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Winter Build Off 2022 - BassVI/V Doubleneck
- Thread starter Jisch
- Start date
It really does, I want to do this lairat style thing on a guitar soon. 
What about putting a narrow V bit in the router and use it to mark some alignment lines on the spoilboard for reference?
That's a good idea - I can use a square to reference off the metal going across the front. I like positive engagement like that better than doing something by sight, but I could use the CNC to drill register pins into the spoil board too.
I have been making steady progress in the 45min before work every morning. I've had to do a fair amount of lumber dimensioning, so it's been a bit slow going. At this point I have all of the body wood dimensioned, I just have to glue it up. I didn't consider how much more work a second neck would add to a build, it's sort of like doing two builds.
I'll get this walnut glued up flush with the neck drop on the two neck blanks then I'll be ready to cut the edges flush with the curve in the laminate edges. I need to think about this process a bit on when and how to cut the top. I added a strip of tiger maple on the edges of the neck blanks, this walnut will be glued to that maple (you'll see this walnut from the back). I need to look at the wood a bit and decide on which side of the wood to use and what direction the grain will go in. I should probably try and make a template with the laminate for my router rather than doing the matching by hand, which will be tedious. The bending templates are not refined enough for this.
I'll get this walnut glued up flush with the neck drop on the two neck blanks then I'll be ready to cut the edges flush with the curve in the laminate edges. I need to think about this process a bit on when and how to cut the top. I added a strip of tiger maple on the edges of the neck blanks, this walnut will be glued to that maple (you'll see this walnut from the back). I need to look at the wood a bit and decide on which side of the wood to use and what direction the grain will go in. I should probably try and make a template with the laminate for my router rather than doing the matching by hand, which will be tedious. The bending templates are not refined enough for this.
I laid it out quickly on the workbench, just to see how it looks. I paid no regard for where the laminates fell, so it's probably way off, just getting a view of the walnut back.
I'm still curious if you're planning to enter the shovel in the partial build category. 
I'm trying to figure out what scale length would be appropriate. It carries dirt, not sure it can carry a tune.I'm still curious if you're planning to enter the shovel in the partial build category.
I'll let myself out.
I arranged the walnut for the back this morning. I glued up two pieces to the VI neck and one to the fiver neck, next I'll glue them all together. There's no denying this is going to be a big instrument. Once I get this all glued up I'll flatten off the top, somehow - it surely won't fit in my router sled! Maybe I'll flatten each side before gluing them together.
Next up time to start working on the neck layout.
I found an orientation I like for both fretboards, then laid out the centerline, zero fret (VI) and nut (fiver), 12th and 24th frets and end of fretboard for each. The fiver will be a 35" scale, to make things easy(?) I'm using a 34" scale but putting the zero fret at the 2nd fret position, this gives me a slightly longer than 30" scale for the VI neck - I need to remember that "slightly longer" part when laying the rest of the body out.
I am working through doing the radius on the CNC machine, not sure I'll have this figured out in time or not, but I was able to get it designed in Fusion360. For those of you who are proficient with CNC and those of you who have never touched it are probably thinking the same thing - "you've done it!". That's nice, but I really don't understand this next step of creating the toolpaths for this. It's not like I've tried hard, yet, but it's something I need to figure out. If this was in 2.5 Carbide Create I'd have no problem going to the next step, but I just don't know Fusion360 well enough, yet.
In the theme of "rebirth" I'll be using ebony that a friend of mine gave me for fretboard binding. He builds and restores high end violins and other stringed instruments. He gave me a box of his throw aways, it includes a few full bass, violin and cello fretboards of the blackest/most consistent ebony I've seen. I'm going to try and use the most logical piece here and not cut up a bass fretboard if I can help it. Unfortunately the undersides of these fretboards are pretty seriously formed, so getting a strip long enough for the fretboards might not be easy - I haven't done any measurements yet. I'll have to adjust the taper on the fretboard based upon the strips of ebony I can harvest.
I should get some time tomorrow morning to continue and maybe a minute at lunch.
Next up time to start working on the neck layout.
I found an orientation I like for both fretboards, then laid out the centerline, zero fret (VI) and nut (fiver), 12th and 24th frets and end of fretboard for each. The fiver will be a 35" scale, to make things easy(?) I'm using a 34" scale but putting the zero fret at the 2nd fret position, this gives me a slightly longer than 30" scale for the VI neck - I need to remember that "slightly longer" part when laying the rest of the body out.
I am working through doing the radius on the CNC machine, not sure I'll have this figured out in time or not, but I was able to get it designed in Fusion360. For those of you who are proficient with CNC and those of you who have never touched it are probably thinking the same thing - "you've done it!". That's nice, but I really don't understand this next step of creating the toolpaths for this. It's not like I've tried hard, yet, but it's something I need to figure out. If this was in 2.5 Carbide Create I'd have no problem going to the next step, but I just don't know Fusion360 well enough, yet.
In the theme of "rebirth" I'll be using ebony that a friend of mine gave me for fretboard binding. He builds and restores high end violins and other stringed instruments. He gave me a box of his throw aways, it includes a few full bass, violin and cello fretboards of the blackest/most consistent ebony I've seen. I'm going to try and use the most logical piece here and not cut up a bass fretboard if I can help it. Unfortunately the undersides of these fretboards are pretty seriously formed, so getting a strip long enough for the fretboards might not be easy - I haven't done any measurements yet. I'll have to adjust the taper on the fretboard based upon the strips of ebony I can harvest.
I should get some time tomorrow morning to continue and maybe a minute at lunch.
Pulling the two sides out of the clamp I noticed I made an error in the thickness of the walnut pieces, I forgot to subtract the top. The walnut is all too thick by about .19", not a big deal. When I'm doing a glue up like this I spend a lot of time concentrating on getting the top edges perfectly flush in doing so I ignored the back, I guess?
I considered putting it through the planer before glue up, but with the drop already cut into to the neck blanks that would be difficult. I went forward with gluing the two halves together, I'll leave that problem for future Jisch - as a note future Jisch hates past Jisch.
I found a cello finger board that was long enough for the bass neck and cut binding pieces out of it. There are a LOT of weird angles on this wood, and I messed up one cut that ruined two pieces, so out of a cello fretboard I got just enough to bind these fretboards. This particular board no only had the "normal" weird angles and carve outs on it, but it also had been removed from an instrument so the back was chipped out from where it was pulled off. A bit frustrating for sure, but I think I got what I need and I think the ebony will look really good against this wood.
I considered putting it through the planer before glue up, but with the drop already cut into to the neck blanks that would be difficult. I went forward with gluing the two halves together, I'll leave that problem for future Jisch - as a note future Jisch hates past Jisch.
I found a cello finger board that was long enough for the bass neck and cut binding pieces out of it. There are a LOT of weird angles on this wood, and I messed up one cut that ruined two pieces, so out of a cello fretboard I got just enough to bind these fretboards. This particular board no only had the "normal" weird angles and carve outs on it, but it also had been removed from an instrument so the back was chipped out from where it was pulled off. A bit frustrating for sure, but I think I got what I need and I think the ebony will look really good against this wood.
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Future Jisch has a CNC router. If future Jisch gets (assuming it can support - not sure what the powerhead is) a typical 1.25" planer bit, it will plane a lot faster than a 3/8" bit will.
I have to remember the CNC, haven't yet accepted that as a tool in the quiver! The power head won't push a 1.25" bit, but if it's just sitting and running, I don't really care how long it takes it to run (once I get comfortable with it!). Thanks for the reminder!
If I'm gonna screw up, I'd rather it be too much than not enough.
This morning was more math and measuring than actually doing much, but I got the VI fretboard cut to width to accommodate the binding and I got it set up for fret slot cutting. Probably the last update until next week based on the dump of snow we got and a planned weekend trip.
I got only a few minutes this morning, but the string saddles for the VI came in over the weekend, so that allows me to get a bit further with the body.
As a bit of an aside: I was messing around with the free design software that came with my CNC machine and realized that I can cut multiscale frets pretty easily, so the BassVI will have 30.5/29.5 scales. I guess I kind of assumed with CNC there's one way to do things, I'm learning that is not the case at all, there are lots of ways to accomplish what you want to do. I'll detail that out when I get the routing bits I need to make this other process work. In any event, I'm putting the fretboards aside for a minute while I wait for those bits to come in.
It's not like this slowed me down at all as there is plenty of other work to do.
I pulled the body out of the clamps and cleaned up the front, it will need more flattening, but I got the glue off and took down the high spots with my hand plane. I laid out the VI string saddles and the bass bridge and got the final position for the upper laminate. With fanned frets I will need to adjust the hole in the bottom of the body a bit, but that was always in flux anyway.
I sanded down the inside of the laminate as the steaming process raised up the grain. Next I'll get a template made to route the edge of the body for a, hopefully, perfect fit. The last time I did this I spent hours sanding the body edge to get the intersection with the laminate perfect. I'd like to avoid that, if possible. I can get the body perfect then just trim the top using a bearing bit. Of course the laminate is not perfectly square, but there's also some flex to it.
This is the point in the build where there's lots to do and I have to work to keep myself concentrated on a specific task, I already feel a bit like I'm jumping around by moving off fretboards and onto the body. I'll spend a bit of time today thinking about the body build process and make sure I'm not wasting time here. Jumping around a little is no big deal as long as I don't do something now I have to undo later on.
As a bit of an aside: I was messing around with the free design software that came with my CNC machine and realized that I can cut multiscale frets pretty easily, so the BassVI will have 30.5/29.5 scales. I guess I kind of assumed with CNC there's one way to do things, I'm learning that is not the case at all, there are lots of ways to accomplish what you want to do. I'll detail that out when I get the routing bits I need to make this other process work. In any event, I'm putting the fretboards aside for a minute while I wait for those bits to come in.
It's not like this slowed me down at all as there is plenty of other work to do.
I pulled the body out of the clamps and cleaned up the front, it will need more flattening, but I got the glue off and took down the high spots with my hand plane. I laid out the VI string saddles and the bass bridge and got the final position for the upper laminate. With fanned frets I will need to adjust the hole in the bottom of the body a bit, but that was always in flux anyway.
I sanded down the inside of the laminate as the steaming process raised up the grain. Next I'll get a template made to route the edge of the body for a, hopefully, perfect fit. The last time I did this I spent hours sanding the body edge to get the intersection with the laminate perfect. I'd like to avoid that, if possible. I can get the body perfect then just trim the top using a bearing bit. Of course the laminate is not perfectly square, but there's also some flex to it.
This is the point in the build where there's lots to do and I have to work to keep myself concentrated on a specific task, I already feel a bit like I'm jumping around by moving off fretboards and onto the body. I'll spend a bit of time today thinking about the body build process and make sure I'm not wasting time here. Jumping around a little is no big deal as long as I don't do something now I have to undo later on.
This thought is constantly in my mind.
Except that I spend way too much time and energy trying not to jump around,... but always do. It's like when you have a partner at work with a few quirky and even bad habits that you adapt to and work around and incorporate into your planning and work flow.
Only, that PITA partner is myself
Was it you that said earlier, present self is always pissed at past self?
Classic.
I looked at doing the back planing on the CNC, I am not at all comfortable "pushing" the limits of the router on that, I don't know its capabilities, but it's a silly thing to push. I did create a file for it, and the toolpath said something like 95 minutes to execute. I could push the feedrate and overlap to optimize it, but again, why when I have other, more powerful routers?
I made a custom router sled - I basically just screwed two pieces of MDF to the sides and ran my sled over the top. It worked great and only took me 20 minutes or so once I decided that's the way I was going to go. It's not perfect, but I'll use the ROS to bring it in closer. Body thickness will probably become an issue later on down the road, I checked my "minimums" earlier in the build, but I forget what they are or how close I was to that. Current Jisch really wasn't that mad at past Jisch this time around, in the grand scheme of mistakes I've made, this is very minor.
This information means almost nothing, but at this stage the body weighed 6.15lbs. There's a lot to remove, but a lot more than that to add to it, but I think I'm going to end up with a decent weight.
I roughly cut the bass side curve on the bandsaw then made a template and used a bearing bit to bring it in. It looks good although I need to figure out the interface to where headless tuning block will mount before I can really test this fully. I need to make a template for the treble side curve and repeat this process. I'll need to get both of those done before I figure out control cavities and chambering.
I also glued up the top, but no pics of that. I got the fret slot bits in yesterday so I'll try a run of the fanned fret board on the CNC on a scrap today at lunch, I think. I woke up last night and realized that I forgot to accommodate for the angle on the zero fret when I drew the string saddles on the body - just writing it down here as either a reminder or as foreshadowing for another "oops".
I made a custom router sled - I basically just screwed two pieces of MDF to the sides and ran my sled over the top. It worked great and only took me 20 minutes or so once I decided that's the way I was going to go. It's not perfect, but I'll use the ROS to bring it in closer. Body thickness will probably become an issue later on down the road, I checked my "minimums" earlier in the build, but I forget what they are or how close I was to that. Current Jisch really wasn't that mad at past Jisch this time around, in the grand scheme of mistakes I've made, this is very minor.
This information means almost nothing, but at this stage the body weighed 6.15lbs. There's a lot to remove, but a lot more than that to add to it, but I think I'm going to end up with a decent weight.
I roughly cut the bass side curve on the bandsaw then made a template and used a bearing bit to bring it in. It looks good although I need to figure out the interface to where headless tuning block will mount before I can really test this fully. I need to make a template for the treble side curve and repeat this process. I'll need to get both of those done before I figure out control cavities and chambering.
I also glued up the top, but no pics of that. I got the fret slot bits in yesterday so I'll try a run of the fanned fret board on the CNC on a scrap today at lunch, I think. I woke up last night and realized that I forgot to accommodate for the angle on the zero fret when I drew the string saddles on the body - just writing it down here as either a reminder or as foreshadowing for another "oops".
I've got a straight fret model built in Fusion360. I think I know how I could make a fanned fret version there as well, but I haven't sat down to try yet. I also have an issue with getting the toolpaths created in F360, I'll figure it out, but again, haven't spent enough time to figure it out.
I was looking at some Youtube videos this weekend and I found a guy who used Fret 2 Find, exported SVG files then imported them into Carbide Create (which is the free CNC software for the machine I bought). I was able to do that pretty easily and create toolpaths. I spent a few minutes this morning re-doing the file as I found a few mistakes in it.
I ran my test fretboard today, obviously running a test is important, evidenced by the result. I slowed the feedrate way down, but I didn't set the depth of cut. After the first fret slot I noticed the cutter wasn't even close to the top of the wood on the first cut. I quickly measured the thickness thinking maybe the test board wasn't consistent end to end - it was. Then I looked closely and the end of the bit had broken off in the first cut. I had some issues with the board moving as well - so it could have been cutting too fast or it could have been the depth of cut was too deep - although the guy I saw do this used 3 cuts to get to .079" deep. This oak is surely not as hard as the fretboard material I'm using.
In any event, I have a couple things to clean up here, I learned stuff, I wish it was a free lesson, but hey sometimes you need to pay, right?
So my lessons here:
- slow down feedrate and reduce depth of cut
- Use the painter's tape/CA method for gluing the fretboard down - the side pressure from the CNC machine is pushing the board a little bit, the thicker double sided tape I typically use flexed under the pressure (I put those mechanical stops in place as it was running).
- Validate the positioning of the fretboard blank, this one looks like it's off center (to be verified), I aligned this one to the metal part of the bed, I should verify it off the X axis on the machine.
- make the tool paths go out past the end of the fretboard - I should have seen this when I was setting up the toolpaths but the offsets I used in Fret 2 Find resulted in frets that were shorter than the board (I think - need to look at that)
I wish my blank wasn't cut to width already, that makes things a bit more difficult. It would be much easier if I cut the slots then put marks on each end for the centerline, then I could just cut off the excess, alignment would be way less crucial.
Absolute worst case I could take a board marked like this and cut fret slots in with the fret saw.
I was looking at some Youtube videos this weekend and I found a guy who used Fret 2 Find, exported SVG files then imported them into Carbide Create (which is the free CNC software for the machine I bought). I was able to do that pretty easily and create toolpaths. I spent a few minutes this morning re-doing the file as I found a few mistakes in it.
I ran my test fretboard today, obviously running a test is important, evidenced by the result. I slowed the feedrate way down, but I didn't set the depth of cut. After the first fret slot I noticed the cutter wasn't even close to the top of the wood on the first cut. I quickly measured the thickness thinking maybe the test board wasn't consistent end to end - it was. Then I looked closely and the end of the bit had broken off in the first cut. I had some issues with the board moving as well - so it could have been cutting too fast or it could have been the depth of cut was too deep - although the guy I saw do this used 3 cuts to get to .079" deep. This oak is surely not as hard as the fretboard material I'm using.
In any event, I have a couple things to clean up here, I learned stuff, I wish it was a free lesson, but hey sometimes you need to pay, right?
So my lessons here:
- slow down feedrate and reduce depth of cut
- Use the painter's tape/CA method for gluing the fretboard down - the side pressure from the CNC machine is pushing the board a little bit, the thicker double sided tape I typically use flexed under the pressure (I put those mechanical stops in place as it was running).
- Validate the positioning of the fretboard blank, this one looks like it's off center (to be verified), I aligned this one to the metal part of the bed, I should verify it off the X axis on the machine.
- make the tool paths go out past the end of the fretboard - I should have seen this when I was setting up the toolpaths but the offsets I used in Fret 2 Find resulted in frets that were shorter than the board (I think - need to look at that)
I wish my blank wasn't cut to width already, that makes things a bit more difficult. It would be much easier if I cut the slots then put marks on each end for the centerline, then I could just cut off the excess, alignment would be way less crucial.
Absolute worst case I could take a board marked like this and cut fret slots in with the fret saw.
I tried v2 of the fanned frets on my CNC.
I used my regular double stick tape and stuck the board to some hardboard, then fastened the hardboard down using clamps. This arrangement allowed me to adjust the fretboard alignment without too much trouble and it held the board very securely. After pulling up V1 I see that I only used 2 pieces of tape, I used 4 this time, much more secure.
I "solved" the alignment problem by running the router down the length of the board in jog mode and aligning the back edge against the tip of the router bit. It turns out that the router is not aligned to the metal piece in the front (it seems).
I ran it super slow - it took 48 minutes to cut the whole thing, but I did it all without breaking a bit. One thing I could do to speed it up is reduce the retract of the router - I think it's pulling back 1/2" or more right now and it's doing it up and down at the plunge speed (which is set incredibly slow right now). That said, 48 minutes is nothing considering I could do other things while this is running. I was actually on a call for most of the time.
I need to remeasure things, but it seems that when the bit is cutting the final pass the top of the cut is past the flute and into the flare, so it's making the top edge of the fret slot wide. It's not a big deal at all, as I will need to radius this board and likely recut the slots, the radius will remove most of that. Just to be sure I pressed a fret in and it's in there very well, it's just the very top that's flared (note I used a 16" radius caul on this flat board so the middle is up a bit).
It will be terrifying to run the "real" board, but I think I'm ready.
I used my regular double stick tape and stuck the board to some hardboard, then fastened the hardboard down using clamps. This arrangement allowed me to adjust the fretboard alignment without too much trouble and it held the board very securely. After pulling up V1 I see that I only used 2 pieces of tape, I used 4 this time, much more secure.
I "solved" the alignment problem by running the router down the length of the board in jog mode and aligning the back edge against the tip of the router bit. It turns out that the router is not aligned to the metal piece in the front (it seems).
I ran it super slow - it took 48 minutes to cut the whole thing, but I did it all without breaking a bit. One thing I could do to speed it up is reduce the retract of the router - I think it's pulling back 1/2" or more right now and it's doing it up and down at the plunge speed (which is set incredibly slow right now). That said, 48 minutes is nothing considering I could do other things while this is running. I was actually on a call for most of the time.
I need to remeasure things, but it seems that when the bit is cutting the final pass the top of the cut is past the flute and into the flare, so it's making the top edge of the fret slot wide. It's not a big deal at all, as I will need to radius this board and likely recut the slots, the radius will remove most of that. Just to be sure I pressed a fret in and it's in there very well, it's just the very top that's flared (note I used a 16" radius caul on this flat board so the middle is up a bit).
It will be terrifying to run the "real" board, but I think I'm ready.
