Brad H Posted February 9, 2021 Report Share Posted February 9, 2021 Am I the only one whose eyes are tricked when viewing sound posts? One minute, it may appear the post is leaning forward, but if I keep looking at it - just like an Escher drawing - I can almost see it leaning the other way. Or, picking up a violin and re-examining a previously set post and thinking, " OK, how did I do that?". I mostly look through the treble f-hole, but will use the bass f-hole, too. The other Escher effect occurs for me when setting a post sans bridge, and then viewing the post after installing the bridge. Usually, I see the post in a more backwards leaning stance after installing the bridge. Quote Link to comment Share on other sites More sharing options...
L.Colburn Posted February 9, 2021 Report Share Posted February 9, 2021 1 hour ago, Brad H said: Am I the only one whose eyes are tricked when viewing sound posts? Do you by any chance wear progressive lenses? There is a not so sweet spot in progressives that can cause distortion. Quote Link to comment Share on other sites More sharing options...
Stringy Posted February 9, 2021 Report Share Posted February 9, 2021 Its because the image in your mind is created by both your eyes together if you look with one eye only then look with the other eye it will appear to lean at different angles. You can try this out by looking at anything with one eye closed, then look with the other eye, while closing the first, what you look at will appear to move slightly, my opthalmologist explained this to me,it can also be due to differences in strength of vision in each eye. Quote Link to comment Share on other sites More sharing options...
David Burgess Posted February 9, 2021 Report Share Posted February 9, 2021 1 hour ago, Brad H said: Am I the only one whose eyes are tricked when viewing sound posts? Nope. The bigger issue is with those who haven't yet realized how easily their eyes can be tricked. Quote Link to comment Share on other sites More sharing options...
Shunyata Posted February 9, 2021 Report Share Posted February 9, 2021 Yes I have noticed this, but I also figured out its a function of your visual reference point. There are multiple surfaces on a violin, all at different angles, and the sound post isn't square to any of them except the garland, which isn't much help. Your process will be most repeatable if you deliberately compare the sound post position against a specific reference point(s) on the violin. This keeps your brain from using whatever you looked at last as the reference point. Quote Link to comment Share on other sites More sharing options...
David Burgess Posted February 9, 2021 Report Share Posted February 9, 2021 13 minutes ago, Shunyata said: Yes I have noticed this, but I also figured out its a function of your visual reference point. There are multiple surfaces on a violin, all at different angles, and the sound post isn't square to any of them except the garland, which isn't much help. Your process will be most repeatable if you deliberately compare the sound post position against a specific reference point(s) on the violin. This keeps your brain from using whatever you looked at last as the reference point. What would you suggest as the reference point, since even the garlands on most antique violins are not consistent or straight? Quote Link to comment Share on other sites More sharing options...
Brad H Posted February 10, 2021 Author Report Share Posted February 10, 2021 I usually wear reading glasses when working on violin setup...and keep both eyes open. Yeah, I get the deal with different reference points. I have learned not to react to my first impression when viewing a post. I also usually hold the violin in as close to horizontal position as I can get. After an initial view, I usually rotate the violin slightly, dipping c-bouts up and down, and can go back to the exact same initial view...and sometimes get a different reading. Additionally, I think we all have our own idea of a "straight" post (assuming we are aiming for straightness). Quote Link to comment Share on other sites More sharing options...
Shunyata Posted February 10, 2021 Report Share Posted February 10, 2021 Some suggestions for reference point include: * edges of top block (when end pin is out), * inserting a vertical reference stick through either f hole, located at a consistent point. *looking at post angle versus back plate at the point of contact (deliberately ignoring the appearance of the post overall) * using a flat shim to measure position of post relative to f hole notch, both N-S and E-W. * bending your post setter so it is at right angles to garland when post is in proper location. None of these are scientifically precise, but together they produce rapid, repeatable results. And that is all we really need to achieve... quick, consistent placement that is in the right neighborhood for fine adjustment. Quote Link to comment Share on other sites More sharing options...
David Burgess Posted February 10, 2021 Report Share Posted February 10, 2021 1 hour ago, Shunyata said: * inserting a vertical reference stick through either f hole, located at a consistent point. How do you know that your vertical reference stick is vertical? Do you attach two bubble levels to the stick, and two more to some place on the violin to determine the straightness on two axis? In other words, I can relate to Brad's challenges, and after many decades in the business, don't find this to be anything close to easy. Quote Link to comment Share on other sites More sharing options...
Brad H Posted February 10, 2021 Author Report Share Posted February 10, 2021 David, thanks for the support... I don't mind being in an apparent minority in perceiving this Escher effect, or reacting differently to posts on different days. Quote Link to comment Share on other sites More sharing options...
Violadamore Posted February 11, 2021 Report Share Posted February 11, 2021 On 2/9/2021 at 6:53 PM, David Burgess said: What would you suggest as the reference point, since even the garlands on most antique violins are not consistent or straight? I hadn't thought about this much, more just doing it, so I went and looked in some violins I'd set posts in. I found that I'm subconsciously referencing to the bridge vertical, which means ultimately to a plane tangent to the top curve at the f-hole notches. Quote Link to comment Share on other sites More sharing options...
Violadamore Posted February 11, 2021 Report Share Posted February 11, 2021 If you ask me how I do that when the bridge isn't there, I don't have a clue, but that's the way my posts line up. Quote Link to comment Share on other sites More sharing options...
Delabo Posted February 11, 2021 Report Share Posted February 11, 2021 This thread begs the question as to why it matters if the post is not absolutely vertical ? The only practical reason I can think of is that the bevel end of the post might did into the top or back a bit leaving an indentation in the wood. Apart from that is it likely to have an observable effect on sound quality or something else ? Quote Link to comment Share on other sites More sharing options...
David Burgess Posted February 11, 2021 Report Share Posted February 11, 2021 2 hours ago, Bill Merkel said: ^A respected maker whose initials rhyme with DB has said violins sound best if the post is vertical. Wasn't me. Sound posts sound best at the location and the angle they sound best, which varies from instrument to instrument. Quote Link to comment Share on other sites More sharing options...
Jeffrey Holmes Posted February 11, 2021 Report Share Posted February 11, 2021 I'm another who doesn't believe "vertical" is a hard-fast rule, though I tend to do my best to start with that when cutting a post. As far as "getting it straight", I work on many old instruments where finding a reliable reference point could be classified as "challenging". It's great when I do, of course. Straight looking from the endpin hole is, in my opinion, less difficult than straight from the side (f hole). If things are wonky (rib corners off 90 degrees, a dip in the rib/plate joint around the c bouts, twisted body, etc... and it doesn't take much to throw off the view) and I can't get a good reference, I sometimes use a china marker to draw a light line across the stop between the ffs. If you hold the violin squarely, directly, in front of you and rotate it away from you, the china marker line can be compared to the post position as a reference point as you go. Not a perfect solution, but a solution non the less. The usual warnings: Don't use a china marker if there are open cracks or exposed wood in the stop area. They are wax, after all. Easily removed from varnish though... Hope this helps. Quote Link to comment Share on other sites More sharing options...
Mark Norfleet Posted February 11, 2021 Report Share Posted February 11, 2021 No. And it's even worse after having had surgery to repair a torn retina, but hopefully will improve after cataract surgery that will be needed to address a side effect of one of the drugs I took post surgery. I've had a few WTF moments in the last few years looking at sound posts.... Quote Link to comment Share on other sites More sharing options...
Bill Merkel Posted February 11, 2021 Report Share Posted February 11, 2021 7 hours ago, David Burgess said: Wasn't me. Sound posts sound best at the location and the angle they sound best, which varies from instrument to instrument. I looked it up and you were talking about fit, not angle. I was remembering angle instead. Sorry. https://maestronet.com/forum/index.php?/topic/339473-deliberately-angled-soundpost/&do=findComment&comment=785084 Quote Link to comment Share on other sites More sharing options...
David Burgess Posted February 11, 2021 Report Share Posted February 11, 2021 2 hours ago, Mark Norfleet said: No. And it's even worse after having had surgery to repair a torn retina, but hopefully will improve after cataract surgery that will be needed to address a side effect of one of the drugs I took post surgery. I've had a few WTF moments in the last few years looking at sound posts.... Might you be up for helping me glue another cello top on sometime soon, or might it come out all wonky? Quote Link to comment Share on other sites More sharing options...
Brad H Posted February 11, 2021 Author Report Share Posted February 11, 2021 7 hours ago, Jeffrey Holmes said: Straight looking from the endpin hole is, in my opinion, less difficult than straight from the side (f hole). Yep. My challenge is N/S orientation. The other factor which affects my perception is lighting. I can sometimes get different readings if I am just bringing light in through the bass f-hole from a lamp versus when using my luthier's light. 13 hours ago, Delabo said: This thread begs the question as to why it matters if the post is not absolutely vertical ? The only practical reason I can think of is that the bevel end of the post might did into the top or back a bit leaving an indentation in the wood. Since the plates converge as they get nearer the bottom block (are not parallel), a post that is cut perfectly perpendicular on both ends (only considering N/S line) will not fit perfectly if set in a vertical position. I agree that the perfect fit of the post ends is more important than whether the post is in a vertical position. I usually cut compound angles on the post ends, so that the tailpiece side of the post ends are cut incrementally "lower" than the bridge sides. How do others deal with the non-parallel plate convergences at the post position. Quote Link to comment Share on other sites More sharing options...
Mark Norfleet Posted February 12, 2021 Report Share Posted February 12, 2021 15 hours ago, David Burgess said: Might you be up for helping me glue another cello top on sometime soon, or might it come out all wonky? Sure, so long as I don't have to make anything straight. Likely next week some time, if you really want to risk it... Quote Link to comment Share on other sites More sharing options...
David Burgess Posted February 12, 2021 Report Share Posted February 12, 2021 4 hours ago, Mark Norfleet said: Sure, so long as I don't have to make anything straight. Likely next week some time, if you really want to risk it... How much risk do you think would be involved? Jill helped me glue the back on, with the ribs still on the form (which she has done many times, and this is much easier than gluing on a plate with the ribs removed from the form). But this most recent time, she said afterward, "Don't ever ask me to do this again". WTF? I didn't yell at her or beat her all that much either during or after the procedure. Sidebar: Norfleet can do many things as well with his eyes closed, as many other people with their eyes open and with 20/20 vision can do. Quote Link to comment Share on other sites More sharing options...
scordatura Posted February 12, 2021 Report Share Posted February 12, 2021 1 hour ago, David Burgess said: But this most recent time, she said afterward, "Don't ever ask me to do this again". I remember Hans Nebel telling us to “profusely pre-apologize “ when getting the spouse to assist in gluing plates to the rib garland! Quote Link to comment Share on other sites More sharing options...
David Burgess Posted February 12, 2021 Report Share Posted February 12, 2021 7 minutes ago, scordatura said: I remember Hans Nebel telling us to “profusely pre-apologize “ when getting the spouse to assist in gluing plates to the rib garland! Oh chit, that reminds me, I haven't pre-apologized for Valentines Day yet. Quote Link to comment Share on other sites More sharing options...
Mark Norfleet Posted February 12, 2021 Report Share Posted February 12, 2021 1 hour ago, David Burgess said: How much risk do you think would be involved? It depends on how much you yell at me. Quote Link to comment Share on other sites More sharing options...
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