Lightweight fretless bass build 30" scale

[JGTay]

The plan is for a laminated through neck of beech & mahogany (what I had to hand) which was started yesterday and the body wings will hopefully be a poplar core with walnut top and bottom. I already have the poplar left over from the dismantled piano and need to source some walnut. This will hopefully end up being the thinnest build I have done, looking at between 24-28mm, should help keep the weight down and it will have one pickup with volume & tone control.

 

This may take a while compared to my usual builds (average time has been 6 weeks start to finish). Funds are non existent, so parts will be as and when money comes in, and in the meantime it is a case of using what I have to hand. I am planning on making a pickup for this, already done a test pickup with thicker wire stock taken from an old extractor fan which only had enough for 2000 winds (completely hand wound...), it worked well but had a very low output and would require a preamp to boost it. I may well use the test pickup in a future build with a preamp, but will need to buy some wire for this one. I may even try making a humbucker.

 

The through neck pieces were cut to size, squared and glued together yesterday. Then this morning I glued on the 'ears' for the headstock (lots of squeeze out ), did a quick sketch of the body shape and after removing the clamps I tried it in position with the rough body shape cut out of cardboard. The shape may change, but the main purpose was to work out the upper horn positioning to end above the 12th fret location for balance. 

 

 

After giving the 'ears' enough time to dry I set about cutting the headstock angle at 9 degrees.

 

 

After that I glued the cut-off to the back of the headstock to provide enough thickness across the length and then set about working out string positions based on 17mm string spacing at the bridge and a 38mm nut so that I could do the positions of the tuners and get a basic shape sketched in for the headstock.

 

 

Will get the basic headstock shape cut tomorrow morning and see what else I can do after that.

[Bizman62]

7 hours ago, JGTay said:

it is a case of using what I have to hand.

I really love that attitude! The end results usually are much more interesting than the ones where someone just buys some AAA+ woods and a bunch of templates to rout a copy of something. I'd rather see some good workmanship than sloppily crafted pornwood!

[JGTay]

Headstock shape and body wings poplar roughly cut. 

Will shape the wings a bit more once I have the walnut, planning on having the poplar show through on the edges similar to the mockingbird build.

[ScottR]

Looking forward to this.

SR

[woodfab]

So far so looking very nice.

[JGTay]

Few updates.

 

The 42 AWG wire arrived on Saturday, had a couple of hours free over the weekend so made the first pickup bobbin and then this afternoon started the wind by hand... got to 40 winds and snap... start again... managed just over 100 winds and snap again. Realised that my skin was too rough and the wire kept snagging on it, so asked the wife for some moisturiser and started over. Success  

 

Managed to do 4000 winds before having to stop for the day, but the moisturiser is working great, getting the right amount of tension in the wire and it flows through the fingers easily. I have also been varnishing the winds at certain intervals, getting plenty on and letting it soak in and then turning the bobbin and doing the same from the other side before continuing the winds, shouldn't be any need for wax potting at the end.

 

Had a few deliveries today as well - Fretboard, double action truss rod and some walnut boards.

The walnut boards are only 100mm wide, so there will be a bit of work getting a seamless join on the wings, but I like a challenge... which is why I decided to go with Leadwood for the Fretboard. Harder than Ebony and apparently very difficult to work, sharp tools are essential  

 

Pretty sure I planned on this build being lightweight, I was told Leadwood was on the heavy side... too damn right it is!!!!

 

Looking forward to this. 

[JGTay]

Finished the first coil of the humbucker this afternoon, did 7000 winds in total and then wired it up to test the output. Works well.  

Managed to keep it looking quite neat, very pleased.

Will make the bobbin for the second coil tomorrow and possibly get started on the winds if I have time. Managed to get a good technique going clockwise, will be strange doing a counter clockwise wind now. 

[henrim]

That pickup winding looks great! 

Is it necessary to do counter clockwise winding on the other one? Isn’t it enough if you just do opposite wiring? If that is for hum cancellation. I’m not deeply knowledgeable about pickups but I don’t think electrons would care which way they flow.

[Bizman62]

@henrim I guess this little article will tell you everything you need to know about single coil polarity and winding direction: https://www.fralinpickups.com/2017/01/23/whats-deal-polarity/

At least it clarified some things to me!

16 hours ago, JGTay said:

Managed to get a good technique going clockwise, will be strange doing a counter clockwise wind now. 

The top and bottom of your pickup look identical to me. Can't you just turn the pickup upside down and and wind it clockwise? When you turn it back the top side up the winding should be counter-clockwise - at least it looked like that when I tested the idea with a piece of cable.

[JGTay]

@Bizman62 The bottom of the bobbin has the threads of the bolts coming though and I use threaded sleeves on the two outer ones to hold it in position whilst winding. Nice idea though.

I have made the second bobbin and got the first 1000 winds on, took the first couple of hundred to get the rhythm going, but it is easier now. 

@henrim Thanks . Yes, for hum cancellation it needs to be opposite wind and the magnet polarity needs to be opposite as well. Had to do a bit of research to understand it.

[henrim]

I get that magnetic polarity and electric polarity need to be opposite on the two coils.

What I’m saying is I’m not getting that the winding direction would do anything. How I see it, it should be sufficient to just wire the ground and hot leads on the other pickup the opposite way. 

I guess I need to do some reading.

[henrim]

Sorry double posting. I do understand that the coils need to be opposite wounds but I’m thinking that could be achieved by swapping the leads instead of physically winding the coils in different directions.

[JGTay]

This is one of the sites I used for research - https://www.stringkingworks.co.uk/single-post/2019/11/28/humbuckers-polarity-and-phase

There are others I read, but this one is good and to the point. 

[henrim]

55 minutes ago, JGTay said:

This is one of the sites I used for research - https://www.stringkingworks.co.uk/single-post/2019/11/28/humbuckers-polarity-and-phase

There are others I read, but this one is good and to the point. 

Cheers, I get what is said on that article. I'll try to explain what I don't get with an image. Then I stop waisting your build thread and go do my homework

In the attached image I have drawn two pickups. Let's say they are both wound in same direction. They are just wired differently. Which effectively makes them opposite windings. The only difference is that on the first one the hot wire starts from the inside of the coil and on the other one it starts from the outside. That is the part I don't get why that order would matter.

Edited November 16, 2022 by henrim

[JGTay]

@henrim I do find all this interesting, and definitely not an interference on the thread.

I believe a few manufacturers do it that way, Seymour Duncan to name one, but I think the traditional/original way was to do opposite winds. I think it helps with coil splitting and keeping the hum cancelling (I may be totally wrong). It is definitely beneficial to know which method has been used when mixing different pickups.

There is so much information available and I have only skimmed the surface so far.

Depending on how this goes, I may do more research on the subject and continue making pickups for my future builds. There is a whole host of information on different types of  winds that I haven't really got into yet. 

[Bizman62]

I'm by no means an expert in pickups or any electronics for that matter, but to me it seems logical that there might be some difference in whether the winding goes from inside out compared to outside in. Most likely nothing drastical, just different. And possibly not different enough to be audible or even measurable. I've learned something similar about capacitors, some of them are marketed as omni-directional and there's no marking for in and out or hot/ground. Yet the design in those still is based on a rolled sheet which has one end on the outside and the other end in the centre, similarly to pickup wire. And installing them in the "right" direction has some effect at least according to what I've heard.

[henrim]

Yes, it is possible that there is a difference. I just don't understand it. And yes, I have heard about polarity of non-polarised capacitors. I have seen that there is even a measurable difference in amplitude using oscilloscope depending which way the cap is installed. Regular non-precission capacitors have pretty wide tolerances so it's hard to say if the difference in "polarity" is more or less meaningful than the effect of 10% tolerance. Which may not be hugely meaningful in general purposes. But yes, at least in theory there is a difference.

I once bought some speaker cable from a HIFI-store in Helsinki and I was told to install the cable in right way. I said that yes, I obviously know there is a polarity in the speakers. But no, that guy was not talking about polarity. He was talking about installing the cable so that the marked side was facing upwards. Or downwards, can't recall. Never cared to check because I seriously doubt that would make any audible or measurable difference. Or maybe it does.

[Bizman62]

6 hours ago, henrim said:

install the cable in right way.

Sounds as valid as using silver wire instead of copper for better audio quality - and yet some people seem to hear the difference in a blind test.

Pondering upon the idea of directioning the cable... Wire is made by pushing metal through a hole, simply put. There's more friction at the outside, at the edge of the hole, which makes the metal stretch differently inside the wire than on the surface. The same effect can be seen when squeezing a tube of, say, tooth paste or some other thick stuff through a nozzle. The bead coming through the nozzle has a direction so to say, something like a gazillion cones in a row, partially inserted to the next one.

[JGTay]

Finished the pickup this afternoon. Did 8000 winds on the second coil, joined the bobbins together and wired it up for testing. Very happy with the sound and output.  

North coil clockwise, south coil counter clockwise and the magnets in reverse polarity on each coil to enable the hum cancellation. 

Not too worried about how it looks as I will be making a cover/surround out of the walnut. The magnets aren't glued in place as I want to get some slightly bigger ones, either 8mm or 10mm. The main thing was getting it made so that I could pre-cut the cavity to size before gluing on the body wings.

[Bizman62]

Wooden pickups are just so yummy! And knowing the bobbins are truly hand wound adds to the respect multiplier. Well done!

BTW that cable looks oddly familiar - USB?

[JGTay]

3 hours ago, Bizman62 said:

BTW that cable looks oddly familiar - USB?

Yes, from an old Microsoft mouse. Perfect pickup cable with shielding and earth cable. Need to make a baseplate for it, but that can wait. 

[JGTay]

Started on the truss rod channel this afternoon. First job was getting it in the correct position and drawing round it.

Then with a straight edge clamped in place along the lines, scored it with a Stanley knife.

Then followed up with a chisel pressed in all the way around.

And out with the freshly sharpened 6mm chisel to remove the wood.

Tested the rod in place. Managed to get most of the way there, only a couple of mm to go, but had to down tools for the evening.

Should be able to get it finished tomorrow and then I can look at getting the fretboard in place.  

[JGTay]

When I woke up this morning and went out to the workshop/shed for my first coffee and cigarette, I sat looking at the truss rod raised out of the channel in the neck and made a mad spur of the moment decision to take a channel out of the bottom of the extremely hard fretboard.

Measured up, 3mm channel needed and this will allow a bit more scope for neck thickness when it comes to shaping.

I then decided to roughly cut the top edge of the fretboard close to size, leaving a few mm to be on the safe side. Then marked out for fret position markers along the top edge, cut them with the fret saw and then filled them with a beech sawdust and wood glue filler. Will see how they look after I start sanding the radius and if I am not happy with the result it will be the second option of using thin aluminium sheet. I have also decided to do the fretboard longer onto the body (28 frets)

Leadwood is hard going, even with a freshly sharpened chisel... got there in the end, not the neatest job, but level all the way along and a nice tight fit on the truss rod, no gaps between the fretboard and neck.

Next up was masking tape over the top of the truss rod and then trimmed to stop glue going in the channel.

And then glued and clamped the fretboard in place.

Really need to replace those smaller clamps, they are all bent out of shape after being over tightened too many times.

I am going to make some adjustments to the body shape, bring the lower horn further back to allow for the extra fret positions and may adjust the top horn joining position for the aesthetics. 

[JGTay]

A quick update of todays progress so far...

Removed the clamps this morning and then got started with the Shinto rasp on the sides.

Can see the fret position markers starting to show along the top edge.

Still need to sand level on the sides, slowly getting there, but I wanted to get the new body shape sketched in to give an idea of how it would look and also get the pickup position somewhere close to final location.

Hopefully you can make out the roughly shaped position of the pencil marks. Think it works... 

[JGTay]

Couple of updates. Yesterday (before the football! ) I decided to get on with the fretboard radius so that I could see how the fret position markers looked, they didn't really work as I had hoped, they were kind of camouflaged against the grain of the fretboard unless you were directly in front of them. Good decision to do the radius before working on getting the sides levelled off, I have moved on to the second fret marker option of using aluminium sheet. 

This morning I measured up and found the best saw with the closest kerf to the sheet, did a test piece first, which worked really well and then set to work marking out then re-cutting the edge slots. Once they were all cut I then did the aluminium pieces to shape, flattened them out and then glued them in the slots. Once the glue had dried it was just a matter of levelling off the aluminium with the top and edge of the fretboard using a file and a quick sand and clean.

Still need to level off both edges of the fretboard.

Need to go over the radius again and take it up through the grades, but very pleased with how well the aluminium is looking.