---------------------------------------------------------- Pietenpol-List Digest Archive --- Total Messages Posted Fri 01/03/03: 10 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:49 AM - Re: mocycle tire pressure (Michael D Cuy) 2. 06:58 AM - Re: question for the guys with skinny wheels (Robert Haines) 3. 07:14 AM - Alamo City Corvair College (Oscar Zuniga) 4. 07:36 AM - Re: Re: question for the guys with skinny wheels (Gadd, Skip) 5. 09:11 AM - Fw: [CorvAIRCRAFT] Alamo City Corvair College (del magsam) 6. 09:49 AM - Re: Re: question for the guys with skinny (Les Schubert) 7. 09:53 AM - Re: Wood landing gear (Mpj01@aol.com) 8. 10:57 AM - Pietenpol engineering (Oscar Zuniga) 9. 01:12 PM - Re: Pietenpol engineering (Mike) 10. 01:37 PM - List of Contributors #2 - Thank You... (Matt Dralle) ________________________________ Message 1 _____________________________________ Time: 04:49:48 AM PST US From: Michael D Cuy Subject: Re: Pietenpol-List: mocycle tire pressure --> Pietenpol-List message posted by: Michael D Cuy >Mike, >I run 45 lbs of pressure in my 3.5 x 18" tires. Is this the reason that >most of my landings are hard? ( I am looking for any excuse) >John ++++++++++++++++++++ John, that is TOO funny ! Actually I stack all the odds in my favor. Low tire pressure, a grass strip, worn-out bungee chords, and a marshmallow seat cushion to make my landings seem better than they are:) Do not archive ________________________________ Message 2 _____________________________________ Time: 06:58:43 AM PST US From: "Robert Haines" Subject: Pietenpol-List: RE: question for the guys with skinny wheels --> Pietenpol-List message posted by: "Robert Haines" Ahhh, an engineering question. :) Skip, I tip my hat to your eyeball engineering skills and let me respectively add additional information to this topic (I don't mean to sound like a smart ass, I just have an engineering degree sitting on a shelf collecting dust and like to think I didn't waste my money, so forgive me please). The point at which the tire will spin on a rim at touchdown is when the friction between the tire and rim is less than the force required to accelerate just the rim AND the acceleration rate of the tire and rim due to the friction between the tire and ground is greater than the previously stated rate. What I mean to say is that if the tire sticks to the ground really well and tries to spin the wheel really fast at touchdown AND the wheel rim is heavy enough and resists the high acceleration it will break free of the tire if the friction between the two isn't great enough. (I'm going to stop now before I get into leverage and moment of inertia, whew.) This is not a problem in grass because there isn't enough friction between the tire and ground. Also, this not a problem on any surface with our big spoke wheels because they have a lot of rim/tire friction area (due to the increased diameter) and the rims are relatively light. Also, the skinnier the wheel the better since rim/tire friction area is the same while the tire/ground friction area is decreased. But as stated earlier, make sure you have adequate tire pressure to keep an decent amount of friction between the tire and rim. Finally, think about this... a motorcycle rider is zipping down the highway at 60mph and has to stop immediately. He pulls the brakes and stops as fast as he can. Do the tires spin on the rims? Robert Haines Du Quoin, Illinois -----Original Message----- Walt, The eyeball engineer in me says you should not have the spun tire problem with large rims, here is my thinking. A 21" rim has 2 beads of 65.97" so over 130" of friction between rubber and rim. The distance between the rim and pavement in my 21" tires is 5", so you have a 5" lever trying to rotate the tire on the rim and 130" of friction trying to stop the rotation. A 4" Cub tire has 2 beads 12.56" so less than 26" of friction and the lever is about 8" long. Seems to me the spun tire problem would be much less with the large rims with small tires on them. Skip, Still turning my aluminum hubs. > For all of you flying with skinny wheels,,,,,,used to fly my Fisher 404 (with standard small wheels) with soft tires cause I didn't have brakes. One day on landing, I spun the tire on the tube and got a flat cause it tore the stem. > My question is,,,has anyone with skinny wheels had problem with tires spinning on tubes? or flats? This came to mind once when I landed on the pavement and heard a chirp. >walt ________________________________ Message 3 _____________________________________ Time: 07:14:06 AM PST US From: "Oscar Zuniga" sqrlnet@yahoogroups.com, STOL@onelist.com Subject: Pietenpol-List: Alamo City Corvair College --> Pietenpol-List message posted by: "Oscar Zuniga" Howdy, Vairheads; I got a call from William Wynne last night. As I suspected, he had left for New Jersey just before Christmas so when he got back to Florida his email account was jammed, his phone answering machine was full, and who knows what he had waiting for him at the post office box. But... we're looking good for the upcoming College and folks who called or wrote to him for parts should be getting action pretty quickly. An important correction to note. William prepared and mailed the most recent Corvair Flyer (his printed newsletter) late at night so he got the dates for the College wrong. If you see something about Jan. 16-17 don't despair... it is still set for Saturday, Jan. 18. William will be arriving sometime around noon on Friday to get set up, but the main workday is Saturday with details and mop-up on Sunday if anyone is still around and wants to do anything further. William will be bringing manuals, prop hubs, oil pans, hybrid studs, and other items that he sells. We will also have a press (for piston pins and crank hubs), compressed air and tools, jigs for holding case halves and cylinders, and assembly lube/form-a-gasket/lubriplate type stuff. Things to bring if you're building an engine (or dismantling, or converting): bring your own hand tools such as wrenches, screwdrivers, and a big hammer ;o) also plenty of carb cleaner and degreaser if you're dismantling or cleaning/prepping. If you have any sort of folding tables or portable workbenches, those will be helpful too. Rags are always needed (such as discarded Texas Aggies shirts) and coffee cans or other containers for dismantled stuff. The CORSA guys might be looking over our shoulders just for fun and general interest, and the local EAA chapter members have all been invited via this month's Chapter newsletter and email. I'll be giving the program on 1/11 to the Chapter and of course it will be on the Corvair. My plan is to have a table up front with the complete, disassembled, painted and prepped engine available for show and tell, as well as the manual available for browsing. There shouldn't be a speck of grease or grime on any of it! Thanks to Mark Langford and Pat Panzera for setting the construction and cleanliness standards high for the rest of us to follow. I will post updates and more detailed directions on getting to San Geronimo Airpark on the http://www.corvaircraft.com main webpage (thanks, Pat!) Oscar Zuniga San Antonio, TX mailto: taildrags@hotmail.com website at http://www.flysquirrel.net ________________________________ Message 4 _____________________________________ Time: 07:36:42 AM PST US From: "Gadd, Skip" Subject: RE: Pietenpol-List: RE: question for the guys with skinny wheels --> Pietenpol-List message posted by: "Gadd, Skip" Robert, Thanks, way more than I wanted to know, cool! Skip -----Original Message----- Ahhh, an engineering question. :) let me respectively add additional information to this topic Robert ________________________________ Message 5 _____________________________________ Time: 09:11:09 AM PST US From: del magsam Subject: Pietenpol-List: Fwd: [CorvAIRCRAFT] Alamo City Corvair College --> Pietenpol-List message posted by: del magsam Note: forwarded message attached. ===== Del-New Richmond, Wi "farmerdel@rocketmail.com" by mta404.mail.yahoo.com with SMTP; 03 Jan 2003 08:44:03 -0800 (PST) by m3.grp.scd.yahoo.com with QMQP; 3 Jan 2003 16:44:00 -0000 by mta1.grp.scd.yahoo.com with SMTP; 3 Jan 2003 16:44:00 -0000 by mta4.rcsntx.swbell.net (iPlanet Messaging Server 5.1 HotFix 1.6 (built Oct 18 2002)) 03 Jan 2003 10:43:44 -0600 (CST) Dragonflylist , Q-List , Smith Miniplane , Corvaircraft , CorvAIRCRAFT , corvair@yahoogroups.com, flycorvair@yahoogroups.com, toms_dragonfly@yahoogroups.com From: Patrick Panzera List-Unsubscribe: Subject: [CorvAIRCRAFT] Alamo City Corvair College --lhJVRaA3EDtVLwHFmqs9kvatzmBy7aZdBqoVjsT Just a reminder, the Alamo City Corvair College is coming up fast! William Wynne will be in attendance at the event hosted by Oscar Zuniga, Jan. 18, 2003, at San Geronimo Airpark (San Antonio), TX. 8T8 (identifier) Click for more info: http://www.corvaircraft.com/ Please pass this along to any other e-mail lists you might belong to... KR, Pietenpol, etc. Even car guys might be interested, as the local Corsa chapter will be involved! Thanks! Pat --lhJVRaA3EDtVLwHFmqs9kvatzmBy7aZdBqoVjsT Just a reminder, the Alamo City Corvair College is coming up fast! William Wynne will be in attendance at the event hosted by Oscar Zuniga, Jan. 18, 2003, at San Geronimo Airpark (San Antonio), TX. 8T8 (identifier) Click for more info: http://www.corvaircraft.com/ Please pass this along to any other e-mail lists you might belong to... KR, Pietenpol, etc. Even car guys might be interested, as the local Corsa chapter will be involved! Thanks! Pat ADVERTISEMENT To unsubscribe from this group, send an email to: corvaircraft-unsubscribe@yahoogroups.com --lhJVRaA3EDtVLwHFmqs9kvatzmBy7aZdBqoVjsT-- ________________________________ Message 6 _____________________________________ Time: 09:49:34 AM PST US From: Les Schubert Subject: Re: Pietenpol-List: RE: question for the guys with skinny wheels --> Pietenpol-List message posted by: Les Schubert If you can all stand one more posting on this question here is my observation. I have played with really old cars for years (model T Fords and the like) and tire slippage on these cars is a real problem with these skinny tires if you don't run adequate pressure . Your average old model T has 23" or 24" rims with 3" or 3 1/2" wide tires. The desired tire pressure is 50 to 60 psi. to prevent tire slippage on hard acceleration or braking (don't laugh). The reason appears to be that the bead areas don't seem to "bite" very well to the rim. These cars also have clincher style tires which don't have a cable bead as you all are familiar with so the rim wraps in a hook fashion around the bead area so you have lots of contact area and still they slip if the pressure is low (30 psi is too low on a car). At 30 psi. they will even slip in normal driving and you will easily get a flat in 100 miles with a torn out valve stem. In 1925 the balloon type tire came on the scene with a 21" or smaller rim and 4 1/2" wide tire and a cable bead and they JUST worked with 30 psi. I think the real change with modern car wheels is the safety style bead with the bead retaining ridge on the rim so the tire is tight to the rim after being stretched over this ridge. If you have tried you will observe that it is really difficult to break a new bead lose from the rim on modern car wheels and correspondingly they tire doesn't slip easily on the rim even with low pressures. You will notice that the wheels we work with don't usually have this ridge behind the tire bead so it is easy to dismount the tires, The glue suggestion sounds like a good one. ps. I have a engineering degree sitting on the shelf as well but it is just gathering dust now. Regards Les in Calgary At 08:57 AM 03/01/2003 -0600, you wrote: >--> Pietenpol-List message posted by: "Robert Haines" > > >Ahhh, an engineering question. :) > >Skip, I tip my hat to your eyeball engineering skills and let me >respectively add additional information to this topic (I don't mean to sound >like a smart ass, I just have an engineering degree sitting on a shelf >collecting dust and like to think I didn't waste my money, so forgive me >please). > >The point at which the tire will spin on a rim at touchdown is when the >friction between the tire and rim is less than the force required to >accelerate just the rim AND the acceleration rate of the tire and rim due to >the friction between the tire and ground is greater than the previously >stated rate. What I mean to say is that if the tire sticks to the ground >really well and tries to spin the wheel really fast at touchdown AND the >wheel rim is heavy enough and resists the high acceleration it will break >free of the tire if the friction between the two isn't great enough. (I'm >going to stop now before I get into leverage and moment of inertia, whew.) > >This is not a problem in grass because there isn't enough friction between >the tire and ground. Also, this not a problem on any surface with our big >spoke wheels because they have a lot of rim/tire friction area (due to the >increased diameter) and the rims are relatively light. Also, the skinnier >the wheel the better since rim/tire friction area is the same while the >tire/ground friction area is decreased. But as stated earlier, make sure >you have adequate tire pressure to keep an decent amount of friction between >the tire and rim. > >Finally, think about this... a motorcycle rider is zipping down the highway >at 60mph and has to stop immediately. He pulls the brakes and stops as fast >as he can. Do the tires spin on the rims? > >Robert Haines >Du Quoin, Illinois > > >-----Original Message----- > >Walt, >The eyeball engineer in me says you should not have the spun tire problem >with large rims, here is my thinking. >A 21" rim has 2 beads of 65.97" so over 130" of friction between rubber and >rim. >The distance between the rim and pavement in my 21" tires is 5", so you have >a 5" lever trying to rotate the tire on the rim and 130" of friction trying >to stop the rotation. > >A 4" Cub tire has 2 beads 12.56" so less than 26" of friction and the lever >is about 8" long. > >Seems to me the spun tire problem would be much less with the large rims >with small tires on them. >Skip, Still turning my aluminum hubs. > > > > For all of you flying with skinny wheels,,,,,,used to fly my Fisher 404 >(with standard small wheels) with soft tires cause I didn't have brakes. >One day on landing, I spun the tire on the tube and got a flat cause it tore >the stem. > > My question is,,,has anyone with skinny wheels had problem with tires >spinning on tubes? or flats? This came to mind once when I landed on the >pavement and heard a chirp. > >walt > > ________________________________ Message 7 _____________________________________ Time: 09:53:32 AM PST US From: Mpj01@aol.com Subject: Re: Pietenpol-List: Wood landing gear --> Pietenpol-List message posted by: Mpj01@aol.com Hi, I've been wrestling with the wood landing gear angles. Do you still have photos of your work? Thanks Mike ________________________________ Message 8 _____________________________________ Time: 10:57:54 AM PST US From: "Oscar Zuniga" Subject: Pietenpol-List: Pietenpol engineering --> Pietenpol-List message posted by: "Oscar Zuniga" Les writes- >ps. I have a engineering degree sitting on the shelf as well but >it is just gathering dust now. Well, I have an engineering degree still hanging on the wall, but darned if that fellow Pietenpol didn't come up with a mighty fine airplane without all us engineers' help anyway! Oscar Zuniga 'do not archive' San Antonio, TX mailto: taildrags@hotmail.com website at http://www.flysquirrel.net ________________________________ Message 9 _____________________________________ Time: 01:12:24 PM PST US Subject: Re: Pietenpol-List: Pietenpol engineering From: Mike --> Pietenpol-List message posted by: Mike Trial and error is the most accurate engineering method but sometimes it's really, really, expensive. Mike PS My engineering degree is hiding in a drawer so it won't get me in trouble. on 1/3/03 10:56, Oscar Zuniga at taildrags@hotmail.com wrote: > --> Pietenpol-List message posted by: "Oscar Zuniga" > > Les writes- > >> ps. I have a engineering degree sitting on the shelf as well but >> it is just gathering dust now. > > Well, I have an engineering degree still hanging on the wall, but darned if > that fellow Pietenpol didn't come up with a mighty fine airplane without all > us engineers' help anyway! > > Oscar Zuniga 'do not archive' ________________________________ Message 10 ____________________________________ Time: 01:37:20 PM PST US From: Matt Dralle Subject: Pietenpol-List: List of Contributors #2 - Thank You... --> Pietenpol-List message posted by: Matt Dralle Dear Listers, I was particularly touched this year by all of the wonderful comments people made regarding the Lists and how much they mean to them. As I have said many times before, running these Lists and creating the many new features is truly a labor of love. I will be shipping out the third and final shipment of Flight Bags and A&P Text Books this afternoon. According to the Post Office, maximum delivery to the most remote of areas is 8 days. I will have no outstanding Gift requests following this shipment, so if you don't get the Gift(s) you requested by, say, the 20th of January, please let me know via email. I would also once again like to thank Andy Gold of the Builder's Bookstore ( http://www.buildersbooks.com ) who so generously supported this year's Fund Raiser with both free and substantially discounted merchandise!! Below you will find the 2002 List of Contributors #2 current as of 12/31/02! Have a look at the list of names there as these are the people that make all of the services possible! I can't thank you all enough for your support and great feedback during this year's Fund Raiser! Once again, THANK YOU for making this year's List Fund Raiser successful! Best regards, Matt Dralle Email List Administrator ------------------- 2002 List of Contributors #2 ----------------- Adamson, Arden Andrews, Donald Bates, Marcus Jr. Bello, Ariel Bowhay, Eustace Boyd, Dave Carpenter, Kenneth Carter, David Clark, Lynn Dezzani, Peter Domascimento, Marcio Enns, Dennis Fogerson, Richard Forero, Bert Gadd, Skip Gardner, Kip Hasper, Joseph Herndon, Richard Hill, Jeff Hurd, James Jefferies, Mark Johnson, Darrell Johnson, Jackie Jones, Eric Kosta, Michael Larson, Glenn Macy, Frank "lucky" Mehrhoff, Stan Metzger, Jim Minichan, David Moore, Robert Moore, Warren Mosher, Doc Mosier, Colby Pahnke, Douglas Reynolds, Richard Reynolds, Stephen Sloan, Alex Slyfield, Skip Tauchen, Bryan Travis, T.E. Uribe, Guillermo Waligroski, Gregg Wentzell, David ------------------- 2002 List of Contributors #2 ----------------- DNA: do not archive