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Rod Pearce

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Posts posted by Rod Pearce

  1. 9 minutes ago, RAc said:

    Uhm, I'd be very hesitant to recommend this strategy to someone new to tuning concepts without these words of caution:

     

    1. This tuner app will probably assume equal Temperament Tuning. IF the Instrument in question is indeed tuned in ET (it likely is, but it's no given!), it's safe to use the "absolute" frequency (but see below). If, however, the Instrument happens to be tuned in something like mean tone tuning, adjusting the needle to 0 may make the reed sound really bad.

     

    2. Prior to attacking the reed,  Larry should double check that the Instrument is otherwise not only in (ET, see above) tune with itself but also in concert pitch (meaning A should be tuned to 440 Hz). If that is not the case, meaning the Instrument is in tune with itself but not with respect to absolute Standard pitch, tuning the reed to a Zero needle will, again, make it sound off. If A is NOT tuned to 440 Hz but the Instrument is in tune with itself, then the 0 needle position for the D# must be adjusted so that it fits the relative Tuning of the Instrument. The tuner App possibly can do that, but it's sort of an expert mode.

    RAc

     

    I made the suggestion of using a chromatic tuner as Larry's original post was referring to a tone generator, which would have required a very good ear to tune the suspect reed. He was also only concerned with a single reed, not a complete re-tune. The suggestion was made in good faith.

  2. Chris, Theo

     

    Thank you for your feedback.

     

    I believe the process I am using is somewhat flawed, as I have been sounding each reed in the concertina sitting on my lap, the reed pan in situ and holding the action box in place without screws while expanding the bellows.  I do have a tuning rig but was unable to get the reeds tuned closely enough to make using it worthwhile.

     

    This afternoon I have made a frame to hold the tuning bellows and will start using this for initial tuning. It should improve the consistency.

     

    When it comes to fine tuning and sounding the reeds in the instrument, do you tune/ install / sound the reeds individually, or do a side at a time to minimise the number of times you need to reassemble the instrument? I went for one at a time, hence the process I described above.

     

    Many thanks

    Rod

  3. Does anyone use this software for tuning concertinas?

     

    I have been using it for a while, and I would like to understand if anyone else experiences what I would call 'bounce' as the tuned reed is sounded. Although I am expanding / contracting the bellows at a steady rate, as if the instrument is being played, I  get different readings on the display depending on where the bellows are in the compression cycle. The reading can vary by as much as 10 cents.

     

    I am assuming I should take the reading as near to the middle of the compression cycle rather than at the start or.finish?

     

    Rod

  4. Tom

     

    Thanks for your very thorough and enlightening explanation. It will take me some time to assimilate it! I am unable to open the attachment, though.

     

    I am taking from this and Lofty's reply that the reeds are probrbly OK and I should look at other factors.

     

    Incidentally. I came across this thread after I posted my initial question. More food for thought.

     

    Rod

     

     

     

  5. Steve

     

    Thanks for your feedback. Much appreciated.

     

    As the concertinas in question have undergone a full refit of valves and pads, I would not expect the valves to be the problem. I am encouraged that your Wheatstone has remained stable, there is hope for me yet.

     

    When tuning I did notice that a number of the reeds appeared to be quite thin as if they had been tuned a number of times previously. I will be fine tuning these instruments again soon so time will tell.

     

    Regards

    Rod

  6. How long would you expect a recently tuned instrument to stay in tune for?

     

    I have tried to find some information by searching the forums but the number of hits from searching 'Tuning' is enormous. So I have opened a new thread on this subject.

     

    I have tuned a number of instruments over the last 12 months, all reeds to within 1.5 cents after several passes. However, I have noticed that when checking the instruments after a few weeks / months a number of reeds have gone out of tune, or just not sounding correctly.

     

    Is this to be expected ie an instrument'ss tuning should be expected to change periodically? If this were the case surely the majority of instruments in day to day use would be out of tune.

    Is it that the reeds are getting past it and are no longer able to retain their tuning for long periods?

     

    Any thoughts would be appreciated

  7. Here is the finished end - minus the strap.

     

    I persevered with the scratch stock to get the curved bevelled edge. I sharpened the end of the scratch stock blade, which seemed to make all the difference. After planing each edge to a straight bevel, I then followed up with the scratch stock to remove the remaining wood and used a curved needle file and glasspaper to achieve the final finish.

     

    I am pretty pleased with the end result, for a first attempt!

     

     

    IMG_1438.JPG

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    • Like 4
  8. I have finished cutting the new end and will shortly be gluing it to the end frame. The existing ends have profiled edges, and I was wondering if anyone could share a way to do this. I have tried making a scratch stock from an old hacksaw blade ( this has worked for me in the past but on a smaller profile). It hasn't worked on this occasion as I need to profile both with and against the grain. The result is too rough. I was thinking about a router of some sort?

     

    Would I be better advised to just finish the edges with a straight bevel?

     

    Picture of existing end attached

     

    Regards

    Rod

     

    IMG_1426.jpg

  9. 22 hours ago, McDouglas said:

    I'm wondering what is the relationship of the number of bellows to a. the volume of the instrument and b. the sustainability of a phrase?  I'm just guessing but I suppose a fine player can play with energy and expression on any instrument.

        

    I've observed that English concertinas seem to range from four to six bellows.  There seems to be a correlation to cost of the instrument. (Is this generally true?)  But what is the impact on the capacity of the instrument?

    I found this recently while I was browsing the net trying to understand more about the relationship between reed thickness and notes. It is very interesting. Have a read and see if it answers your question.

     

    http://www.concertinaconnection.com/concertina%20reeds.htm

      Bellows pressure
              The airflow in a concertina is generated by expanding and contracting the bellows. The
              amount of air pressure generated is determined by the player. The more force the player
              applies to the bellows, the higher the air pressure. The size of the bellows also play a role
              in the amount of pressure that can be generated.

              If the same amount of force (F) is applied by the player, smaller bellows will generate more
              air pressure than large bellows. Pressure is the force applied by the player, divided by the
              size of the bellows: P = F : S.  This formula illustrates that the pressure generated on a
              concertina is much greater than on a full size accordion.

  10. 9 hours ago, alex_holden said:

    The most difficult part is getting the holes exactly over the pin holes in the action platform (if they are misaligned the buttons won't be vertical and the action will be sticky).

     

    Thanks Alex - this is all very valuable info.

     

    I do have the original end with button holes intact, so with care I should be able to use this as a template for the new end, when I am happy with it.

    • Like 1
  11. IMG_1337.thumb.JPG.cbf801531620c52680725dcbcbaf42cd.JPGMy second attempt, using a No 0 Pegas skip blade. It's better, but the intricate pattern I am attempting is leading to a number of very fine pieces between the holes in places.I'm not sure it will stand up to being used as a replacement for the original end it is supposed to be replacing. You will notice I have not plucked up the courage to attempt the button holes or the makers badge hole yet - that ia for another day. Still, I am quite please with the overall attempt, and only one broken (worn out) blade!

    IMG_1334.JPG

     

    IMG_1337.thumb.JPG.cbf801531620c52680725dcbcbaf42cd.JPG

     

     

    • Like 1
  12. On 7/30/2018 at 7:54 AM, alex_holden said:

    I recommend not cutting ends from solid wood - they often crack in the short grain areas. Better to laminate your own plywood by veneering a board with the veneer grain running perpendicular to the core grain.

     

    Alex

    I.m just browsing through some old posts and noticed this one from you about not using solid wood, but veneered plywood.

     

    two questions spring to mind:

    - does using plywood not affect the sound quality - for example, a concert guitar is made from the best quality tonewood, not ply.

    - who sells plywood of the required quality and thickness? I guess you use a specialist supplier?

     

    Rod

  13. Personally I prefer to use a handheld fretsaw; I don't get precise enough control with my scroll saw. I use a platform that lifts the work up quite close to my face and wear mild magnifying glasses. There is a bright LED panel above my workbench. I've recently changed to Pegas No. 0 skip tooth blades for cutting wooden ends. My preferred saw frame has an 8" deep throat and can hold a fairly high tension.

     

    Alex

     

    I have made a platform using some odds and ends I had lying around, so it has cost me nothing. It fits in my vice so it can be raised / lowered easily to the appropriate height. I have bought a fretsaw (couldn't get an 8 inch one)  and I already had some Pegas No 1 blades. So this afternoon I have been hard at it with the new approach. Progress is slow but promising. I will share the finished end when I manage to complete the piercings - hopefully in a day or two.

     

    You will notice the platform top is small in comparison, this is purely because I didn't have a larger piece to hand. But it seems to work fine. Time will tell.

     

    Rod

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  14. Alex

     

    Thank you for your reply and for sharing some very valuable insights. I will need to up my game! Fortunately I had the foresight to buy enough rosewood to make 4 sides, so I will start again using a fretsaw. My pattern is a bit rough and ready as I have attempted to trace the pattern on the good side.

     

    When you have finished sawing, do you make any attempt to improve the finish inside the cuts, or leave them as sawn? I only ask because the original ends on this instrument appear to be machined and show no saw marks.

  15. Hi everyone. I am new to the forum and am seeking some advice. I have repaired a few concertinas in the last few years as a hobby following retirement, and so far I have limited my endeavours to the mechanical components, polishing and tuning. Recently I have acquired an instrument (by Campbells of Glasgow?), very similar to a 20 key Lachenal Anglo I have, with a lot of damage to the fretwork on one end, and decided to have a go at making a new end. I thought I would use my scroll saw for the job and have purchased some rosewood from a reputable luthier supplier in the UK.

     

    So far I have completed about half of the work but I have to say that I am not very happy with the finish I am getting. I am comparing it to the good end which is cut so precisely that anything I do by hand is going to look inferior.

     

    Am I wasting my time trying to repair in this way, and is it likely to devalue the instrument?

     

    Any thoughts / advice would be much appreciated.

     

    Best regards

    Rod

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