---------------------------------------------------------- Pietenpol-List Digest Archive --- Total Messages Posted Thu 04/17/03: 10 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:58 AM - Stress relief of parts (rhartwig11@juno.com) 2. 05:48 AM - Re: Landing gear (Doyle K. Combs) 3. 06:57 AM - Landing gear placement (Michael D Cuy) 4. 07:15 AM - bending metal and nesting (Robert Haines) 5. 08:51 AM - Re: Stress relief of parts (Hubbard, Eugene) 6. 04:43 PM - Re: Stress relief of parts (John Carmen) 7. 05:49 PM - Prop Hub (Isablcorky@aol.com) 8. 07:42 PM - Re: Prop Hub (Ted Brousseau) 9. 07:42 PM - Re: Landing gear placement (Ted Brousseau) 10. 10:04 PM - Re: Stress relief of parts (Les Schubert) ________________________________ Message 1 _____________________________________ Time: 04:58:48 AM PST US Subject: Pietenpol-List: Stress relief of parts From: rhartwig11@juno.com --> Pietenpol-List message posted by: rhartwig11@juno.com John, I have to question the statement that sand blasting will stress relieve parts. Stress relief involves the proper heat application and cooling to affect physical changes through the entire thickness of the metal. Blasting only affects the surface (unless you blast too long on thin sheet). Blasting can remove light scratches that could lead to cracking. Dick H. Time: 06:02:23 PM PST US From: "John Carmen" Subject: Re: Pietenpol-List: machined parts online --> Pietenpol-List message posted by: "John Carmen" Sand blasting and the like will stress relive the part. do it before and after the part is bent. and add a larger radius to the bend that is going with the grain. Remember not to use the sand that did steel on aluminum for the metal particles will get in the aluminum and corrode it. My two cents if anyone cares. John C. ________________________________ Message 2 _____________________________________ Time: 05:48:11 AM PST US From: "Doyle K. Combs" Subject: Re: Pietenpol-List: Landing gear --> Pietenpol-List message posted by: "Doyle K. Combs" Would you be willing to share the demensions of the landing gear placement? I will have brakes and need to know where to put the gear? Thanks Doyle Combs ----- Original Message ----- From: "Leon Stefan" Subject: Pietenpol-List: Landing gear > --> Pietenpol-List message posted by: lshutks@webtv.net (Leon Stefan) > > Hi Dennis: I built my landing gear with the wheels positioned foreward > per Bill Rewey's directions. It's not a Corvair thing, It's a brake > thing. Bill told me that the original placement is fine with no brakes, > but the tail end weight is too light if you are using brakes. It is > done to help prevent nose over. Leon S. Ks. > > ________________________________ Message 3 _____________________________________ Time: 06:57:55 AM PST US From: Michael D Cuy Subject: Pietenpol-List: Landing gear placement --> Pietenpol-List message posted by: Michael D Cuy Hello Doyle--- I just looked this number up for another Piet builder last night from my records. When Frank Pavliga and his father built Sky Gypsy they moved the gear forward quite a bit (with a Ford engine installed at the time) and it proved to make the tail too difficult to raise on takeoff. After they had one too many engine problems with the Ford, they replaced it w/ a Cont. 65 and built a new straight axle gear and positioned the axle 20" aft of the fire wall. I did the same and am happy with this location as Frank is with his. Mike C. ________________________________ Message 4 _____________________________________ Time: 07:15:35 AM PST US From: "Robert Haines" Subject: Pietenpol-List: bending metal and nesting --> Pietenpol-List message posted by: "Robert Haines" Regarding nesting parts for a CNC cutting operation and the bending direction, it's somewhat impossible to know which way the grain will be unless you yourself are running the CNC. Imagine that you have a 5' by 5' sheet which could be placed on the CNC table however. But regardless of how you plan to have the operator orient the grain, there are several reasons that it won't happen (i.e. it's Friday afternoon, or all the shop has is a piece of scrap that your parts fit on in only one way but it's got the wrong grain orientation). My suggestion is to then lay out parts at 45 degrees. Grain in sheet metal runs in the direction that it was rolled and it's safe to assume that it runs in either the x-axis or the y-axis of that square sheet. It's also fairly safe to assume that the operator is going to lay the sheet on the table orthogonal to the table. So if your part is cut so that all bends are 45 degrees to orthogonal, you split the difference between a correct grain orientation and an incorrect one. It's not optimum, but this is the real world. Robert Haines Du Quoin, Illinois ________________________________ Message 5 _____________________________________ Time: 08:51:41 AM PST US From: "Hubbard, Eugene" Subject: RE: Pietenpol-List: Stress relief of parts --> Pietenpol-List message posted by: "Hubbard, Eugene" I took the statement to suggest that sandblasting might be a bit like shot peening. Whether the impact carries enough energy to make a difference, I wouldn't know, and sort of doubt. Gene -----Original Message----- From: rhartwig11@juno.com [mailto:rhartwig11@juno.com] Subject: Pietenpol-List: Stress relief of parts --> Pietenpol-List message posted by: rhartwig11@juno.com John, I have to question the statement that sand blasting will stress relieve parts. Stress relief involves the proper heat application and cooling to affect physical changes through the entire thickness of the metal. Blasting only affects the surface (unless you blast too long on thin sheet). Blasting can remove light scratches that could lead to cracking. Dick H. Time: 06:02:23 PM PST US From: "John Carmen" Subject: Re: Pietenpol-List: machined parts online --> Pietenpol-List message posted by: "John Carmen" Sand blasting and the like will stress relive the part. do it before and after the part is bent. and add a larger radius to the bend that is going with the grain. Remember not to use the sand that did steel on aluminum for the metal particles will get in the aluminum and corrode it. My two cents if anyone cares. John C. ________________________________ Message 6 _____________________________________ Time: 04:43:28 PM PST US From: "John Carmen" Subject: Re: Pietenpol-List: Stress relief of parts --> Pietenpol-List message posted by: "John Carmen" Sand blasting and bead blasting will have the same effect yet will have different cosmetic effect on the surface. This is based on my experience using both. if one wanted to have a polished surface then use walnut shells, but this will not effect the material. Blasting moves the metal, almost like burnishing yet its more aggressive. Either will stress relive the outside surface of a material. this is where the cracks propagate from. You will find the connecting rods and other engine parts are bead blasted to stress relive, this is because sand has a tendency to impregnate in the metal, whereas bead are less likely to. If a part has internal stresses one would have to take another route. But we are talking about thin metal that will be bent, so blasting will stress relive the outside surface which went under tension and or compression from the bending. the inside is not effected, if and only a proper radius is made. If too small a radius is made then the inner will be over stressed and the part is ruined. welding will cause inner stresses, and stiffness closer to the weld, this requires different method to relive the stress, heating and cooling with various times and chemicals. Ever notice that when something welded is broke the broke is at the weld???? I have heated parts and dipped them in burnt motor oil to carburize ( case Harding) the surface, a crude Bluing method. any questions? John C. ----- Original Message ----- From: "Hubbard, Eugene" Subject: RE: Pietenpol-List: Stress relief of parts > --> Pietenpol-List message posted by: "Hubbard, Eugene" > > I took the statement to suggest that sandblasting might be a bit like shot > peening. Whether the impact carries enough energy to make a difference, I > wouldn't know, and sort of doubt. > > Gene > > -----Original Message----- > From: rhartwig11@juno.com [mailto:rhartwig11@juno.com] > To: pietenpol-list@matronics.com > Subject: Pietenpol-List: Stress relief of parts > > > --> Pietenpol-List message posted by: rhartwig11@juno.com > > John, > I have to question the statement that sand blasting will stress relieve > parts. Stress relief involves the proper heat application and cooling > to affect physical changes through the entire thickness of the metal. > Blasting only affects the surface (unless you blast too long on thin > sheet). Blasting can remove light scratches that could lead to cracking. > > Dick H. > > > Time: 06:02:23 PM PST US > From: "John Carmen" > Subject: Re: Pietenpol-List: machined parts online > > --> Pietenpol-List message posted by: "John Carmen" > > > Sand blasting and the like will stress relive the part. do it before > and > after the part is bent. and add a larger radius to the bend that is > going > with the grain. Remember not to use the sand that did steel on aluminum > for > the metal particles will get in the aluminum and corrode it. > > My two cents if anyone cares. > > John C. > > ________________________________ Message 7 _____________________________________ Time: 05:49:34 PM PST US From: Isablcorky@aol.com Subject: Pietenpol-List: Prop Hub --> Pietenpol-List message posted by: Isablcorky@aol.com Pieters, Putting out the word to try and find a servicable prop hub and flange for a tapered shaft A-65 continental. Any and all help will be appreciated. Cash money waiting. RePiet can't fly without it. Corky in beautiful weathered Louisiana where Piet flying is such a pleasant experience. You say it's snowing outside? ________________________________ Message 8 _____________________________________ Time: 07:42:16 PM PST US From: "Ted Brousseau" Subject: Re: Pietenpol-List: Prop Hub --> Pietenpol-List message posted by: "Ted Brousseau" I found a fellow with a Continental 65 in Lakeland while I was at Sun n Fun. He said it had around 400 hours SMOH, if I remember correctly. He wants $4000 - or $4500 with a beautiful wooden prop. He took it off a Tcraft to replace with an 85. If anyone is interested let me know and I will dig out his card and give you the info. Oh, he also said the Slick mags were almost new. Ted Brousseau ----- Original Message ----- From: Subject: Pietenpol-List: Prop Hub > --> Pietenpol-List message posted by: Isablcorky@aol.com > > Pieters, > > Putting out the word to try and find a servicable prop hub and flange for a > tapered shaft A-65 continental. Any and all help will be appreciated. Cash > money waiting. > RePiet can't fly without it. > > Corky in beautiful weathered Louisiana where Piet flying is such a pleasant > experience. You say it's snowing outside? > > ________________________________ Message 9 _____________________________________ Time: 07:42:16 PM PST US From: "Ted Brousseau" Subject: Re: Pietenpol-List: Landing gear placement --> Pietenpol-List message posted by: "Ted Brousseau" Mike, Thanks for that info on placement of the gear. Could you add where the front of the wing, or CG falls in relation to the fire wall? This would be most helpful for all people no matter which version they were building. Ted Brousseau Building the itsy bitsy version from the flying manual plans, but still taking a long time to build.... ----- Original Message ----- From: "Michael D Cuy" Subject: Pietenpol-List: Landing gear placement > --> Pietenpol-List message posted by: Michael D Cuy > > Hello Doyle--- I just looked this number up for another Piet builder last > night from my records. When Frank Pavliga and his father built Sky Gypsy > they moved the gear forward quite a bit (with a Ford engine installed at > the time) and it proved to make the tail too difficult to raise on > takeoff. After they had one too many engine problems with the Ford, they > replaced it w/ a Cont. 65 and built a new straight axle gear and positioned > the axle 20" aft of the fire wall. I did the same and am happy with this > location as Frank is with his. > > Mike C. > > ________________________________ Message 10 ____________________________________ Time: 10:04:18 PM PST US From: Les Schubert Subject: Re: Pietenpol-List: Stress relief of parts --> Pietenpol-List message posted by: Les Schubert John My experience is that things always break immediately beside the weld in what is called the heat affect zone. The weld itself rarely breaks if done correctly. In doing weld tests the heat affect zone is what causes all the heartburn. Les At 07:41 PM 17/04/2003 -0400, you wrote: >--> Pietenpol-List message posted by: "John Carmen" > >Sand blasting and bead blasting will have the same effect yet will have >different cosmetic effect on the surface. This is based on my experience >using both. if one wanted to have a polished surface then use walnut >shells, but this will not effect the material. Blasting moves the metal, >almost like burnishing yet its more aggressive. Either will stress relive >the outside surface of a material. this is where the cracks propagate >from. You will find the connecting rods and other engine parts are bead >blasted to stress relive, this is because sand has a tendency to impregnate >in the metal, whereas bead are less likely to. If a part has internal >stresses one would have to take another route. But we are talking about >thin metal that will be bent, so blasting will stress relive the outside >surface which went under tension and or compression from the bending. the >inside is not effected, if and only a proper radius is made. If too small a >radius is made then the inner will be over stressed and the part is ruined. >welding will cause inner stresses, and stiffness closer to the weld, this >requires different method to relive the stress, heating and cooling with >various times and chemicals. Ever notice that when something welded is >broke the broke is at the weld???? I have heated parts and dipped them in >burnt motor oil to carburize ( case Harding) the surface, a crude Bluing >method. > >any questions? > >John C. > > >----- Original Message ----- >From: "Hubbard, Eugene" >To: >Subject: RE: Pietenpol-List: Stress relief of parts > > > > --> Pietenpol-List message posted by: "Hubbard, Eugene" > > > > > I took the statement to suggest that sandblasting might be a bit like shot > > peening. Whether the impact carries enough energy to make a difference, I > > wouldn't know, and sort of doubt. > > > > Gene > > > > -----Original Message----- > > From: rhartwig11@juno.com [mailto:rhartwig11@juno.com] > > To: pietenpol-list@matronics.com > > Subject: Pietenpol-List: Stress relief of parts > > > > > > --> Pietenpol-List message posted by: rhartwig11@juno.com > > > > John, > > I have to question the statement that sand blasting will stress relieve > > parts. Stress relief involves the proper heat application and cooling > > to affect physical changes through the entire thickness of the metal. > > Blasting only affects the surface (unless you blast too long on thin > > sheet). Blasting can remove light scratches that could lead to cracking. > > > > Dick H. > > > > > > Time: 06:02:23 PM PST US > > From: "John Carmen" > > Subject: Re: Pietenpol-List: machined parts online > > > > --> Pietenpol-List message posted by: "John Carmen" > > > > > > Sand blasting and the like will stress relive the part. do it before > > and > > after the part is bent. and add a larger radius to the bend that is > > going > > with the grain. Remember not to use the sand that did steel on aluminum > > for > > the metal particles will get in the aluminum and corrode it. > > > > My two cents if anyone cares. > > > > John C. > > > > > >