From: "KR-net users group digest" To: "kr-net digest recipients" Subject: kr-net digest: November 17, 1999 Date: Thursday, November 18, 1999 12:34 AM KR-net users group Digest for Wednesday, November 17, 1999. 1. Pushrod diameters 2. Re: Fuel tanks and CG 3. Re: Pushrod diameters 4. Re: Pushrod diameters 5. Re: PushrodS 6. Help, please 7. Re: Help, please 8. Re: Help, please 9. Tip for Shaping/Sanding Foam 10. Re: Help, please 11. C of G and Fuel Tank 12. Re: Pushrod vs cables 13. Re: kr-net digest: November 15, 1999 14. CG shift with header tank 15. Re: Pushrod vs cables ---------------------------------------------------------------------- Subject: Pushrod diameters From: "John Martindale" Date: Wed, 17 Nov 1999 2:36:16 X-Message-Number: 1 Hi folks I was wondering whether Don Reid meant 5/8" tube not 3/8". What is the engineering concensus on the diameter needed (a bait to you Don)? I was told it should be able to support a 90lb load without deflection at centre span which means that the pushrod from rear spar to elevator in Don Clarkes drawings should be about 1 1/2" in diameter. Any discussion here? What is minimium size that could do away with a mid span support? What about the shorter lengths between stick and rear spar and also the aileron assy. So far, I've used 5/8" x .035" throughout. Regards Aussie John. ---------------------------------------------------------------------- Subject: Re: Fuel tanks and CG From: "Ronald R. Eason" Date: Wed, 17 Nov 1999 06:45:39 -0600 X-Message-Number: 2 This is a multi-part message in MIME format. ------=_NextPart_000_0015_01BF30C7.5C5A2520 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit -----Original Message----- From: KRBLUCH@aol.com To: KR-net users group Date: Tuesday, November 16, 1999 8:56 PM Subject: [kr-net] Re: Fuel tanks and CG >There is room for a small fuel tank on the cockpit floor just ahead of the >front spar. > >--- >You are currently subscribed to kr-net as: jrlkc@mindspring.com >To unsubscribe send a blank email to leave-kr-net-110995W@telelists.com >Mine fits, and it is suspended above the floor. The largest dimension is height, narrow- width and depth is OK. It's is tall and skinny, 7 Gal. with 3/8" vent, 2 1/2" outlets facing rearword for clime and acceleration. KRRon ------=_NextPart_000_0015_01BF30C7.5C5A2520 Content-Type: text/x-vcard; name="Ronald R. Eason Sr..vcf" Content-Transfer-Encoding: quoted-printable Content-Disposition: attachment; filename="Ronald R. Eason Sr..vcf" BEGIN:VCARD VERSION:2.1 N:Eason Sr.;Ronald;R. FN:Ronald R. Eason Sr. ORG:J.R.L. Engineering Consortium Ltd.;Engineering TITLE:C.E.O., President TEL;WORK;VOICE:816-468-4091 TEL;HOME;VOICE:816-468-4425 TEL;PAGER;VOICE:816-989-9692 TEL;WORK;FAX:816-468-5465 TEL;HOME;FAX:816-468-5465 ADR;WORK:;jrlkc@mindspring.com;7333 North = Brooklyn;Gladstone,;MO.;64118-2329;U.S.A. LABEL;WORK;ENCODING=3DQUOTED-PRINTABLE:jrlkc@mindspring.com=3D0D=3D0A7333= North Brooklyn=3D0D=3D0AGladstone,, MO. 64118-232=3D 9=3D0D=3D0AU.S.A. ADR;HOME:;;7333 N. Brooklyn;Gladstone,;MO.;64118-2329;U.S.A. LABEL;HOME;ENCODING=3DQUOTED-PRINTABLE:7333 N. = Brooklyn=3D0D=3D0AGladstone,, MO. 64118-2329=3D0D=3D0AU.S.A. URL: URL:http://jrl-engineering.com EMAIL;INTERNET:ron@jrl-engineering.com EMAIL;PREF;INTERNET:jrlkc@mindspring.com REV:19991117T124538Z END:VCARD ------=_NextPart_000_0015_01BF30C7.5C5A2520-- ---------------------------------------------------------------------- Subject: Re: Pushrod diameters From: Donald Reid Date: Wed, 17 Nov 1999 08:41:52 -0500 X-Message-Number: 3 > I was wondering whether Don Reid meant 5/8" tube not 3/8". What is the > engineering concensus on the diameter needed (a bait to you Don)? You are right, I made a boo-boo when I was typing. 5/8" x 0.035 is the size that I used and what I meant to say. Sorry. All of my pushrods are relatively short and 5/8" is more than enough. > I was > told it should be able to support a 90lb load without deflection at centre > span which means that the pushrod from rear spar to elevator in Don Clarkes > drawings should be about 1 1/2" in diameter. Any discussion here? I am not sure where you got this one from. 90 pounds sounds arbitrary (if I spelled that right). Just off the top of my head, the design case would be something like a combination of two loads. One would be the tubing in compression (pushing together on each end) combined with a bending load that is a result of the weight of the tubing and the design load factor of the airplane. A pushrod will tend to sag under G loading the same way your cheeks sag when you pull G's. When these two loads are combined, the pushrod would tend to bend and then the failure would be by buckling. Long pushrods that are supported only at the ends do need to be large in diameter but can be fairly thin wall. The elevator pushrod in my father's bi-plane is like that and is on the order of 1 1/2" in diameter but I do not have any engineering data on it. -- Don Reid Bumpass, Va. mailto:donreid@erols.com KR2XL at http://www.erols.com/donreid/kr_page.htm Ultralights at http://www.erols.com/donreid/usua250.html ---------------------------------------------------------------------- Subject: Re: Pushrod diameters From: Mike Mims Date: Wed, 17 Nov 1999 08:01:47 -0800 (PST) X-Message-Number: 4 --- John Martindale wrote: > Hi folks > > I was wondering whether Don Reid meant 5/8" tube not > 3/8". What is the engineering concensus on the diameter needed (a bait to you Don)? Hey I checked my Yahoo mail account and noticed that it was still signed on to the KRNet. Lots of interesting things being kicked around in the last little while. I respect the idea of using a push rod system but I am curious as to what you are gaining and is it worth it? Seems to me a push rod system is much more expensive than cables as well as much heavier. Its not any safer than cables and I can hardly begin to imagine that a KR needs a more sensitive, precise control system. Anyway I just wanted people to think about what they are doing and realize they could be wasting time and money. I think a lot of people get caught up in the “cool factor” thing and forget what the KR is all about. Yeah the Lancair 4p has push-rods and its cool but you are not building a Lancair 4p! As for the header tank dilemma, you should just build your motor mount so that its not possible to get to far aft. I think Jeff Scott’s is setup this way. I built my motor mount so that there is no way (at gross weight) the aft CG can be exceeded. When I do the calcs on my fuel burn the CG moves aft very little. Believe it or not the largest percentage of the mass on the header tank is only a few inches in font of the forward limit. So adding or removing weight from this area has little effect (I will post the shift in inches if you want). I know you have all read the horror stories about KR2s with two people and no fuel going into flat spins but I can almost guarantee that these plans were NOT setup properly to begin with. Do the math and you will see the header tank scare is not worth all the extra work that will be involved in building wing tanks and transfer pumps and,….. As a matter of fact I can almost bet you will end up with something that is more likely to kill you than a CG shift and that is a fuel system that is too complicated and relies on pumps to supply fuel to the engine. What has killed more homebuilt pilots than anything else? Fuel flow problems! Keep it simple and go flying! ===== __________________________________________________ Do You Yahoo!? Bid and sell for free at http://auctions.yahoo.com ---------------------------------------------------------------------- Subject: Re: PushrodS From: Kr2cooper@aol.com Date: Wed, 17 Nov 1999 11:30:01 EST X-Message-Number: 5 Thanks to everyone who replied to my pushrod question. I have been educated in this area and that is what KR net is all about. Jack Cooper kr2cooper@aol.com Fayetteville, NC ---------------------------------------------------------------------- Subject: Help, please From: "Edwin Blocher" Date: Wed, 17 Nov 1999 11:24:33 -0600 X-Message-Number: 6 Somewhere I saw a drawing for a tapering jig to taper spars on a table saw. I don't remember where it was. Can any one help? Thanks, ED Ed Blocher Moody, AL mailto:ed_blocher@msn.com Check out all the latest on my home page. http://homepages.msn.com/Terminus/edsKR/ ---------------------------------------------------------------------- Subject: Re: Help, please From: "Ken Jordan" Date: Wed, 17 Nov 1999 9:58:28 X-Message-Number: 7 Edwin, Try page 20 of the KR2 plans. Regards, Ken J 50% KR2 retract ---------------------------------------------------------------------- Subject: Re: Help, please From: "Richard McCall" Date: Wed, 17 Nov 1999 15:56:16 -0600 X-Message-Number: 8 ED, The builder's manual has info on setting up a jig for cutting the forward spars. Rich McCall Harker Hts, TX ----- Original Message ----- From: Edwin Blocher To: KR-net users group Sent: Wednesday, November 17, 1999 11:24 AM Subject: [kr-net] Help, please > Somewhere I saw a drawing for a tapering jig to taper spars on a table saw. > I don't remember where it was. Can any one help? > Thanks, ED > Ed Blocher > Moody, AL > mailto:ed_blocher@msn.com > Check out all the latest on my home page. > http://homepages.msn.com/Terminus/edsKR/ > > > > > --- > You are currently subscribed to kr-net as: planecraft@earthlink.net > To unsubscribe send a blank email to leave-kr-net-110995W@telelists.com > > ---------------------------------------------------------------------- Subject: Tip for Shaping/Sanding Foam From: "Ken Jordan" Date: Wed, 17 Nov 1999 13:59:23 X-Message-Number: 9 I've been cutting and shaping scrap pieces of foam to line the cockpit area before gluing the floor down. Cutting the shape with a 'key hole' saw is easy, but it's still too thick. I was able to quickly sand the foam by using the concrete drive- way just outside the garage as 'sandpaper'. Works better than 36 grit Alum Oxide and keeps the dust outside, too!-) Regards, Ken J 50% KR2 retract ---------------------------------------------------------------------- Subject: Re: Help, please From: Donald Reid Date: Wed, 17 Nov 1999 17:16:16 -0500 X-Message-Number: 10 Edwin Blocher wrote: > > Somewhere I saw a drawing for a tapering jig to taper spars on a table saw. > I don't remember where it was. Can any one help? > Thanks, ED Go to the KR Construction FAQ page. http://www.evansville.net/~boeing/project_viking/ I wrote an article on a taper jig that is very accurate and not hard to use. -- Don Reid Bumpass, Va. mailto:donreid@erols.com KR2XL at http://www.erols.com/donreid/kr_page.htm Ultralights at http://www.erols.com/donreid/usua250.html ---------------------------------------------------------------------- Subject: C of G and Fuel Tank From: "fly" Date: Thu, 18 Nov 1999 11:48:35 +1300 X-Message-Number: 11 This is a multi-part message in MIME format. ------=_NextPart_000_0021_01BF31BA.D8B3BFC0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable My KR2 special has done 580hr's and has a 70 litre tank between the = fire wall and instrument panel. This feeds a gravity fed only Stromberg = CD150 carb and that powers my RevMaster 2100D. There is an on/off tap = under the tank and that is all. With two 190lb people on board and = about 10 litres of fuel there are NO problems with the c of g and the = stalls while slightly sloppy are still easily recoverable. I believe you = should all forget about the 8' and concentrate on 6'' as the full c of g = range. My c of g "problem" doesn't exist because of an extended engine = mount and prop extension totalling 9''. Somebody mentioned in a recent = post a setup the same as this (could it have been MM) and it works. My = baby first flew in 1984 and is still going strong although we have two = badly cracked heads at present. Good to see you are still around Mike. = You are needed. Cheers and beers.............Dave Email: fly@paradise.net.nz Pictures: http://homepages.paradise.net.nz/~fly=20 ------=_NextPart_000_0021_01BF31BA.D8B3BFC0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
My KR2 special has done 580hr's and has = a  70=20 litre tank between the fire wall and instrument panel. This feeds a = gravity fed=20 only Stromberg CD150 carb and that powers my RevMaster 2100D. There is = an on/off=20 tap under the tank and that is all. With two 190lb people on board and = about 10=20 litres of fuel there are NO problems with the c of g and the stalls = while=20 slightly sloppy are still easily recoverable. I believe you should all = forget=20 about the 8' and concentrate on 6'' as the full c of g range. My c of g=20 "problem" doesn't exist because of an extended engine mount and prop = extension=20 totalling 9''. Somebody mentioned in a recent post a setup the same as = this=20 (could it have been MM) and it works. My baby first flew in 1984 = and is=20 still going strong although we have two badly cracked heads at present. = Good to=20 see you are still around Mike. You are needed.
          &nbs= p;      =20 Cheers and beers.............Dave
Email:  fly@paradise.net.nz
Pictures:&= nbsp; http://homepages.paradise.= net.nz/~fly 
------=_NextPart_000_0021_01BF31BA.D8B3BFC0-- ---------------------------------------------------------------------- Subject: Re: Pushrod vs cables From: RFG842@aol.com Date: Wed, 17 Nov 1999 19:32:39 EST X-Message-Number: 12 Totally agree that cables are cheaper, lighter and require less construction except in one place, underneath the seat. I have the RR dual control setup and the top cable had already rubbed a hole thru the canvas seat. I'm scared to think of what would happen if someone sat on the cable during flight and jammed the elevators. Besides weighting 190, I have a lot of chubby friends. Would think a pushrod on the bottom attach point thru the rear spar to a bellcrank and cables to the tail would be just about right. Believe it would solve the seat problem. Will probably rebuild mine to adopt this since a small pushrod and bellcrank and shorten the cables will be all that is needed. Can use the original pulley fittings on the rear spar with spacers for the bellcrank Just a thought. Bob ---------------------------------------------------------------------- Subject: Re: kr-net digest: November 15, 1999 From: David McKelvey Date: Fri, 12 Nov 1999 22:50:03 -0600 X-Message-Number: 13 Good point, Rutan said, before you put anything in your airplane Gognij@aol.com wrote: > Bob Smith, > > A few years ago, I had the opportunity to fly Martin Roberts airplane. > This was just before he took the VW engine out of the plane. He and I , with > full tanks on a hot 100 degree summer day took off from his local airport > their in Jenks OK., and had a beautiful flight. I am sure that we had a very > far aft C.G. on the airplane with our loading. Marti had wing tanks at that > time that were full of gas when we took off. I must say however as I flew the > airplane myself, I found it to fly much like a Piper T-tail arrow. I have > 17,000 hours and have flown many airplanes since 1975, and I must say that > the KR2 flies very nice. RELAX, keep your airplane light, and we will soon > fly together at a KR event. I should be flying my KR2 soon, I am working on > the canopy at this time. What is soon?.........6 months I hope? > > --- > You are currently subscribed to kr-net as: davmck@gte.net > To unsubscribe send a blank email to leave-kr-net-110995W@telelists.com throw it in the air, if it falls back down, it's too heavy!(paraphrased) Thats been my building motto. dave Grapevine TX ---------------------------------------------------------------------- Subject: CG shift with header tank From: Mike Mims Date: Wed, 17 Nov 1999 18:36:04 -0800 (PST) X-Message-Number: 14 Here are the numbers, this is with 400 pounds in the seats and a 17 gallon header tank. The difference in CG with the header tank full and empty is a 1.15 inch shift in the CG. If you cant build a motor mount to compensate for that your in trouble! :o) Like I said, if there are KRs that find themselves in trouble because the header tank happens to be empty then they were not right to begin with. Happy building! ===== __________________________________________________ Do You Yahoo!? Bid and sell for free at http://auctions.yahoo.com ---------------------------------------------------------------------- Subject: Re: Pushrod vs cables From: Mike Mims Date: Wed, 17 Nov 1999 18:37:26 -0800 (PST) X-Message-Number: 15 Agreed the push rod under the seat is a great idea. I am thinking about this one myself because the top cable is right where I would rather have an arm-rest. Mark Langfords setup seems to be the one to copy. --- RFG842@aol.com wrote: > Totally agree that cables are cheaper, lighter and > require less construction > except in one place, underneath the seat. > > I have the RR dual control setup and the top cable > had already rubbed a hole > thru the canvas seat. I'm scared to think of what > would happen if someone > sat on the cable during flight and jammed the > elevators. Besides weighting > 190, I have a lot of chubby friends. > > Would think a pushrod on the bottom attach point > thru the rear spar to a > bellcrank and cables to the tail would be just about > right. Believe it would > solve the seat problem. > > Will probably rebuild mine to adopt this since a > small pushrod and bellcrank > and shorten the cables will be all that is needed. > Can use the original > pulley fittings on the rear spar with spacers for > the bellcrank > > Just a thought. > > Bob > > --- > You are currently subscribed to kr-net as: > kr2sflyer@yahoo.com > To unsubscribe send a blank email to > leave-kr-net-110995W@telelists.com > > ===== __________________________________________________ Do You Yahoo!? Bid and sell for free at http://auctions.yahoo.com --- END OF DIGEST --- You are currently subscribed to kr-net as: johnbou@ipinc.net To unsubscribe send a blank email to leave-kr-net-110995W@telelists.com