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| Deflection tsting calculations http://luthiersforum.com/forum/viewtopic.php?f=10101&t=47963 |
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| Author: | Colin North [ Thu Jun 30, 2016 4:42 pm ] |
| Post subject: | Deflection tsting calculations |
Can anyone give me, or direct me to a website which will give me, a formula for calculating long grain Modulus of Elasticity from deflection testing, preferably in metric units? I've spent a fair bit of time looking and have turned up nothing, although I'm sure I've seen it before somewhere. |
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| Author: | Trevor Gore [ Thu Jun 30, 2016 6:27 pm ] |
| Post subject: | Re: Deflection tsting calculations |
Design P1-24 or P4-39/40. |
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| Author: | Colin North [ Thu Jun 30, 2016 6:40 pm ] |
| Post subject: | Re: Deflection tsting calculations |
Got it, thanks and The volume was actually at my elbow as I read your post, I'd looked it out to search. |
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| Author: | jfmckenna [ Thu Jun 30, 2016 8:51 pm ] |
| Post subject: | Re: Deflection tsting calculations |
You got that? I didn't The P's and Q's that is. I just started deflection testing too and tried searching as well for others methods and so on. I finally came to the conclusion that it's a big secret and you have to figure it all out yourself. So I have a brick with cork glued to it, a dial caliper, some blocks to raise the top up on and just add the weight, repeat 3 times, take the average, and record it. I guess after about 20 more guitars I will have a personal data set that will start to provide results. |
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| Author: | Trevor Gore [ Fri Jul 01, 2016 12:59 am ] |
| Post subject: | Re: Deflection tsting calculations |
jfmckenna wrote: You got that? I didn't The P's and Q's that is. Page references for the book. A lot easier than trying to write out math formulae on a text-based forum. jfmckenna wrote: I just started deflection testing too and tried searching as well for others methods and so on. I finally came to the conclusion that it's a big secret and you have to figure it all out yourself... ... I guess after about 20 more guitars I will have a personal data set that will start to provide results. No need to re-invent the wheel. According to Charles Fox (referring to the book) "This is exactly what you want, and you can begin wielding this valuable knowledge almost immediately instead of waiting a lifetime to attain it." Thank you Charles! |
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| Author: | jfmckenna [ Fri Jul 01, 2016 8:23 am ] |
| Post subject: | Re: Deflection tsting calculations |
Oh I see! Yes, been meaning to get the books for some time now. My problem is I buy books, shelf them, and never read them. That or I spend all my money on wood Holiday weekend coming up might give me time to finally sit down and finish the Somogyi books and then move on... Looks like it's out of stock? Is there a digital version? |
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| Author: | Trevor Gore [ Fri Jul 01, 2016 7:08 pm ] |
| Post subject: | Re: Deflection tsting calculations |
jfmckenna wrote: Looks like it's out of stock? Is there a digital version? It's not really the sort of book that lends itself to digital. I'm currently proofing the 2nd edition pre-prints from the printer. Should be back in stock toward the end of August, if all goes to plan. |
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| Author: | CharlieT [ Fri Jul 01, 2016 8:45 pm ] |
| Post subject: | Re: Deflection tsting calculations |
Trevor Gore wrote: I'm currently proofing the 2nd edition pre-prints from the printer. Trevor, will there be significant differences between the 1st and 2nd editions? |
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| Author: | Durero [ Sat Jul 02, 2016 12:03 am ] |
| Post subject: | Re: Deflection tsting calculations |
CharlieT wrote: Trevor Gore wrote: I'm currently proofing the 2nd edition pre-prints from the printer. Trevor, will there be significant differences between the 1st and 2nd editions? +1 Also very interested to know. |
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| Author: | Trevor Gore [ Sat Jul 02, 2016 12:35 am ] |
| Post subject: | Re: Deflection tsting calculations |
CharlieT wrote: Trevor, will there be significant differences between the 1st and 2nd editions? Probably greater than 98% the same. I've changed out a few of the "free standing" photos for better/more interesting ones; the photos in Build are all a little bit larger and better colour balanced; there's a bit more on intonation/compensation, there's a better double-acting truss rod. There's minor changes to some of the equations so that they are easier to check (there was a residual error of ~0.5% (iirc) that was driving people mad when trying to check their calcs, but of no consequence in real life). There's the new foreword by Charles Fox (referred to above) and a commendation by Tommy Emmanuel. Otherwise, it was about correcting typos and re-wording a few explanations to help reduce the possibility of any ambiguity. So if you already have Edition 1, I wouldn't be rushing out to update to Edition 2, unless you have plenty of spare cash that you want to throw in my direction! |
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| Author: | Bob Shanklin [ Sat Jul 02, 2016 9:41 am ] |
| Post subject: | Re: Deflection tsting calculations |
Trevor, are you going to have the updates online for those of us that have the first edition? Bob |
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| Author: | Trevor Gore [ Sun Jul 03, 2016 4:11 am ] |
| Post subject: | Re: Deflection tsting calculations |
Bob, quite a lot up of updates came as a consequence of discussions in "the book" section of the ANZ Luthiers Forum. So in a sense many of the updates are already on line. |
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| Author: | printer2 [ Sun Jul 03, 2016 10:57 am ] |
| Post subject: | Re: Deflection tsting calculations |
Trevor Gore wrote: Bob, quite a lot up of updates came as a consequence of discussions in "the book" section of the ANZ Luthiers Forum. So in a sense many of the updates are already on line. Are they complied in one thread? |
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| Author: | Trevor Gore [ Sun Jul 03, 2016 6:25 pm ] |
| Post subject: | Re: Deflection tsting calculations |
They are all in one sub-forum. Just follow the link above. |
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| Author: | CharlieT [ Mon Jul 04, 2016 10:01 am ] |
| Post subject: | Re: Deflection tsting calculations |
Trevor Gore wrote: Probably greater than 98% the same. I've changed out a few of the "free standing" photos for better/more interesting ones; the photos in Build are all a little bit larger and better colour balanced; there's a bit more on intonation/compensation, there's a better double-acting truss rod. There's minor changes to some of the equations so that they are easier to check (there was a residual error of ~0.5% (iirc) that was driving people mad when trying to check their calcs, but of no consequence in real life). There's the new foreword by Charles Fox (referred to above) and a commendation by Tommy Emmanuel. Otherwise, it was about correcting typos and re-wording a few explanations to help reduce the possibility of any ambiguity. So if you already have Edition 1, I wouldn't be rushing out to update to Edition 2, unless you have plenty of spare cash that you want to throw in my direction! Thank you Trevor! |
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