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Pinless Bridge - Problems? http://www-.luthiersforum.com/forum/viewtopic.php?f=10102&t=8418	Page 1 of 2

Author:	j.Brown [ Tue Sep 12, 2006 3:02 am ]
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Does anyone have experience with pinless bridges? Are there any problems inherent in their design? Pros/Cons? And is there more lateral force on the bridge than a pinned design? -j.

Author:	SimonF [ Tue Sep 12, 2006 3:48 am ]
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J, I have always used a pinless bridge. I do believe you have a bit more pulling action on the bridge because the ball ends pull on the bridge itself as oppossed to the bridge plate. I have talked to Dermot Mcilroy who builds guitars in a similiar fashion to George Lowden (both use pinless bridges) and he said he has never had a problem. He builds quite a few guitars a year and worked at Lowden for something like 10 years. So I think he is a good one too trust on the stability of a pinless bridge. So here is my take: While there might be more pulling forces on the bridge, a good glue joint between the bridge and soundboard are more than sufficient to endure. For what it is worth, Lowden and Mcilroy use Titebond and have had no trouble. -- Simon

Author:	peterm [ Tue Sep 12, 2006 4:24 am ]
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I only use pinless bridges....I use the J.Elliot style of pinless bridge and don't see any difference in the "pull" versus a regular bridge.

Author:	j.Brown [ Tue Sep 12, 2006 4:31 am ]
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Any tips/pointers/specs on pinless bridge construction? -j.

Author:	Michael Dale Payne [ Tue Sep 12, 2006 4:54 am ]
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[QUOTE=peterm] I only use pinless bridges....I use the J.Elliot style of pinless bridge and don't see any difference in the "pull" versus a regular bridge.[/QUOTE] There is a big difference and that is that there is no force pulling the bridge patch and top towards the bridge (compression loading) as there is with a pinned bridge. There is some compression loading at the saddle on both types of bridges but this load is not true perpendicular to the top bridge plane. it is enough off perpendicular to be more of shear or rotating load than compression. On a pin-less bridge all the force beyond the saddle, however is in shear, meaning the load is constantly trying to separate the bridge from the top at the ball end of the strings. as apposed to a vast percentage of this force being in compression when using a pinned bridge. This means that the string are trying to rotate the bridge around the moment of the compression load created by the dowmward string loading of the saddle. Whether this is enough added shear to worry with may be debatable but without a doubt you are adding shear loading. Ovation and others that use pin-less bridges over-come the shear loading by bolting the bridge to the bridge plate with 2 bolts. this adds the compression to cance out the shear. MichaelP38972.624224537

Author:	Chas Freeborn [ Tue Sep 12, 2006 5:38 am ]
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Here is how Mike Doolin does it: http://www.doolinguitars.com/pinless.html -C

Author:	crazymanmichael [ Tue Sep 12, 2006 5:46 am ]
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taylor for a time also used pinless bridges. i still have one. mine shows no sign of glue line failure after about 12 or 13 years, and i can't recall ever having to repair one of theirs.

Author:	peterm [ Tue Sep 12, 2006 6:31 am ]
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Michael, the J.Elliot style pinless bridge actually goes all the way down through the bridge patch pulling up on the patch and top almost as a regular bridge would...peterm38972.6470949074

Author:	Michael Dale Payne [ Tue Sep 12, 2006 7:16 am ]
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There are many variances. I just did not want J to not consider counteracting the shear load in case He wanted to use one of the premanufactured pin-less bridges on the market, similar to the type that Ovation puts on their guitars They are ok if bolted but I have repaired a bunch of early Applause and craftsman built guitars with generic pin-less bridges that did not have the two bolts tying them to the top and or bridge plate. They almost always pull of if not bolted down. My example loading example is of that generic pin-less type.

Author:	peterm [ Tue Sep 12, 2006 7:25 am ]
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Michael, I know exactly what you mean... thats why I did mine Elliot's way!

Author:	Dave White [ Tue Sep 12, 2006 8:27 am ]
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[QUOTE=MichaelP] [/QUOTE] Michael, That's interesting. I once asked Alan Carruth in a post here if there was a difference in the way a pinned or pinless bridge works the top and he said he thought not. My suspicion is that the pinless "drives" the top more and form the forces your diagramms show this could well be the case. A bit like the bucking bronco though - you have to keep the pinless bridge on the top. Until the last guitar I made I have only done pinless bridges. In the early days I did not pay enough attention to getting the bottom of the bridge matched to the top profile and had a few pop. Since correcting for this and using hot hide glue to glue them down I have not had any problems. I wouldn't dream of putting bolts in them to hold them down - if you do this you may as well do a pinned bridge anyway. Pluses - I think they drive the top a little more, you don't have the worry of lost pins, and when the bridge is glued on you just fit the strings and don't have to fiddle with pin hole reaming etc. Minuses - Bridge design is somewhat limited by the need for the string holes at the back, the ball ends can damage the finish behind the bridge if strings are not carefully changed, and changes in humidty and subsequent top movements can put extra stress on them. I like both - pinless and pinned. The Elliot/Doolin design is very elegant and a sort of hybrid imho.

Author:	Steve Saville [ Tue Sep 12, 2006 8:56 am ]
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Why is the Doolin style called pinless? It has pins. My first guitar was an Ovation and I always loved the pinless feature on that guitar. It always bugs me when people don't make the holes in the ball ends line up. It is easy to do, just use an old E or A string and place it through the ball ends before you tighten the strings. (Yes, I know - I should get a life. )

Author:	TRein [ Tue Sep 12, 2006 9:36 am ]
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Interesting topic. I have been mulling this over myself. [QUOTE=Dave White] I wouldn't dream of putting bolts in them to hold them down - if you do this you may as well do a pinned bridge anyway. [/QUOTE] I can't see the "horror" of adding 2 small machine screws to hold the pinless bridge on. To me it seems preferable to drilling 6 big holes all the way through the bridge, top, and bridge plate as we have on a pinned design. One of the big advantages of the pinless bridge is it just has to be stronger than a pinned one. 6 fairly close-spaced holes through the top at the point of greatest tension (as we have on a pinned bridge) must be considered a weakening factor. Add tho this equation the fact that the bridge pins do not make really great contact with the surrounding surfaces; if they did, you could not pull the pins out easily. Plus, the bridge plate on a pinless guitar could be selected for acoustic and/or structural considerations, maybe even spruce, rather than for density, which is required in a pinned bridge to withstand the ball ends of the strings. It is interesting that manufacturers have gone to bigger and bigger bridge plates to counteract the bellying up behind the bridge. The holes drilled through the top of a pinned bridge essentially "hinge" the top through the center of the pin holes, with the area behind the holes being lifted up and the area in front of the holes being pushed down. I have seen bridge plates on old guitars that were split through the center of the holes and folded right along this axis.

Author:	Dave White [ Tue Sep 12, 2006 7:25 pm ]
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[QUOTE=TRein] Interesting topic. I have been mulling this over myself. [QUOTE=Dave White] I wouldn't dream of putting bolts in them to hold them down - if you do this you may as well do a pinned bridge anyway. [/QUOTE] I can't see the "horror" of adding 2 small machine screws to hold the pinless bridge on. [/QUOTE] Thomas, If you are relying on screws to hold something then the strength is going to come from what you screw into. If I didn't trust the glue to hold the pinless bridge on then I'm not sure I'd want to put my trust in 2 small machine screws in the top and bridgeplate. I think I'd prefer the bridge to pop with just glue! You are right about the bridgeplate material in the plus column for pinless bridges - you can use bridgeplates that have the grain in the same direction as the top and use spruce etc. Also you have more freedom in bracing design in and under the bridge area.

Author:	crazymanmichael [ Tue Sep 12, 2006 11:45 pm ]
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re the use of bolts as holddowns on pinless bridges; as stated above, taylor was an example of a maker who used the pinless bridges with no bolts, albeit only for a time, and i have seen no trouble from their guitars done in that manner. in contrast, gibson, and many lesser brands, used bolts on pinned bridges, and i can't count the number of those i have had to reglue over the years. i think it is more a matter of how well the work is done. i won't get into the physics of how the two methods differ in their sound generation. but the taylor i have and those i have worked on which had the pinless bridges were typical taylors. if you like taylor's tonal characteristics, and i do, that's a good thing. unfortunately, the ovations tend to be typical ovations...

Author:	Michael Dale Payne [ Wed Sep 13, 2006 1:20 am ]
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[QUOTE=Dave White] Michael, That's interesting. I once asked Alan Carruth in a post here if there was a difference in the way a pinned or pinless bridge works the top and he said he thought not. My suspicion is that the pinless "drives" the top more and form the forces your diagramms show this could well be the case. A bit like the bucking bronco though - you have to keep the pinless bridge on the top. Until the last guitar I made I have only done pinless bridges. In the early days I did not pay enough attention to getting the bottom of the bridge matched to the top profile and had a few pop. Since correcting for this and using hot hide glue to glue them down I have not had any problems. I wouldn't dream of putting bolts in them to hold them down - if you do this you may as well do a pinned bridge anyway. Pluses - I think they drive the top a little more, you don't have the worry of lost pins, and when the bridge is glued on you just fit the strings and don't have to fiddle with pin hole reaming etc. Minuses - Bridge design is somewhat limited by the need for the string holes at the back, the ball ends can damage the finish behind the bridge if strings are not carefully changed, and changes in humidty and subsequent top movements can put extra stress on them. I like both - pinless and pinned. The Elliot/Doolin design is very elegant and a sort of hybrid imho.[/QUOTE] Dave I am not sure about pin-less driving the diaphragm more. I have some doubts about that, my self. Also my examples show only the direction of forces of the static loading and in no way represent energy transferal. I am not sure that either drives the top more or less. just that with out bolting the bridge to the top and bridge plate the conventional pin-less bridge has much more load in shear than a pinned bridge. In my pea brain having the terminal node of the string in direct contact to the bridge plate will in part more energy in to the top than the terminal node of the string in contact with the outer surface of the bridge. But here we are talking minute differences If the posting system of the bridge continues the path into the bridge plate then the terminal node is at the end of that path.MichaelP38973.4387731481

Author:	Dave White [ Wed Sep 13, 2006 2:11 am ]
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[QUOTE=MichaelP] In my pea brain having the terminal node of the string in direct contact to the bridge plate will in part more energy in to the top than the terminal node of the string in contact with the outer surface of the bridge.[/QUOTE] Michael, It's tricky to think about isn't it. You may well be right but my pea brain tells me that if the ball ends of the string are anchored in the very place the strings are meant to be vibrating then this negates some of this. Swings and roundabouts . . . pinned and pinless, it's all so confusing

Author:	Dave Rector [ Wed Sep 13, 2006 3:32 am ]
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I was wondering if you could use a pinless bridge and bolt it on with some of those hollow bolts like Stew Mac sells to temporarily mount a bridge. Seems like that would reduce the weight of the bolts considerably.

Author:	Michael Dale Payne [ Wed Sep 13, 2006 3:41 am ]
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Actually a smaller nut & bolt would be better. with hollow bots the chance of failure and deformation is much higher. The load caring ability of smaller solid bolt would be much better and I believe the weight will be about the same or even less.

Author:	Todd Rose [ Wed Sep 13, 2006 6:00 am ]
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One thing to consider is the bridge plate, just in case you were thinking you don't need one with a pinless bridge. There may be some who would dispute this, but one function of the bridge plate (whose grain runs in the same direction as the bridge) is to stabilize the cross-grain wood movement of the top in the bridge area so the bridge/top glue joint doesn't fail.Todd Rose38973.6260300926

Author:	Dave White [ Wed Sep 13, 2006 6:52 am ]
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[QUOTE=Todd Rose] One thing to consider is the bridge plate, just in case you were thinking you don't need one with a pinless bridge. There may be some who would dispute this, but one function of the bridge plate (whose grain runs in the same direction as the bridge) is to stabilize the cross-grain wood movement of the top in the bridge area so the bridge/top glue joint doesn't fail.[/QUOTE] Todd, I've seen Frank Ford's Frets.com post on bridgeplates where he advocates that the bridgeplate grain direction should be the same as the top saying: "If I had my way, guitars would be made with bridge plate grain running parallel to the top grain to avoid the chipping between holes, and the tendency to curl or crack in the direction of the string pull". On my cedar/maple Grand Concert guitar I used a bridgeplate made of Shane's wonderful Lutz spruce with the grain direction parallel to the top in conjunction with a pinless bridge and I really love the way the sound of that guitar is developing:

Author:	Philip Perdue [ Wed Sep 13, 2006 9:10 am ]
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J, I don’t know if this will help or not but pinless bridges are common on ukuleles. Here is a photo of a glyph ukulele with a pinless bridge. I would send a picture of mine but I’m not at home. Typically with the ukulele we just tie a large knot or add a bead at the end of the string because the end is just plain string.

Author:	SniderMike [ Wed Sep 13, 2006 12:59 pm ]
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My girlfriend's Tacoma has a "pinless" bridge, but the strings go all the way through the soundboard and sit in "grooves" for lack of a better word. Has anyone seen one of these? I don't care for it too much; it's hard to get the strings to seat properly. It is a decent sounding d**n**t though. I'm curious if anyone here has tried anything similar (that is, pinless, but thru the top)??? Mike

Author:	Todd Rose [ Wed Sep 13, 2006 7:01 pm ]
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[QUOTE=Dave White] I've seen Frank Ford's Frets.com post on bridgeplates where he advocates that the bridgeplate grain direction should be the same as the top saying: "If I had my way, guitars would be made with bridge plate grain running parallel to the top grain to avoid the chipping between holes, and the tendency to curl or crack in the direction of the string pull". On my cedar/maple Grand Concert guitar I used a bridgeplate made of Shane's wonderful Lutz spruce with the grain direction parallel to the top in conjunction with a pinless bridge and I really love the way the sound of that guitar is developing: [/QUOTE] Dave, your bracing may suffice to keep the cross-grain movement of the top to a minimum, especially with that brace running right across directly beneath the bridge plate. By the same token, though, I would think that that cross grain brace, along with all the diagonal bracing surrounding the plate, would cancel out any sound difference that could theoretically be made by aligning the grain of the bridge plate with the grain of the top. But that's just my own theorizing. At any rate, on my own guitars I'll continue to use a cross-grain bridge plate with my pinless bridges for the added security on that bridge/top glue joint. Frank's comments seem to me more applicable to a pinned bridge. With all due respect to Frank -- and I do, indeed, respect him immensely -- I wonder if he stopped and thought about the wood movement issue when he made that comment. It's not something that's often mentioned when discussing bridge plates, but I consider it an important consideration, especially with pinless bridges, which depend entirely on that glue joint to hold things together under the stress of string tension and humidity changes over the course of decades.

Author:	Michael Dale Payne [ Fri Sep 15, 2006 12:35 am ]
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That bridge plate Frank was patching looked quarter-sawn to me. If you use a quartersawn bridge plate this chip out is to be expected. I was taught an assume everyone used rif-sawn orientation on bridge plates for this very reason.

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