuff's great, and I've spent hours and hours chewing it off of my fingers! Like what was said previously, I'd be weary of using it on a KR in any structural or permanent bonding area. It might not be bad for light-temporary tacking where a bond is required instantly. Vince Bozik - -- Vince Bozik - Athens, Georgia Mailto:ICBM@ix.netcom.com ------------------------------ Date: Fri, 25 Apr 1997 13:30:49 -0400 From: Vince Bozik Subject: KR: ? on Trim Tabs O.K. So here I go showing my ignorance and inexperience again... From what I've gathered from this list, trim tabs are used to push the elevator in the opposing direction, thereby causing a reaction. So, if the trailing edge of the tab is moved into the upwards direction, the elevator is forced in the downward(causing the nose of the plane to rotate down) direction. What I don't understand is: If the force required to move the elevator down moves it down, and the setup finds it's equalibrium and stablizes, How the heck does this affect the pitch of the plane? What I mean is: The same force that is making the trim tab move the elevator(or rudder) down, is getting an equal and opposite force from the other side, otherwise the tab would be fully effective putting all of the throw into the elevator and would not serve a purpose. Granted, the elevator has more area than the tab, but this would mean that less of the elevator would be introduced into the airflow than the trim tab because it has more of an effect as a result of it's greater area, allowing it to balance the forces. Because of this balance, I don't see how it's gonna work that way. Is it the chord change and the change in the angle of attack that explains it? There seems like there'd be a better, or at least a more efficient, way of trimming out an aircraft. Eh?? That's all, and If I just caused any confusion with my inexperienced way of explaining things, let me know and I'll find a better way of explaining it. I hope! Another question: Have any of you seen those extentions on the bottom of ailerons? They run from the aileron, are angled forward of it's axis, and have a little "wing" on the end of them. They have an effect of balancing the resistance that the airflow has when the aileron is introduced into the airflow. Because of their longer arm, there's not much surface area on them. I've seen these on a Cap 231, on the ailerons and elevator, and am thinking that they're for reducing the stick pressure needed for aerobatics during extreme aileron travel. They're not mechanical, but are just "there," as part of the aileron. Would these serve a purpose on a KR? I doubt anyone is snap rolling the heck out of these things(KR's), or doing inverted flat spins! YEA! Vince Bozik - -- Vince Bozik - Athens, Georgia Mailto:ICBM@ix.netcom.com ------------------------------ Date: Fri, 25 Apr 1997 13:46:02 -0400 From: Vince Bozik Subject: Re: KR: ? on Trim Tabs > That's all, and If I just caused any confusion with my inexperienced > way of explaining things, let me know and I'll find a better way of > explaining it. I hope! Oops! > Another question: Have any of you seen those extentions on the bottom > of ailerons? They run from the aileron, are angled forward of it's axis, > and have a little "wing" on the end of them. They have an effect of > balancing the resistance that the airflow has when the aileron is > introduced into the airflow. Because of their longer arm, there's not > much surface area on them. I've seen these on a Cap 231, on the ailerons > and elevator, and am thinking that they're for reducing the stick > pressure needed for aerobatics during extreme aileron travel. They're > not mechanical, but are just "there," as part of the aileron. Would > these serve a purpose on a KR? I doubt anyone is snap rolling the heck > out of these things(KR's), or doing inverted flat spins! YEA! I forgot... If anyone would like a diagram, I'm sure I could work something up in a dwg of bmp format. - -- Vince Bozik - Athens, Georgia Mailto:ICBM@ix.netcom.com ------------------------------ End of krnet-l-digest V1 #2 ***************************