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Prostheta

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Posts posted by Prostheta

  1. Hah, well this is why I dislike wading into active vs. passive discussions. I'm glad that Fluence have managed to blur that line enough to make some people question their stance either side of that. There are even those that don't understand pickups yet still have strong opinions on things....because that's what they read somewhere. Beyond the physical build of the pickup itself, an active circuit doesn't need to use 20k/25k pots in the circuit however because the preamps provide low output impedance, they just can. It helps "drive" the cable, or more specifically makes cable losses disappear. That's often why people refer to actives as "shrill", "bright", "snappy" or "sterile". It's the things you don't normally hear because of how passives are weak high impedance components with a degree of high end rolloff in the cable. If you have the opportunity, experiment with active pickups but using a standard passive circuit. You lose some of the benefits of active pickups providing a strong signal, but gain some of that passive familiarity. Dynamics still differ, because actives push a more dynamic signal less prone to the softer, squishier response of passives.

    It's a huge and misunderstood conversation, I think. I get a lot of flak from both sides because I agree with neither dogmatically. Often I think that people get more joy (or some sort of emotion) out of endlessly debating these subjects rather than gaining joy from their guitars!

  2. Thanks. I am still having some minor issues with the top in terms of making the seams close. This isn't anything important as long as I can slice it into a series of 2D contours for swift 2.5D machining. It may affect virtualisation/visualisation and some of the subtractive modelling processes since they are not closed solids, but hey. It achieves the aim it needs to.

    Even with simultaneous 5-axis machining of a fine contour with a ball end mill as an option, I still think that it is an excessive amount of machine cycle time when a trained sanding operator aware of what a carve is meant to achieve can concentrate the final shaping and dress work, etc. in far less time than a CNC fiddle-farting around contours to tenths of a mm. A lot of this project is highly theoretical since even if I produce one proof of concept, it will not go through the same sort of processes as I will be discussing in the writeup from a manufacturing viewpoint. For example, workholding jigs using either pneumatic clamps or vacuum for efficient part-to-part changeover, ideally working on a CNC with a split bed. Not sure if the Biesse Rover C6 has split bed as an option like the Homag/Weeke Venture 316L did. This gets to being beyond the scope of my project work very quickly....not sure if I should waste energy on producing theoretical throughput and cost analysis....although the autistic side of me is willing to go feet first, just because.

    Speaking of Maple tops....my original guitar's top was surprisingly high grade, but not eye-poppingly gauche like some. No idea how I would try and acquire such a piece since it was both subtle and high grade.

    137-2.jpg

    • Like 1
  3. It could be any number of things, and yes, bit of a zombie thread.

    I would have mentioned that Fender necks are often prone to a phenomenon called an S-curve. I'm not an expert on Fender necks and I am sure that it occurs with other bolt-on designs also. Simply put, the most flexible part of a neck is within the rounded part, and it is under the most tension around the 12th fret. Above there the neck becomes stiffer and under less tension, especially where it becomes the heel. This results in an uneven curvature under string tension which is what the StewMac jig that holds the neck in playing tension without strings for levelling is intended to achieve. Whether this is exclusively an issue with certain types of truss rod, fingerboard vs. skunk stripe construction, not sure. Most people add in a bit of falloff to the upper fret area anyway; a few strokes extra after levelling.

    • Like 1
  4. I might add that it is possible to buy 9v PP3 sized Li-Ion batteries with a built-in USB recharging port. It doesn't affect the mounting arrangement that is under discussion here, however they're a nice modern option.

    I would simply make that aluminimum folded tray a little larger and put a layer of 2-3mm foam rubber inside. Easy.

  5. I prefer to look at it from a more conservative point of view in terms of managing expectations. Technology will always progress and refine itself, but knowing what is workable and achievable at any one time is far more practical. When I was working on the Stratford CTRL groundworks remediation and contaminated ground management projects back in the UK, I had introduced DGPS handhelds that promised all manner of things from the presentations and datasheets. In reality, not so much. If you've got a scientist trekking across a muddy lunar-like landscape trying to acquire a 10cm accurate datapoint for a gas sampling point....you know you're not really going to get that in the real world. Still, better than 10-15m of straight GPS is always good and enough to validate sample drilling locations. I love and I hate tech.

  6. Definitely. Even though I am certain that the accuracy in point capture has improved in that time, I would say that the speed of capture in terms of the sheer number of points that can be captured and discriminated via processing in real time is a greater gain. These scanners can acquire several tens of millions of points within a few seconds at full pelt, however what is actually added to the capture data is likely a small fraction of that. The shutter speed required a lot of finessing between the front and the sides of the Ibanez S' scan. That was a test run for the Horizon, and I figured out how to specifically extract what I needed.

    None of the original scan data exists in the model. I needed to establish the flat top plane's perimeter and cross-sections of the "carve" contour radiating from that to the edges. Overlaying them both shows that how I interpret the original shape to have been pre-sanding post-CNC is pretty defensible. Enough so that it could be taken through the same sort of serial obliteration sanding as LTDs tend to get, or detail sanding with an understanding of the carve's features as with more expensive Japanese models.

  7. A small update on this one, more in how it is progressing as an overall objective arc. I've probably mentioned that I am studying another degree in CAD, including 3D scanning and a number of other subjects. Part of this is a small (relatively speaking) project bringing together multiple aspects into one demonstrative project. Mine is focusing on the design of production and manufacturing techniques for scaling a prototype out to a repeatable efficient....you know the sort of line here....

    Whilst I am not moving in the direction of manufacturing instruments, my experience of developing manual and CNC processing led me to using the carved top Mirage/Horizon prototype. It brings together almost all study areas, most importantly applying them in a practical real world manner rather than leaving them as a theoretical study that doesn't really leave you with the important hands-on experience. Anyway.

    I scanned the contours of an ESP Horizon using a Creaform HandySCAN 3D laser scanner which produced a point cloud that VXElements can post-process into features and meshes directly Inventor/SolidWorks, or as a mixture of meshes and primitive geometry in standard file formats like STL/STEP/IGES, etc. The objective was to derive basic geometry and contour information in order to recreate the top contours from a series of sweeps, network surfaces, etc.

    Näyttökuva 2023-05-11 084423.png

     

    Normally this scanner can derive a mesh to 0,25mm with depth information highly dependent on surface readability. Gloss surfaces introduce a lot of noise, so I had to lean heavily into the post-processing interpretation of the mesh. For example, the software can identify planes and sections of cylinders with a reasonable degree of reliability but with a noisy surface this gets a lot more variable to the point that manual intervention is necessary. The example above is heavily treated with defeaturing, hole removal and all sorts of surface recovery. Raw scan data tends to be more like this....the "orange peel" looks of the surfaces is the scanner's laser refracting within the clearcoat, giving highly variable depth information:

     

    Näyttökuva 2023-05-11 085353.png

     

    It's not bad, and enough to get a good headstart on deriving contour information as long as you have a mind for reverse-engineering....my Ibanez S that I scanned here shows that there's a lot more free-form contouring than ESP who really seem to go for predictable geometrically-based features.

    Näyttökuva 2023-05-11 093116.png

    Näyttökuva 2023-05-11 093634.png

    • Like 2
  8. They're useful, however I think they're only good at identifying errors that need spot correction such as super low or high/loose frets. Levelling a board with a springy loose fret creates bigger issues. That's just me anyway. I think any tool is good if you have a specific need of it for a defined use. Once a neck is in service, fret rockers become less useful as most neck rarely go back to absolute dead straight once the rod is relaxed and they're no longer under tension.

    • Like 1
  9. That's what I thought. Paper is good to maybe 1200-1500 beyond which it can have diminishing returns, at least for me. I probably don't have the best technique for paint. 3/5/10 using separate pads for each sounds like a reasonable medium without going crazy with every grade. I saw the 12 Black, but it seems odd in that it isn't a final polish....it's right up in the medium-fine end, so I fail to see what it adds in that range that deeper polishes don't. Hologramming is a thing though.

  10. I think that I'd stay with wet sanding and skip 35 to the next grade like 20. Four bottles seems like quite an investment though. I'm thinking of how to sort the clearcoat over the white pearl and black of my two M-IIs. Shame I don't have ready access to compounds from when I fabricated Corian fittings for the cruise ships; even 250ml goes a long way.

  11. Again, I'm probably preaching to the converted here however it really does help to spend time tuning the blade, getting the wheels balanced and coplanar and aligning the bearings. Setup setup setup.

    Here's a beast for you.

    https://www.weinig.com/en/solid-wood/band-resaws/variosplit-900/variosplit-900.html

    Now THAT is a resawing machine, even if it is on the side of line automation. Those can automatically throw out clean 3mm splits with no issues at all.

  12. I get that. Nina and myself both say that about each other but neither of us believe it. Between us we give each other the ground to walk on, somehow.

    Your good lady is absolutely correct. Buy once, hurt once. Buy cheap, pay forever. Tools and machines below a constantly-rising point are rarely made to be serviceable or repairable these days, mostly I think as a consequence of artificial pressures thanks to cheap made-to-be-disposable warranty-free imports. That's a nice bandsaw! If you've not done so already, spend time balancing everything and hunting down every source of vibration. If possible, anchor it to the concrete with some fibre-reinforced rubber in compression to balance. If you can stand a coin on the table with the machine running, you're golden. This usually means fine-tuning your blade, especially around the weld. You probably already know this anyway.

    The sander you have is exactly the same one as I have. A nice thing to add to it is a hole to fit a fence for thinning down the rear of headstocks on the left of the drum. I've considered making one using precision drawer slides so the headstock can be DSTed to a sliding fence, but not gotten around to that yet. The manual method is good enough given patience and thought on physical control of the workpiece.

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