Original Posted By: "Larry Vetter"
If you're considering using a Corvair for your Piet then plan to attend one ofthe three upcoming Corvair Colleges. The return on investment is incredible.CC26: 18 - 20 Sep, Mexico, MO, Zenith FactoryCC27: 8 - 10 Nov, Barnwell, SC, PF Beck & FriendsCC28: 28 Feb - 2 Mar, San Marcos, TX, Shelley & meSee you there!--------Kevin "Axel" PurteeRebuilding NX899KPAustin/San Marcos, TXRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Dynamic balancing ?
Pietenpol-List: Dynamic balancing ?
Re: Pietenpol-List: Dynamic balancing ?
Original Posted By: Gary Boothe
Its been suggested by the previous owner that both wooden props I have be dynamicallybalanced. Both were carved by a prop carving machine. I haven't researcheddynamic balancing, but have heard it was rather expensive. Have any of you using a hand carved or machine carved prop had one dynamicallybalanced? Doesn't it require balancing the prop to the engine? Thanks for any input. LarryRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Re: Pietenpol-List: Dynamic balancing ?
Its been suggested by the previous owner that both wooden props I have be dynamicallybalanced. Both were carved by a prop carving machine. I haven't researcheddynamic balancing, but have heard it was rather expensive. Have any of you using a hand carved or machine carved prop had one dynamicallybalanced? Doesn't it require balancing the prop to the engine? Thanks for any input. LarryRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Re: Pietenpol-List: Dynamic balancing ?
Pietenpol-List: Re: Dynamic balancing ?
Original Posted By: "tools"
Larry,My Corvair powered Piet has flown with 3 hand carved props, all hand balanced on3 axis and adjusted to track true within 1/8". All ran very smoothly, but Ihave no idea if dynamic balance would improve anything.GaryNX308MBSent from my iPhoneOn Aug 14, 2013, at 7:18 AM, "Larry Vetter" wrote:> > Its been suggested by the previous owner that both wooden props I have be dynamicallybalanced. Both were carved by a prop carving machine. I haven't researcheddynamic balancing, but have heard it was rather expensive.> Have any of you using a hand carved or machine carved prop had one dynamicallybalanced? Doesn't it require balancing the prop to the engine? > Thanks for any input.> Larry> > > > > Read this topic online here:> > http://forums.matronics.com/viewtopic.p ... 697#406697> > > > > > > > > > ________________________________________________________________________________Subject: Pietenpol-List: Re: Dynamic balancing ?
Larry,My Corvair powered Piet has flown with 3 hand carved props, all hand balanced on3 axis and adjusted to track true within 1/8". All ran very smoothly, but Ihave no idea if dynamic balance would improve anything.GaryNX308MBSent from my iPhoneOn Aug 14, 2013, at 7:18 AM, "Larry Vetter" wrote:> > Its been suggested by the previous owner that both wooden props I have be dynamicallybalanced. Both were carved by a prop carving machine. I haven't researcheddynamic balancing, but have heard it was rather expensive.> Have any of you using a hand carved or machine carved prop had one dynamicallybalanced? Doesn't it require balancing the prop to the engine? > Thanks for any input.> Larry> > > > > Read this topic online here:> > http://forums.matronics.com/viewtopic.p ... 697#406697> > > > > > > > > > ________________________________________________________________________________Subject: Pietenpol-List: Re: Dynamic balancing ?
Re: Pietenpol-List: Re: Dynamic balancing ?
Original Posted By: Ken Bickers
In the case of a propeller, dynamic balancing is more effective than static balancingwhen it's installed where it's going to be used. In other words, there is NO advantage taking the prop somewhere and asking themto dynamically balance it and return it. It has to be installed on YOUR plane.And if you ever remove it, you've lost that advantage, it would have to bedone again (unless CAREFULLY reinstalled EXACTLY like it was... never a certainty).The reason for this is a propeller is not thick, compared to it's diameter, it'sa "single plane" balancing problem. Careful static balancing (where you hangit and determine the heavy blade and either remove a bit, or add some varnishto the other blade) is completely effective. A crankshaft, on the other hand, is long compared to it's diameter and NEEDS tobe dynamically balanced. It can be perfectly statically balanced but still beso out of balance the engine won't even run... Static balancing cannot detectmulti plane problems. So, do you need dynamic balancing? First, lets say with a known good propeller(and metal for it's repeatability) does your engine run smoothly? It's a subjectivething, but still, it's a reasonable thing to ask and the common guy'sdetermination is a decent evaluation. If so, then, your engine is well balanced(unless the prop JUST HAPPENS to correct a problem). So if you REALLY wantto be sure, run the engine. Remove the prop, move it one bolt hole and repeat.Do this six times and see if there's really any noticeable difference. Ifnot, you can say with reasonable conviction, your engine is well balanced.Now, make sure your wood prop is properly statically balanced. Put it on yourengine and run it. Is it smooth? If not, the problem HAS to be in the mountingof the prop. Dynamic balancing can correct this problem. However, you coulddo like before, try the prop in all six possible locations and see if the problemgoes away or gets better enough (EVERYTHING that rotates vibrates, it'sreally a matter of it being smooth enough for the application). If so, you'veempirically balanced the thing yourself, using guestimates just like balancinga ceiling fan. There may also be the problem of the prop being in the rightlocation for hand propping. If it does vibrate, like I said, the problem is in the mounting. Or the prop wasstatically balanced about a center of rotation DIFFERENT than the center ofrotation your prop sees on your engine. So...If we're talking about, say, a Cont A65 with a taper shaft, static balance theprop with the hub in place and you'll likely solve your problems.If you don't have a removable hub, you just REALLY REALLY need to be anal aboutstatic balancing with a WELL FITTING dummy hub to make sure you're balancingabout the correct center of rotation. Does this make sense?If your prop fits loosely on your hub, you HAVE to dynamically balance... or remanufacturethe hub on the prop to where it does fit will and repeatably, givingyou a chance at proper static balancing.This is a weird area. I went to Oshkosh's dynamic balancing workshop a coupleyears ago. The guys GIVING the seminar, were equipment salesmen who really didn'tunderstand dynamic balancing, which shocked me. Shoot away with any questions,I'll do my best to explain more if necessary!Read this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Wed, 14 Aug 2013 08:52:52 -0600Subject: Re: Pietenpol-List: Re: Dynamic balancing ?
In the case of a propeller, dynamic balancing is more effective than static balancingwhen it's installed where it's going to be used. In other words, there is NO advantage taking the prop somewhere and asking themto dynamically balance it and return it. It has to be installed on YOUR plane.And if you ever remove it, you've lost that advantage, it would have to bedone again (unless CAREFULLY reinstalled EXACTLY like it was... never a certainty).The reason for this is a propeller is not thick, compared to it's diameter, it'sa "single plane" balancing problem. Careful static balancing (where you hangit and determine the heavy blade and either remove a bit, or add some varnishto the other blade) is completely effective. A crankshaft, on the other hand, is long compared to it's diameter and NEEDS tobe dynamically balanced. It can be perfectly statically balanced but still beso out of balance the engine won't even run... Static balancing cannot detectmulti plane problems. So, do you need dynamic balancing? First, lets say with a known good propeller(and metal for it's repeatability) does your engine run smoothly? It's a subjectivething, but still, it's a reasonable thing to ask and the common guy'sdetermination is a decent evaluation. If so, then, your engine is well balanced(unless the prop JUST HAPPENS to correct a problem). So if you REALLY wantto be sure, run the engine. Remove the prop, move it one bolt hole and repeat.Do this six times and see if there's really any noticeable difference. Ifnot, you can say with reasonable conviction, your engine is well balanced.Now, make sure your wood prop is properly statically balanced. Put it on yourengine and run it. Is it smooth? If not, the problem HAS to be in the mountingof the prop. Dynamic balancing can correct this problem. However, you coulddo like before, try the prop in all six possible locations and see if the problemgoes away or gets better enough (EVERYTHING that rotates vibrates, it'sreally a matter of it being smooth enough for the application). If so, you'veempirically balanced the thing yourself, using guestimates just like balancinga ceiling fan. There may also be the problem of the prop being in the rightlocation for hand propping. If it does vibrate, like I said, the problem is in the mounting. Or the prop wasstatically balanced about a center of rotation DIFFERENT than the center ofrotation your prop sees on your engine. So...If we're talking about, say, a Cont A65 with a taper shaft, static balance theprop with the hub in place and you'll likely solve your problems.If you don't have a removable hub, you just REALLY REALLY need to be anal aboutstatic balancing with a WELL FITTING dummy hub to make sure you're balancingabout the correct center of rotation. Does this make sense?If your prop fits loosely on your hub, you HAVE to dynamically balance... or remanufacturethe hub on the prop to where it does fit will and repeatably, givingyou a chance at proper static balancing.This is a weird area. I went to Oshkosh's dynamic balancing workshop a coupleyears ago. The guys GIVING the seminar, were equipment salesmen who really didn'tunderstand dynamic balancing, which shocked me. Shoot away with any questions,I'll do my best to explain more if necessary!Read this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Wed, 14 Aug 2013 08:52:52 -0600Subject: Re: Pietenpol-List: Re: Dynamic balancing ?
Re: Pietenpol-List: Re: Dynamic balancing ?
Original Posted By: Michael Perez
Pietenpol-List: Re: Dynamic balancing ?
Original Posted By: "tools"
It depends on what you want. I work on the base and know people that work in the museum restoration shop. What do you want?SteveOn Aug 14, 2013, at 8:02 AM, "Douwe Blumberg" wrote:> Hey,> > Does anyone have a contact at the Dayton/Wright Patterson Air Force Museum? > > Douwe> > ============================================================================================================================================> ________________________________________________________________________________Subject: Pietenpol-List: Re: Dynamic balancing ?
It depends on what you want. I work on the base and know people that work in the museum restoration shop. What do you want?SteveOn Aug 14, 2013, at 8:02 AM, "Douwe Blumberg" wrote:> Hey,> > Does anyone have a contact at the Dayton/Wright Patterson Air Force Museum? > > Douwe> > ============================================================================================================================================> ________________________________________________________________________________Subject: Pietenpol-List: Re: Dynamic balancing ?
Re: Pietenpol-List: Dynamic balancing ?
Original Posted By: Larry Vetter
Larry,Here is my new prop balance gizmo. Temporary steel prop plate with a tiny hole drilled in the center, 1/4" steel rod ground to a point, point of rod placed up though prop center hole and into drilled hole in plate. Place a small bubble level in the center. Once that bubble is in the center all must be right, right? I rebalanced my curvy prop with this also and discovered I needed to add some lead to one side.Dan HelsperPuryear, TN-----Original Message-----
Larry,Here is my new prop balance gizmo. Temporary steel prop plate with a tiny hole drilled in the center, 1/4" steel rod ground to a point, point of rod placed up though prop center hole and into drilled hole in plate. Place a small bubble level in the center. Once that bubble is in the center all must be right, right? I rebalanced my curvy prop with this also and discovered I needed to add some lead to one side.Dan HelsperPuryear, TN-----Original Message-----
Pietenpol-List: Dynamic balancing ?
Original Posted By: Michael Perez
Pietenpol-List: Re: Dynamic balancing ?
Original Posted By: "tools"
This one from an Irish Piet builder, who happened to catch Dan Helsper'sPiet and Dan Yocum's Piet in the background.Gary BootheNX308MB________________________________________________________________________________Subject: Pietenpol-List: Re: Dynamic balancing ?
This one from an Irish Piet builder, who happened to catch Dan Helsper'sPiet and Dan Yocum's Piet in the background.Gary BootheNX308MB________________________________________________________________________________Subject: Pietenpol-List: Re: Dynamic balancing ?
Pietenpol-List: Re: New photo emerges from Brodhead 2012
Original Posted By: "Bill Church"
Mike, have you considered a donor crank? That would get you off to a good start.,Dan, two things. You are generally correct IF the tiny hole is EXACTLY in themiddle. Exactly like determined to within a couple thousanths of an inch, notnecessarily by hand with a ruler kind of thing. Within a couple thou isn't verydifficult in a machine shop environment. A couple tenths, a different matter...but not necessary.Second, that isn't a very precise bubble for the level of accuracy desired. Idon't know if GOOD bubbles are available in that configuration...Read this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: New photo emerges from Brodhead 2012
Mike, have you considered a donor crank? That would get you off to a good start.,Dan, two things. You are generally correct IF the tiny hole is EXACTLY in themiddle. Exactly like determined to within a couple thousanths of an inch, notnecessarily by hand with a ruler kind of thing. Within a couple thou isn't verydifficult in a machine shop environment. A couple tenths, a different matter...but not necessary.Second, that isn't a very precise bubble for the level of accuracy desired. Idon't know if GOOD bubbles are available in that configuration...Read this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: New photo emerges from Brodhead 2012
Original Posted By: "Gary Boothe"
You can tell that the photo wasn't from 2013, because nobody is wearing a parka.BCRead this topic online here:http://forums.matronics.com/viewtopic.p ... __________
You can tell that the photo wasn't from 2013, because nobody is wearing a parka.BCRead this topic online here:http://forums.matronics.com/viewtopic.p ... __________
RE: Pietenpol-List: Re: Dynamic balancing ?
Original Posted By: owner-pietenpol-list-server(at)matronics.com
Tools,Are you kidding? You are aware, aren't you, that Dan is talking about 'handcarved' props. Seems to me he is taking balancing to a whole new level - punintended. You should try making one, some time.Gary BootheNX308MB-----Original Message-----
Tools,Are you kidding? You are aware, aren't you, that Dan is talking about 'handcarved' props. Seems to me he is taking balancing to a whole new level - punintended. You should try making one, some time.Gary BootheNX308MB-----Original Message-----
Re: Pietenpol-List: Re: Dynamic balancing ?
Original Posted By:> owner-pietenpol-list-server(at)matronics.com
+1Make that +2 since I know you're well versed in making your own hand carved props,Gary, having made 2 or 3 yourself. -- Dan Yocumyocum137(at)gmail.comOn Aug 15, 2013, at 9:11 AM, "Gary Boothe" wrote:> > Tools,> > Are you kidding? You are aware, aren't you, that Dan is talking about 'hand> carved' props. Seems to me he is taking balancing to a whole new level - pun> intended. You should try making one, some time.> > Gary Boothe> NX308MB> > > -----Original Message-----
+1Make that +2 since I know you're well versed in making your own hand carved props,Gary, having made 2 or 3 yourself. -- Dan Yocumyocum137(at)gmail.comOn Aug 15, 2013, at 9:11 AM, "Gary Boothe" wrote:> > Tools,> > Are you kidding? You are aware, aren't you, that Dan is talking about 'hand> carved' props. Seems to me he is taking balancing to a whole new level - pun> intended. You should try making one, some time.> > Gary Boothe> NX308MB> > > -----Original Message-----
Pietenpol-List: Re: Dynamic balancing ?
Original Posted By: "AircamperN11MS"
Usually props are put on dummy hub and balanced on balancing ways. That's howthey were balanced in the 30's, when they were ALL hand carved. Still, balanceis balance, if you want a prop to run smoothly, it has to be balanced.The hub placed level requires EXTREME precision as there is very little movementfor a significant change in balance. A good and simple system, but to be aseffective as a balancing way system, that little vial has to be pretty decentlymanufactured. The balancing way system requires a more accurate hub. As witheverything in life, it's always something... So, no, I'm not kidding. I will build a prop, not sure what that has to do withhow to balance something effectively. What did I miss there? I have machinedmulti bolt hole patterns concentric with a precision hub for vertical headadapters for milling machines, the functional equivalent of a prop hub... doesthat count? I have also carved and balanced wood systems, large flat belt pulleysfor line shaft driven machines... Not sure what part of the system I apparentlydon't have any knowledge about to apply the subject matter informationto. Perhaps you do and can add to the discussion?Read this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: Dynamic balancing ?
Usually props are put on dummy hub and balanced on balancing ways. That's howthey were balanced in the 30's, when they were ALL hand carved. Still, balanceis balance, if you want a prop to run smoothly, it has to be balanced.The hub placed level requires EXTREME precision as there is very little movementfor a significant change in balance. A good and simple system, but to be aseffective as a balancing way system, that little vial has to be pretty decentlymanufactured. The balancing way system requires a more accurate hub. As witheverything in life, it's always something... So, no, I'm not kidding. I will build a prop, not sure what that has to do withhow to balance something effectively. What did I miss there? I have machinedmulti bolt hole patterns concentric with a precision hub for vertical headadapters for milling machines, the functional equivalent of a prop hub... doesthat count? I have also carved and balanced wood systems, large flat belt pulleysfor line shaft driven machines... Not sure what part of the system I apparentlydon't have any knowledge about to apply the subject matter informationto. Perhaps you do and can add to the discussion?Read this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: Dynamic balancing ?
Original Posted By: Dan Yocum
I have been flying a wood prop for over 40 years and have never done a dynamicbalance on one. I would not waste the time or money doing it. A static balancelike shown in the Pics is just fine. The reason I say what I do is rathersimple. The moisture in the prop moves from one blade to the other and is alwayson the move. The best thing we can do to prevent this from occurring is topark the prop in the horizontal position after shut down. I do this every time.If you park the prop with one of the blades down, the moisture will flowto the lower blade defeating the whole dynamic balance you paid good money for.You should check the static balance each time you put a new coat of finishon it or even touch up the black paint on the back. Rather simple and easy.My three cents, Now lets go flying.--------Scott LiefeldFlying N11MS since March 1972Steel TubeC-85-12Wire WheelsBrodhead in 1996Read this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Thu, 15 Aug 2013 09:39:52 -0500
I have been flying a wood prop for over 40 years and have never done a dynamicbalance on one. I would not waste the time or money doing it. A static balancelike shown in the Pics is just fine. The reason I say what I do is rathersimple. The moisture in the prop moves from one blade to the other and is alwayson the move. The best thing we can do to prevent this from occurring is topark the prop in the horizontal position after shut down. I do this every time.If you park the prop with one of the blades down, the moisture will flowto the lower blade defeating the whole dynamic balance you paid good money for.You should check the static balance each time you put a new coat of finishon it or even touch up the black paint on the back. Rather simple and easy.My three cents, Now lets go flying.--------Scott LiefeldFlying N11MS since March 1972Steel TubeC-85-12Wire WheelsBrodhead in 1996Read this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Thu, 15 Aug 2013 09:39:52 -0500
Re: Pietenpol-List: Re: Dynamic balancing ?
Original Posted By: Michael Perez
Pietenpol-List: Re: Dynamic balancing ?
Original Posted By: Michael Perez
Thanks guys for all the replies so far. Dan, I don't know for sure if he even balancedthe props, but will check with the previous owner. I will most likelycheck them anyway. I also don't know what pitch they are, he didn't say and its not marked on theprop anywhere that I have found. Thank you all again. LarryRead this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Thu, 15 Aug 2013 08:26:52 -0700 (PDT)
Thanks guys for all the replies so far. Dan, I don't know for sure if he even balancedthe props, but will check with the previous owner. I will most likelycheck them anyway. I also don't know what pitch they are, he didn't say and its not marked on theprop anywhere that I have found. Thank you all again. LarryRead this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Thu, 15 Aug 2013 08:26:52 -0700 (PDT)
RE: Pietenpol-List: Re: Dynamic balancing ?
Original Posted By: owner-pietenpol-list-server(at)matronics.com
There is nothing exact about hand carving a prop. Without going into detail,once the two blades are carved, on can only hope that they are very close toeach other in thrust. There are an infinite number of ways to be off. Tofocus on thousands of an inch is a waste of time. After all the careful work, the only thing that counts is how well the propperforms. That applies to both hand carved and machine carved props, asvarious prop makers have different ways of measuring pitch.The reason for my comment was two-fold:1) Real World: Most hand-carved prop makers have not had, and do not haveprecision machine equipment. Center hole is drilled on a drill press, which,at the best, will be squared and leveled with a t-square and/or a bubblelevel.2) Two bladed hand carved props are difficult enough, and have always beenbalanced by eye. On a 1-10 scale of difficulty, Dan's 4-bladed prop isa....15! The very fact that he figured out how to get all of that through aband saw is incredible! The fact that it balances at all is a monumentalsuccess! Yet you choose to focus on the type of bubble level he used...therefore, myremark, "Are you kidding?"Gary BootheNX308MB-----Original Message-----
There is nothing exact about hand carving a prop. Without going into detail,once the two blades are carved, on can only hope that they are very close toeach other in thrust. There are an infinite number of ways to be off. Tofocus on thousands of an inch is a waste of time. After all the careful work, the only thing that counts is how well the propperforms. That applies to both hand carved and machine carved props, asvarious prop makers have different ways of measuring pitch.The reason for my comment was two-fold:1) Real World: Most hand-carved prop makers have not had, and do not haveprecision machine equipment. Center hole is drilled on a drill press, which,at the best, will be squared and leveled with a t-square and/or a bubblelevel.2) Two bladed hand carved props are difficult enough, and have always beenbalanced by eye. On a 1-10 scale of difficulty, Dan's 4-bladed prop isa....15! The very fact that he figured out how to get all of that through aband saw is incredible! The fact that it balances at all is a monumentalsuccess! Yet you choose to focus on the type of bubble level he used...therefore, myremark, "Are you kidding?"Gary BootheNX308MB-----Original Message-----
Re: Pietenpol-List: Re: Dynamic balancing ?
Original Posted By: Jack
I got my genuine reproduction flying hat in the mail and I love it.--------Building steel fuselage aircamper.Read this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Re: Pietenpol-List: Re: Dynamic balancing ?
I got my genuine reproduction flying hat in the mail and I love it.--------Building steel fuselage aircamper.Read this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Re: Pietenpol-List: Re: Dynamic balancing ?
Pietenpol-List: Re: Dynamic balancing ?
Original Posted By: "AircamperN11MS"
Scott I have and I can't find the article, it looked pretty slick...Sent from my iPadJack TextorOn Aug 15, 2013, at 1:31 PM, "AircamperN11MS" wrote:> > Here is another way to build your own static balance tool. I have not built onemyself but had seen it printed somewhere and drew this up quickly from memory.I don't see any reason it wouldn't work. > > Please don't take me wrong on my last post. dynamic balancing is good and I thinkit has its place with metal and constant speed props but I really don't thinkwe need it on our Piets. They are simple machines. > > Attached is the rough drawing I made. Has anyone ever used this method before?> > --------> Scott Liefeld> Flying N11MS since March 1972> Steel Tube> C-85-12> Wire Wheels> Brodhead in 1996> > > > > Read this topic online here:> > http://forums.matronics.com/viewtopic.p ... 787#406787> > > > > Attachments: > > http://forums.matronics.com//files/2013 ... 67_571.pdf> > > > > > > ________________________________________________________________________________Subject: Pietenpol-List: Re: Dynamic balancing ?
Scott I have and I can't find the article, it looked pretty slick...Sent from my iPadJack TextorOn Aug 15, 2013, at 1:31 PM, "AircamperN11MS" wrote:> > Here is another way to build your own static balance tool. I have not built onemyself but had seen it printed somewhere and drew this up quickly from memory.I don't see any reason it wouldn't work. > > Please don't take me wrong on my last post. dynamic balancing is good and I thinkit has its place with metal and constant speed props but I really don't thinkwe need it on our Piets. They are simple machines. > > Attached is the rough drawing I made. Has anyone ever used this method before?> > --------> Scott Liefeld> Flying N11MS since March 1972> Steel Tube> C-85-12> Wire Wheels> Brodhead in 1996> > > > > Read this topic online here:> > http://forums.matronics.com/viewtopic.p ... 787#406787> > > > > Attachments: > > http://forums.matronics.com//files/2013 ... 67_571.pdf> > > > > > > ________________________________________________________________________________Subject: Pietenpol-List: Re: Dynamic balancing ?
Original Posted By: "Gary Boothe"
I think it was published in one of our Tech Counselor magazines. I am over fiftyand my memory stinks.
--------Scott LiefeldFlying N11MS since March 1972Steel TubeC-85-12Wire WheelsBrodhead in 1996Read this topic online here:http://forums.matronics.com/viewtopic.p ... __________
I think it was published in one of our Tech Counselor magazines. I am over fiftyand my memory stinks.
--------Scott LiefeldFlying N11MS since March 1972Steel TubeC-85-12Wire WheelsBrodhead in 1996Read this topic online here:http://forums.matronics.com/viewtopic.p ... __________RE: Pietenpol-List: Re: Dynamic balancing ?
Original Posted By: owner-pietenpol-list-server(at)matronics.com
#2 is to your question, Scott. These two photos show almost all one needs toknow about prop balancing tools...from the prop carving demo's at AirVenture.I should point out, the attached is from a prop carving essay that I gotfrom Dan Helsper, and wish to emphasize that ANYONE capable of building aPietenpol is capable of making their own prop...with the tools they alreadyhave! Do not be misled by claims of machinest type tools, or terms like "athousandth of an inch", or dynamic balancing.#3 is a picture of my Piet with the current prop, made from poplar. Iconfess, that I am purchasing a Culver prop, as I need a bench mark forfuture carvings. My goal will be to make my Piet fly as well as MikeGroah's, so I am working to change things to be similar to his. I have thesame engine, but also want the same climb, cruise and cooling numbers.Gary BootheNX308MB-----Original Message-----
#2 is to your question, Scott. These two photos show almost all one needs toknow about prop balancing tools...from the prop carving demo's at AirVenture.I should point out, the attached is from a prop carving essay that I gotfrom Dan Helsper, and wish to emphasize that ANYONE capable of building aPietenpol is capable of making their own prop...with the tools they alreadyhave! Do not be misled by claims of machinest type tools, or terms like "athousandth of an inch", or dynamic balancing.#3 is a picture of my Piet with the current prop, made from poplar. Iconfess, that I am purchasing a Culver prop, as I need a bench mark forfuture carvings. My goal will be to make my Piet fly as well as MikeGroah's, so I am working to change things to be similar to his. I have thesame engine, but also want the same climb, cruise and cooling numbers.Gary BootheNX308MB-----Original Message-----
Pietenpol-List: Re: Dynamic balancing ?
Original Posted By: "tools"
That is another great way to balance a prop Scott and I've used that method. I made up a gidgee (technical term for prop hub fitting) wherebyI hung my Corby Starlet prop assembly from a cable and simply drilled a hole and put a bolt, lockwasher, and nut on the spinner back plate at aposition which brought the cable into the center of my gidgee and balanced the whole deal very nicely.Mike C.________________________________________________________________________________Subject: Pietenpol-List: Re: Dynamic balancing ?
That is another great way to balance a prop Scott and I've used that method. I made up a gidgee (technical term for prop hub fitting) wherebyI hung my Corby Starlet prop assembly from a cable and simply drilled a hole and put a bolt, lockwasher, and nut on the spinner back plate at aposition which brought the cable into the center of my gidgee and balanced the whole deal very nicely.Mike C.________________________________________________________________________________Subject: Pietenpol-List: Re: Dynamic balancing ?
Pietenpol-List: Re: Scott's method for prop balancing.
Original Posted By: "AircamperN11MS"
Gary,I love those pics and writeups. Superbly elegant and simple. However, it doesn'taddress the inital question... If you have the luxury of drilling your bolthole pattern AFTER you balance it, it is indeed a simple matter of indexingit off where you have determined the prop will balance. However, if you balanceAFTER, it's critical that you balance at the exact center of the bolt holepattern or it just doesn't matter. Indeed, for practical purposes none of this matters... Hell, the easy way wouldbe to mock up the prop on the crank, without pistons installed and use the crankshaft as your hub, and the crank bearings as your balancing ways. You'llbe ahead of the game as in that stead, how you mount it IS how it'll mount inuse. But, if you ARE going to balance, and spend any time doing it, may as well do itas correctly as possible. If you don't, you could be making things worse, orjust never really fixing anything which is frustrating and time wasting. If you're relying on a bubble, and the bubble isn't repeatable, it's a doomed cause.You MIGHT get good results, and if you do, great. But if you don't, andyou don't realize the level on which you base your results is a causal factor,how could you proceed?Dynamic balancing is a GREAT way to check and correct stuff. Things in balancelast longer and are more reliable. There are non phase methods of dynamic balancingthat means decent dynamic balancing is possible with a cell phone app!AND a fair amount of knowing what's going on, which while a little esoteric,isn't difficult to pick up on. There are quite a few EAA chapters and such who own dynamic balancing set ups andbreak out their equipment and play around at fly-in's and such.Read this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: Scott's method for prop balancing.
Gary,I love those pics and writeups. Superbly elegant and simple. However, it doesn'taddress the inital question... If you have the luxury of drilling your bolthole pattern AFTER you balance it, it is indeed a simple matter of indexingit off where you have determined the prop will balance. However, if you balanceAFTER, it's critical that you balance at the exact center of the bolt holepattern or it just doesn't matter. Indeed, for practical purposes none of this matters... Hell, the easy way wouldbe to mock up the prop on the crank, without pistons installed and use the crankshaft as your hub, and the crank bearings as your balancing ways. You'llbe ahead of the game as in that stead, how you mount it IS how it'll mount inuse. But, if you ARE going to balance, and spend any time doing it, may as well do itas correctly as possible. If you don't, you could be making things worse, orjust never really fixing anything which is frustrating and time wasting. If you're relying on a bubble, and the bubble isn't repeatable, it's a doomed cause.You MIGHT get good results, and if you do, great. But if you don't, andyou don't realize the level on which you base your results is a causal factor,how could you proceed?Dynamic balancing is a GREAT way to check and correct stuff. Things in balancelast longer and are more reliable. There are non phase methods of dynamic balancingthat means decent dynamic balancing is possible with a cell phone app!AND a fair amount of knowing what's going on, which while a little esoteric,isn't difficult to pick up on. There are quite a few EAA chapters and such who own dynamic balancing set ups andbreak out their equipment and play around at fly-in's and such.Read this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: Scott's method for prop balancing.
Original Posted By: "Gary Boothe"
Thanks Mike, Pictures are worth a thousand words. Yours looks great.--------Scott LiefeldFlying N11MS since March 1972Steel TubeC-85-12Wire WheelsBrodhead in 1996Read this topic online here:http://forums.matronics.com/viewtopic.p ... __________
Thanks Mike, Pictures are worth a thousand words. Yours looks great.--------Scott LiefeldFlying N11MS since March 1972Steel TubeC-85-12Wire WheelsBrodhead in 1996Read this topic online here:http://forums.matronics.com/viewtopic.p ... __________
RE: Pietenpol-List: Re: Dynamic balancing ?
Original Posted By: owner-pietenpol-list-server(at)matronics.com
If you had ever made a prop, you would know that the center hole, 1/4", isthe first thing done...in every board, prior to laminating! A simple jigwith the bolt pattern is used, at any time after laminating, to drill theholes. You are complicating this whole issue, which does little to helpothers who may be contemplating this endeavor. Why don't you first make a prop, fly it on your Piet, then tell us how youdid it?Gary BootheNX308MB-----Original Message-----
If you had ever made a prop, you would know that the center hole, 1/4", isthe first thing done...in every board, prior to laminating! A simple jigwith the bolt pattern is used, at any time after laminating, to drill theholes. You are complicating this whole issue, which does little to helpothers who may be contemplating this endeavor. Why don't you first make a prop, fly it on your Piet, then tell us how youdid it?Gary BootheNX308MB-----Original Message-----
Pietenpol-List: Re: Dynamic balancing ?
Original Posted By: Ryan Mueller
Pietenpol-List: Re: Dynamic balancing ?
Original Posted By: "Dick N"
Dan I like your balancer. One thing I can add though from my own experience isthat the CG of the prop is not on the top surface, it is inside 'somewhere close'to one half the thickness of the hub. If you machine a plug that fits thebore of the prop shaft hole, then you can lower the fulcrum point into thebore of the prop shaft hole in the prop. The balancer becomes way more sensitive.You can also make different plugs to fit different props if needed. Youwant to get close to the 3D CG point, slightly above it. If below obviously itwill never balance. Rather than relying on the bubble level, simply get a lengthof clear plastic tubing and clamp it to the table on each side by the propellertips. Add water to the tube till the level is adjacent to the prop tip.Gravity is a harsh mistress but in this case she gives us a super accuratereference line. If you want to involve children as a learning experience, getthem to add the water with food coloring, they'll have fun and learn somethingat the same time!JoeRead this topic online here:http://forums.matronics.com/viewtopic.p ... __________
Dan I like your balancer. One thing I can add though from my own experience isthat the CG of the prop is not on the top surface, it is inside 'somewhere close'to one half the thickness of the hub. If you machine a plug that fits thebore of the prop shaft hole, then you can lower the fulcrum point into thebore of the prop shaft hole in the prop. The balancer becomes way more sensitive.You can also make different plugs to fit different props if needed. Youwant to get close to the 3D CG point, slightly above it. If below obviously itwill never balance. Rather than relying on the bubble level, simply get a lengthof clear plastic tubing and clamp it to the table on each side by the propellertips. Add water to the tube till the level is adjacent to the prop tip.Gravity is a harsh mistress but in this case she gives us a super accuratereference line. If you want to involve children as a learning experience, getthem to add the water with food coloring, they'll have fun and learn somethingat the same time!JoeRead this topic online here:http://forums.matronics.com/viewtopic.p ... __________
Re: Pietenpol-List: T.C. is back
Original Posted By: Lawrence Williams
Hi Larry I am glad your back. I am going with wifee to AAA on Labor Day Weekend. I hope to see you there.Dick N. ----- Original Message -----
Hi Larry I am glad your back. I am going with wifee to AAA on Labor Day Weekend. I hope to see you there.Dick N. ----- Original Message -----
Re: Pietenpol-List: T.C. is back
Original Posted By:> Lawrence Williams
Dick you flying or driving? Haven't been there for 3 or 4 years. May try and rearrange my schedule to attend via motorhome...Sent from my iPadJack TextorOn Aug 19, 2013, at 11:19 AM, "Dick N" wrote:> Hi Larry> I am glad your back. I am going with wifee to AAA on Labor Day Weekend. I hope to see you there.> Dick N.> ----- Original Message -----
Dick you flying or driving? Haven't been there for 3 or 4 years. May try and rearrange my schedule to attend via motorhome...Sent from my iPadJack TextorOn Aug 19, 2013, at 11:19 AM, "Dick N" wrote:> Hi Larry> I am glad your back. I am going with wifee to AAA on Labor Day Weekend. I hope to see you there.> Dick N.> ----- Original Message -----
Re: Pietenpol-List: Re: Dynamic balancing ?
Original Posted By: scudrun
Joe,Yes good point about trying to lower the fulcrum point. This would give a more accurate reading.Dan HelsperPuryear, TN -----Original Message-----
Joe,Yes good point about trying to lower the fulcrum point. This would give a more accurate reading.Dan HelsperPuryear, TN -----Original Message-----
Re: Pietenpol-List: T.C. is back
Original Posted By: Lawrence Williams
Thank God. Now I don't have to be quite as vigilante while scanning the list posts!Dan HelsperPuryear, TN-----Original Message-----
Thank God. Now I don't have to be quite as vigilante while scanning the list posts!Dan HelsperPuryear, TN-----Original Message-----
Re: Pietenpol-List: T.C. is back
Original Posted By: Jack
Hi Jack I am taking my camper we will be in the SW campground. I hope you can make it also.Dick N. ----- Original Message -----
Hi Jack I am taking my camper we will be in the SW campground. I hope you can make it also.Dick N. ----- Original Message -----