Circular harp brain-dump
May. 27th, 2016 00:55![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
torquillIf I don't unload my project-brain, I'm going to have trouble sleeping, and I'm not wired enough to pull a Tony Stark right now. Besides, I have stuff to do tomorrow. So...
For those who haven't been following along, I put up a GoFundMe to gather enough money to get the tools and materials necessary to build six handheld circular harps. These are about the size and shape of a cookie tin, with 15 strings splayed across the top (the mockup had 14, but I believe I can fit one more in). The idea was to make six, sell them for at least enough to cover materials for another set -- now that I would have all the tools I needed -- and start peddling them to musicians and dabblers for $150 each. Affordable for a handheld musical instrument, but a good profit margin for me. The fundraiser netted about $400 in a week, and off I went.
I made a circle-cutting jig for my benchtop bandsaw, and used that to make a wood-bending frame out of two circles of plywood and some scrap 2x3. The circle jig will also cut tops and bottoms for the harps themselves. So that was two tools down.
Yesterday I bought a 9' board of sugar maple which was 3/4" by almost 6", a piece of lauan plywood (it makes a really good soundboard, oddly enough, and I already have a second one), and a 10' piece of 4" ABS pipe and the necessary fittings to make it into a steamer pipe. I also picked up some sheet cork and paint: airbrush paint and reducer, and a metallic gold paint. I got them because I was in the area, though the paint job I want to do on one of these harps is still a ways off.
So tomorrow I'll go to the Adult Ed woodshop, whose teacher I've already spoken with, to pay my $15 and make use of a far more massive bandsaw... my little three-wheeler doesn't have the necessary blade tension to do resawing, and I need to reliably and cleanly cut a 3/4"x3" piece of maple into a 3/8"x3" piece. A couple of the great beasts at the woodshop can do that with ease, and I had figured the shop cost into my fundraiser. I expect to get eight good pieces out of the 9' board, and I'd hoped for twelve but one end of it may be poor enough quality that it won't bend well... I was a little rushed at MacBeath, and it felt like they had a large number of 5 1/2" board and several 7" boards, but very few of the 6" I wanted. I can still use whatever leftover maple is in good shape for things like tailpieces and braces, and if it's just unsightly but still bends well I can simply paint the instrument rather than staining it. When you figure that the board I got was a little over $20, the maple really isn't the most expensive part of all this.
Once I have my resawn pieces, I'll be able to really pin down the dimensions of the form clamps I've been making. I spent a good part of tonight cutting lengths of 3/4"-square Doug Fir and fitting them together via bridle joints to make brackets, ] The throat of this clamp will be lined with cork, and will hold the steamed wood against the curved edge of the bending form; one leg is fixed at 90 degrees, and I can slap it into place so that the peg on its end fits into a hole on the form, then bring the other leg down to slip its peg into the hole on the other side. I should be able to do that with one hand, quickly, while I hold the wood on the form with the other, then move on to the next for a total of 20 clamps along a 32-inch form. At least that's the idea. Until I have the real dimensions of the wood, however, I can't conclusively determine the length of the screws I need (which act as pegs), nor the positioning of the holes in the form to accommodate them. I can guess, but I need it to be as precise as possible for a good result.
I suspect I'll have to wait at some point while I get a hardware order shipped... I can buy just about all of this at the local Ace Hardware, but I can cut the cost in half (particularly with the brass fittings for the harps) by ordering online. Once I determine the hardware for the clamps, I may put in my order and work on the steamer while that ships.
I need a few bolts for the steamer, too, but that's not a huge expense. The idea is that the 4" pipe has threaded clean-out adaptors on either end, a couple of holes next to them to let steam and water out, some bolts for the wood to rest on in the center of the pipe, and a T fitting in the middle to accept steam from a generator. My brother gave me a Chinese medicine-pot which is designed to boil hard until the water reaches a certain level, then turn off -- thus avoiding the fire hazard of steam generators that can go dry. Its top fits a canning funnel quite neatly, and its spout can be a relief. I need to get some hose to run between the funnel and the pipe, but after that all I need is an extension cord and a cradle to attach to a sawhorse, and I'm good to go.
I priced nylon string as well as brass wire... I'm not sure how the wire-strung instruments will sound, and I may decide to offer nylon as an option (or even a preferred configuration) depending on how the first couple come out. Brass can cut through crowd noise very well, but it's not so nice on the fingers, and may lend itself to fingernails or a pick instead of plucking or strumming.
I need to confer with the exhaustive notes I picked up on the lengths and diameters of harp strings for particular frequencies, both to add a 15th string and to choose the wire/string gauge. Those notes are what made this project possible in the first place, and I should make sure I'm following them closely to ensure the instruments are properly engineered.
So that should be it. I'll go off now and see whether I can sleep.
For those who haven't been following along, I put up a GoFundMe to gather enough money to get the tools and materials necessary to build six handheld circular harps. These are about the size and shape of a cookie tin, with 15 strings splayed across the top (the mockup had 14, but I believe I can fit one more in). The idea was to make six, sell them for at least enough to cover materials for another set -- now that I would have all the tools I needed -- and start peddling them to musicians and dabblers for $150 each. Affordable for a handheld musical instrument, but a good profit margin for me. The fundraiser netted about $400 in a week, and off I went.
I made a circle-cutting jig for my benchtop bandsaw, and used that to make a wood-bending frame out of two circles of plywood and some scrap 2x3. The circle jig will also cut tops and bottoms for the harps themselves. So that was two tools down.
Yesterday I bought a 9' board of sugar maple which was 3/4" by almost 6", a piece of lauan plywood (it makes a really good soundboard, oddly enough, and I already have a second one), and a 10' piece of 4" ABS pipe and the necessary fittings to make it into a steamer pipe. I also picked up some sheet cork and paint: airbrush paint and reducer, and a metallic gold paint. I got them because I was in the area, though the paint job I want to do on one of these harps is still a ways off.
So tomorrow I'll go to the Adult Ed woodshop, whose teacher I've already spoken with, to pay my $15 and make use of a far more massive bandsaw... my little three-wheeler doesn't have the necessary blade tension to do resawing, and I need to reliably and cleanly cut a 3/4"x3" piece of maple into a 3/8"x3" piece. A couple of the great beasts at the woodshop can do that with ease, and I had figured the shop cost into my fundraiser. I expect to get eight good pieces out of the 9' board, and I'd hoped for twelve but one end of it may be poor enough quality that it won't bend well... I was a little rushed at MacBeath, and it felt like they had a large number of 5 1/2" board and several 7" boards, but very few of the 6" I wanted. I can still use whatever leftover maple is in good shape for things like tailpieces and braces, and if it's just unsightly but still bends well I can simply paint the instrument rather than staining it. When you figure that the board I got was a little over $20, the maple really isn't the most expensive part of all this.
Once I have my resawn pieces, I'll be able to really pin down the dimensions of the form clamps I've been making. I spent a good part of tonight cutting lengths of 3/4"-square Doug Fir and fitting them together via bridle joints to make brackets, ] The throat of this clamp will be lined with cork, and will hold the steamed wood against the curved edge of the bending form; one leg is fixed at 90 degrees, and I can slap it into place so that the peg on its end fits into a hole on the form, then bring the other leg down to slip its peg into the hole on the other side. I should be able to do that with one hand, quickly, while I hold the wood on the form with the other, then move on to the next for a total of 20 clamps along a 32-inch form. At least that's the idea. Until I have the real dimensions of the wood, however, I can't conclusively determine the length of the screws I need (which act as pegs), nor the positioning of the holes in the form to accommodate them. I can guess, but I need it to be as precise as possible for a good result.
I suspect I'll have to wait at some point while I get a hardware order shipped... I can buy just about all of this at the local Ace Hardware, but I can cut the cost in half (particularly with the brass fittings for the harps) by ordering online. Once I determine the hardware for the clamps, I may put in my order and work on the steamer while that ships.
I need a few bolts for the steamer, too, but that's not a huge expense. The idea is that the 4" pipe has threaded clean-out adaptors on either end, a couple of holes next to them to let steam and water out, some bolts for the wood to rest on in the center of the pipe, and a T fitting in the middle to accept steam from a generator. My brother gave me a Chinese medicine-pot which is designed to boil hard until the water reaches a certain level, then turn off -- thus avoiding the fire hazard of steam generators that can go dry. Its top fits a canning funnel quite neatly, and its spout can be a relief. I need to get some hose to run between the funnel and the pipe, but after that all I need is an extension cord and a cradle to attach to a sawhorse, and I'm good to go.
I priced nylon string as well as brass wire... I'm not sure how the wire-strung instruments will sound, and I may decide to offer nylon as an option (or even a preferred configuration) depending on how the first couple come out. Brass can cut through crowd noise very well, but it's not so nice on the fingers, and may lend itself to fingernails or a pick instead of plucking or strumming.
I need to confer with the exhaustive notes I picked up on the lengths and diameters of harp strings for particular frequencies, both to add a 15th string and to choose the wire/string gauge. Those notes are what made this project possible in the first place, and I should make sure I'm following them closely to ensure the instruments are properly engineered.
So that should be it. I'll go off now and see whether I can sleep.
