Re: [MBZ] OT - sort of - bearings
That's why I prefer to land on grass strips - tires. If the plane is too big, then don't fly it. On Sat, Sep 1, 2018 at 9:49 AM Floyd Thursby via Mercedes < mercedes@okiebenz.com> wrote: > Back in the 70s when I worked as a summer intern at NASA Langley in the > flight research dept I brought up this idea, thought it would save on > tires. I had been flying for awhile at that point, and always cringed > at touchdown when I heard the tires squeal. Then being in the flight > research group I would see the planes land and hear the same thing, they > had the forst F-15s there too that had these little tiny tires it looked > like, they got beat up pretty good. I figured if they could get up to > some speed first it would save rubber and stress. For some reason no > one thought it was a good idea, I'm sure it had been thought of before, > it was kinda simply intuitive, but I guess for some reasons unclear it > has never happened. > > --FT > > > On 9/1/18 12:01 AM, Scott Ritchey via Mercedes wrote: > > As I recall from Test Pilot School days, it's been tried but it > increased the required runway length. Tires were cheaper than runways. > > > >> -Original Message- > >> From: Craig via Mercedes > > ... > >> Several years ago I submitted to NASA Tech Briefs Idea Contest my idea > of > >> putting curved sheet metal "buckets", not unlike those of water > turbines, on > >> the wheels of aircraft to spin up the wheels and tires when the landing > gear > >> was deployed so there would not be sudden angular acceleration of the > >> wheels at touchdown. > >> > >> They were not interested. > >> > >> But I still don't see why that would not be a good idea. Grant? > >> > >> > >> Craig > >> > >> ___ > >> http://www.okiebenz.com > >> > >> To search list archives http://www.okiebenz.com/archive/ > >> > >> To Unsubscribe or change delivery options go to: > >> http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > > > > > > ___ > > http://www.okiebenz.com > > > > To search list archives http://www.okiebenz.com/archive/ > > > > To Unsubscribe or change delivery options go to: > > http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > > > > > > -- > --FT > > > ___ > http://www.okiebenz.com > > To search list archives http://www.okiebenz.com/archive/ > > To Unsubscribe or change delivery options go to: > http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > > -- OK Don *“Travel is fatal to prejudice, bigotry and narrow-mindedness, and many of our people need it sorely on these accounts.”* – Mark Twain "There are three kinds of men: The ones that learns by reading. The few who learn by observation. The rest of them have to pee on the electric fence for themselves." WILL ROGERS, *The Manly Wisdom of Will Rogers* 2013 F150, 18 mpg 2017 Subaru Legacy, 30 mpg 1957 C182A, 12 mpg - but at 150 mph! ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] OT - sort of - bearings
Unfortunately, airplane air speed and wheel speed, driven by a turbine device at the rim diameter would not directly relate to a controlled speed limit... Loads of variables to consider in calculation of what "can happen" so whip out the old K&E slide rule and sharpen your #2's, but gut calc's say, don't do it...[otherwise known as "SWAG", Scientific Wild Ass Guess] On Sat, Sep 1, 2018 at 12:51 PM, Mitch Haley via Mercedes < mercedes@okiebenz.com> wrote: > > > On September 1, 2018 at 1:38 PM G Mann via Mercedes < > mercedes@okiebenz.com> wrote: > > > > Also, if you used air turbine device to spin up the wheels... how do you > > control tire rotation speed? > > Max rpm should be a function of airspeed. > There's already a limit on the airspeed at which you can drop wheels... > > ___ > http://www.okiebenz.com > > To search list archives http://www.okiebenz.com/archive/ > > To Unsubscribe or change delivery options go to: > http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > > ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] OT - sort of - bearings
After noticing that most jet aircraft have flat bottoms, and how often planes overshoot runways, I thought of attaching something like brake lining to the bottom of jets and attaching the bottom to hydraulic shock absorbers which would lower the friction material covered bottom before landing. Think of how much quicker and safer a plane would land with all that brake lining slowing it down far faster than brakes and tires. It would also eliminate the need for emergency slides and elaborate boarding equipment since the passengers cold just step in and out of the plane. It wold also end the problem of passengers unfastening their seat belts before landing. The first few times someone in the back rown found himself in somebodies lap on the front row, other passengers would get the message. Besides that, all the flames and smoke billowing out from underneath the plane would make air travel more exciting and help out the airlines business. I'm going to send my idea to Elon Musk who will try anything as long as the govenment pays for it. Gerry . G Mann wrote: > Great thought. Now design the entire system without adding one ounce of > weight or another system that can fail to the aircraft. oops being > an aircraft, you need to also have a "redundant system" so if one wheel > spin up fails, a fail safe system can take over... can't have one wheel set > spinning and the other side dead stop... it would generate control issues > on touch down... bad ju ju... > > Also, if you used air turbine device to spin up the wheels... how do you > control tire rotation speed? Rubber tires have rotation speed limits > before failure... an air turbine at flight approach speeds, uncontrolled, > could spin the tires to explosion... or early failure due to repeated > excess spin speed... oops another bad ju ju... > > Answer keep buying new tires... in long term... cheap and safe... > compared to potential risks. > > On Sat, Sep 1, 2018 at 8:22 AM, Mitch Haley via Mercedes < > mercedes@okiebenz.com> wrote: > > > Build brushless motors into the hubs. > > Power various aircraft functions while braking the plane, and use them to > > speed match the wheels upon landing. > > Call it hybrid drive technology and governments will mandate it whether it > > makes sense in practice or not. > > > > Mitch. > > > > ___ > > http://www.okiebenz.com > > > > To search list archives http://www.okiebenz.com/archive/ > > > > To Unsubscribe or change delivery options go to: > > http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > > > > > ___ > http://www.okiebenz.com > > To search list archives http://www.okiebenz.com/archive/ > > To Unsubscribe or change delivery options go to: > http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > -- arche...@embarqmail.com --- This email has been checked for viruses by AVG. https://www.avg.com ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] OT - sort of - bearings
> On September 1, 2018 at 1:38 PM G Mann via Mercedes > wrote: > > Also, if you used air turbine device to spin up the wheels... how do you > control tire rotation speed? Max rpm should be a function of airspeed. There's already a limit on the airspeed at which you can drop wheels... ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] OT - sort of - bearings
Great thought. Now design the entire system without adding one ounce of weight or another system that can fail to the aircraft. oops being an aircraft, you need to also have a "redundant system" so if one wheel spin up fails, a fail safe system can take over... can't have one wheel set spinning and the other side dead stop... it would generate control issues on touch down... bad ju ju... Also, if you used air turbine device to spin up the wheels... how do you control tire rotation speed? Rubber tires have rotation speed limits before failure... an air turbine at flight approach speeds, uncontrolled, could spin the tires to explosion... or early failure due to repeated excess spin speed... oops another bad ju ju... Answer keep buying new tires... in long term... cheap and safe... compared to potential risks. On Sat, Sep 1, 2018 at 8:22 AM, Mitch Haley via Mercedes < mercedes@okiebenz.com> wrote: > Build brushless motors into the hubs. > Power various aircraft functions while braking the plane, and use them to > speed match the wheels upon landing. > Call it hybrid drive technology and governments will mandate it whether it > makes sense in practice or not. > > Mitch. > > ___ > http://www.okiebenz.com > > To search list archives http://www.okiebenz.com/archive/ > > To Unsubscribe or change delivery options go to: > http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > > ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] OT - sort of - bearings
Build brushless motors into the hubs. Power various aircraft functions while braking the plane, and use them to speed match the wheels upon landing. Call it hybrid drive technology and governments will mandate it whether it makes sense in practice or not. Mitch. ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] OT - sort of - bearings
Back in the 70s when I worked as a summer intern at NASA Langley in the flight research dept I brought up this idea, thought it would save on tires. I had been flying for awhile at that point, and always cringed at touchdown when I heard the tires squeal. Then being in the flight research group I would see the planes land and hear the same thing, they had the forst F-15s there too that had these little tiny tires it looked like, they got beat up pretty good. I figured if they could get up to some speed first it would save rubber and stress. For some reason no one thought it was a good idea, I'm sure it had been thought of before, it was kinda simply intuitive, but I guess for some reasons unclear it has never happened. --FT On 9/1/18 12:01 AM, Scott Ritchey via Mercedes wrote: As I recall from Test Pilot School days, it's been tried but it increased the required runway length. Tires were cheaper than runways. -Original Message- From: Craig via Mercedes ... Several years ago I submitted to NASA Tech Briefs Idea Contest my idea of putting curved sheet metal "buckets", not unlike those of water turbines, on the wheels of aircraft to spin up the wheels and tires when the landing gear was deployed so there would not be sudden angular acceleration of the wheels at touchdown. They were not interested. But I still don't see why that would not be a good idea. Grant? Craig ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com -- --FT ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] OT - sort of - bearings
As I recall from Test Pilot School days, it's been tried but it increased the required runway length. Tires were cheaper than runways. > -Original Message- > From: Craig via Mercedes ... > Several years ago I submitted to NASA Tech Briefs Idea Contest my idea of > putting curved sheet metal "buckets", not unlike those of water turbines, on > the wheels of aircraft to spin up the wheels and tires when the landing gear > was deployed so there would not be sudden angular acceleration of the > wheels at touchdown. > > They were not interested. > > But I still don't see why that would not be a good idea. Grant? > > > Craig > > ___ > http://www.okiebenz.com > > To search list archives http://www.okiebenz.com/archive/ > > To Unsubscribe or change delivery options go to: > http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] OT - sort of - bearings
I remember reading about something on the order of Craigs idea back in the 707 era when tires had to be changed/recapped after 6 landings. IIRC there were rubber/fabric "flaps" built into the sidewall(s) of the tires that spun the wheels before touchdown. Probably read about it in Popular Science or Popular Mechanics which often published articles about "proposed" solutions to problems that hadn't become working models yet. Never saw anything else about it, so it must not have worked or the cost/benefit ratio might have been off. Gerry ... G Mann via Mercedes wrote: > Creative thought... it raises real practical questions about how to control > wheel speed at touchdown the angular loading is a real issue... watch > the blast of tire smoke that happens on landing and the long streaks of > tire rubber that gets scrubbed off while wheels are going from dead stop to > landing speed of 170 MPH... > > Even at 400,000 lbs landing weight... every ounce of structure has to "pay > it's way" in aviation... > > On Fri, Aug 31, 2018 at 6:17 PM, Mitch Haley via Mercedes < > mercedes@okiebenz.com> wrote: > > > > > > On August 31, 2018 at 9:03 PM Craig via Mercedes > > wrote: > > > Several years ago I submitted to NASA Tech Briefs Idea Contest my idea of > > > putting curved sheet metal "buckets", not unlike those of water turbines, > > > on the wheels of aircraft to spin up the wheels and tires when the > > landing > > > gear was deployed so there would not be sudden angular acceleration of > > the > > > wheels at touchdown. > > > > Savonius powered landing gear? > > I wonder how much force it takes to start them turning. > > > > The real question, is it worth making the gear bay doors larger? > > > > Mitch > > > > ___ > > http://www.okiebenz.com > > > > To search list archives http://www.okiebenz.com/archive/ > > > > To Unsubscribe or change delivery options go to: > > http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > > > > > ___ > http://www.okiebenz.com > > To search list archives http://www.okiebenz.com/archive/ > > To Unsubscribe or change delivery options go to: > http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > -- arche...@embarqmail.com --- This email has been checked for viruses by AVG. https://www.avg.com ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] OT - sort of - bearings
Creative thought... it raises real practical questions about how to control wheel speed at touchdown the angular loading is a real issue... watch the blast of tire smoke that happens on landing and the long streaks of tire rubber that gets scrubbed off while wheels are going from dead stop to landing speed of 170 MPH... Even at 400,000 lbs landing weight... every ounce of structure has to "pay it's way" in aviation... On Fri, Aug 31, 2018 at 6:17 PM, Mitch Haley via Mercedes < mercedes@okiebenz.com> wrote: > > > On August 31, 2018 at 9:03 PM Craig via Mercedes > wrote: > > Several years ago I submitted to NASA Tech Briefs Idea Contest my idea of > > putting curved sheet metal "buckets", not unlike those of water turbines, > > on the wheels of aircraft to spin up the wheels and tires when the > landing > > gear was deployed so there would not be sudden angular acceleration of > the > > wheels at touchdown. > > Savonius powered landing gear? > I wonder how much force it takes to start them turning. > > The real question, is it worth making the gear bay doors larger? > > Mitch > > ___ > http://www.okiebenz.com > > To search list archives http://www.okiebenz.com/archive/ > > To Unsubscribe or change delivery options go to: > http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > > ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] OT - sort of - bearings
On Fri, 31 Aug 2018 21:17:00 -0400 (EDT) Mitch Haley via Mercedes wrote: > > > On August 31, 2018 at 9:03 PM Craig via Mercedes > > wrote: Several years ago I submitted to NASA > > Tech Briefs Idea Contest my idea of putting curved sheet metal > > "buckets", not unlike those of water turbines, on the wheels of > > aircraft to spin up the wheels and tires when the landing gear was > > deployed so there would not be sudden angular acceleration of the > > wheels at touchdown. > > Savonius powered landing gear? Yes, that's a good way to describe it. > I wonder how much force it takes to start them turning. I guess that depends upon how much preload they have on the bearings (I presume they are tapered roller bearings). > The real question, is it worth making the gear bay doors larger? I didn't think of that, figuring the buckets would be small enough to not require modifying anything other than the wheel rim. Craig ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] OT - sort of - bearings
> On August 31, 2018 at 9:03 PM Craig via Mercedes > wrote: > Several years ago I submitted to NASA Tech Briefs Idea Contest my idea of > putting curved sheet metal "buckets", not unlike those of water turbines, > on the wheels of aircraft to spin up the wheels and tires when the landing > gear was deployed so there would not be sudden angular acceleration of the > wheels at touchdown. Savonius powered landing gear? I wonder how much force it takes to start them turning. The real question, is it worth making the gear bay doors larger? Mitch ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] OT - sort of - bearings
On Fri, 31 Aug 2018 17:38:46 -0700 G Mann via Mercedes wrote: > Landing weights on commercial aircraft are often in the 400,000 lb > range or above... Takeoff weights often exceed 750,000 lbs... add to > the landing weight load, all factors such as side loads [ie cross wind > loads] and landing speeds nearing 200 mph, so the tires at touch down > are NOT turning, then suddenly have landing loads plus speed and > acceleration loads... the amount of loading force at the bearing point > of internal contact requires a high degree of precision and material > integrity.. > > Smaller, non commercial use aircraft, have lighter loads, but still make > wheel contact at close to 100 mph [in the case of light twin engine > aircraft... same requirements... just not quite as severe... > > All loading in the aircraft use is potentially in ways an auto would > never see... Several years ago I submitted to NASA Tech Briefs Idea Contest my idea of putting curved sheet metal "buckets", not unlike those of water turbines, on the wheels of aircraft to spin up the wheels and tires when the landing gear was deployed so there would not be sudden angular acceleration of the wheels at touchdown. They were not interested. But I still don't see why that would not be a good idea. Grant? Craig ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] OT - sort of - bearings
Landing weights on commercial aircraft are often in the 400,000 lb range or above... Takeoff weights often exceed 750,000 lbs... add to the landing weight load, all factors such as side loads [ie cross wind loads] and landing speeds nearing 200 mph, so the tires at touch down are NOT turning, then suddenly have landing loads plus speed and acceleration loads... the amount of loading force at the bearing point of internal contact requires a high degree of precision and material integrity.. Smaller, non commercial use aircraft, have lighter loads, but still make wheel contact at close to 100 mph [in the case of light twin engine aircraft... same requirements... just not quite as severe... All loading in the aircraft use is potentially in ways an auto would never see... On Fri, Aug 31, 2018 at 3:22 PM, Mitch Haley via Mercedes < mercedes@okiebenz.com> wrote: > > > On August 31, 2018 at 5:55 PM Craig via Mercedes > wrote: > > > > High rated bearings are intended for precision applications like aircraft > > instruments or surgical equipment. > > > >*** Lower graded bearings are intended for the vast majority > >of applications such as vehicles, mechanical hobbies, > >skates, skateboards, fishing reels and industrial machinery. *** > > > > High ABEC rated bearings allow optimal performance of critical > > applications requiring very high RPM and smooth operation. > > I can't imagine where in a car, or an aircraft outside of a turbine engine > or gyroscope, a ABEC 9 (Class 2) bearing would be noticeably smoother than > a ABEC 7. > > Mitch. > > ___ > http://www.okiebenz.com > > To search list archives http://www.okiebenz.com/archive/ > > To Unsubscribe or change delivery options go to: > http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > > ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] OT - sort of - bearings
> On August 31, 2018 at 5:55 PM Craig via Mercedes > wrote: > > High rated bearings are intended for precision applications like aircraft > instruments or surgical equipment. > >*** Lower graded bearings are intended for the vast majority >of applications such as vehicles, mechanical hobbies, >skates, skateboards, fishing reels and industrial machinery. *** > > High ABEC rated bearings allow optimal performance of critical > applications requiring very high RPM and smooth operation. I can't imagine where in a car, or an aircraft outside of a turbine engine or gyroscope, a ABEC 9 (Class 2) bearing would be noticeably smoother than a ABEC 7. Mitch. ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] OT - sort of - bearings
On Fri, 31 Aug 2018 16:57:29 -0400 (EDT) Mitch Haley via Mercedes wrote: > I always thought ABEC 5 = Class 5 were darn smooth bearings. > https://en.wikipedia.org/wiki/ABEC_scale > > It's the ABEC 1 stuff (class 6X) that you want to avoid. >From the page at the link above (with emphasis added), There are five classes from largest to smallest tolerances: 1, 3, 5, 7, 9. The higher ABEC classes provide better precision, efficiency, and the possibility of greater speed capabilities, *** but do not necessarily allow the components to spin faster. *** The ABEC rating does not specify many critical factors, such as load handling capabilities, ball precision, materials, material Rockwell hardness, degree of ball and raceway polishing, noise, vibration, and lubricant. *** Due to these factors, an ABEC 3 classified bearing could perform better than an ABEC 7 bearing. *** Bearings not conforming to at least ABEC 1 cannot be classified as precision bearings as their tolerances are too loose. The scale also works as a guide for consumers to make informed decisions about the type of bearing they desire, despite not knowing factors related to materials, manufacturing, and performance. High rated bearings are intended for precision applications like aircraft instruments or surgical equipment. *** Lower graded bearings are intended for the vast majority of applications such as vehicles, mechanical hobbies, skates, skateboards, fishing reels and industrial machinery. *** High ABEC rated bearings allow optimal performance of critical applications requiring very high RPM and smooth operation. Craig ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] OT - sort of - bearings
I always thought ABEC 5 = Class 5 were darn smooth bearings. https://en.wikipedia.org/wiki/ABEC_scale It's the ABEC 1 stuff (class 6X) that you want to avoid. ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] OT - sort of - bearings
> OK wrote: > ... Class 2 aviation grade FAA-PMA bearings (Timken > designates these with a -20629 suffix). > Tighter tolerance and higher quality control than Class 4 > automotive bearings. > Maybe try to source class 2 for MBs??? I like the idea! Probably need to replace the races with the bearings. ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
