mistermikev Posted September 9 Author Report Share Posted September 9 2 hours ago, Bizman62 said: Two questions: When adjusting a single action rod, the entire length of it should move more or less freely. A tightly fitted rod may snag which is why some builders have used plastic straws to reduce friction. Notice that friction can increase because of corrosion on the metal, direction of wood grain and fluids crystalizing in the wood cells. Have you taken that into account? Moisture is my other concern. Just a few weeks ago the hygrometre was at 40%, now at 60% despite not having had much rain. Actually we're breaking hot weather records this September! Anyhow, as wood swells with humidity, increasing thickness rather than length, will there be a risk of cracking if there's no wiggle room? i believe that folks use a 'straw' or truss rod sheath to prevent glue from sticking to the truss rod should it get in there... which in the case of a comp rod I don't think is nearly as much of a problem. I don't recall ever seeing a comp rod sold w a sheath. for a comp rod... the mechanism is that the nut clamps down on wood at one end, and the anchor clamps down at the other... the wood/rod between them is compressed (you probably know this, just stating explicitly for the sake of argument). I just do not see how it could snag since in theory there is no need for any spinning on the rod nor any movement north/south. In fact coupling between the wood and the truss rod in my mind should make it more effective since any/all pressure applied should be converted to bend instead of twist. the anchor for this particular variant of a truss rod involves a nut through a square hole... and one of the way they fail is if that coupling is allowed to move. afa moisture... well one of the benefits of removing all the air from the cavity is no air = no moisture getting in. no risk of rust because the rod is stainless. again in this case... even if the rod was prone to rust... since there is no movement required like in a double action... rust wouldn't really pose an issue. wood swelling is a possible achilles heel... but the rod isn't "tight as a drum" in there. it could be easily placed/removed while I was setting it up as it is actually slightly less than 3/16". All this said - if we look at the allied luthier truss rods... which can be bought w a wooden sheath... and are sold 'en mass'... if it was gonna be a problem they would have covered that ground for me. all this is said fully understanding that I could be wrong. Guess we'll find out! Quote Link to comment Share on other sites More sharing options...
Bizman62 Posted September 9 Report Share Posted September 9 5 hours ago, mistermikev said: I just do not see how it could snag since in theory there is no need for any spinning on the rod nor any movement north/south. In fact coupling between the wood and the truss rod in my mind should make it more effective since any/all pressure applied should be converted to bend instead of twist. the anchor for this particular variant of a truss rod involves a nut through a square hole... and one of the way they fail is if that coupling is allowed to move. It's true they don't rotate. But they do move length vise inside the slot. When tightnened inside a curved slot the toughest part is at the top of the curve. Without any longitudinal movement the other half of the rod would stay relaxed while the nut half would be tight. The rod has to be evenly tensioned to work - if you think about tuning, the strings are tight in all three sections: From tuner to nut, between the nut and bridge and between bridge and stoptail/ferrule. If the nut/bridge slots snag you'll get all sorts of funky noise. Even inside a straight slot there'd be some movement. When tightening the rod it stretches a bit and the wood compresses a bit. There will be friction. Then again, when stretched the rod also gets thinner but is that change significant enough? A rubber band can be stretched to double of its length to halve its diameter, with steel that's not an option. Plus it would be somewhat cumbersome to have a foot long threaded rod sticking from the headstock Regarding moisture, sealing the adjusting end of the rod isn't an easy task. The tightness along the length of the rod is no issue, bare end grain under the adjusting nut can be. End grain has capillary properties as you've noticed when grain filling. Of course you can seal the end grain around the hole and even put a gasket between the washer and the wood. Not to mention that most protective coatings aren't vapour proof, only spill proof. No exact proof about anything here, just thinking out loud. I know that you can make a permanent bond with metals by dropping a frozen pole into a heated hole, wood acts somewhat differently. Quote Link to comment Share on other sites More sharing options...
mistermikev Posted September 9 Author Report Share Posted September 9 To say it moves lengthwise is not accurate... semantics but it bends, not moves... it would only move if there was room to move and this would be bad for this design. I don't think u r thinking about the two dif channels correctly. There is no more or less room to move in a tight square channel than an equally tight curved channel... just more/less gap. As such there is zero percent more likelihood of expansion causing issue. moisture... end grain would be the sm risk for any similar comp rod... but with a square channel w added air there would b .00000000000percent1% additional risk That said I do appreciate the thoughts. Quote Link to comment Share on other sites More sharing options...
mistermikev Posted September 9 Author Report Share Posted September 9 Lol phone! Quote Link to comment Share on other sites More sharing options...
Andyjr1515 Posted September 9 Report Share Posted September 9 Other than the propensity to rattle if the channel is too big and the rod is not under tension, the fit of the channel to the rod will have no impact on the rod's ability to bend the neck. A curved rod with fixed anchor points at either end will always try to straighten when shortened. If you epoxy the rod in the slot, then it won't easily shorten and its effectiveness will be affected. But a bit of wood glue overspill in the slot stuck to the rod will loosen off pretty much as soon as the trussrod nut is started to be tightened... What was your concern, @mistermikev ? 1 Quote Link to comment Share on other sites More sharing options...
mistermikev Posted September 9 Author Report Share Posted September 9 No concerns... but you def validated my thoughts and i am very thankful for the confirmation! 1 Quote Link to comment Share on other sites More sharing options...
Bizman62 Posted September 10 Report Share Posted September 10 10 hours ago, mistermikev said: I don't think u r thinking about the two dif channels correctly. There is no more or less room to move in a tight square channel than an equally tight curved channel... just more/less gap. Ahh... didn't understand that we were discussing round v.s. square. "Too tight" was my only concern, the reasons being partially similar to how tight a neck pocket should be. 2 Quote Link to comment Share on other sites More sharing options...
mistermikev Posted September 10 Author Report Share Posted September 10 2 hours ago, Bizman62 said: Ahh... didn't understand that we were discussing round v.s. square. "Too tight" was my only concern, the reasons being partially similar to how tight a neck pocket should be. right on, this was all productive discussion for me either way and for that I appreciate. reinforcing things. in the end and to me - this is a cool detail, nothing more/less. 1 Quote Link to comment Share on other sites More sharing options...
mistermikev Posted September 21 Author Report Share Posted September 21 so... this is my favorite moment of building guitars... when everything starts to come together. I put my workpiece on a guitar stand while my wife and I watch a movie... and I just keep finding myself looking at it. no picasso... and a long road to hall yet... but it starts to resemble the vision in my head. so this is the jig I built to cut the delicate 4deg headstock angle a full body shot... closeup of what I would estimate one (among many) of the great challenges of a les paul - 7 layer binding. has been on my bucket list for a spell... wanted to do 5 layer for the headstock... was my original plan... but the little "horns" ended up being mostly binding... and it didn't look right in digital mockups... so had to hang my head and retreat to doing 3 layer. getting these little 45's and radius meeting points right was easily the most challenging thing I've done on this build. 1 Quote Link to comment Share on other sites More sharing options...
ADFinlayson Posted September 22 Report Share Posted September 22 Niiice, that binding job on the headstock is killer, ebony must have been really delicate up in the pointy bits. So did you put the break angle into the neck instead of the pocket? I seem to remember Freddy's Frets build a box like that for his neck tenons in his building les pauls series but I also thought he put the break angle into the body. 1 Quote Link to comment Share on other sites More sharing options...
mistermikev Posted September 22 Author Report Share Posted September 22 1 hour ago, ADFinlayson said: Niiice, that binding job on the headstock is killer, ebony must have been really delicate up in the pointy bits. So did you put the break angle into the neck instead of the pocket? I seem to remember Freddy's Frets build a box like that for his neck tenons in his building les pauls series but I also thought he put the break angle into the body. thank you sir. yes, those little ebony nubs were delicate... just a sliver. no, the neck angle was in the body, the neck is just flat, but where the body meets the neck requires a matching 4 degree sliver cut off. I suppose with either cut you could do it either way. if the angle was in the tenon or not... you will still have a meeting place that has to be cut with a slight angle. you could build up the body there (not common) or similarly cut the angle into the little "overhang" part of the neck. haven't studied the prs style tenon - don't you have a similar angle to cut? or is the tenon the full width of the neck? Quote Link to comment Share on other sites More sharing options...
Bizman62 Posted September 22 Report Share Posted September 22 17 minutes ago, mistermikev said: haven't studied the prs style tenon - don't you have a similar angle to cut? or is the tenon the full width of the neck? It's full width, saves a lot of effort in mating the neck and body. And looks the same if the fitting is tight enough. 1 Quote Link to comment Share on other sites More sharing options...
mistermikev Posted September 22 Author Report Share Posted September 22 7 minutes ago, Bizman62 said: It's full width, saves a lot of effort in mating the neck and body. And looks the same if the fitting is tight enough. ah... yeah that simplifies things. that said, the lp style join is really clever. there are still lines where the overhang meets the body... but the actual lines where the tenon meets the body are blind - hidden by the over hang on the heel and fretboard overhang on the body. Would have been a bucket list item for me except I've done it before. Quote Link to comment Share on other sites More sharing options...
ADFinlayson Posted September 22 Report Share Posted September 22 39 minutes ago, mistermikev said: thank you sir. yes, those little ebony nubs were delicate... just a sliver. no, the neck angle was in the body, the neck is just flat, but where the body meets the neck requires a matching 4 degree sliver cut off. I suppose with either cut you could do it either way. if the angle was in the tenon or not... you will still have a meeting place that has to be cut with a slight angle. you could build up the body there (not common) or similarly cut the angle into the little "overhang" part of the neck. haven't studied the prs style tenon - don't you have a similar angle to cut? or is the tenon the full width of the neck? Ah yeah of course it's the overhangy bit, no I tend to do mine like PRS style full width tenon, I find it a lot easier and I also like to do a round rather than square shape where the neck meets the body, that would be a real PITA to do on a gibson style neck. It has occurred to me though that I go through similar motions doing an acoustic bolt on mortice and tenon joint although it's a slightly different method to achieve the same thing. 1 Quote Link to comment Share on other sites More sharing options...
mistermikev Posted September 22 Author Report Share Posted September 22 31 minutes ago, ADFinlayson said: Ah yeah of course it's the overhangy bit, no I tend to do mine like PRS style full width tenon, I find it a lot easier and I also like to do a round rather than square shape where the neck meets the body, that would be a real PITA to do on a gibson style neck. It has occurred to me though that I go through similar motions doing an acoustic bolt on mortice and tenon joint although it's a slightly different method to achieve the same thing. right on. I would assume your acoustic has an angled neck then. pretty sure epifony did a straight tenon bolt on back in the day. not sure if I've seen anyone else do that. at the end of the day... if the neck doesn't go flying off on it's own... then "great success". 1 Quote Link to comment Share on other sites More sharing options...
mistermikev Posted October 7 Author Report Share Posted October 7 took another shot at my marlin overlay... wanted to do a cleaner job... also decided to cut some inlays and to a split parallelogram fretboard... 1 Quote Link to comment Share on other sites More sharing options...
Bizman62 Posted October 7 Report Share Posted October 7 Your inlay blocks are all slanted! Is it just an optical illusion that the angles of the corners seem to vary? The 1st, 12th and 21st seem to have sharper corners which seems odd supposing that you've cut the pieces and slots with the CNC. Quote Link to comment Share on other sites More sharing options...
henrim Posted October 7 Report Share Posted October 7 That marlin certainly looks crisp! The fretboard though. Your parallelograms seem a bit off and I find the unparallel lines somewhat busy. That dissonance may get worse once the strings are on (or maybe not). I guess you just stretched the shapes to fit the slots, but it would probably have been better idea to keep the angles consistent. Or better and better, but likely easier on the eyes. Edit: apparently one of my guidelines in the drawing got out off place too, but you get idea. Quote Link to comment Share on other sites More sharing options...
mistermikev Posted October 7 Author Report Share Posted October 7 2 hours ago, Bizman62 said: Your inlay blocks are all slanted! Is it just an optical illusion that the angles of the corners seem to vary? The 1st, 12th and 21st seem to have sharper corners which seems odd supposing that you've cut the pieces and slots with the CNC. so... these were done with the concept of following the exact lines/edge of the fretboard... with the exact sm dist above, below and between... so they don't vary... but given square edges it's probably an optical illusion. Quote Link to comment Share on other sites More sharing options...
mistermikev Posted October 7 Author Report Share Posted October 7 1 hour ago, henrim said: That marlin certainly looks crisp! The fretboard though. Your parallelograms seem a bit off and I find the unparallel lines somewhat busy. That dissonance may get worse once the strings are on (or maybe not). I guess you just stretched the shapes to fit the slots, but it would probably have been better idea to keep the angles consistent. Or better and better, but likely easier on the eyes. Edit: apparently one of my guidelines in the drawing got out off place too, but you get idea. so... I did them several different ways and chose this one as my fav. first started off copying a 295 exactly, but that was on a 24.75 scale guitar w a very wide nut. then did them with the sm angle all the way down, then finally decided to do them to exact geometric measurements of this neck. the lines follow the edge of the fretboard exactly. once strings are on... they will end right before the low and high strings. afa the angles... the progress from 15 to 20 degrees. this is how they were done on my 295. I guess we'll see once strings are on... but I liked how they looked on my drawing against the actual edges of the fretboard. I think the square edge of the blank probably doesn't help. Quote Link to comment Share on other sites More sharing options...
henrim Posted October 7 Report Share Posted October 7 Ok, good if you like it. Though, maybe we are not looking at the same thing. The attached picture hopefully illustrates better what I mean. Actually, the angles are somewhat random, so it may not be just a result from stretching. Quote Link to comment Share on other sites More sharing options...
mistermikev Posted October 7 Author Report Share Posted October 7 yes, I knew what you meant. the lowest is a 15, then the next 3 are 17, the next 3 are 18 and the top 2 are 21... if I remember correctly... yes that was intentional. I'll take the constructive criticism. Quote Link to comment Share on other sites More sharing options...
henrim Posted October 7 Report Share Posted October 7 Ok then, it's an artistic choice you are happy with. So I'm cool with it too, although my geometry studies and design education would disagree. Quote Link to comment Share on other sites More sharing options...
mistermikev Posted October 7 Author Report Share Posted October 7 "Yeah, well that's just like... your opinion man" -the big lebowski. At the end of all... it's the finished guitar and how it looks that will determine if it was the right choice or not. On the one hand you have made me doubt myself, on the other: I'm confident in my body of work. 1 Quote Link to comment Share on other sites More sharing options...
Bizman62 Posted October 7 Report Share Posted October 7 3 hours ago, henrim said: Actually, the angles are somewhat random, so it may not be just a result from stretching. Thanks for verifying that my eyes weren't playing tricks on me! 3 hours ago, mistermikev said: yes that was intentional. Whew, good to know! Quote Link to comment Share on other sites More sharing options...
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