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Gestation of a harp - update

  • Zep
    Zep of the Cross Strung

    Hello to all,

    For those who haven't followed the previous postings - I'm building a wire strung harp based on reading on the matter, looking at examples, reasoning it out, improvising.  I'm not working off specific plans.  I don't necessarily recommend this for anyone else, and its not expecially cheaper.    However, I may want to build other harps, or other musical instruments, and this is a start. 

    This is my first attempt at harp building, and my woodworking skills are all self-taught, and not that extensive.  However, I intend to continue to keep at it, and I'll try to do the best job I can of it.  It'll be my creation, such as it is, and there is a kind of satisfaction in that!

    Here's a photo log of the progress I've made to date.  Most recently, I've cut out the shapes of the neck and the column, as you can see.

     harp construction log

    Obviously, not exactly original - its kind of very loosely modeled on historic irish harps

    Not shown so far are the supports on the top of the soundbox for the neck, or the way the neck will be attached without glue to the body, or the endpiece that will be located under the bottom of the harp, for the column to rest on.

    Its now only 2 months since I started this.  Given the limited amount of time I had to put towards this project, I'm pleased with the progress.

    You can find the previous thread by going to google, and using the advanced search feature to search harpcolumn for the word "gestation."

    Comments?  Questions?  My main intent was to provide an update - I'm really still working at it, and for all its amateurishness, I'm enjoying the process-

    Michael



    replies to "Gestation of a harp - update"
    • Liam
      Liam M

      Hello Michael,

       

      It looks as if you are making fine progress, I am afraid I am still twanging strings in the jig frame trying to learn the proper dimensions.....  Curious, your sound holes seem small... were you aiming at higher frequencies?

    • Zep
      Zep of the Cross Strung

      Hi Liam,

      I’ve seen various historic harps with small soundholes, even in the bass part of the soundboard, so at least that feature is not without precedent.  I can always make those soundholes larger.

      To join the neck to the column, I’m using what I’ll call a pseudo-mortise – the neck is comprised of 4 layers of 3/8” baltic birch plywood, with the middle 2 layers having a cutout for where the column will go – hence the “pseudo-mortise.”

      I’m making the column of – don’t laugh too hard – hickory.  This, I am told, is the strongest domestic American wood.  I have a ¾ inch thickness piece that should fit right into the pseudo-mortise, when cut to the right shape.  It will be externally layered with 3/8” plywood on both sides, and should fit nicely underneath the neck.  

      The worst part about this is that the harp is likely to be unduly heavy!  I have some plans to reduce weight, if that really becomes necessary.  

      No guarantees about the aesthetic value of this project!  I’ll start to worry more about the aesthetics once the functional aspects of the harp have been completed, assuming they’re reasonably acceptable.

      I just bought an inexpensive hand-held belt sander.  My plan is to do the heavy duty sanding required outside.  I dress in full regalia – blue full length lab coat, face mask, goggles, ear protectors.  Must look pretty funny to the neighbors!

      By the way – among the various things I already regret – I regret using plywood for the sides – for the same money, I could have used high quality wood.  Also, I would have used a solid, thick piece of spruce for the soundboard.  

      I don’t regret not working directly from a plan, although I really don’t recommend that for anyone else.  But for me, without the discovery/struggle/experimental aspect to this whole project, I wouldn’t have been motivated enough to try it.  I recognize that it might be a valid criticism, to suggest that I’m “reinventing the wheel” as regards harp-building.

      And now that I've talked everyone's ear off about my project - Liam, what are you aiming for as regards your jig frame?


      Michael

    • Zep
      Zep of the Cross Strung

      Hi to all,

      I've added a few more pictures to update my progress.  See the "harp construction log" link in post #1 above.

      Michael

    • Kay
      Kay Lister

      Michael ,

      Looks like it's coming along nicely.  Can't wait to see it all finished!

      Kay

    • Unknown
      Unknown User

      Hi Mike, Fascinated. Sorry couldn't access photos. I gather you are prepared for teething troubles, or worse. I designed and built a nylon string X-strung lap harp last year, and had several imajor worries on completing, which I was able to overcome; now, I have a delightfully sounding harp.

      I used 1/8 in. doorskin plywood, the better grade 5-laminae sort for the soundboard, and it really sounds great. I wonder if your neck is strong enough - I think you'd need at least the same thickness, probably thicker, in a good hardwood, e g hickory, rather than plywood, which is usually made from softwood!. Have you thought that the neck wood has to hold the tuning pins with strings tuned up, without slipping?

      Have you any idea how much a tension load your harp will have to deal with?
      Maybe I coud help you with this, as it could be worth knowing.


      The neck-body joint needs to be strong, especially to stop the neck being pivoted sideways. I use a mortise and tenon joint, 3/8 in deep, screwed together.

      Have you read Jerry Brown's book, "Design and Construction of Folk Harps"? I haven't!

    • Zep
      Zep of the Cross Strung

      Kay,

      Thank you for your encouragement.  Yes, I'm getting excited about how this is all going to turn out!  I've still got some major design decisions to make, which I'm mulling over/researching, like how to attach the neck to the top of the soundboard, and how to attach the column to the base of the soundbox.  There are also multiple structural reinforcements I want to include, like strategically placed screws to make sure that  the top of the soundbox doesn't pull up from the back, under tension.  After I have it strung up and basically functional, my plan is to attend to how to maximize its sound potential.  The last step will be to put the aesthetic finishing touches on it (assuming I get that far, without catastrophic collapse!).  I'm not expecting something major to go wrong, but I'm trying to be realistic-
      Michael

      Rodney,

      A cross strung harp seems like another level of challenge from a structural point of view.  I find it encouraging that you designed and built it, and its holding up-

      For the neck, I'm using 1.5 inches of baltic birch plywood - that's about 36 plies, and it feels very solid - I'm not too concerned about its failing, but lets hope I've got that right!  I know that people use both laminated wood, and actual plywood, for the neck.  In all places, the neck is at least 3.5 inches high, in addition to being 1.5" thick.

      Since its 26 strings, figuring approximately 30lbs per string, that would be 780lbs.  Realistically, the true figure is likely to be somewhere between 650 and  900lbs, I think  In any event, at this point, I don't know what I would have done too differently.   The soundboard  is 3/8" baltic birch, and I won't be surprised if I have to remove some stock from inside the soundbox to get it to sound at least acceptably.  I'm going to put some reinforcement on the inside, to keep the soundboard from pulling up and causing the sides to collapse, but I frankly don't really expect that.  Overall, I've tried to err on the side of caution, to the point, probably, of over-building the harp.

      I don't think I'll use a mortise and tenon joint on the neck/body joint - instead, I may  glue supports on both sides of the neck (and particularly on the string side), and attach those with large screws from under the top of the soundbox as well.  The back of the neck may be stabilized with a large dowel running through it and the supports in a transverse fashion.  I may use some other supports for this as well.

      I have read Jerry Brown's book, and found it extremely helpful.  There is a stringing chart in that book, also really very useful.  I also have his collection of articles from the folk harp journal, and I've been referring to those as needed as I go along.  I considered using his radiussed neck/body joint, but think that may be too ambitious for me at this point.  Maybe on my next harp!

      When you come down to it, there's an element of uncertainty here.  I expect it will work, but if it doesn't, I'll try to figure out what went wrong (it may be very obvious, in retrospect), and decide what to do from there-
      Michael


    • Liam
      Liam M

      Michael, if you have pin slippage, it is not impossible to drill out the pin holes further to insert birch dowels and then drill them for your pins. Remember my mistake when I tried to power seat my zithers?

      I will be back on  mine now as the grand bed project is finally moving on to the paint team!

      Rodney, you know from an engineering standpoint, cross strung really appears to be a good idea.

      Now a question for all that floats continuously in the back of my head.... Why don't we just add the extra strings for the accidentals from the beginning? You know, like the piano black keys?  Why levers, pedals, cams and what all?  There is probably a simple reason why not... but I am at a loss to understand it.

    • Zep
      Zep of the Cross Strung

      Liam,

      Thank you for your suggestion about inserting birch (or other hardwood dowels, I assume) in the event of pin slippage.  I'll consider that should it become necessary, when I get up to that stage.  Would rosin also work?  I also have some compound i bought at a store that sells only violin family instruments, to prevent peg slippage.  I assume that that might work for the zither pins - the tension per string is pretty similar.

      Here's a site that relates to the in-line chromatic harp:

      re: inline chromatic harp

      An issue they raise is that the distance between adjacent "black" and
      "white" strings wold get pretty narrow, so the harp would be suitable only for
      being played with fingernails. 

      Rodney,

      If you did not work from a design or from books/articles, what did you use as a basis for the design features of your cross strung harp?

      Michael


    • Liam
      Liam M

      Thanks Michael!!  I like the concept!  Of course fingernails, (Or in my case Alaska Piks), are what I use anyway, so there is not an issue there for me.

    • Liam
      Liam M

      I tried rosin and chalk dust as well, but I was past that point and the dowels were my only answer. I also believe the parallell grain alignment to the pin helps as well. I chose the birch dowels as they are slightly "elastic" and seem to return more to the original shape when stressed...now they are inserted in cherry and did cause a mild cracking at first, but I have measured and monitored it since the original cracks appeared and there has been no progression. I suspect the birch swelled a wee bit more from the glue then the cherry did.  I tried a test block later and the same phenomena occurred only after gluing although the fit was perfect, tests prior to gluing showed no cracking whatsoever. So if you do dowel, I recommend a very thin glue application. Hmmmm... Just in thinking as well, my arch is three ply cherry and yours is multi ply also, correct? So even if you suffer the mild cracking, the structural effect is insignificant.

    • Liam
      Liam M

      Hmmmm I am going to send the designer some questions... why not equidistant with the accidentals just a tad higher?

    • Unknown
      Unknown User

      Hi Michael and others, Sorry this is late, I've been tied up, especially with travel.

      Yes, the cross strung does make it easier to engineer a harp, seeing 5/12 of the tension comes from one side of the harp, so it can be made lighter, and so more responsive acoustically.

      Your neck:body joint sounds good, I did that myself on my first harp after the diatonic strings pulled the neck out of alignment -it was only held by 4 slim screws, and these reinforcing blocks worked to stabilise the neck. I make them with a 3/8 in. deep mortise joint now, as I said before. This mortise to take the shoulder end of the neck  is cut in a shoulder plate that is fastened with 4 strong screws to the 1 in. thick top plate of the soundbox.

      As to my design, it's really quite simple. I just start by choosing the range and number of strings, and use established string spacing data. I draw a full scale side view, starting with a sloping line to represent the soundboard. Next I choose the angle of the strings to the soundboard -35 degrees in my case, to get a compact harp. (Actually, Latin harps have low angles here - 18 to 22 degrees in the few I've measured, both the old Spanish ones, as well as those from Latin America, but this seems to give them very long soundboards -which probably helps to give them their loud sound).

      Then, I choose a point from the top plate of the soundbox to the eyelet point of the topmost string, say 1-1/4 to 1-1/2 inches, and from this point draw a line at 35 deg. to the soundboard line to denote the topmost diatonic string. Next I draw a line at right angles to this line, and mark the spacing of the diatonic strings on it, and another one the same about 8 ins. below -I produce the top string line thru the soundbox to do this.

      I draw the two parallel curves representing the lines of bridge pins on the neck, one for the diatonic strings and the other for the chromatic strings. Then two more curved lines parallel with the first two to represent the lines of the tuning pins. Oh, I plot the point for the bridge pin of the top string, usually C6 in my case according to its vibrating length, which is around 7 inches, on the lowest pin line.

      Then I draw the lines for the rest of the strings parallel to the top string, and at right angles to the working lines, according to the string spaces already marked. Where the string lines meet the bridge pin lines marks the points for the bridge pins. Oh, the line for the chromatic strings pass exactly half way between the diatonic string lines, and pass to the second line which is for the chromatic bridge pins. Next, I construct lines running at a 30 deg. angle sloping backwards from the bridge pin points up to the lines of the tuning pins to mark the points for the tuning pins for both the diatonic and the chromatic strings. This angle is the break angle.

      To complete the neck profile, I draw two other lines approx. parallel to the lowest and highest pin lines, and about 1 inch away, to mark the bottom and top edge of the neck. I allow 5/8 in clearance between the lowest string and the back of the straight pillar, which is parallel to the strings. My necks are about 4 inches wide and 1-3/8 in. thick, and pillars 1-1/4 ins. (min.).

      The string lines are drawn down to meet the soundboard, to mark the points for the soundboard eyelets.

      Maybe this does seem complicated -but if you just do one step at a time, like I figured it out at first, it should make sense. If not, you are welcome to email me.

      I make the soundbox wide but just deep enough to get my hand inside to fit the strings in the parallelo-planar shape that William Rees recommends (thanks, William). The soundboard is glued into 5/16 in. deep grooves near the front edges of the solid mahogany sides which are 7/16 or 1/2 inch thick, as well as in the top plate, which is 1 in. thick. The base plate is 3/4 in thick mahogany, with a projection centre front to take the base if the pillar. The sides overlap the top and base plates, and the bottom edge of the sound board overlaps the base plate, and is fastened with an edge strip that's 1/2 x 5/16 mahogany .

      Ok, I know photos are needed -I shall make some available as soon as I can, but right now I'm away from home, though I did bring two harps with me to finish, but I have very few tools, will have to use a friend's workshop. Also, I've yet to get the fittings and strings -I use zither pins, bridge pins, and eyelets from Robinsons of CA.

      I should add I live in Belize, Central America, where we can still get tonewoods as good as any, I think - Spanish cedar, a strong softwood, and mahogany, which is a strong, medium weight wood, and I use santa maria, a medium hardwood for necks and string bars.

      This is plenty for now, more next time!

      Blessings to all!

    • Zep
      Zep of the Cross Strung

      Rod,

      Thank you for the info.  The cross-strung harp really is intriguing.  Its hard to find videos of it being proficiently played, but I see that recently, Harper Tasche has put out some videos of his playing one.  Here's an example:

      Harper Tasche playing Greensleeves

      You've obviously researched harp building a great deal, as anyone who really tries to build one that's not pre-cut (i.e., kit) or pre-planned (i.e., plans) must.  I've also read some of William Rees' material relating to the harp.

      The most challenging thing I've found to date is getting precision cuts, both in terms of dimensions of the wood, and in terms of angles.  I attribute this to my lower-end power tools, and my relative lack of skill.  Moreover, I've found that over-zealous use of a power sander poses its own dangers (in terms of removing too much material).  I continue to take the necessary safety measures (hearing, vision and respiratory protection, and never using power tools when tired!).  I mention this because you never know who'll take inspiration from what you've written, and its worth mentioning that safety is really of crucial importance-

      By way of progress report - I've got the column cut out, and the three "plies" laminated (the 3/4" hickory sandwiched between  2   3/8"-pieces of baltic birch).  I have to sand it more, and fit it more precisely to the top of the sound board, and the base.

      At the moment, I'm sidelined some - a relatively mild case of tennis elbow, but I really don't want it to worsen.  The completion of the harp is really within sight (say a few weeks at most of intensive work), but I'm going to take it as slow as necessary, get physical therapy, etc.  I'll complete the harp as I am able.

      By the way, how's it coming playing the cross strung harp?  Apart from Harper Tasche, who plays the cross-strung with fantastic facility and apparent ease, in  videos of other players I've seen, the players seem like they're struggling a great deal. 

      I wouldn't mind coming across a video of someone playing complex, multi-chordal staight-ahead jazz on the cross-strung harp, but I haven't found it yet!

      Michael

    • Unknown
      Unknown User

      Michael, Yes, we do need to practice safety, as you say. I've discovered that mahogany and Spanish cedar are mildly poisonous, so need to use a dust mask when sanding. I might mention that I live in Belize, Central America, where these timbers grow.

      Harper Tasche is sure the maestro of the cross strung. The secret I think to developing skill in playing cross strung is to get a good grounding with playing mainly the diatonic strings, in the key of C, then G and Bb, same as learning piano or keyboard. The keys with more sharps and flats are learned later. I might say, it's great to just pluck a chromatic string with my right hand ring finger or pinkie, or my left hand thumb or index finger, smoothly and easily.

      I might mention that my technique is quite simple, actually I got it from traditional Paraguayan style. I figure out the melody by ear with my right hand, then a simple bass accompt. with triads, lastly the alto part a third, fourth, or fifth below the melody. Then, practice, practice, and more practice!

      Right now, I'm back in Australia seeing my kids, and have no harp to practice! I brought one in pieces to assemble, finish, and fit up, but am having delays. Hopefully will complete it next week. It's a 3 octave lap harp, range C3-C6 (mid C is C4), and Latin-style cross-strung, like all my harps.

      Pity re your tennis elbow, Mike. I've had that twice. Just have to wait patiently, though hydrotherapy should help it to heal, and quickly.

      Blessings,

      Rod

    • Zep
      Zep of the Cross Strung

      Rod,

      I hadn't heard of the use of hydrotherapy for tennis elbow before you mentioned it, but I've since read up on it some.  This injury has been discussed in the past on this forum, and I read the posts - one thing I learned is that acupuncture has been used for this injury, and some of the people who posted found that it helped them.  In any event, the physical therapy that I'm receiving seems to be making some difference for me.  And very fortunately, the tennis elbow has only slighly impaired my harp playing.

      Per my readings, from sanding wood, there are a few risks - that for some woods, the dust is considered poisonous, as you mentioned; in some people, it leads to some kind of allergic reaction, depending on the wood;  and the possibility that you're inhaling microparticles that you can't see when you sand any wood, which I'm told may go deep into your lungs and get lodged there- all good reasons to wear, consistently and correctly, a mask designed to prevent the inhalation of microparticles like sawdust (in the U.S., this would be referred to as an N95 filter, at minimum, but these go up to P99 and P100).

      I was also wondering whether exposure of your eyes to sawdust (e.g., without eye protecting) from normal hand-sanding of wood was a health problem.  I wasn't finding, in an internet search, any consistent health issue in this regard.  However, I was finding my eyes getting irritated from sanding when wearing safety glasses, which had an opening in the bottom, over my regular glasses.  As a result, now, I will only sand with eye protection that completely covers my eyes.  Also, when you're using power tools, obviously, good eye protection is a must.

      I'm about ready to start moving forward again with the harp construction.  A number of times, I was tempted to simply buy a wire strung harp - there are some pretty reasonable ones out there - but I resisted doing so, knowing that if I bought one, all work on the one I'm constructing would surely cease.  My intent is to see this project through!

      Here's my current plan for the next step of construction - use a dowel through the top of the soundbox to attach the neck so the neck can swivel, fit the neck to the column and the column to the base, and attack a few strings, and then see how the neck "wants" to orient itself on the top of the soundbox - that is the orientation I'll use, which I'll reinforce with wood supports on top of the sound box on each side of the neck.  My tentative plan is to still use the transverse dowel through the neck to keep it from lifting up from the back due to string tension. 

      I'll post a link to more pictures as it makes sense to do so.

      Michael


    • Unknown
      Unknown User

      Hi everybody.

      Yes, we should never compromise safety, which may be taken to include how we move and play our harps to avoid strain and muscular tension etc. I guess this is where Pilates, Feldenkrais (think that's the right spelling) or Tai Chi would help. 

      Mike, that's seems a novel way to do the neck/soundbox joint. However, won't that end up with the neck being out-of-square with the soundboard? On my first harp, with 32 strings (19 diatonic:13 chromatic), I joined  the neck to a "shoulder plate" with just 2 screws, and the shoulder plate to the top plate of the soundbox with 4 screws. Soon after starting to play it, the greater tension of the 19 strings pulled the neck out -of -square with the soundboard, and upset the string spacing (a most critical feature in cross-strungs). I fixed it by taking the strings off, and fitting a reinforcing block with 2 strong screws to the side of the neck, and 2 screws into the top plate of the body, and that worked.

      Blessings,
      Rod

    • Zep
      Zep of the Cross Strung

      Rod,

      I believe the wood supports will keep the neck from falling over while just a few strings are attached.  Once I've settled on an orientation for the neck, I"ll  glue and screw in the wood shoulder supports.  That should keep the neck from keeling over under string pressure.  I'm also not adverse to putting in some additional screws or bolts to attach the neck to the top of the soundbox-the main issue is that the neck be attached in a way that is reversible/replaceable, and I hope, not add too much additional weight to the harp.

      Just right now, the challenge is to fit the neck to the column so that the column ends at the correct place, and at the correct angle, right next to the bottom of the soundbox.  The neck-column angle will have to be cut, or sanded further, or both.   Sounds simple, but I want to be really careful so that I don't end up creating more work for myself by getting it wrong, to the extent that I can avoid that-

      Michael

    • Zep
      Zep of the Cross Strung

      Hi to all again,

      To my shear amazement, I have actually put the harp together.  I strung it up, and tuned it up - (I'm still in the process of doing that- its only been 2 days, and the harp hasn't stabilized yet), but it hasn't collapsed in on itself!

      Here are some additional pictures.  The sequence really does kind of tell a story, although some of the details of putting the column together are missing:

      Harp Construction Log

      I went for the fairly traditional way of attaching the neck to the top of the soundbox - using supports on either side, although instead of a mortise and tenon holding the neck to the soundbox, I used fairly thick, long screws.

      Its definitely a mongrel, as far as wood is concerned.  The supports on either side of the neck are made of jatoba,  there's hickory in the center of the column, and the base is white oak.  A strip of walnut runs down the front of the soundboard, and the inner long soundboard support is hard maple.

      It plays very pleasingly, at least to my ear, definitely exceeding my expectations.  It could be a little louder, and I'm debating removing some non-structural stock from the sides of the soundboard.

      String gauges vary from .012 to .024.  I tried thicker strings for the bass but it seemed that the tension was disporportionately high, relative to the other strings.

      One of the strings is not spaced properly - its too close to one of its neighbors.  I'll probably have to remove the peg, glue a dowel in its hole, and redrill it.

      String spacing is wide enough for playing using fingertips, not one's nails.

      Weight is about 18 lbs - not unheard of for a wire-strung harp.

      Broadly speaking, the next step has to do with aesthetic decisions about finishing it, varnishing, designs etc.  I haven't decided, but as usual, I'm open to the non-traditional. 

      All told, in materials, and not counting my time, or the tools I owned before I started this project, I've spent approximately $400 U.S.

      Michael


    • Zep
      Zep of the Cross Strung

      Hi again-

      A correction - to enhance the sound, I may remove some non-structural stock from the sides of the soundbox

      But I may just as well not - It may just not be worth the risk.  We'll see-

      Michael

    • Zep
      Zep of the Cross Strung

      And one more correction - the 4 lowest strings are .032s, not .024s. 

      Michael