---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Thu 11/07/13: 13 ---------------------------------------------------------- Today's Message Index: ---------------------- 0. 12:04 AM - Coming Soon - The List of Contributors - Please Make A Contribution Today! (Matt Dralle) 1. 02:28 AM - Re: Bussing W58 Series Breakers (Jay Hyde) 2. 02:39 AM - Re: Bussing W58 Series Breakers (Bob Verwey) 3. 06:37 AM - Re: Bussing W58 Series Breakers (Robert L. Nuckolls, III) 4. 07:08 AM - Re: Bussing W58 Series Breakers (Bill Bradburry) 5. 09:05 AM - Re: Bussing W58 Series Breakers (Bill) 6. 09:33 AM - Re: Bussing W58 Series Breakers (Robert L. Nuckolls, III) 7. 10:33 AM - Re: Bussing W58 Series Breakers (R. curtis) 8. 10:45 AM - Re: Bussing W58 Series Breakers (William Mills) 9. 01:04 PM - Copper sheet specs redux (Robert L. Nuckolls, III) 10. 06:40 PM - Re: Bussing W58 Series Breakers (Kelly McMullen) 11. 07:25 PM - Re: Bussing W58 Series Breakers (Bill) 12. 07:31 PM - Re: Bussing W58 Series Breakers (Kelly McMullen) ________________________________ Message 0 _____________________________________ Time: 12:04:40 AM PST US From: Matt Dralle Subject: AeroElectric-List: Coming Soon - The List of Contributors - Please Make A Contribution Today! Each year at the end of the List Fund Raiser, I post a message acknowledging everyone that so generously made a Contribution to support the Lists. Its my way of publicly thanking everyone that took a minute to show their appreciation for the Lists. Please take a moment and assure that your name is on that List of Contributors (LOC)! As a number of members have pointed out over the years, the List seems at least as valuable a building / entertainment tool as your typical magazine subscription! Assure that your name is on this year's LOC! Show others that you appreciate the Lists. Making a Contribution to support the Lists is fast and easy using your Credit card or Paypal on the Secure Web Site: http://www.matronics.com/contribution or by dropping a personal check in the mail to: Matt Dralle / Matronics 581 Jeannie Way Livermore CA 94550 I would like to thank everyone that has so generously made a Contribution thus far in this year's List Fund Raiser! Remember that its YOUR support that keeps these Lists going and improving! Don't forget to include a little comment about how the Lists have helped you! Best regards, Matt Dralle Matronics Email List Administrator ________________________________ Message 1 _____________________________________ Time: 02:28:19 AM PST US From: "Jay Hyde" Subject: RE: AeroElectric-List: Bussing W58 Series Breakers I do the same, however, the copper tube (I use the stuff that is used as water pipes in houses) is hard drawn and slightly brittle. To get around that I use a small blowtorch to heat it up until it glows red hot and then let it cool in air. That anneals it and makes it softer and more resistant to cracking and easier to form- like when you flatten it. Jay From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of R. curtis Sent: 06 November 2013 10:43 PM Subject: Re: AeroElectric-List: Bussing W58 Series Breakers Can a circuit board carry enough current though? The copper layers don't look very thick. On the other hand, the brass strips that are found in home electrical stores seem a bit oversized to the task. Something I have found that works great is soft copper tubing. You can purchase by the foot at your local hardware store. Take a 1/4" diameter piece and flatten gently with a hammer and it makes a great bus bar. If you want to attach it to the CB's with screws you can drill holes and screw it on or solder if you prefer. a similar method makes a nice forrest of tabs for grounding. Roger _____ .. Do you have a slow PC? Try a free scan! ________________________________ Message 2 _____________________________________ Time: 02:39:21 AM PST US From: Bob Verwey Subject: Re: AeroElectric-List: Bussing W58 Series Breakers C'mon guys, you can buy copper strip cut to size, and save yourself a lot of hassle. Plus it looks better! Best... Bob Verwey IO 470 A35 ZU-DLW On 7 November 2013 12:27, Jay Hyde wrote: > I do the same, however, the copper tube (I use the stuff that is used as > water pipes in houses) is hard drawn and slightly brittle. To get around > that I use a small blowtorch to heat it up until it glows red hot and the n > let it cool in air. That anneals it and makes it softer and more resista nt > to cracking and easier to form- like when you flatten it. > > > Jay > > > *From:* owner-aeroelectric-list-server@matronics.com [mailto: > owner-aeroelectric-list-server@matronics.com] *On Behalf Of *R. curtis > *Sent:* 06 November 2013 10:43 PM > *To:* aeroelectric-list@matronics.com > *Subject:* Re: AeroElectric-List: Bussing W58 Series Breakers > > > Can a circuit board carry enough current though? The copper layers don =92t > look very thick. On the other hand, the brass strips that are found in > home electrical stores seem a bit oversized to the task. > > > Something I have found that works great is soft copper tubing. You can > purchase by the foot at your local hardware store. Take a 1/4" diameter > piece and flatten gently with a hammer and it makes a great bus bar. If > you want to attach it to the CB's with screws you can drill holes and scr ew > it on or solder if you prefer. a similar method makes a nice forrest of > tabs for grounding. > > > Roger > > > ------------------------------ > > > . > SPAMfighter href="http://www.spamfighter.com/SLOW-PCfighter?cid=sigen ">slow > PC? Try a free scan! > > > *www.aeroelectric.com * > > *www.buildersbooks.com * > > *www.homebuilthelp.com * > > *www.mypilotstore.com * > > *www.mrrace.com * > > *http://www.matronics.com/contribution * > > *http://www.matronics.com/Navigator?AeroElectric-List * > > *http://forums.matronics.com * > > * > =========== m> ldersbooks.com> .com> com> om/contribution> =========== www.matronics.com/Navigator?AeroElectric-List> =========== =========== > * > > ________________________________ Message 3 _____________________________________ Time: 06:37:20 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Bussing W58 Series Breakers At 04:38 AM 11/7/2013, you wrote: >C'mon guys, you can buy copper strip cut to size, and save yourself >a lot of hassle. Plus it looks better! > I'll second that but with foundations in physics. Review the articles on our website that cite the term "gas tight" http://tinyurl.com/mjjl9dt I'll remind Listers that connectivity-magic happens when two conductors are held together with such force and rigidity across compliant surfaces that (1) ingress of moisture laden air and (2) relative motion between conductors is prevented. This design goal is the reason why round-wires and terminals become decidedly un-round under the crush of a crimped joint -OR- encapsulated in a cocoon of metal in the soldered joint. The most problematic joints in a wiring system are installer-fabricated with poor regard for process. Threaded fasteners are particularly needful of attention to details of flatness, force and rigidity. This is why the fuse-blocks dropped onto B&C's counter at OSH turned out to be a kind of installer's dream for relief of worries about knowledge and skill sets. First, the metal to metal joints were minimized. All but the threaded stud on the end of the assembly are manufactured for integrity and service life. If the builder can get a nice flat flag on an AMP terminal cinched down on a 10-32 stud, probabilities for very low risk and cost of ownership are good. The circuit breakers under discussion are suited to service in appliances and/or systems were design goals call for protection of a single feeder. But lining a bunch of them up on a panel with some notion of bussing their supply terminals is a mis-application of original design goals. The technical definition of a buss is a conductive structure ideally comprised of one piece of metal from which numerous taps supply power to various loads in the system with an architecture that prevents any single failure from propagating beyond the single feeder. Here's a collection of pictures for a 'buss and breaker' structure removed from a legacy Piper airplane . . . http://tinyurl.com/lmbcm66 http://tinyurl.com/lucl439 http://tinyurl.com/myhmoew The OBAM aviation builder-sphere is replete with arguments against religious observation of legacy design goals, "Well, the guy next to me in the hanger has been flying this (you fill in the blank) for years and hasn't had a bit of trouble." Given that our art is beginning its second century of real-life application, there are constellations of lessons-learned derived from a distillation of proven recipes for success re-enforced by understanding of the physics upon which they're built. Nobody stands over us with a rule book under one arm and a citation book under the other . . . but there ARE folks who we pay to worry that would be glad to assume that role in our craft. That event will mark the time when innovation and exploration of new ideas will slow to a crawl . . . if not halt completely. We would do well to expand our understanding of the arts and science while propagating it to the greatest number of interested individuals. There will always be those who don't find value in this endeavor . . . most will survive with little more than an elevated cost of ownership and laundry soap for the underwear. But a few will become candidates for trial in the Court of Dark-n-Stormy Nights where the narrator was not on board the airplane. The short response is, "buy already mill-flat materials from which to craft buss bars and fat-terminal jumpers". It is the exceedingly rare OBAM aviation shop that can take a round piece of metal and achieve such flatness. See: http://tinyurl.com/khymmf3 http://tinyurl.com/leunhah Bob . . . ________________________________ Message 4 _____________________________________ Time: 07:08:38 AM PST US From: "Bill Bradburry" Subject: RE: AeroElectric-List: Bussing W58 Series Breakers There seems to be a typo on this ebay site. I don't think that one cubic inch of copper weighs 4 pounds! ?? http://www.ebay.com/itm/48-oz-1-16-Flat-Copper-Sheet-Plate-4-x-4-/2711921244 76?pt=LH_DefaultDomain_0 &hash=item3f244f6c3c Bill _____ From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L. Nuckolls, III Sent: Thursday, November 07, 2013 9:36 AM Subject: Re: AeroElectric-List: Bussing W58 Series Breakers At 04:38 AM 11/7/2013, you wrote: C'mon guys, you can buy copper strip cut to size, and save yourself a lot of hassle. Plus it looks better! I'll second that but with foundations in physics. Review the articles on our website that cite the term "gas tight" http://tinyurl.com/mjjl9dt I'll remind Listers that connectivity-magic happens when two conductors are held together with such force and rigidity across compliant surfaces that (1) ingress of moisture laden air and (2) relative motion between conductors is prevented. This design goal is the reason why round-wires and terminals become decidedly un-round under the crush of a crimped joint -OR- encapsulated in a cocoon of metal in the soldered joint. The most problematic joints in a wiring system are installer-fabricated with poor regard for process. Threaded fasteners are particularly needful of attention to details of flatness, force and rigidity. This is why the fuse-blocks dropped onto B&C's counter at OSH turned out to be a kind of installer's dream for relief of worries about knowledge and skill sets. First, the metal to metal joints were minimized. All but the threaded stud on the end of the assembly are manufactured for integrity and service life. If the builder can get a nice flat flag on an AMP terminal cinched down on a 10-32 stud, probabilities for very low risk and cost of ownership are good. The circuit breakers under discussion are suited to service in appliances and/or systems were design goals call for protection of a single feeder. But lining a bunch of them up on a panel with some notion of bussing their supply terminals is a mis-application of original design goals. The technical definition of a buss is a conductive structure ideally comprised of one piece of metal from which numerous taps supply power to various loads in the system with an architecture that prevents any single failure from propagating beyond the single feeder. Here's a collection of pictures for a 'buss and breaker' structure removed from a legacy Piper airplane . . . http://tinyurl.com/lmbcm66 http://tinyurl.com/lucl439 http://tinyurl.com/myhmoew The OBAM aviation builder-sphere is replete with arguments against religious observation of legacy design goals, "Well, the guy next to me in the hanger has been flying this (you fill in the blank) for years and hasn't had a bit of trouble." Given that our art is beginning its second century of real-life application, there are constellations of lessons-learned derived from a distillation of proven recipes for success re-enforced by understanding of the physics upon which they're built. Nobody stands over us with a rule book under one arm and a citation book under the other . . . but there ARE folks who we pay to worry that would be glad to assume that role in our craft. That event will mark the time when innovation and exploration of new ideas will slow to a crawl . . . if not halt completely. We would do well to expand our understanding of the arts and science while propagating it to the greatest number of interested individuals. There will always be those who don't find value in this endeavor . . . most will survive with little more than an elevated cost of ownership and laundry soap for the underwear. But a few will become candidates for trial in the Court of Dark-n-Stormy Nights where the narrator was not on board the airplane. The short response is, "buy already mill-flat materials from which to craft buss bars and fat-terminal jumpers". It is the exceedingly rare OBAM aviation shop that can take a round piece of metal and achieve such flatness. See: http://tinyurl.com/khymmf3 http://tinyurl.com/leunhah Bob . . . ________________________________ Message 5 _____________________________________ Time: 09:05:02 AM PST US Subject: Re: AeroElectric-List: Bussing W58 Series Breakers From: Bill I disagree with letting it "cool in air" *unless* the alloys of copper water-pipe and spark-plug gaskets differ significantly which I doubt*.* As a fledgling A&P in 1973 we were taught to heat copper spark-plug gaskets to "cherry red" and *quench immediately in water*. I admit having no experience with allowing the gaskets to cool in air. Here's an EAA demo: http://www.eaavideo.org/video.aspx?v=57437956001 Respectfully - Bill SF bay area > On 7 November 2013 12:27, > you > wrote: > >> I do the same, however, the copper tube (I use the stuff that is used as >> water pipes in houses) is hard drawn and slightly brittle. To get around >> that I use a small blowtorch to heat it up until it glows red hot and then >> let it cool in air. That anneals it and makes it softer and more resistant >> to cracking and easier to form- like when you flatten it. >> > ________________________________ Message 6 _____________________________________ Time: 09:33:35 AM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: Bussing W58 Series Breakers At 09:08 AM 11/7/2013, you wrote: >There seems to be a typo on this ebay site. I don't think that one >cubic inch of copper weighs 4 pounds! ?? > >http://www.ebay.com/itm/48-oz-1-16-Flat-Copper-Sheet-Plate-4-x-4-/271192124476?pt=LH_DefaultDomain_0&hash=item3f244f6c3c > >Bill > That's an unfortunate citation. In the time before etched circuit boards, copper was rated/sold by gage and/or thickness times some dimension that described area. Then came copper clad ecb materials where somebody thought it was a good idea to speak to the thickness of copper not in terms of thickness but in some new convention like 'ounces per square foot'. It's a close cousin to logic that speaks of 'circular mil area' of a wire. A 10AWG solid wire is 102 mils in diameter with a real cross section of 3.14 x (.051)^2 = 0.00816 square inches. 10AWG said to have a CMA of 102^2 or 10,400 'circular mils'. It's 'handier' to rate current density in a wire in Amps per CMA . . . it's a discipline specific vernacular for folks who work with wires a lot . . . but it bugs a physicist. The ounces per square foot are easier to measure/verify than the actual thickness of the copper where 1 ounce per square foot is 1.344 mils. Copper has a density of 5.168 oz/cu-in. So a sheet of copper 1" square and ".001344" thick will have weight of 5.168 x 0.001344 = .006945 oz/sq-in x 144 = 1.000 oz/sq foot. Getting back to the eBay ad, we have .062" thick for 0.323 oz/sq-in x 144 = 46.5 oz/sq-ft. Hence the citation for "48 oz" copper . . . a description that would be meaningless to guys who do copper gutters and flashing . . . or buss bars in airplanes. Bob . . . ________________________________ Message 7 _____________________________________ Time: 10:33:39 AM PST US From: "R. curtis" Subject: Re: AeroElectric-List: Bussing W58 Series Breakers I disagree with letting it =22cool in air=22 unless the alloys of copper wate r-pipe and spark-plug gaskets differ significantly which I doubt. Air cooling of the cherry red hot copper will anneal it, however it wil l anneal to a softer state if you quench the copper in water. Roger -- Do you have a slow PC=3F Try a Free scan http://www.spamfighter.com/SLOW-PCfi ghter=3Fcid=sigen ________________________________ Message 8 _____________________________________ Time: 10:45:13 AM PST US Subject: Re: AeroElectric-List: Bussing W58 Series Breakers From: William Mills VGhhbmsgeW91IGZvciB0aGlzIGNsYXJpZmljYXRpb24uwqAKCkJpbGwKCkRvIG5vdCBhcmNoaXZl CgoKU2VudCB2aWEgdGhlIFNhbXN1bmcgR2FsYXh5IE5vdGXCriBJSSwgYW4gQVQmVCA0RyBMVEUg c21hcnRwaG9uZQoKLS0tLS0tLS0gT3JpZ2luYWwgbWVzc2FnZSAtLS0tLS0tLQpGcm9tOiAiUi4g Y3VydGlzIiA8bXJzcHVkYW5kY29tcGFueUB2ZXJpem9uLm5ldD4gCkRhdGU6IDExLzA3LzIwMTMg IDEwOjMyIEFNICAoR01ULTA4OjAwKSAKVG86IGFlcm9lbGVjdHJpYy1saXN0QG1hdHJvbmljcy5j b20gClN1YmplY3Q6IFJlOiBBZXJvRWxlY3RyaWMtTGlzdDogQnVzc2luZyBXNTggU2VyaWVzIEJy ZWFrZXJzIAogCgrCoApJIGRpc2FncmVlIHdpdGggbGV0dGluZyBpdCAiY29vbCBpbiBhaXIiwqB1 bmxlc3MgdGhlIGFsbG95cyBvZiBjb3BwZXIgd2F0ZXItcGlwZSBhbmQgc3BhcmstcGx1ZyBnYXNr ZXRzIGRpZmZlciBzaWduaWZpY2FudGx5IHdoaWNoIEkgZG91YnQuCsKgCkFpciBjb29saW5nIG9m IHRoZSBjaGVycnkgcmVkIGhvdCBjb3BwZXIgd2lsbCBhbm5lYWwgaXQsIGhvd2V2ZXIgaXQgd2ls bCBhbm5lYWwgdG8gYSBzb2Z0ZXIgc3RhdGUgaWYgeW91IHF1ZW5jaCB0aGUgY29wcGVyIGluIHdh dGVyLgrCoApSb2dlcgoKSSBhbSB1c2luZyB0aGUgRnJlZSB2ZXJzaW9uIG9mIFNQQU1maWdodGVy LgpTUEFNZmlnaHRlciBoYXMgcmVtb3ZlZCAxMzc4IG9mIG15IHNwYW0gZW1haWxzIHRvIGRhdGUu CgpEbyB5b3UgaGF2ZSBhIHNsb3cgUEM/IFRyeSBhIGZyZWUgc2NhbiEKCgpfLT09PT09PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PQpfLT0KXy09 ICAgICAgIC0tIFBsZWFzZSBTdXBwb3J0IFlvdXIgTGlzdHMgVGhpcyBNb250aCAtLQpfLT0gICAg ICAgICAgIChBbmQgR2V0IFNvbWUgQVdFU09NRSBGUkVFIEdpZnRzISkKXy09Cl8tPSAgIE5vdmVt YmVyIGlzIHRoZSBBbm51YWwgTGlzdCBGdW5kIFJhaXNlci4gIENsaWNrIG9uCl8tPSAgIHRoZSBD b250cmlidXRpb24gbGluayBiZWxvdyB0byBmaW5kIG91dCBtb3JlIGFib3V0Cl8tPSAgIHRoaXMg eWVhcidzIFRlcnJpZmljIEZyZWUgSW5jZW50aXZlIEdpZnRzIHByb3ZpZGVkCl8tPSAgIGJ5Ogpf LT0KXy09ICAgICAqIEFlcm9FbGVjdHJpYyB3d3cuYWVyb2VsZWN0cmljLmNvbQpfLT0gICAgICog VGhlIEJ1aWxkZXIncyBCb29rc3RvcmUgd3d3LmJ1aWxkZXJzYm9va3MuY29tCl8tPSAgICAgKiBI b21lYnVpbHRIRUxQIHd3dy5ob21lYnVpbHRoZWxwLmNvbQpfLT0gICAgICogTXkgUGlsb3QgU3Rv cmUgd3d3Lm15cGlsb3RzdG9yZS5jb20KXy09ICAgICAqIFJhY2UgQ29uc3VsdGluZyB3d3cubXJy YWNlLmNvbQpfLT0KXy09ICAgTGlzdCBDb250cmlidXRpb24gV2ViIFNpdGU6Cl8tPQpfLT0gICAt LT4gaHR0cDovL3d3dy5tYXRyb25pY3MuY29tL2NvbnRyaWJ1dGlvbgpfLT0KXy09ICAgVGhhbmsg eW91IGZvciB5b3VyIGdlbmVyb3VzIHN1cHBvcnQhCl8tPQpfLT0gICAgICAgICAgICAgICAgICAg ICAgICAgICAgICAtTWF0dCBEcmFsbGUsIExpc3QgQWRtaW4uCl8tPQpfLT09PT09PT09PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PQpfLT0gICAgICAg ICAgLSBUaGUgQWVyb0VsZWN0cmljLUxpc3QgRW1haWwgRm9ydW0gLQpfLT0gVXNlIHRoZSBNYXRy b25pY3MgTGlzdCBGZWF0dXJlcyBOYXZpZ2F0b3IgdG8gYnJvd3NlCl8tPSB0aGUgbWFueSBMaXN0 IHV0aWxpdGllcyBzdWNoIGFzIExpc3QgVW4vU3Vic2NyaXB0aW9uLApfLT0gQXJjaGl2ZSBTZWFy Y2ggJiBEb3dubG9hZCwgNy1EYXkgQnJvd3NlLCBDaGF0LCBGQVEsCl8tPSBQaG90b3NoYXJlLCBh bmQgbXVjaCBtdWNoIG1vcmU6Cl8tPQpfLT0gICAtLT4gaHR0cDovL3d3dy5tYXRyb25pY3MuY29t L05hdmlnYXRvcj9BZXJvRWxlY3RyaWMtTGlzdApfLT0KXy09PT09PT09PT09PT09PT09PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT0KXy09ICAgICAgICAgICAgICAg LSBNQVRST05JQ1MgV0VCIEZPUlVNUyAtCl8tPSBTYW1lIGdyZWF0IGNvbnRlbnQgYWxzbyBhdmFp bGFibGUgdmlhIHRoZSBXZWIgRm9ydW1zIQpfLT0KXy09ICAgLS0+IGh0dHA6Ly9mb3J1bXMubWF0 cm9uaWNzLmNvbQpfLT0KXy09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09 PT09PT09PT09PT09PT09PT09PT0K ________________________________ Message 9 _____________________________________ Time: 01:04:52 PM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Copper sheet specs redux I've had some direct emails asking about the selection of copper sheet for fabrication of bus bars. It seems that copper is sold in a market that adopted the Birmingham guage system as opposed to the Brown and Sharp tables common to the brass and aluminum markets. Then there's the stainless steel guys who have their own tables . . . sigh . . . This excerpt from a copper sheet gauge table illustrates the reason why our calculated weight earlier this morning was a bit different than the cited weight in the Ebay ad. The "48 oz" copper being offered was indeed a couple mils thicker than 1/16" thus explaining the difference. Emacs! When bussing breakers the maximum loads you might see on a bus bar can't be more than alternator rating. Assume 60A alternator. 10AWG wire example I cited earlier this morning has a cross section of 0.0082 sq-in. 10AWG round wire will produce a 10C rise with 30A of current flowing in it. If ALL alternator current is fed to the center of a one-piece bus bar and equally distributed to half the bus on each side, then the bus carries 30 A max, probably much less. A 16 Gauge copper buss bar (.065" thick) 1/2" wide has a copper cross section of .065 x .5 or 0.032 square inches. This is 4x larger than a 10AWG wire so we can expect temperature rise to be no more than 2.5 degrees C. Run all the current to one end of the bus bar such that the whole 60A flows through the copper. Heating value rises by the square of current. So 2x current is 4x heat or 4x temperature rise so we're back up to 10C max at end where the feeder is attached. The nice thing is that flat copper sheet will reject heat better than a round wire so the expected rise will be LESS than the round wire equivalent. Now, consider the same, 0.064" copper jumped between two contactor FAT wire terminals. Let's make the jumper 1" wide for 1/2 the resistance per inch of the bus bar example above. So 60A of alternator current would bring our rise down to 5C. Hit it with a 200A starter current for 3x current, 9x rise and the strip of copper could be expected to rise about 50C during cranking. But it's got more area than wire and is heat-sinked to the studs on either end so the heating will be less than 50C. Even less considering that most cranking intervals are but a few seconds . . . too short for the rise to stabilize. This little exercise suggests that .065" copper in 1/2" wide strips is just fine behind the panel . . . and 1" strips is okay between contactors, probably no more marginal for heat rejection than the starter itself. A piece of 1/8" copper would drop the 50C rise to 25C at 200A in 10AWG wire equivalents . . . MUCH more headroom. One could fabricate a thicker contactor-jumper from two layers of 1/16" copper. Get all the joints bright and clean. Torque the fasteners down tight. All will be right with the universe. Bob . . . ________________________________ Message 10 ____________________________________ Time: 06:40:19 PM PST US From: Kelly McMullen Subject: Re: AeroElectric-List: Bussing W58 Series Breakers Hmmm, Your A&P school had it wrong. With pure copper, such as spark plug gaskets it makes zero difference whether you quench or not. Other metals are very different, but copper does not need quenching. http://en.wikipedia.org/wiki/Annealing_%28metallurgy%29 Quenching with most metals makes it harder, not softer. Copper again is an exception where quenching doesn't harden, but it doesn't soften either. On 11/7/2013 10:03 AM, Bill wrote: > I disagree with letting it "cool in air" */unless/* the alloys of > copper water-pipe and spark-plug gaskets differ significantly which I > doubt*.* > * > * > As a fledgling A&P in 1973 we were taught to heat copper spark-plug > gaskets to "cherry red" and */quench immediately in water/*. > I admit having no experience with allowing the gaskets to cool in air. > > Here's an EAA demo: > http://www.eaavideo.org/video.aspx?v=57437956001 > > Respectfully - > Bill > SF bay area > > On 7 November 2013 12:27, > you > wrote: > > I do the same, however, the copper tube (I use the stuff that > is used as water pipes in houses) is hard drawn and slightly > brittle. To get around that I use a small blowtorch to heat > it up until it glows red hot and then let it cool in air. > That anneals it and makes it softer and more resistant to > cracking and easier to form- like when you flatten it. > > * > > * ________________________________ Message 11 ____________________________________ Time: 07:25:01 PM PST US Subject: Re: AeroElectric-List: Bussing W58 Series Breakers From: Bill Hi Kelly - Likely it was a time consideration: quench instantly in water rather than gradually in air. BTW, water quenching wasn't learned in school. As a "fledgling A&P" I was a graduate, licensed and employed at an FBO/Repair Station (water quenching learned here). No matter, both systems work equally well. As I said initially below; "I admit having no experience with allowing the gaskets to cool in air". Now I know TWO systems. Thanks for the input - Bill On Thu, Nov 7, 2013 at 6:38 PM, Kelly McMullen wrote: > kellym@aviating.com> > > Hmmm, > Your A&P school had it wrong. With pure copper, such as spark plug gaskets > it makes zero difference whether you quench or not. > Other metals are very different, but copper does not need quenching. > http://en.wikipedia.org/wiki/Annealing_%28metallurgy%29 > Quenching with most metals makes it harder, not softer. Copper again is an > exception where quenching doesn't harden, but it doesn't soften either. > > On 11/7/2013 10:03 AM, Bill wrote: > >> I disagree with letting it "cool in air" */unless/* the alloys of copper >> water-pipe and spark-plug gaskets differ significantly which I doubt*.* >> * >> * >> As a fledgling A&P in 1973 we were taught to heat copper spark-plug >> gaskets to "cherry red" and */quench immediately in water/*. >> I admit having no experience with allowing the gaskets to cool in air. >> >> Here's an EAA demo: >> http://www.eaavideo.org/video.aspx?v=57437956001 >> >> Respectfully - >> Bill >> SF bay area >> >> On 7 November 2013 12:27, >> you >> wrote: >> >> I do the same, however, the copper tube (I use the stuff that >> is used as water pipes in houses) is hard drawn and slightly >> brittle. To get around that I use a small blowtorch to heat >> it up until it glows red hot and then let it cool in air. >> That anneals it and makes it softer and more resistant to >> cracking and easier to form- like when you flatten it. >> >> * >> >> * >> > > ________________________________ Message 12 ____________________________________ Time: 07:31:18 PM PST US From: Kelly McMullen Subject: Re: AeroElectric-List: Bussing W58 Series Breakers Sure. I maintain enough extra gaskets that I put fresh ones on, the anneal the old ones at my leisure. I just string them on some old safety wire, heat, then let cool and they are ready for next plug servicing. On 11/7/2013 8:23 PM, Bill wrote: > Hi Kelly - > > Likely it was a time consideration: quench instantly in water rather > than gradually in air. > > BTW, water quenching wasn't learned in school. As a "fledgling A&P" I > was a graduate, licensed and employed at an FBO/Repair Station (water > quenching learned here). No matter, both systems work equally well. As > I said initially below; "I admit having no experience with allowing > the gaskets to cool in air". Now I know TWO systems. > > Thanks for the input - > Bill > > On Thu, Nov 7, 2013 at 6:38 PM, Kelly McMullen > wrote: > > > > > Hmmm, > Your A&P school had it wrong. With pure copper, such as spark plug > gaskets it makes zero difference whether you quench or not. > Other metals are very different, but copper does not need > quenching. http://en.wikipedia.org/wiki/Annealing_%28metallurgy%29 > Quenching with most metals makes it harder, not softer. Copper > again is an exception where quenching doesn't harden, but it > doesn't soften either. > > On 11/7/2013 10:03 AM, Bill wrote: > > I disagree with letting it "cool in air" */unless/* the alloys > of copper water-pipe and spark-plug gaskets differ > significantly which I doubt*.* > * > * > As a fledgling A&P in 1973 we were taught to heat copper > spark-plug gaskets to "cherry red" and */quench immediately in > water/*. > I admit having no experience with allowing the gaskets to cool > in air. > > Here's an EAA demo: > http://www.eaavideo.org/video.aspx?v=57437956001 > > Respectfully - > Bill > SF bay area > > On 7 November 2013 12:27, > you > wrote: > > I do the same, however, the copper tube (I use the > stuff that > is used as water pipes in houses) is hard drawn and > slightly > brittle. To get around that I use a small blowtorch > to heat > it up until it glows red hot and then let it cool in > air. That anneals it and makes it softer and more > resistant to > cracking and easier to form- like when you flatten it. > > * > > * > > > =================================== > om" target="_blank">www.aeroelectric.com > ooks.com" target="_blank">www.buildersbooks.com > et="_blank">www.homebuilthelp.com > et="_blank">www.mypilotstore.com > "_blank">www.mrrace.com > ="_blank">http://www.matronics.com/contribution > le, List Admin. > =================================== > -List" > target="_blank">http://www.matronics.com/Navigator?AeroElectric-List > =================================== > http://forums.matronics.com > =================================== > > > * > > * ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.