Victory Pete Posted October 26, 2017 Report Share Posted October 26, 2017 I did a Google search for 'Radius In Acoustic Top" an found this Forum. The thread I was reading is now "Archived", so I could not post. I just finished a StewMac Rosewood Dread kit. I glued the top braces to a flat surface like the instructions directed me to. I also now have a 28' radius dish for the next guitars I am building. I am not sure if I should use it as the guitar I just finished has incredible volume and bright tone with great projection, it puts my HD-28 to shame. I am wondering if this is because of the 'Pre-stressed top". Thanks for your help VP Quote Link to comment Share on other sites More sharing options...
Victory Pete Posted October 26, 2017 Author Report Share Posted October 26, 2017 How do you edit a post? I see no Edit button? Quote Link to comment Share on other sites More sharing options...
Victory Pete Posted October 26, 2017 Author Report Share Posted October 26, 2017 This is how I put the taper on the top and back ribs. One side of the 2x4 is for the top with a steeper angle and the other side is for the back with a shallow angle. Now that I have the 28' radius, I may use it for this job for the top. I don't have a dish for the back. Quote Link to comment Share on other sites More sharing options...
ScottR Posted October 26, 2017 Report Share Posted October 26, 2017 Hey Pete, I'm going to let one of our acoustic builders respond to your projection question...although I assume the answer is both yes and that other factors come into play as well. The edit button will show up after you get a few more posts under your belt. In the meantime, let me know what you'd like edited and I can do it for you. SR Quote Link to comment Share on other sites More sharing options...
Victory Pete Posted October 26, 2017 Author Report Share Posted October 26, 2017 Hi Scott, I just have misspelling. feel free to fix them if you want. I always need an Edit button. Quote Link to comment Share on other sites More sharing options...
Victory Pete Posted October 26, 2017 Author Report Share Posted October 26, 2017 Here is my 1998 HD-28 that is about to get a bridge replacement. 1 Quote Link to comment Share on other sites More sharing options...
ScottR Posted October 27, 2017 Report Share Posted October 27, 2017 15 hours ago, Victory Pete said: Hi Scott, I just have misspelling. feel free to fix them if you want. I always need an Edit button. Yep, that's what I mostly use it for too. SR Quote Link to comment Share on other sites More sharing options...
Victory Pete Posted October 27, 2017 Author Report Share Posted October 27, 2017 (edited) 2 hours ago, ScottR said: Yep, that's what I mostly use it for too. SR Can you Fix "Acoustic" in the main title please. Thanks. I see I can Edit this post but not the previous posts. When can I Edit those? Edited October 27, 2017 by Victory Pete Quote Link to comment Share on other sites More sharing options...
ScottR Posted October 27, 2017 Report Share Posted October 27, 2017 6 minutes ago, Victory Pete said: Can you Fix "Acoustic" in the main title please. Thanks. I see I can Edit this post but not the previous posts. When can I Edit those? Sorry, I missed that one. New members have the ability to edit for a short period after posting. After a minimum set number of posts have been reached, your member status will upgrade and the edit button will become permanent. Perhaps @Prostheta can add a bit of insight as to what the time frame/minimum post counts are. SR Quote Link to comment Share on other sites More sharing options...
Victory Pete Posted October 27, 2017 Author Report Share Posted October 27, 2017 (edited) 22 minutes ago, ScottR said: Sorry, I missed that one. New members have the ability to edit for a short period after posting. After a minimum set number of posts have been reached, your member status will upgrade and the edit button will become permanent. Perhaps @Prostheta can add a bit of insight as to what the time frame/minimum post counts are. SR I don't understand what this "Edit" probation is all about, I have never seen that in any Forum yet. So my very first posts their is no ability to Edit at all and then after some time, I guess a day, I can Edit the post I just made only for a short periods of time afterwards? Then at some time in the future I can Edit freely? Edited October 27, 2017 by Victory Pete Quote Link to comment Share on other sites More sharing options...
ScottR Posted October 27, 2017 Report Share Posted October 27, 2017 I believe it stems from a spam epidemic we had a few years back where we had a rash of accounts open for the sole reason of launching spam in the first post.....or something along those lines. Limiting permissions in the new accounts took care of the problem. I probably have some of those details wrong, it was before my time as a mod, but the gist of that scenario is correct. I don't know if the edit function is tied to a package of permissions or can be turned on or off individually. Carl @Prostheta will likely be able to answer those type questions, when he gets back online. SR Quote Link to comment Share on other sites More sharing options...
Prostheta Posted October 27, 2017 Report Share Posted October 27, 2017 Yes, it's mostly a mix of function abuse issues we've had in the past. If you have any problems, just drop us a note. Happy to help out. It's probably best to prune these posts so as not to derail the subject.... Quote Link to comment Share on other sites More sharing options...
Prostheta Posted October 27, 2017 Report Share Posted October 27, 2017 Funny that you mention a kit build. I've had an acoustic on my mind for a year or two now. Thing is, I know my idea is unlikely to produce fruitful results any more than a kit would, both in terms of experience and end result. I'm sure that a kit would be ideal for orientation before disappointing myself with the guitar design that I truly want....! As far as I can discern, "pre-stressing" is bringing the wood down below the minimum EMC that it would experience in service, then letting it acclimate back to "normal". A lot of guitar makers don't do this, and bring wood from green down to "normal" and not below. In service, if it dries too much then it can crack....pre-stressing is more weeding out the wood that can't hack being too dry. I might be off tack here a bit, however it seems more of a yield and in-service guarantee of sorts than some sort of treatment. Certainly useful for manufacturers anyway. Quote Link to comment Share on other sites More sharing options...
Victory Pete Posted October 29, 2017 Author Report Share Posted October 29, 2017 (edited) On 10/27/2017 at 4:25 PM, Prostheta said: Funny that you mention a kit build. I've had an acoustic on my mind for a year or two now. Thing is, I know my idea is unlikely to produce fruitful results any more than a kit would, both in terms of experience and end result. I'm sure that a kit would be ideal for orientation before disappointing myself with the guitar design that I truly want....! As far as I can discern, "pre-stressing" is bringing the wood down below the minimum EMC that it would experience in service, then letting it acclimate back to "normal". A lot of guitar makers don't do this, and bring wood from green down to "normal" and not below. In service, if it dries too much then it can crack....pre-stressing is more weeding out the wood that can't hack being too dry. I might be off tack here a bit, however it seems more of a yield and in-service guarantee of sorts than some sort of treatment. Certainly useful for manufacturers anyway. I still am not sure about this topic, I am waiting for a response from StewMac. It seems gluing the braces down on a flat surface vs. a radius surface has put some extra stiffness in the top. It sure sounds loud and clear. I don't know if this is good or not. I have 3 more kits to put together soon so I would like to know what is best for the future builds. Also, how do I view my recent Threads and Posts? Usually there is a "Control Panel" on these Forums for that sort of thing. Edited October 29, 2017 by Victory Pete Quote Link to comment Share on other sites More sharing options...
Prostheta Posted October 29, 2017 Report Share Posted October 29, 2017 Find your username anywhere and a hovercard should come up with the cursor over it. "Find Content" should be what you're looking for. Alternatively, go to the menu at the top of the page and hit the drop-down where your username is for control panel-ly things. Quote Link to comment Share on other sites More sharing options...
Victory Pete Posted October 29, 2017 Author Report Share Posted October 29, 2017 1 minute ago, Prostheta said: Find your username anywhere and a hovercard should come up with the cursor over it. "Find Content" should be what you're looking for. Alternatively, go to the menu at the top of the page and hit the drop-down where your username is for control panel-ly things. Okay got it, Thanks 1 Quote Link to comment Share on other sites More sharing options...
Andyjr1515 Posted November 5, 2017 Report Share Posted November 5, 2017 On 26/10/2017 at 9:57 PM, Victory Pete said: I did a Google search for 'Radius In Acoustic Top" an found this Forum. The thread I was reading is now "Archived", so I could not post. I just finished a StewMac Rosewood Dread kit. I glued the top braces to a flat surface like the instructions directed me to. I also now have a 28' radius dish for the next guitars I am building. I am not sure if I should use it as the guitar I just finished has incredible volume and bright tone with great projection, it puts my HD-28 to shame. I am wondering if this is because of the 'Pre-stressed top". Thanks for your help VP Hi I've only just picked this one up - apologies for the delay. To radius or not is one of those topics where there is probably no definitive answer. Most - but not all - commercial acoustic steel-string builders put a spherical radius on the top and the back. 'Typically' this is around 25' radius at the top and 15' radius at the back. However, from the various reading and discussion I've had, I've never been convinced that there is a concensus as to the actual and proven advantages. The great majority of acoustic builders follow pretty closely the 30's (?) Martin dimensions, radii and bracing patterns. I'm sure Martin did a lot of trial and error builds before they hit on that particular design, but again - as far as I can work out - many modern builders generally work on the basis of 'it works alright then why change it?'. I HAVE seen detailed scientific studies of harmonic response of various top and bracing designs, but I haven't personally seen any similar studies of flat vs radiussed. So my own personal views: There are one or two noted manufacturers that do flat tops. As far as I know, all classical guitars have flat tops. So, personally, my view is that it sonically it probably makes little difference. The only thing it might do is 'tension' the top as you would tension a drum skin. The back does pretty much nothing sonically on an acoustic guitar. Hence the simple bracing. It is there for volume projection and unlikely to be impacted by the radius. You could argue maybe that it 'focuses' the sound like a headlight reflector...but I think that is unlikely Brace design, node position, top thickness, top wood, etc, however, does make a HUGE difference to the tone. I do 'tap tuning' personally and have had enough success to know that it works; I absolutely don't understand how to optimise it, though! Having said all that, do I radius the tops and backs? Yes And why is that? Because for the first build, I followed a plan that had radius in. And it worked. And it sounds great. And for the second build...I did it because I'd already made the radius dishes and - well, it worked for the first one, so why risk changing anything else? Maybe not very scientific, but reasonably pragmatic! But - the build challenges. Well....most of the REALLY difficult parts of an acoustic build are directly or indirectly caused by the radii. And remember, classical guitars are flat. And they can project beautiful tones in an unamplified auditorium. So maybe my reasoning is not even pragmatic Hope this helps Andy 1 Quote Link to comment Share on other sites More sharing options...
Victory Pete Posted November 5, 2017 Author Report Share Posted November 5, 2017 (edited) 4 minutes ago, Andyjr1515 said: Hi I've only just picked this one up - apologies for the delay. To radius or not is one of those topics where there is probably no definitive answer. Most - but not all - commercial acoustic steel-string builders put a spherical radius on the top and the back. 'Typically' this is around 25' radius at the top and 15' radius at the back. However, from the various reading and discussion I've had, I've never been convinced that there is a concensus as to the actual and proven advantages. The great majority of acoustic builders follow pretty closely the 30's (?) Martin dimensions, radius's and bracing patterns. I'm sure Martin did a lot of trial and error builds before they hit on that particular design, but again - as far as I can work out - the builders generally work on the basis of 'it works alright then why change it?'. I HAVE seen detailed scientific studies of harmonic response of various top and bracing designs, but I haven't personally seen any similar studies of flat vs radiussed. So my own personal views: There are one or two noted manufacturers that do flat tops. As far as I know, all classical guitars have flat tops. So, personally, my view is that it sonically it probably makes little difference. The only thing it might do is 'tension' the top as you would tension a drum skin. The back does pretty much nothing sonically on an acoustic guitar. Hence the simple bracing. It is there for volume projection and unlikely to be impacted by the radius. You could argue maybe that it 'focuses' the sound like a headlight reflector...but I think that is unlikely Brace design, node position, top thickness, top wood, etc, however, does make a HUGE difference to the tone. I do 'tap tuning' personally and have had enough success to know that it works; I absolutely don't understand how to optimise it, though! Having said all that, do I radius the tops and backs? Yes And why is that? Because for the first build, I followed a plan that had radius in. And it worked. And it sounds great. And for the second build...I did it because I'd already made the radius dishes and - well, it worked for the first one, so why risk changing anything else? Maybe not very scientific, but reasonably pragmatic! But - the build challenges. Well....most of the REALLY difficult parts of an acoustic build are directly or indirectly caused by the radii. And remember, classical guitars are flat. And they can project beautiful tones in an unamplified auditorium. So maybe my reasoning is not even pragmatic Hope this helps Andy Thanks for the response. I feel that the tension put into the top from a flat gluing surface gives this guitar I just finished remarkable volume, It seems to blow away my 1998 HD-28. Edited November 5, 2017 by Victory Pete Quote Link to comment Share on other sites More sharing options...
Andyjr1515 Posted November 5, 2017 Report Share Posted November 5, 2017 17 minutes ago, Victory Pete said: Thanks for the response. I feel that the tension put into the top from a flat gluing surface gives this guitar I just finished remarkable volume, It sees to blow away my 1998 HD-28. Sounds like a great result, whatever the factors in play are I'm not sure what additional tension results from gluing on a flat surface - or have I misunderstood what you are saying? Quote Link to comment Share on other sites More sharing options...
Victory Pete Posted November 5, 2017 Author Report Share Posted November 5, 2017 (edited) 9 minutes ago, Andyjr1515 said: Sounds like a great result, whatever the factors in play are I'm not sure what additional tension results from gluing on a flat surface - or have I misunderstood what you are saying? Radius braces glued to a flat top creates tension in the glue joint when the clamps are removed. They are fighting each other. Edited November 5, 2017 by Victory Pete Quote Link to comment Share on other sites More sharing options...
Andyjr1515 Posted November 5, 2017 Report Share Posted November 5, 2017 3 minutes ago, Victory Pete said: Radius braces glued to a flat top creates tension in the glue joint when the clamps are removed. They are fighting each other. Ooohh - I now understand what you are saying! I had assumed the braces were flat backed as well. OK - so basically, you will roughly end up with the same shaped top as if you were using a radius dish. Clever. Although, knowing how much my home-made GoBar top already bends under the tension from the rods pressing the guitar top into the radius dish, I'm not at all sure I would trust mine to press curved braces hard enough to ensure the required clamping force for a decent glue joint! Quote Link to comment Share on other sites More sharing options...
Victory Pete Posted November 5, 2017 Author Report Share Posted November 5, 2017 2 hours ago, Andyjr1515 said: Ooohh - I now understand what you are saying! I had assumed the braces were flat backed as well. OK - so basically, you will roughly end up with the same shaped top as if you were using a radius dish. Clever. Although, knowing how much my home-made GoBar top already bends under the tension from the rods pressing the guitar top into the radius dish, I'm not at all sure I would trust mine to press curved braces hard enough to ensure the required clamping force for a decent glue joint! The actual resulting radius in the top is less than the radius of the brace as the top tries to force it straight. Quote Link to comment Share on other sites More sharing options...
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