Wednesday, 10 September 2008

Now I've gone and done it.

It's finished. Woohoo!


MoonBassAlpha has been created and now it has got to stand up to being used. I have taken the opportunity to take some some higher resolution images before it gets scratched and bashed!




The ash (light wood either side of the neck) has really come to life now that the oil / wax finish has been applied. The grain figuring is quite pleasing. The controls in the upper cutaway are for the fboard LEDs, whilst the lower cutaway has two volume knobs and a pickup selector switch. The switch is a special 4 pole on-on-on variety that allows the coils in each pickup to be connected in series, parallel or use only a single coil. This gives a good range of tonal flexibility.






The side you see when you're playing it...






...and the side you see when you're lying on the floor.



The walnut stripe sandwiched between the ash front and back offers a nice contrasting warm colour.






The back looks nice too. The red of the padauk is quite striking, and the grain of the wenge shows up with what looks like alternating black / milk chocolate stripes. The back of the neck looks a little bulky, but there are a lot of wires that are routed around the trussrod and into the upper horn at that point.

Although difficult to see all of them here, the copper plates used as control covers were polished for me by Ace. Good work, but then you should see his car...






This one reminds me that at an early stage I dismissed the constraints imposed by a stand. I wanted the guitar to look how I wanted it to look when it was being played, rather than make it terribly sensible when it is resting. The downside is that although it is perched on the stand for the photos, it really needs its own stand built. If I sneeze it will probably fall off.






The front of the headstock has a hole in it...










...and so does the back. I am glad that the trussrod adjustment is done at the body end - it leaves the headstock less cluttered.





I had to take a few shots without the flash so that the fboard animation could be seen. Here's a few, but the pacman in particular doesn't come out too well on longer exposure times as it is moving! It does show the idea though.



Sound wise the guitar has a good solid bottom end, helped by the dense woods and slightly thicker-than-normal neck profile. The pickup switch and volumes allow several tone combinations. I really like the single pickup coil sound which comes through very clean. The humbucking switch positions give more depth to the sound with the series position having a really fat sound.



I am really pleased with the bass, but there are a couple of things I didn't get quite right.


1. Sharp internal angles are very difficult to sand and oil/wax, so they look a little rough in places.


2. Stoning the fboard is a skill that I don't think I have mastered yet. The fboard is reasonable, but still slightly wavy, causing some fret buzz in places. The string action is around 2.5-3.0mm so it can't be that bad.


3. The circuitry that drives the LEDs can be heard! It is only faint, and with the rest of the band doing their job it would never be heard, but for recording purposes it is best to leave the animation off. I reckon it looks the biz, so I'm still happy to put up with it.


Next up is to rebuild my bass amp - the power amp is fine, but the signal stages are showing signs of wear. I think that it was too complicated last time, so its time to rethink what is needed in the way of signal crunching controls. At least this shouldn't cause any splinters.


Don't worry - there are other mad people out there building weird things in their garages.

Wednesday, 27 August 2008

Nearly Finished

The Battery Holder

I must admit that the battery holder is a bit of an afterthought. Now I have nowhere else left to put the batteries other than in the end, just above the throughneck. Still, I want to make it user friendly so I want a battery holder that requires no tools to open and allows changes to be quick and easy.



I toyed with the idea of springy clips but in the end I have gone for a disc with a flat cut into it. Access to the batteries is by rotating the disc (shown in the left hand side picture) so that the flat allows them to pass in and out of their slot. Turning the disc to virtually any other position stops them from falling out (right hand side picture). It is not particularly elegant but it is functional and allows me to leave the tools at home.





Pickup Lines


To mount the pickups (after I had removed all the wood from their fixing points) I cut some small plates from the same piece of copper bar that was used for the nut. The pickup holes had recesses cut into them with a chisel and holes were made to fasten the plates to the wood. The mounting holes for the pickups were threaded with an M3 tap so that M3x30mm mushroom headed bolts could be used.


Doing it this way I can remove the pickups and plates to give access to the volume pot if it ever needs attention. I just need to remember to put the pot in before the pickup when it is finally assembled.




The pickup plates in place. They have two fixings at the top and just the one at the bottom which allows room for the cable to escape into the volume control cavity.


What a good fit! - no doubt helped by the camera angle.

I fitted the pickups and put the strings on to check the clearance between them. I noticed that the bridge pickup was further away from the strings than the neck pickup (due to the neck angle) so I had to pack the pickup plates out by 2mm to get a more consistent gap.

I had a play on the bass (acoustically) and all seemed well, but the frets were still inclined to buzz and their lower edge was quite scratchy on my left hand. After 'playtime' all the hardware was removed in preparation for finishing.

Before I got onto the proper finishing job, I decided this was a good opportunity to restone the frets. Last time I was probably a bit too tentative, so this time I ground off a bit more until my trusty 12" steel ruler verified that all was flat. The frets were sanded and wire-wooled to get back to a civilised profile and the bottom edges carefully filed smooth.

Finishing


Moon Bass Alpha was already pretty well shaped so it was just a case of removing knocks and grubby fingermarks as well as ensuring that the padauk was all the same shade of red as it seems to dull down after a while. I went through the different grades of sandpaper (80, 150, 180, 320) which took 3 long hours.

Not that exciting, but a necessary hurdle to make it look as professional as possible. I don't want to get it out of the gig-bag only for a layman to instantly comment that it looks homemade. I am hoping they will fooled into thinking it is a rare custom beast...

Once the sanding was finished and the dust removed, I rubbed in a coat of Danish Oil. The picture shows the difference this makes as it really brings out the full character of the wood. The PVC look on the fboard is just to prevent the oil soaking into the wrong places.



The oil is allowed to dry overnight before it is rubbed down with 0000 grade wirewool. This is like wiping clouds over the surface - 0000 grade wirewool is sooooooo fine! The oil / wirewool was done three times over the course of a week and after the last wirewool session a layer of beeswax / carnauba wax was applied and buffed to a pleasant sheen. Nice.

Tuesday, 19 August 2008

Making Square Holes

To make the pickup holes the same size a template was created using MDF. The pickups are Bartolini M34 Soapbars - a matched bridge / neck pair. They measure 89mm by 39mm, with a radiussed corner. Ideally this needs to be replicated on the template.

The template was made on the small milling machine at work, using the XY table to give a shape with decent right angles. It was then fastened onto the guitar with double sided tape and the router fitted with a straight 'follower' bit to follow the outline without destroying the template.







Masking tape was used to mark the positions of the pickups. As the position affects the sound it seemed a good idea to place them as far apart as possible. Practical reasons prevent this distance from becoming too great. The bridge pickup could be mounted straight alongside the bridge, but the string movement at this point is quite small resulting in a weedy output. The front pickup could butt upto the end of the fboard, but my occasional ventures into slapping & popping use that area to get under the D & G strings. I would keep bashing my fingers on a pickup if it was sited there, so again it has to be moved back by a couple of inches to give me finger room.



The template was restuck to the other position and the second pickup hole was routed. It finished up a shade too tight to get the pickups in and had to be whittled with sandpaper and hand chisels to give a good fit.






A small oversight has caused the bridge pickup hole to enter both the rear control cavities. Apart from having to move the batteries elsewhere, the main problem is that the pickup fixing screws will have nothing to fasten to. Not that I could find woodscrews that long and thin anyway...



Before the pickups were routed, the guitar was strung to check that the truss rod worked, check the balance, but mostly because I just wanted to play it albeit acoustically. Fortunately the rod worked fine after a three-quarter turn to give just the right amount of neck relief, but I couldn't get the action down as low as I would like. I just ran out of bridge adjustment.



There is some neck angle (angle between the neck and body) but this was something that I found difficult to accurately calculate beforehand (I didn't know how thick the fboard was going to end up after all the shaping). The only thing for it at this stage was to recess the body by around 3mm so that when the bridge is fully wound down the strings will be practically bottomed out on the frets.






It is a scary proposition to get the router back out all over the front of MoonBassAlpha especially near the fboard and all those nice curves stand a chance of getting gouged by a power tool gone crazy, but it needed to be done. Spacer blocks were taped to the top of the body as the router needs a flat surface to work from.




3mm was removed from the wenge / padauk and part of the ash. It was then blended back to keep the general shape. The top curve was able to be extended into the body more as it joins the top of the fboard. On the whole it looks remarkably similar to how it was beforehand (which is good) but now I will have the adjustment needed to set it up properly later on.



I just need to work out how to fix the bridge pickup without preventing one of the volume pots from being fitted or changed...

Sunday, 3 August 2008

Shapely

The neck can be shaped now. More woodwork - more sawdust. It is amazing how many different places the stuff gets into!



The neck was roughly shaped with a round surform at each end before the spokeshave was introduced to it. I don't get chance to wield my spokeshave often so this was quite an opportunity. It was a job to be taken gently as gouging out a big lump of wood at this point would be rather annoying, so I removed small strips at a time in between smoothing the shape with coarse sandpaper. It has ended up with a 'D' shaped profile, with a larger radius in the middle, tightening towards the edges. The shape was blended into the headstock and onto the body at the other end until it seemed to belong together.









Once the neck was shaped & sanded to a smooth finish it was turned round and the frets were for a good sorting. After a scratch or two on the fboard I decided to put masking tape over the surface so that further work would not wreck any further. The frets were levelled with an oil stone block. It needed a fair bit of levelling as the fboard was a bit thin and wobbly once it was glued on to the rest of the neck.

I looked at getting some fret files, but they seemed stupidly pricey. I used needle files, sandpaper and finished off with wire wool. It doesn't look to bad, though I think in hindsight that the rough side of the oilstone was a bit too extreme.





The zero fret was bashed in just like the others. I had hoped that with the main frets being filed down, that the zero fret would be sufficiently proud (0.5mm ish) to do its job.

Oh. It was about the same as the rest. I thought the levelling had taken a lot more off, but I suppose to make a zero fret work properly it has to be taller fretwire. I pulled the fret out whilst pondering and then took the easy way out and sawed through the fboard at the zero fret position in preparation for a more conventional nut.

The next pic shows the newly cropped fboard and a sawn piece of copper bar that will become the nut. Why copper? I had some 6mm bar ready to hand.






The copper bar was used to mark a line on the headstock so that a groove could be made for it. I rumaged around and found a thin chisel (1/8") which was ideal. The bar was a good tight fit in the slot and then it was shaped to become nuch more 'nutly'. I carefully marked the centre point of the strings with a saw, but did not size them fully at this stage.

It looks a bit chunky and should be a good substitute for a zero fret. I don't like the idea of the nut being made out of a soft plastic as it may absorb some of the string vibration. It finishes off the the top of the fboard nicely - especially as there is no truss rod cover.






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Monday, 28 July 2008

The Good, The Bad And The Ugly

Now the fboard is on I really wanted to know an answer to one of the "you-won't-know-until-you-get-there" questions. During the initial sketching phase I was trying to achieve a blend of visual balance along with a mechanical balance.

The visual balance has had one or two detours along the way but I am still quite happy with the its appearance. The mechanical balance has always been something that would be hideously lengthy to try and calculate to any degree of accuracy and just isn't worth the effort.

So now the bass is in one piece I thought it would be well worth slapping some of the major components on and try it out. First up was the strap buttons. I must admit I was not foreseeing any difficulties here, but the way the top horn curves downwards required a short drill to avoid the neck being in the way. The Dremel just about squeezed in!

The Hipshot Type A bridge was marked out as accurately as possible on a guitar with no straight edges or a centreline and fitted with the supplied self-tapping screws. It looks good, though part of me wanted to fit a thick brass plate on the back and use bolts to clamp the bridge on more firmly. Maybe one day...



As can be seen above, the volume controls and pick-up switch have also been fitted temporarily. These are not wired up yet, mostly because the pick-ups are still in a box.

The Schaller M4 series tuners were fitted onto the headstock. On the original sketch the tuners were angled in sympathy with the headstock outline. In practice the tuners have a worm drive that can be above or below the main tuner shaft.

If I swap the tuners over from left to right, there is sufficient room to angle them and get my fingers in without bashing my knuckles on the wood. The downside is that the tuners operate backwards which will seriously do my head in over the passage of time.

The tuners were put back to normal and straightened up. This comes under the heading of bad as I am sure with more planning this could have been resolved, but it is just going to have to stay that way now.



The control cavity plates were recessed into the back of the bass. This is the ugly part. The cutting of a curved outline with a straight chisel across different woods was always going to be a bit fraught, but the end result is quite scruffy.

I would like to present a whole range of excuses, such as "it was too hot" but it was largely impatience. I wanted to get this relatively dull part finished so I could move on to something more interesting. Fortunately it is on the back and the careful photography hides most of the undulating gaps. The brass covers were fixed with any available screws, but will eventually will be finished off with a shine and fitted properly.

The two AA batteries just about squeeze into the top control cavity, between the switches. The animation circuitry and LEDs are still working.



Once all these jobs were done, a strap was fitted and the bass was tried out in a stringless fashion. The overall balance was quite good - not particularly nose heavy, but fitting a large brass nut could change that to some extent. It seemed quite happy sitting at the usual 30degrees.

The tuners, bridge and strap buttons will have to be removed again before the neck is shaped to prevent them from getting damaged. Fitting them again will be much easier as the holes will be already in place. I've still got to try and cram the pickups onto the front of the body without fouling any of the switches & pots hidden underneath. There's only one way to find out...

Monday, 21 July 2008

Bodywork

Before the top section of the body is joined to the neck the remainder of the control cut-out was marked out (on the neck) and then removed with a drill and chisels. Before the two parts were mated together a paper tube was wrapped around the wires that go between the control cutouts so that the wires don't get covered in glue. One day I may need to carry out some repairs so I need the wires to be changeable.



After the cutout was done, it was time to get back to the glue and clamps. Fortunately I had already dowelled the join so there was little chance of the parts drifting out of alignment, but a good dose of pressure helps keep the joint gap under control. The neck side of things was straight and flat, but the mating face on the body had a slight curve across its width (due to my lop-sided sanding). As it was pretty good along its length I decided to leave it alone instead of risking a compound curve.

Getting all the wires through from the neck LEDs was a tight squeeze, but hopefully that means it won't rattle later on...



Once the top part was fastened on, the same process was applied to the lower part. This was a lot easier as there is no wiring going on down there at the moment. The control cavity was finished off and I made sure that I can get the pickup switch in.

The brass cover plate was fitted over the PCB once all the LED wires were plugged in and a temporary battery holder tucked in. The animation part still works!



Clamping and gluing the lower part. The fboard is still protected by tape in case I have a further attack of clumsiness.



After both bosy sections were glued into place the surfaces were blended together. The front and back had to be planed with a small jack plane and finished off with sandpaper. The upper and lower horns fade into the fboard using a round surform and more sandpaper. Finally the bottom of the guitar (ie below the bridge when it is standing upright) has had its curve finished off.



It is good to be able to pick the guitar up normally now and sit it on my lap. I need to think about a stand. I have a couple of stands for my other guitars, but these have fairly conventional shapes. MoonBassAlpha will need an angled stand...

Thursday, 17 July 2008

Fretting

The fboard has now been levelled along its length and cambered across its width. The fretwire I am using is straight. This needs to be radiused a bit tighter than the fboard camber so that the frets will sit properly when they are hammered in. Bending the fretwire by hand will probably result in very uneven twisted frets so another gadget needs to be thrown together.



The fret bender is a board with three ball bearing races on it. The fretwire is drawn back and forth whilst applying pressure to the third bearing mounted on a bracket. It did the job OK and all three lengths were ready for fitting.

Before the frets were slapped in, I had to get the width of the neck wood to match the width of the fboard. It was originally left oversize so that the placement of the fboard on the neck wasn't too critical, but now that is fixed the excess material can be removed. I used a small 7" jack plane to remove most of the Padauk and finished off with coarse sandpaper. The back of the neck will be shaped later, but it is good to start getting the neck close to its finished size.

The newly uncovered wood is quite brightly coloured and shows how some of the previously exposed Padauk has aged over the last few months. The picture also shows that the small fret marker dots have almost disappeared, but the ghost and pacman are reasonably visible.



A practice fret was bashed in an offcut of the neck wood and seemed to go in without breaking or splitting the wood.

The first fret went in at the body end. I don't tend to play much at that end of the guitar so if the first few are a bit lumpy it won't be too serious. The technique outlined in Melvyn Hiscocks book was used - ie cut oversized, tap the ends in first, followed by the middle, and this seemed to work fine.







After a few frets it became apparent that the camber on the fboard was not as uniform as it should be. The edges had a little too much taken off, giving a change of radius. This resulted in the frets sitting down nicely over the central three-quarters, but the very ends were slightly proud. More tapping, bashing, thumping, & drifting did not make this any better and re shaping the frets to include a change of radius sounds difficult, time consuming and will probably result in an instrument that feels wrong, so they were left alone.

After all the frets were fitted, the ends were trimmed with a Dremel with a small grinding wheel. Some of the fboard gap filler (PVA/paint) was used to fill the visible ends of the fret slots top and bottom. The slightly proud frets were treated to some superglue to ensure they remain in their position and do not relax or fall out at a later stage.

The zero fret was not fitted at this stage as the frets still need to be levelled or dressed. This needs to be slightly higher than the others so it needs to be hammered in after the levelling has been done.