From: krnet-bounces+johnbou=speakeasy.net@mylist.net To: John Bouyea Subject: KRnet Digest, Vol 347, Issue 511 Date: 12/14/2005 9:00:09 PM Send KRnet mailing list submissions to krnet@mylist.net To subscribe or unsubscribe via the World Wide Web, visit http://mylist.net/listinfo/krnet or, via email, send a message with subject or body 'help' to krnet-request@mylist.net You can reach the person managing the list at krnet-owner@mylist.net When replying, please edit your Subject line so it is more specific than "Re: Contents of KRnet digest..." Today's Topics: 1. A little hanger flying (jeffyork40@qx.net) 2. Ken Rand photo. (Mark Jones) 3. Props (pedro@heroic.co.uk) 4. RE: Insurance (Jack Cooper) 5. Re: Props (billstarrs@peoplepc.com) 6. R?f. : KR> Props (Serge VIDAL) 7. Re: Props (JIM RALEIGH) 8. Prop choice - power requirements (Peter Diffey) 9. Re: Props (JAMES C FERRIS) 10. Landing gear (mains) (Ron Smith) 11. Re: Prop choice - power requirements (MFREEMAN2@indy.rr.com) 12. unsubscribe (Berry Coppage) ---------------------------------------------------------------------- Message: 1 Date: Wed, 14 Dec 2005 08:02:50 -0500 From: Subject: KR> A little hanger flying To: "KRnet" , "Ed Janssen" Message-ID: <000b01c600ae$c3183190$6864a8c0@server> Content-Type: text/plain; charset="iso-8859-1" I was actually at a small airport back a few years ago and seen a mini max EROS in an open hanger. I thought it looked like the coolest little airplane I had ever seen. It reminded me of a RANs airplane, but I do not remember the model. Anyway, the guy had painted the EROS red. I did not get to see it run or fly as the owner was not around. For that matter there was not a single person around on the airport. But as I said , my thoughts where "man is that a cool little airplane" I used to travel a lot more then I do today. When I would be out of town on business, I would make a point of trying to find the local airport or I would actually drive secondary roads just to find remote little airports. I just wanted to be around airplanes. This habit of finding airports got me to a lot of very remote and sometimes very small airports. Most of the time, I would find the airport but there would not be a single person there. Most of the airports would have the open community hangers so I could just walk through and look at plane after plane. By the way, one of the coolest airports I ever got to was, Washington County airport in Southern Indiana. The FBO was manned by the local EAA chapter. Everyone in the chapter signed up to share their duty. The fuel pump was on the honor system and I think it had a box that you would slip you money into. The walls where cover in the torn t shirts, solo awards. They have a little fly in every fall I believe. I went a few times and it was an awesome big little fly in. This reminds me of the time I was at another little airport somewhere in Indiana. A guy flew in with a small Rans. I think it was a model S-9 or something like that. Anyway , he pulls up to me because I was standing close to the water hose. He gets out of his little plane and begins to wash it off. To wash the bottom of the plane, he grabs a lawn chair that was sitting near by. You know, one of those web lawn chairs. He grabs one side of his plane and lifts it up and sets the landing gear down in the lawn chair. He then could slid under the airplane and finishes washing it. I was so amazed by this I had to watch. We talked and when he finished, he climbed in, grabbed a pull starter, you know, like to ones you find on a snow mobile, pulls it, the engine comes to life and he taxi's off. That was many years ago and I am sure it was before I had my pilots license. Not that you wanted to hear all this but, what the heck, I wrote it anyway. I guess this is as close to hanger flying as I am going to get today. As far as the next KR gathering, yes I plan to go, but the next time I promise myself to have the KR there. I thought I was going to have it there last fall. But, I had not solved my oil temp problem, which as I mentioned previously, may not have even been a problem anyway. Oh , and on that subject, I also realized that my oil temp sensor is very close to my exhaust, so I may have even been picking up inaccurate readings anyway. So , as soon as I finish my baffling redo, I will relocate my oil temp unit also. Ok, its getting near the holidays and I guess I am getting a little sentimental. Don't ban me from the list, remember, I did mention my oil temp problem and the fact my sensor is to close to the exhaust so there may be some official KR value there. Have a great day, Jeff York KR-2 Flying N839BG Home page http://web.qx.net/jeffyork40/ My KR-2 http://web.qx.net/jeffyork40/Airplane/ to see my KR-2 Email jeffyork40@qx.net ----- Original Message ----- From: "Ed Janssen" To: Sent: Tuesday, December 13, 2005 8:20 PM Subject: Re: Hi Jeff Re: KR> Re:Wet Runways in the winter > Jeff, > > I can sure relate to family commmittments. I've had five boys myself. > All that's behind me now though. Good luck on finishing up the plane. > It's sure a beauty. > > I just finished up scratch-building a Minimax Eros (if you know what > they > are) and is now flying. I also have a KR-2 project that needs refurbishing, > so now that I have something to fly, I guess I'll get back to work on > it. > > Maybe you'll make the next Gathering. > > Ed > > Ed Janssen > mailto:ejanssen@chipsnet.com > ----- Original Message ----- > From: > To: "Ed Janssen" > Sent: Tuesday, December 13, 2005 4:31 PM > Subject: Re: Hi Jeff Re: KR> Re:Wet Runways in the winter > > > > Yes , I flew it several times ( about 16 hours worth) before taking > > it > down > > for what I thought would be a little cowling mod. > > > > The story on that is , a friend and fellow pilot ( who also built a > > homebuilt and is a professional pilot, just to qualify him) thought > > that > the > > oil temps where to high. We had been flying it around for several > > hours when he noticed this on the last of many take offs. > > > > So , I began the search to fix this issue. I began by modifying the lower > > cowling as we suspected the low pressure side was actually to high > > due to > > the intake. > > > > Well, with kids, job change and so on, that modification alone ended > > up taking a over a year. Oh, I also forgot to mention losing my > > hanger as > well. > > I ended up having to store the plane for over a year. > > > > Forward to near present. > > > > After getting the cowling done, and getting back into hanger of my > > own ( shared the last one) I began the slow and not so regular > > procedure of putting it back together. > > > > Once back together, I took it back up. Several taxi tests and such > > as I wanted to re acquaint myself with it. > > > > It was just like riding a bike. Took only a little while to get the > > hang > of > > it. > > > > The result of several flight tests showed no change in oil temps. I > > then noticed a string of KR net messages on the subject of temps. > > The bottom > line > > of those emails lead me to believe that I may not have really had a > > oil > temp > > problem after all. My oil temps where seeing 220 F. Since this was > > in > climb > > but I was afraid of cooking an engine per my friends thoughts. I > > then decided to redo my engine baffling. > > > > This is where I am at present. You can see pictures of current state > > of baffle work on my website. > > > > I also got involved with a Piper Cherokee. That I think I will have > > to > back > > out of it as the pre inspection was not what I was lead to believe > > and now > > that same mechanic is telling me a whole different story on the > > annual. > Long > > story but the short of it is that I think I am backing out of that > > deal. > > > > So between watching my kids and house chores , job, yada yada... I > > am getting there. > > > > I know, if you have your priorities straight.. and I do, I love my > > plane > but > > not to the extent of having my 3 year old trying to sleep in my van > > or running around while I work on my plane. > > > > I just need to figure out how to have more hours in the day and more free > > time on the weekends. > > > > Jeff York > > KR-2 Flying > > N839BG > > Home page http://web.qx.net/jeffyork40/ > > My KR-2 http://web.qx.net/jeffyork40/Airplane/ to see my KR-2 > > Email jeffyork40@qx.net > > > > ----- Original Message ----- > > From: "Ed Janssen" > > To: > > Sent: Tuesday, December 13, 2005 4:03 PM > > Subject: Hi Jeff Re: KR> Re:Wet Runways in the winter > > > > > > > Jeff, > > > > > > I remember first seeing a picture of your beautiful KR2 shortly > > > after > you > > > bought it quite some time ago. I haven't seen any flight reports. Have > > you > > > actually flown it yet? > > > > > > Ed > > > > > > Ed Janssen > > > mailto:ejanssen@chipsnet.com > > > ----- Original Message ----- > > > From: > > > To: "KRnet" > > > Sent: Tuesday, December 13, 2005 10:42 AM > > > Subject: Re: KR> Re:Wet Runways in the winter > > > > > > > > > > What I meant to say was that in 18 years of flying, he may have never > > > really > > > > thought of this situation as being a problem > > > > > > > > It also brought to my mind the thought that wheel pants ( not > > > > in his > > > > situation) and other items may allow for ice build up from > > > > splashing > > water > > > > on the taxiways. > > > > > > > > Or in other words, it refreshes our minds to remember that > > > > winter > flying > > > > brings with it additional things to consider other then just how > > > > to > stay > > > > warm when we fly. > > > > > > > > Not sure if I am getting my point across but what I am trying to > > > > say > > that > > > I > > > > was glad I read this because it made me think. > > > > > > > > Jeff York > > > > KR-2 Flying > > > > N839BG > > > > Home page http://web.qx.net/jeffyork40/ > > > > My KR-2 http://web.qx.net/jeffyork40/Airplane/ to see my KR-2 > > > > Email jeffyork40@qx.net > > > > > > > > ----- Original Message ----- > > > > From: "Ron Freiberger" > > > > To: "'KRnet'" > > > > Sent: Tuesday, December 13, 2005 10:59 AM > > > > Subject: RE: KR> Re:Wet Runways in the winter > > > > > > > > > > > > > How do you preflight ice buildup? > > > > > > > > > > Ron Freiberger > > > > > mail to ronandmartha@earthlink.net > > > > > > > > > > > > > > > > > > > > > > > > > Subject: Re: KR> Re:Wet Runways in the winter > > > > > > > > > > I think Kip's story say's a lot for all of us to think about. > > > > > > > > > > The fact that he has flown this plane for 18 years and never > > > > > had > this > > > > > problem. Therefore this was never part of his preflight. WOW > > > > > !! > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > _______________________________________ > > > > > Search the KRnet Archives at > http://www.maddyhome.com/krsrch/index.jsp > > > > > to UNsubscribe from KRnet, send a message to KRnet-leave@mylist.net > > > > > please see other KRnet info at http://www.krnet.org/info.html > > > > > > > > > > > > > > > > > > > > > _______________________________________ > > > > Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp > > > > to UNsubscribe from KRnet, send a message to > > > > KRnet-leave@mylist.net please see other KRnet info at > > > > http://www.krnet.org/info.html > > > > > > > > > > > > > > > > ------------------------------ Message: 2 Date: Wed, 14 Dec 2005 11:33:43 -0600 From: "Mark Jones" Subject: KR> Ken Rand photo. To: "KR Net \(E-mail\)" Message-ID: <26D1C67793459F43BF8DA235F92B1F35C10424@tulsaexchange.tulsaokmail.com> Content-Type: text/plain; charset="iso-8859-1" Bob Stone has sent me a photo of Ken and himself from back in 1974. This is one of the better photos I have seen of Ken. We thought we would share this with all of you. Here is the link: http://flykr2s.com/kenrand.html Mark Jones (N886MJ) Wales, WI Visit my "NEW" KR CorvAIRCRAFT web site: http://www.flykr2s.com Email: mailto:flykr2s@wi.rr.com ------------------------------ Message: 3 Date: Wed, 14 Dec 2005 17:55:03 -0000 (GMT) From: Subject: KR> Props To: Message-ID: <17640.139.149.1.203.1134582903.squirrel@www.heroic.co.uk> Content-Type: text/plain; charset=iso-8859-1 Hi, the size of a prop is given as 2 numbers diameter/pitch. In terms of maximum speed, the pitch is the important number a one inch pitch would give 2.84 mph, so a 49in pitch prop would give a max speed of 139 mph at 3000 revs and 64in pitch gives 181 mph at 3000 revs. VWs are normally limited to around 3400revs( in UK by PFA edict ), so a 49in prop would give me a max of 138mph. this is regardless of how big the prop is - that's the max speed. At this speed the blades angle of attack becomes zero, so it cannot provide any more thrust. The only way I can get to go any faster is by increasing revs. So given that I want ground clearance, I am limited to say 60 inch diam. Now if you imagine a prop that is about the same width as a tape measure, it will obviously need less energy to turn it than big fat wide blades, so the designer has to come up with a prop that will have:- 1 have a theoretical max speed somewhat higher than the required max speed. 2 shovels sufficient air to overcome the aircraft drag at the required max speed. 3 is not stalled at speed below the aircraft take off speed. 4 does not produce so much drag that the engine cannot produce full power at take off speed. I am puzzled why prop manufactures only give the diam/pitch figures for a prop, when as explained above the prop width/cord is vitally important when choosing a prop I suspect that it is not that Senns & Sturba have different ways of specing a prop, rather one makes fatter props. Pete Diffey St Albans, UK ------------------------------ Message: 4 Date: Wed, 14 Dec 2005 13:32:58 -0500 From: "Jack Cooper" Subject: RE: KR> Insurance To: "KRnet" Message-ID: <410-2200512314183258640@earthlink.net> Content-Type: text/plain; charset=US-ASCII I'm currently looking for life insurance. Talking to an agent on the phone a few days ago I told him I was a pilot and ask about aviation exclusion. He ask about my hours and said that there would be an aviation rider. Then I ask about experimental aviation, he said the policy did not address experimental aviation so any flying activity would be covered by the aviation rider. This remains to be seen because while I'm sure an agent wouldn't lie to a person just to sell a policy, they might mislead or just don't know the facts of a policy, just like the agent I bought a universal life policy from several years ago which is now so expensive I cant afford it any more. He says it is under funded and to keep it in force I need to cut the face value to about 1/3 of what it is now and that will keep it in force until I'm 85 years old. I'll read the small print next time. Jack Cooper > [Original Message] > From: Mark Jones > To: ; KRnet > Date: 12/13/2005 4:19:36 PM > Subject: RE: KR> Insurance > > Very true. You need to sit down with your carrier and find out. My employers insurance excludes experimental aviation however I have been a customer of Allstate for almost 30 years and I have a very healthy policy with them that covers me in any situation. My agent told me I could jump out of a plane with no parachute on and I would be covered. The rider for this type of coverage is a lot less than you think it would be, especially if your carrier also does your cars and homeowners. > > Mark Jones (N886MJ) > Wales, WI > Visit my web site: http://www.flykr2s.com > Email: mailto:flykr2s@wi.rr.com > > > > -----Original Message----- > From: krnet-bounces@mylist.net [mailto:krnet-bounces@mylist.net]On > Behalf Of Colin Rainey > Sent: Tuesday, December 13, 2005 3:07 PM > To: krnet@mylist.net > Subject: KR> Insurance > > > Kenneth and netters > Anyone looking at either life insurance or health insurance needs to > look closely at the aviation exclusions. Most cover a commercial flight as a paying passenger of scheduled flights with an air carrier. Almost all that I have seen that are "standard" employment or personal offerings have exclusions for: 1) flights as pilot in command or passenger of any small aircraft (under 12,500# takeoff weight), unscheduled flights, or gliders; 2) skydiving; 3) any form or type of flight instruction. > > AOPA and EAA have companies that they are endorsing that make policies available that DO cover in the case of accidents in General Aviation airplanes. Some still have exclusions if flying in an experimental aircraft. Mine covers me while flying any plane, PIC or as instructor, but does not cover me while flying my KR2. > > Just some thoughts... > > > Colin Rainey > brokerpilot96ta@earthlink.net > EarthLink Revolves Around You. _______________________________________ > Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp > to UNsubscribe from KRnet, send a message to KRnet-leave@mylist.net > please see other KRnet info at http://www.krnet.org/info.html > > _______________________________________ > Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp > to UNsubscribe from KRnet, send a message to KRnet-leave@mylist.net > please see other KRnet info at http://www.krnet.org/info.html ------------------------------ Message: 5 Date: Wed, 14 Dec 2005 11:01:06 -0700 From: Subject: Re: KR> Props To: "KRnet" Message-ID: <004601c600d8$5c0a4270$9aebf004@Bill> Content-Type: text/plain; charset="iso-8859-1" Thanks Pedro! You one pretty smart fellow ----- Original Message ----- From: To: Sent: Wednesday, December 14, 2005 10:55 AM Subject: KR> Props Hi, the size of a prop is given as 2 numbers diameter/pitch. In terms of maximum speed, the pitch is the important number a one inch pitch would give 2.84 mph, so a 49in pitch prop would give a max speed of 139 mph at 3000 revs and 64in pitch gives 181 mph at 3000 revs. VWs are normally limited to around 3400revs( in UK by PFA edict ), so a 49in prop would give me a max of 138mph. this is regardless of how big the prop is - that's the max speed. At this speed the blades angle of attack becomes zero, so it cannot provide any more thrust. The only way I can get to go any faster is by increasing revs. So given that I want ground clearance, I am limited to say 60 inch diam. Now if you imagine a prop that is about the same width as a tape measure, it will obviously need less energy to turn it than big fat wide blades, so the designer has to come up with a prop that will have:- 1 have a theoretical max speed somewhat higher than the required max speed. 2 shovels sufficient air to overcome the aircraft drag at the required max speed. 3 is not stalled at speed below the aircraft take off speed. 4 does not produce so much drag that the engine cannot produce full power at take off speed. I am puzzled why prop manufactures only give the diam/pitch figures for a prop, when as explained above the prop width/cord is vitally important when choosing a prop I suspect that it is not that Senns & Sturba have different ways of specing a prop, rather one makes fatter props. Pete Diffey St Albans, UK _______________________________________ Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp to UNsubscribe from KRnet, send a message to KRnet-leave@mylist.net please see other KRnet info at http://www.krnet.org/info.html ------------------------------ Message: 6 Date: Wed, 14 Dec 2005 20:08:22 +0100 From: Serge VIDAL Subject: R?f. : KR> Props To: KRnet Cc: krnet@mylist.net, krnet-bounces@mylist.net Message-ID: Content-Type: text/plain; charset="iso-8859-1" People tend to forget that a propeller is an airfoil. Compared to an aircraft, diameter and pitch would basically give you wing span and angle of attack, right? Now, you still have to define the wing profile and wing chord. This is more than enough to justify huge differences from one propeller to the other, even if the basic definition (diameter and pitch) is the same. I just recovered my E-mail today after nearly one week of computer failure. I owe a few guys an answer. Just be patient, please. Serge Vidal KR2 "Kilimanjaro Cloud" Paris, France Envoyé par : krnet-bounces@mylist.net 14/12/2005 18:55 Veuillez répondre à KRnet Remis le : 14/12/2005 18:55 Pour : cc : (ccc : Serge VIDAL/DNSA/SAGEM) Objet : KR> Props Hi, the size of a prop is given as 2 numbers diameter/pitch. In terms of maximum speed, the pitch is the important number a one inch pitch would give 2.84 mph, so a 49in pitch prop would give a max speed of 139 mph at 3000 revs and 64in pitch gives 181 mph at 3000 revs. VWs are normally limited to around 3400revs( in UK by PFA edict ), so a 49in prop would give me a max of 138mph. this is regardless of how big the prop is - that's the max speed. At this speed the blades angle of attack becomes zero, so it cannot provide any more thrust. The only way I can get to go any faster is by increasing revs. So given that I want ground clearance, I am limited to say 60 inch diam. Now if you imagine a prop that is about the same width as a tape measure, it will obviously need less energy to turn it than big fat wide blades, so the designer has to come up with a prop that will have:- 1 have a theoretical max speed somewhat higher than the required max speed. 2 shovels sufficient air to overcome the aircraft drag at the required max speed. 3 is not stalled at speed below the aircraft take off speed. 4 does not produce so much drag that the engine cannot produce full power at take off speed. I am puzzled why prop manufactures only give the diam/pitch figures for a prop, when as explained above the prop width/cord is vitally important when choosing a prop I suspect that it is not that Senns & Sturba have different ways of specing a prop, rather one makes fatter props. Pete Diffey St Albans, UK _______________________________________ Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp to UNsubscribe from KRnet, send a message to KRnet-leave@mylist.net please see other KRnet info at http://www.krnet.org/info.html ------------------------------ Message: 7 Date: Wed, 14 Dec 2005 13:23:27 -0600 From: "JIM RALEIGH" Subject: Re: KR> Props To: "KRnet" Message-ID: <001801c600e3$dd07f420$7fc91b45@HPAuthorizedCustomer> Content-Type: text/plain; charset="iso-8859-1" Everyone keeps looking at formulas for speed that a prop will give you and they will never work because they are not air screws. They are air foils that give a certain amount of thrust at a certain rpm. Thrust overcomes drag and unless you know how much drag you have you can't predict your speed. I don't know anyone that knows how much drag a KR has especially since each one is different. A B25 will go 300 mph or 9.58 ft per revolution of the prop. A smaller prop on a P51 gives it 400 Mph or 14.08 ft. per revolution. Go figure. ----- Original Message ----- From: To: Sent: Wednesday, December 14, 2005 11:55 AM Subject: KR> Props > Hi, the size of a prop is given as 2 numbers diameter/pitch. > > In terms of maximum speed, the pitch is the important number a one > inch pitch would give 2.84 mph, so a 49in pitch prop would give a max > speed of 139 mph at 3000 revs and 64in pitch gives 181 mph at 3000 > revs. > > VWs are normally limited to around 3400revs( in UK by PFA edict ), so > a 49in prop would give me a max of 138mph. this is regardless of how > big the prop is - that's the max speed. At this speed the blades angle > of attack becomes zero, so it cannot provide any more thrust. The only > way I can get to go any faster is by increasing revs. > > So given that I want ground clearance, I am limited to say 60 inch > diam. > > Now if you imagine a prop that is about the same width as a tape > measure, it will obviously need less energy to turn it than big fat > wide blades, so the designer has to come up with a prop that will > have:- > > 1 have a theoretical max speed somewhat higher than the required max speed. > 2 shovels sufficient air to overcome the aircraft drag at the required > max speed. 3 is not stalled at speed below the aircraft take off > speed. 4 does not produce so much drag that the engine cannot produce > full power at take off speed. > > I am puzzled why prop manufactures only give the diam/pitch figures > for a prop, when as explained above the prop width/cord is vitally > important when choosing a prop > > I suspect that it is not that Senns & Sturba have different ways of > specing a prop, rather one makes fatter props. > > Pete Diffey > St Albans, UK > > > > > > _______________________________________ > Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp > to UNsubscribe from KRnet, send a message to KRnet-leave@mylist.net > please see other KRnet info at http://www.krnet.org/info.html ------------------------------ Message: 8 Date: Wed, 14 Dec 2005 23:25:38 +0000 From: Peter Diffey Subject: KR> Prop choice - power requirements To: krnet@mylist.net Message-ID: <43A0A9F2.2020303@heroic.co.uk> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Hi, Has anybody ever published a power/max speed graph for a typical KR2 and a similar thing for a typical KR2S. There is a website http://www.mh-aerotools.de/airfoils/javaprop.htm. It has a Java applet you can use to design your own prop, you just need to put in max speed, max power, prop diam, and it will work out pitch, and blade chord.. Thats where this power/max speed graph comes in, given I know how much power my engine produces, I need to know the max speed - then bingo I can ask prop people intellegent questions instead of the usual finger in air approach. Pete Diffey St Albans, UK ------------------------------ Message: 9 Date: Wed, 14 Dec 2005 21:57:44 -0500 From: JAMES C FERRIS Subject: Re: KR> Props To: krnet@mylist.net Message-ID: <20051214.215745.1548.0.mijnil@juno.com> Content-Type: text/plain; charset=us-ascii You are correct, props are airfoils and the airfoil one uses can have a large effect on the performance. A supercritical airfoil can increase the drag rise Mach number as much as 15 percent which means a larger diameter prop can be used at the same RPM if the outside20 percent used a supercritical airfoil. Jim On Wed, 14 Dec 2005 13:23:27 -0600 "JIM RALEIGH" writes: > Everyone keeps looking at formulas for speed that a prop will give > you and > they will never work because they are not air screws. They are air > foils > that give a certain amount of thrust at a certain rpm. Thrust > overcomes > drag and unless you know how much drag you have you can't predict > your > speed. I don't know anyone that knows how much drag a KR has > especially > since each one is different. A B25 will go 300 mph or 9.58 ft per > revolution of the prop. A smaller prop on a P51 gives it 400 Mph or > 14.08 > ft. per revolution. Go figure. > ----- Original Message ----- > From: > To: > Sent: Wednesday, December 14, 2005 11:55 AM > Subject: KR> Props > > > > Hi, the size of a prop is given as 2 numbers diameter/pitch. > > > > In terms of maximum speed, the pitch is the important number a one > inch > > pitch would give 2.84 mph, so a 49in pitch prop would give a max > speed of > > 139 mph at 3000 revs and 64in pitch gives 181 mph at 3000 revs. > > > > VWs are normally limited to around 3400revs( in UK by PFA edict ), > so a > > 49in prop would give me a max of 138mph. this is regardless of how > big the > > prop is - that's the max speed. At this speed the blades angle of > attack > > becomes zero, so it cannot provide any more thrust. The only way I > can get > > to go any faster is by increasing revs. > > > > So given that I want ground clearance, I am limited to say 60 inch > diam. > > > > Now if you imagine a prop that is about the same width as a tape > measure, > > it will obviously need less energy to turn it than big fat wide > blades, so > > the designer has to come up with a prop that will have:- > > > > 1 have a theoretical max speed somewhat higher than the required > max > speed. > > 2 shovels sufficient air to overcome the aircraft drag at the > required max > > speed. > > 3 is not stalled at speed below the aircraft take off speed. 4 does > > not produce so much drag that the engine cannot produce > full power > > at take off speed. > > > > I am puzzled why prop manufactures only give the diam/pitch > figures for a > > prop, when as explained above the prop width/cord is vitally > important > > when choosing a prop > > > > I suspect that it is not that Senns & Sturba have different ways > of > > specing a prop, rather one makes fatter props. > > > > Pete Diffey > > St Albans, UK > > > > > > > > > > > > _______________________________________ > > Search the KRnet Archives at > http://www.maddyhome.com/krsrch/index.jsp > > to UNsubscribe from KRnet, send a message to > KRnet-leave@mylist.net > > please see other KRnet info at http://www.krnet.org/info.html > > > _______________________________________ > Search the KRnet Archives at > http://www.maddyhome.com/krsrch/index.jsp > to UNsubscribe from KRnet, send a message to KRnet-leave@mylist.net > please see other KRnet info at http://www.krnet.org/info.html > > ------------------------------ Message: 10 Date: Wed, 14 Dec 2005 20:33:14 -0800 (PST) From: Ron Smith Subject: KR> Landing gear (mains) To: "krnet@mylist.net" Message-ID: <20051215043314.24977.qmail@web81702.mail.mud.yahoo.com> Content-Type: text/plain; charset=iso-8859-1 Has anyone ever made fiberglass mains for the Kr with a similar construction to the Grove gear? What I'm talking about is a bow like structure that would be flat along the bottom, then a curved arc from the fuselage to the wheels. I was thinking of 1/2 inch foam for the inside core, with spruce where the main brackets attach ( to avoid the crush effect), and a taper down to solid aluminum where the wheel axles attach. I was going to use unidirectional fiberglass with a buildup to the point where I would have about 13k lb failure point. I guess I could just fork out 1000 dollars for the Grove Gear, but I like experimenting. Any thoughts? --------------------------------- Yahoo! Shopping Find Great Deals on Holiday Gifts at Yahoo! Shopping ------------------------------ Message: 11 Date: Wed, 14 Dec 2005 23:38:11 -0500 From: MFREEMAN2@indy.rr.com Subject: Re: KR> Prop choice - power requirements To: KRnet Message-ID: Content-Type: text/plain; charset=us-ascii It say the "page cannot be displayed". it's either gone for good or the server is down. ----- Original Message ----- From: Peter Diffey Date: Wednesday, December 14, 2005 6:25 pm Subject: KR> Prop choice - power requirements > Hi, > > Has anybody ever published a power/max speed graph for a typical > KR2 and > a similar thing for a typical KR2S. > > There is a website http://www.mh-aerotools.de/airfoils/javaprop.htm. > > It has a Java applet you can use to design your own prop, you just > need > to put in max speed, max power, prop diam, and it will work out > pitch, > and blade chord.. > > Thats where this power/max speed graph comes in, given I know how > much > power my engine produces, I need to know the max speed - then > bingo I > can ask prop people intellegent questions instead of the usual > finger in > air approach. > > Pete Diffey > St Albans, UK > > _______________________________________ > Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp > to UNsubscribe from KRnet, send a message to KRnet-leave@mylist.net > please see other KRnet info at http://www.krnet.org/info.html > ------------------------------ Message: 12 Date: Wed, 14 Dec 2005 22:54:51 -0600 From: "Berry Coppage" Subject: KR> unsubscribe To: Message-ID: <000601c60133$af2930f0$6401a8c0@berrycoppage> Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original unsubscribe ------------------------------ _______________________________________________ See KRnet list details at http://www.krnet.org/instructions.html End of KRnet Digest, Vol 347, Issue 511 *************************************** ================================== ABC Amber Outlook Converter v4.20 Trial version ==================================