Search found 14 matches

by stepheneb
Wed Jan 16, 2019 5:18 pm
Forum: Instrument Builders Forum
Topic: Fret seating problem
Replies: 27
Views: 50717

Re: Fret seating problem

I have one of these small Irwin Japanese pull saws I bought years ago for less than $10 and it works great for cutting fret slots. https://www.irwin.com/tools/handsaws/dovetaildetail-saw Measured with feeler gauges an actual cut kerf in a fret board is 0.020" -- which seems to be just about perfect ...
by stepheneb
Sun Nov 25, 2018 12:08 pm
Forum: Instrument Builders Forum
Topic: Interesting intonation problems with two small high-performance guitars I just completed
Replies: 18
Views: 17902

Re: Interesting intonation problems with two small high-performance guitars I just completed

Frequency response for the White Pine top with 200 gram side weights.
frequency-response-WhitePine-top-20181124-bridge.png
frequency-response-WhitePine-top-20181124-bridge.png (31.16 KiB) Viewed 17653 times
by stepheneb
Sun Nov 25, 2018 10:19 am
Forum: Instrument Builders Forum
Topic: Interesting intonation problems with two small high-performance guitars I just completed
Replies: 18
Views: 17902

Re: Interesting intonation problems with two small high-performance guitars I just completed

Hi Martin, I started by holding the speaker just as you describe, as close as practical to lower bout and over the bridge. I had a hard time getting the tea leaves to migrate effectively. By resting the speaker on the strings over the sound hole it seemed to work a bit better. I was also under a fam...
by stepheneb
Sun Nov 25, 2018 10:08 am
Forum: Instrument Builders Forum
Topic: Interesting intonation problems with two small high-performance guitars I just completed
Replies: 18
Views: 17902

Re: Interesting intonation problems with two small high-performance guitars I just completed

An interesting aspect of collecting the intonation data in Audacity is that it's very easy to correlate the much sharper initial drop in the shape of the amplitude decay curve with notes that seem "dull" and more "thunky" when I play them compared to nearby notes. I already knew the most likely reas...
by stepheneb
Sun Nov 25, 2018 8:09 am
Forum: Instrument Builders Forum
Topic: Interesting intonation problems with two small high-performance guitars I just completed
Replies: 18
Views: 17902

Re: Interesting intonation problems with two small high-performance guitars I just completed

I made a few changes and collected more intonation data and tried to force some visible chladni patterns on the top. Changes: 1. Reduced the side mass weights from 300 to 200 grams. 2. Took 0.1 mm off of frets (about 1.15 to 1.05 mm) and re-crowned. 3. Lowered nut 0.1 mm. 4. Lowered saddle 0.2 mm. C...
by stepheneb
Fri Nov 23, 2018 6:56 pm
Forum: Instrument Builders Forum
Topic: Interesting intonation problems with two small high-performance guitars I just completed
Replies: 18
Views: 17902

Re: Interesting intonation problems with two small high-performance guitars I just completed

I re-collected all the scale tone intonation errors by collecting audio samples of each scale tone in Audacity. I actually had to do this twice, once at 8000 Hz to get high-resolution spectral data and again at 22050 Hz to get better resolution data for the pitch detect plugin to process. I used my ...
by stepheneb
Thu Nov 22, 2018 3:31 pm
Forum: Instrument Builders Forum
Topic: Interesting intonation problems with two small high-performance guitars I just completed
Replies: 18
Views: 17902

Re: Interesting intonation problems with two small high-performance guitars I just completed

Trevor, That's an interesting suggestion to look for low-order harmonics of a root around 215 Hz. I'll grab some loose black tea and get out the low-frequency speaker and amp combo I use for Chladni patterns and investigate. I can also measure the pitch of the scale tones where I'm getting large int...
by stepheneb
Thu Nov 22, 2018 10:45 am
Forum: Instrument Builders Forum
Topic: Interesting intonation problems with two small high-performance guitars I just completed
Replies: 18
Views: 17902

Re: Interesting intonation problems with two small high-performance guitars I just completed

Without changing the guitar I collected the same intonation data using the lightest practical fretting pressure to get a clear note (presumably simulating what the effect might be if I lowered the fret height bit). Intonation-errors-300-gram-side-mass-weights-light-fretting.png While many of the int...
by stepheneb
Thu Nov 22, 2018 10:27 am
Forum: Instrument Builders Forum
Topic: Interesting intonation problems with two small high-performance guitars I just completed
Replies: 18
Views: 17902

Re: Interesting intonation problems with two small high-performance guitars I just completed

Responding to earlier questions: Nut slot depth: I checked the nut slots and the strings are sitting about half way into the filed slots. Action at fret 1 when fretting between frets 2 and 3: strings 6, 4, 3, 2, and 1 have about 0.25 mm gap to top of fret 1. string 5 has about 0.1 mm gap. Overall ac...
by stepheneb
Thu Nov 22, 2018 6:50 am
Forum: Instrument Builders Forum
Topic: Interesting intonation problems with two small high-performance guitars I just completed
Replies: 18
Views: 17902

Re: Interesting intonation problems with two small high-performance guitars I just completed

I added two graphs to my article (and attached images to this post) showing intonation errors for the guitar with the White Pine top and Martin 540 phosphor bronze light strings. The first is for the case with no attached side mass weights. The second is for the case with 300 grams of attached side ...
by stepheneb
Wed Nov 21, 2018 6:41 pm
Forum: Instrument Builders Forum
Topic: Interesting intonation problems with two small high-performance guitars I just completed
Replies: 18
Views: 17902

Re: Interesting intonation problems with two small high-performance guitars I just completed

Hi Jeff, The graphs and intonation error tables are all from the White Pine guitar using Martin M540 phosphor bronze light strings. With the sound hole open (without any side mass weights) I measure the Helmholtz at 115 and the monopole at 213. In the intonation error table for no side mass weights ...
by stepheneb
Wed Nov 21, 2018 3:26 pm
Forum: Instrument Builders Forum
Topic: Interesting intonation problems with two small high-performance guitars I just completed
Replies: 18
Views: 17902

Interesting intonation problems with two small high-performance guitars I just completed

I've recently finished two small high-performance steel-string guitars inspired by the 1918 Martin 1-18 plans Ted Nelson created for GAL. By "finished" I mean in the last couple of weeks I've finally got the bridges glued on and have done some initial work on action and intonation. The guitars of co...
by stepheneb
Thu Jul 27, 2017 12:26 am
Forum: Instrument Builders Forum
Topic: Relief for Mac users (I think!)
Replies: 7
Views: 8590

Re: Relief for Mac users (I think!)

Trevor, do you have any info on the program author? Am wondering if the SINEGENX source code is available? Would like to extend the program to use a USB PowerMate knob/button to sweeep frequency (https://griffintechnology.com/us/powermate). From the About section of the program: Author: J R Smith – ...
by stepheneb
Wed Jul 26, 2017 7:56 am
Forum: Instrument Builders Forum
Topic: Uncoiling fretwire
Replies: 12
Views: 18082

Re: Uncoiling fretwire

I know this is an old thread -- but I've gotten here twice with google searches -- so I thought I'd describe a simple way I adapted the stewmac fret bender (which only increases curves) to straighten a coil of 43080 EVO gold fret wire. I used a C-clamp and large fender washer to position and clamp a...