Pietenpol-List: tailwheel springs

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Pietenpol-List: tailwheel springs

Post by matronics »

Original Posted By: "Gadd, Skip"
Doc Mosher's recent comments about tailwheel springs are well taken.There is one thing more, the springs should not be lax. There should bea certain degree of tension in each spring. This is a ground looppreventer.Mike B Piet N687MB ( Mr Sam )________________________________________________________________________________
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RE: Pietenpol-List: Pictures finally posted

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Original Posted By: "Bert Conoly"
>Kirk wrote:>I now have soon pictures posted.>Check them outKirk,Looks like you got an original Pietenpol cowl with that plane, since it wasmade in Minn. in 1981 it is real possible the builder got the cowl fromPietenpol himself. The two fiberglass parts of the cowl look exactly likethe parts I got from Dwayne Tauba, which are said to be from Pietenpol'smold.Work on the engine looks great.Skip, in Atlanta still working on landing gear.________________________________________________________________________________
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RE: Pietenpol-List: tailwheel springs

Post by matronics »

Original Posted By:> douweblumberg(at)earthlink.net
Douwe,All the sonex guys use a direct linkage. No springs.=C2- This way you don't need differential braking.Doug DeverIn beautiful Stow Ohio=C2-
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Pietenpol-List: tailwheel springs

Post by matronics »

Original Posted By: "Douwe Blumberg"
One more thing...There was some talk (writing??) awhile back about not using tailwheelsprings and it set me to thinking. What would happen if one didn't usesprings, just straight cables?Obviously, bumps and jerks will be transmitted directly to the rudder bar,which is about the only downside I can see. Seems like you'd get rid ofsome potential uncontrolled movement back there without springs, and you'dsave a few ounces.In you flyer's experiences, how bad can the bumps and jerks be from thetailwheel, and what do you think of this idea?ThanksDouwe,ps: finished windscreens, now doing leather cockpit coaming, which is veryrewarding. Got the Red Baron thing going!!________________________________________________________________________________
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Pietenpol-List: tailwheel springs

Post by matronics »

Original Posted By: Doug Dever
Subject: Pietenpol-List: tailwheel springs One more thing... There was some talk (writing??) awhile back about not using tailwheel springs and it set me to thinking. What would happen if one didn't use springs, just straight cables? Obviously, bumps and jerks will be transmitted directly to the rudder bar, which is about the only downside I can see. Seems like you'd get rid of some potential uncontrolled movement back there without springs, and you'd save a few ounces. In you flyer's experiences, how bad can the bumps and jerks be from the tailwheel, and what do you think of this idea? Thanks Douwe, ps: finished windscreens, now doing leather cockpit coaming, which is very rewarding. Got the Red Baron thing going!!________________________________________________________________________________
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Re: Pietenpol-List: tailwheel springs

Post by matronics »

Original Posted By: Douwe Blumberg
Subject: Re: Pietenpol-List: tailwheel springsDouwe, I can't comment on the actual stress or hardship on the rudder assembly or tailwheelthat would result from having no springs but I can speak as a tailwheelinstructor about their importance. With such a long moment between main landing gear and the tailwheel of a conventionalgear airplane you really don't "steer" a tailwheel aircraft as much as"nudge" the tail in the opposite direction you want the nose of the aircraft topoint. That is accomplished by a series of gentle rudder peddal "jabs" in thedirection you want the nose to go accompanied by some smaller jabs in the oppositedirection to keep the aircraft from veering too much toward your intendedcourse. A check and balance if you will (not meant to insult anyone on thelist who has a bunch of tailwheel experience but rather to help the prolificbuilders who haven't flown much with the little wheel on the back). The springs do a lot to dampen a pilot's nudges both in the direction they wantto go as well as their offsetting nudges in the opposite. A tailwheel that washard cabled without springs may allow ease of taxiing at very slow speeds butwould be very difficult to use on a take off or landing rollout where the "dance"of light jabs left and right are required. The amplitude of these controlinputs and their frequency change with increasing or descreasing ground speedmaking it just about humanly impossible for a pilot to keep up with directcable linkages. Compare it to a bounce recovery where an inexperienced studentattempts to recover by pushing forward on the stick only to make his or herproblems worse by chasing the resulting porpose. I also think you would probably encounter greater wear in your tailwheel tire andassembly if it were not dampened with springs which would necessitate a biggerand more robust tailwheel negating any weight benefits of having no springs.My long winded opinion only. Scott Knowlton -----Original Message-----
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RE: Pietenpol-List: tailwheel springs

Post by matronics »

Original Posted By:> douweblumberg(at)earthlink.net
Douwe=2CAll the sonex guys use a direct linkage. No springs. This way you don't need differential braking.Doug DeverIn beautiful Stow Ohio
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RE: Pietenpol-List: tailwheel springs

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Original Posted By:> flyingscott_k(at)hotmail.com
Scott=2CNot to be contradictory. (you have more tg time than me.) But=2C to bring up the point that all of the Sonex TW guys use direct (no spring) steering and virtually none have differential braking. With several hundred flying=2C everyone says it works great and is the easiest taildragger to fly. Now I do know that there will be days that nothing will help except for the wheel on the other end. I landed a C210 once in a 38kt 80deg xwind and I'm glad I was flying a 210 and not a 180. There were days we counld not even taxi the 180 as the wind would spin it around with both brakes locked! But I digress. My question is would you really need the jabs on the rudder if the tw was direct steer? negating=2C of course=2C the senario I just describedDoug DeverIn beautiful Stow Ohio
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Re: Pietenpol-List: tailwheel springs

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Original Posted By: Ken Chambers
I vote for springs. I've even gotten advice to go a stepfurther and not run the tailwheel steering cables taut,but to leave them a little loose or slack in order to provide just a bit less reaction while dancing on therudder pedals. The springs provide some damping of thedance and a lower tension (or slack) in the cables wouldalso remove some of the instant reaction.When I first taxied 41CC I was amazed at how sensitive itwas to steering inputs on the concrete apron, and how precisely I could steer it around the ramp without use ofthe brakes. After actually flying it a while, I've cometo wish that I could decouple the tailwheel from therudder a bit more and I may try some softer springs ormaybe back off of the cable tension a bit. Sometimes thenose veers a bit due to the tailwheel response whenyou only meant to use rudder. Hard to explain until yougo fly and taxi your airplane, but in any case I'd staywith the springs for sure.Oscar ZunigaAir Camper NX41CCSan Antonio, TXmailto: taildrags(at)hotmail.comwebsite at http://www.flysquirrel.net ________________________________________________________________________________Date: Wed, 7 Oct 2009 11:18:11 -0500Subject: Re: Pietenpol-List: tailwheel springs
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Re: Pietenpol-List: tailwheel springs

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Original Posted By: ken.riffic(at)gmail.com
Has anybody thought about not having springs? Just had to go there=3B-)Doug DeverIn beautiful Stow OhioDate: Wed=2C 7 Oct 2009 11:18:11 -0500Subject: Re: Pietenpol-List: tailwheel springs
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Post by matronics »

Original Posted By: Ross Alexander
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Re: Pietenpol-List: tailwheel springs

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Original Posted By: Dan Yocum
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RE: Pietenpol-List: tailwheel springs

Post by matronics »

Original Posted By:> bcharvet(at)bellsouth.net
I disagree=2C but my personal experience is only with an ultralight with direct steering. No problems. There are=2C however several hundred Sonexs flying with direct steering. Mine will be direct steer=2C but hey=2C I only have a couple hundred hrs tg time. Most of it ultralight.Doug DeverIn beautiful Stow Ohio> Date: Wed=2C 7 Oct 2009 15:23:09 -0400
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Re: Pietenpol-List: tailwheel springs

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Original Posted By: Douwe Blumberg
I think the springs also help eliminate shimmying, although logically you would think it would increase it. Just think, ALL Cubs, Champs, Taylorcrafts, Cessnas, etc, etc, etc use them. There MUST be a good reason.Gene ----- Original Message -----
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RE: Pietenpol-List: tailwheel springs

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Original Posted By: generambo(at)msn.com
Gene=2CThere must be a good reason you can't put full fuel=2C pax and baggage in most cert. aircraft either. I can't figure it out.Doug DeverIn beautiful Stow Ohio
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Pietenpol-List: tailwheel springs

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Original Posted By: Jeff Boatright
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Re: Pietenpol-List: tailwheel springs

Post by matronics »

Original Posted By: "Clif Dawson"
Just like in racing. If you want to be succesful, copy the leaders.Clif I think the springs also help eliminate shimmying, although logically you would think it would increase it. Just think, ALL Cubs, Champs, Taylorcrafts, Cessnas, etc, etc, etc use them. There MUST be a good reason. Gene________________________________________________________________________________
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Pietenpol-List: Re: tailwheel springs

Post by matronics »

Original Posted By: "skellytown flyer"
Subject: Re: Pietenpol-List: Western Piets availabele next week?In a message dated 10/9/2009 4:23:21 P.M. Eastern Daylight Time, jimboyer(at)hughes.net writes:--> Pietenpol-List message posted by: Jim John,If you don't mind a 40 mile detour off I-80 you are welcome to come to Santa Rosa and see my Piet under construction. I have the fuselage on wheels,wing ribs done, tail surfaces done, engine mount done, and engine about ready to hang.lSanta Rosa is North of San Francisco on highway 101 and about 40 miles West of I-80 via highway 12.My address is 3504 BAnyan St and phone is 707-571-8001.It would be nice to have a visitor and get some constructive comments.Cheers,Jim B.Jim BoyerSanta Rosa, CAPietenpol builder with CorvairOn Oct 9, 2009, AMsafetyC(at)aol.com wrote: Going to Portland, Sacramento and Stockton next week looking for Piets, second request got 2 reply's anyone else interested? Lemme no John________________________________________________________________________________Subject: Pietenpol-List: Re: tailwheel springs
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Pietenpol-List: Re: bell crank spring for trim control

Post by matronics »

Original Posted By: "skellytown flyer"
I just quickly scanned the answers but didn't see what I would say is a big reason-if you are running the leaf type tail spring like I am-as it flattens outit will get longer and if you have no springs in there to give it some reliefsomething is going to give. might not notice it at the time but who knows whatdamage could occur? maybe a cracked rudder,bent control horn or such? RaymondRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: bell crank spring for trim control
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Post by matronics »

Original Posted By: "Gene Rambo"
I'd guess the spring tension would mainly depend on how well your CG is set upand how well you have the angle of your horizontal stabilizer set so you don'thave so much need for stick pressure in flight.a Rans S-12 I had once used bungeecord wound around a plastic wheel and attached to the elevator linkage.workedfair but the cord wasn't that great over time.I basically ignored it andflew the plane.but it didn't need that much stick pressure.probably a simple trimtab would have been better. RaymondRead this topic online here:http://forums.matronics.com/viewtopic.p ... __________
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Re: Pietenpol-List: Re: tailwheel springs

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Original Posted By: skellytown flyer
there it is!! I was not thinking when I said there had to be a reason that all light aircraft use springs, I forgot that it is for exactly that--to allow the leaf spring to move without causing damage that a solid cable definitely would. Duh!Gene ----- Original Message -----
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> Pietenpol-List: Re: tailwheel springs

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Original Posted By:> skellflyer1(at)yahoo.com
Sonex runs a direct linkage and uses a round springDoug DeverIn beautiful Stow Ohio> Subject: Pietenpol-List: Re: tailwheel springs
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Re: Pietenpol-List: Re: tailwheel springs

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Original Posted By: Robert Ray
Subject: Re: Pietenpol-List: Re: tailwheel springs
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Re: Pietenpol-List: Re: tailwheel springs

Post by matronics »

Original Posted By: Doug Dever
Apples and oranges. As has been noted, with our type of standard, curvedsprings, the wheel moves further aft as it moves upward. The Sonex springis a long straight bar, parallel with the cables that does NOT get longer with weight on it.Hence, no need for the springs.Clif Sonex runs a direct linkage and uses a round spring Doug Dever In beautiful Stow Ohio ________________________________________________________________________________
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RE: Pietenpol-List: Re: tailwheel springs

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Original Posted By: CDAWSON5854(at)shaw.ca
Wheather a straight curved or hinged setup the geometry will change when flexed. Doug DeverIn beautiful Stow Ohio
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RE: Pietenpol-List: Re: tailwheel springs

Post by matronics »

Original Posted By: chiefpepperhead(at)hotmail.com
Just one more thought about springs. Geometry is the key and it is much easier to control geometry with a pivot rather than a spring. In a car when you turn the wheel the inner wheel must travel farther=2C or somehow make a tighter radius. This is called scrubb angle. It is all done with geometry. Some designers do it by actually turning the inner wheel farther. Some such as Ford do it by changing camber on the inner wheel. All done without springs in the linkage. Controlling geometry on the Piet would be a simple matter with the trailing link type tw as opposed to the single leaf.Doug DeverIn beautiful Stow Ohio
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> Pietenpol-List: tailwheel springs

Post by matronics »

Original Posted By: Doug Dever
> thlink.net>> > One more thing...> > There was some talk (writing??) awhile back about not using tailwheel> springs and it set me to thinking. What would happen if one didn't use> springs=2C just straight cables?> > Obviously=2C bumps and jerks will be transmitted directly to the rudder bar=2C> which is about the only downside I can see. Seems like you'd get rid of> some potential uncontrolled movement back there without springs=2C and you'd> save a few ounces.> > In you flyer's experiences=2C how bad can the bumps and jerks be from the> tailwheel=2C and what do you think of this idea?> > Thanks> > Douwe=2C> > ps: finished windscreens=2C now doing leather cockpit coaming=2C which is very> rewarding. Got the Red Baron thing going!!> > ============================================> > > =0A_________________________________________________________________=0AHotmail: Trusted email with Microsoft=92s powerful SPAM protection.=0A________________________________________________________________________________
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> Re: Pietenpol-List: tailwheel springs

Post by matronics »

Original Posted By:> Douwe Blumberg
> Subject: Re: Pietenpol-List: tailwheel springs> tmail.com>> > Douwe=2C > > I can't comment on the actual stress or hardship on the rudder assembly or tailwheel that would result from having no springs but I can speak as a tailwheel instructor about their importance. > > With such a long moment between main landing gear and the tailwheel of a conventional gear airplane you really don't "steer" a tailwheel aircraft as much as "nudge" the tail in the opposite direction you want the nose of the aircraft to point. That is accomplished by a series of gentle rudder peddal "jabs" in the direction you want the nose to go accompanied by some smaller jabs in the opposite direction to keep the aircraft from veering too much toward your intended course. A check and balance if you will (not meant to insult anyone on the list who has a bunch of tailwheel experience but rather to help the prolific builders who haven't flown much with the little wheel on the back). > > The springs do a lot to dampen a pilot's nudges both in the direction they want to go as well as their offsetting nudges in the opposite. A tailwheel that was hard cabled without springs may allow ease of taxiing at very slow speeds but would be very difficult to use on a take off or landing rollout where the "dance" of light jabs left and right are required. The amplitude of these control inputs and their frequency change with increasing or descreasing ground speed making it just about humanly impossible for a pilot to keep up with direct cable linkages. Compare it to a bounce recovery where an inexperienced student attempts to recover by pushing forward on the stick only to make his or her problems worse by chasing the resulting porpose. > I also think you would probably encounter greater wear in your tailwheel tire and assembly if it were not dampened with springs which would necessitate a bigger and more robust tailwheel negating any weight benefits of having no springs. My long winded opinion only. > Scott Knowlton > > -----Original Message-----
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Re: Pietenpol-List: tailwheel springs

Post by matronics »

Original Posted By: Douwe Blumberg
I think the springs also help eliminate shimmying=2C although logically you would think it would increase it. Just think=2C ALL Cubs=2C Champs=2C Taylorcrafts=2C Cessnas=2C etc=2C etc=2C etc use them. There MUST be a good reason.Gene----- Original Message -----
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Pietenpol-List: Re: Vi Kapler's Piets

Post by matronics »

Original Posted By: "dwilson"
> > To: pietenpol-list(at)matronics.com> >> skellflyer1(at)yahoo.com>> >> > I just quickly scanned the answers but didn't see what I would say is a> big reason- if you are running the leaf type tail spring like I am-as it> flattens out it will get longer and if you have no springs in there to give> it some relief something is going to give. might not notice it at the time> but who knows what damage could occur? maybe a cracked rudder,bent control> horn or such? Raymond> >> >> >> >> > Read this topic online here:> >> > http://forums.matronics.com/viewtopic.p ... 328#267328> >> >> >> > >> >> >>> ------------------------------> Hotmail: Free, tru84/direct/01/' target='_new'>Get it now.>> *>> *>>________________________________________________________________________________Subject: Pietenpol-List: Re: Vi Kapler's Piets
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Re: Pietenpol-List: Re: tailwheel springs

Post by matronics »

Original Posted By: "jim"
Apples and oranges. As has been noted=2C with our type of standard=2C curvedsprings=2C the wheel moves further aft as it moves upward. The Sonex springis a long straight bar=2C parallel with the cables that does NOT get longer with weight on it.Hence=2C no need for the springs.ClifSonex runs a direct linkage and uses a round springDoug DeverIn beautiful Stow Ohio =0A_________________________________________________________________=0AHotmail: Trusted email with Microsoft=92s powerful SPAM protection.=0A________________________________________________________________________________
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RE: Pietenpol-List: Re: tailwheel springs

Post by matronics »

Original Posted By: CDAWSON5854(at)shaw.ca
Wheather a straight curved or hinged setup the geometry will change when flexed. Doug DeverIn beautiful Stow Ohio
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