Posts posted by Stephen Churchill
On 4/10/2020 at 11:07 AM, catnip said:
Hi Stephen, Can you easily port it to an android phone?
Unfortunately there is no way to directly port from iOS to android. However, I’m working on implementing the functionality in android. Hopefully this will be available on a month or two.
I've made an replacement iPhone app for the MAG-ic Probe to help with using it without a computer. Thanks to Liam at MAG-ic Tech for his assistance. You can view the screen shots and list of features here: https://apps.apple.com/us/app/magic-caliper/id1505243118?ls=1
I find this kind of scientific research very interesting and i'm glad someone is doing it. However, to the layman the paper implies a link to tonal quality by invoking the Stradivarius name.
To see how the press interpret such a paper look no further than the title of The Strad's coverage of the paper:
"Research suggests chemical wood treatment may account for the ‘Stradivarius sound’"
Sorry, looks like I already parted with it.
I believe I ended up with a 2nd of these by accident. I'll check my collection and get back to you.
I should have mentioned it has the logo "TUBBS" on it.
I don't know John, but I saw this on craiglist and thought someone here might be interested. The posting is on craiglist, here's the link, some pictures there:
GREATLY REDUCED AND INCLUDES MODEL 5 SHOPSMITH!!!
MAKE AN OFFER!!!
I am posting this for my neighbor and friend, prominent Violin Maker, John Speak. John is now 86 years old and has decided to retire. The money will be used for ongoing medical expenses for he and his lovely wife.
This is a truly amazing collection of everything you need to start a violin-making, guitar-making or any string instrument-making or repair business. This is a collection of tools, many custom made, and components, that has spanned more than 30 years of building and repairing wooden stringed instruments. The photos do not come close to capturing all the hundreds of tools, parts and pieces that will instantly put you in business.
The only way to appreciate this collection is to come and see it. It is truly a priceless collection. The asking price is absolutely a pittance of what this collection is worth.
I am not going to attempt to list everything, but here are a few of what you'll find:
Luthier clamps in every imaginable size for 1/16 violins up to contra bass
Huge assortment of new and used cello floor pegs
Large assortment of violin, viola and cello tailpieces
Assortment of new violin and viola chin rests
Large assortment of violin, viola, cello and bass ivory and rosewood tuning pegs
Many boxes of violin, viola, cello and bass strings and bridges of many various qualities
Beautiful vintage toolbox with unusual, custom hand tools (see pics)
Glue pot with lots of glue
Custom made saws
Sound posts for violins, violas, cellos and bass
Bridge cutting and adjusting tools
Classical guitar tuning machine heads
Peg hole reamers - all sizes with peg cutters
Sound post setters - all sizes
Miscellaneous bow frogs - used, many sizes
Assorted fine tuners
Large assortment of violin, viola, cello endpins
Scroll carving chisels
Many, many custom, miscellaneous wood carving tools
Tailguts, nylon - all sizes
And on and on - just look at the incredible assortment of hand tools on the table
ALSO HUGE BONUS: INCLUDES a ShopSmith (we believe Model 5) in very good condition with a big assortment of accessory tools. It is shown in the very last photo. This is the quintessential workhorse of any wood shop.
WE WILL NOT PART OUT THIS COLLECTION - BUYER TAKES ALL!
Please contact me to set up an appointment with John. Cash or Paypal (+ 3%). Thank you.
call or text:
- ☎ (323) 309-7225
reply by email:
I can't see the picture if you meant to post it this time.
I replaced the cartridge heater element in mine with a CIR-30202/120V from Omega.ca. Its a 1/2" diameter, 2" long 250W unit. http://www.omega.ca/pptst_eng/CIR_12.html
I'm assuming you're in North America so 120V is fine. Check your length and diameter. The wattage should ok. Also a good time to pick up a PID and thermocouple off ebay and give yourself a nice accurate bending iron temperature control.
Happy New Year all!
Off topic somewhat- I read some time ago about making a homemade varnish with styrofoam and laquer thinner. The thinner melts the styrofoam to liquid form. Has anyone tried that or do the chemical/scientist people have an opinion?
Styrofoam is expanded polystyrene.
I see two problems with this. The first is you're coating your resonant body with plastic which i would think would dampen vibration. The seconds is that since its plastic and not oxidizing to form larger polymer changes, so you probably would find it hard to build up any kind of thickness since the solvent in the new coat would take off the old coat.
The first poster was the Muir-MacKenzie “long” Strad in the early 80’s. This was because that was the fiddle that co-incidetly hapened to be lying around on Roger’s table when the then editor, Anne Inglis visited the workshop in Bremen, and got ganged up on for having nowt worth reading in her Magazine, and asked for positive suggestions instead of critisism.
The first one I came across was the Guarneri ‘del Gesu’ violin 1733 in April'84, then the G.B. Guadagnini's ‘Lachmann Schwechter’ 1776 violin in Feb-85. Then the Muir-Mackenzie followed in December. But that's reconstructed from old ads, so I could be wrong. Perhaps these were re-issued?
I ordered a bunch and there was a single shipping charge.
I made a hygrometer based on Oak glued cross-wise to Maple. This means the tangential shrinkage is being compared to the axial movement. I used thin pieces for each and laminated them together with epoxy to keep the 50% point near the center (it was about 50% humidity when i did the epoxying). The oak is 1.3mm and the maple about 2.0mm.
In late summer the humidity in my workshop was about 45-55%. Now it's drier - with a cold front moving this week in it dropped to about 20% today. So I've seen a fairly wide range of humidities on on the hygrometer.
The hygrometer is 76cm long (~30 inches), and moves about 21cm from 46% (its center) to 21% (today's measurement). I used aniline dye to color the hygrometer but not seal the wood.
The hygrometer represents the % of humidity in the workshops better than a digital hygrometer which reacts more or less instantaneously to changes in ambient humidity.
Next: The sensitivity to humidity to the thickness is very high. By reducing the thickness by10 (10mm to 1 mm) the movement of the hygrometer should increase by about 3x. A good result should be obtainable with two Maple veneers, I'll try this when I get some time.
I love my Knew Concepts saw. The blade rotates 45 or 90 degrees and it is insanely light weight.
Coincidentally i came across an interview with the co-creator of Knew Concepts just a few days ago. They talk about the aluminum and the titanium versions. Very cool.. Its definitely on my wish list.
Very cool stuff.
A quick search indicates the best wood to use would be Oak, Hickory, Dogwood, or Beech. Birch and Sugar Maple are close 2nd choices. On the other end of the spectrum (smaller reaction to changes in humidity) are Teak, Redwood, Cedar, mahogany, Pine, Ash, Butternut. Spruce is only a little better. This is based on readily available shrinkage rates from green to kiln dry.
Also interesting is that tangential (slab cut) rates of change are typically double that of radial (quarter cut).
So i'm going to find some slab cut Oak and see what I can make!
I have had some success with bending a thin scraper over the fingerboard. Alternatively you could sand with a block and plenty of cork on it.
Use a wedge (like a piece of cedar shim they use to square up door frames) to create a tapered feeler gage. With a straight end along the length of the finger board you can push the feeler gage underneath. Mark on the gage the thicknesses you're going for. Courntall suggests .75mm under the E and 1mm under the G. I think the E doesn't need that much.
The hollowing should be even end to end. You can move a shorter straight end (maybe a 10cm rule or prepare a piece of wood 8-10cm long) along the fingerboard to check the consistency of the curve.
A second thought... I guess the higher height on the g side could compensate for the extra hollowing. Then they might have the same height at the mid point down the fingerboard...but I never bothered.
Interesting, I don't follow Strobel's measurements then.
I think you're fine. My Fingerboards are symmetrical, except for hollowing. My edges are 4.5-5mm on each side and made even across at the 42mm radius. The finger board is not flat from nut to bridge, but hollowed with a small hollow under the e-string and a larger hollow under the g-string (I'd have to check what I set these to).
No offense to Mr Strobel, but I don't know why you'd want the G-side thicker...
To cut it down a shooting board would work great. I just put it vertically in vice and carefully work it down. You need to mark your goal line first of course. To clamp it on I use a hollowed piece of spruce with some cork contact-cemented on.
Here's some fingerboard pics from my first build
On my first I used a bass bar clamp to hold it.
The Courtnall book gives 24 at the nut and 42 at the bridge side. The length sought be 270mm. It should be thinned so you end up with 4.5mm on the vertical side (all the way down, but the end near the bridge can move up a bit.
This one :
( low angle version ) works nicely for me. Blades are excellent steel and once sharpened stay sharp
for a long time. Bit pricey but I'm all thumbs and I don't like to have to fight the tool, too. The ability
to close the mouth to a hair helps a lot. A toothed plate, for thinning ribs is available, too. I have
spare blades at different angles up to almost scraping plane territory. That takes care of the low/high
angle issue. And bevel up planes are somehow easier to keep sharp than bevel downs.
Stanley has a 91/2 and a 601/2 which are very nice, fully adjustable but on the heavy side.
I second this..
The Stanley isn't lapped. So you'll need to invest several days lapping and $50 is materials.
I also find the 9 1/2 controls are too high (CORRECTION: Mine is Stanley Bailey not a 9 1/2).
I love the Lee Valley Low Angle Block Plane, it works considerably nicer than my original Bailey.
I've had a few. I cut the button off my first back.
On my third or fourth bridge I was dismayed to discover I had some how tapered it incorrectly, the perpendicular side was nearer the finger board.
But what was bizarre was the next bridge. Knowing my mistake i took extra care. DSoo you can imagine my horror when it was wrong again! I really thought the universe was conspiring against me that day...
PS. A fellow student, no doubt excited about nearing the completion of his violin, put his label on the wrong side.
If you're aiming for 5.5 mm starting thickness then i guess you're following the Hargrave Classical Cremona technique.One alternative is what is in the Courtnall & Johnson book. They have 4mm edges, 4.5mm in the corners. The platform is flat and the channel cut into this before fluting. Mark with a Purfling marker and cut with a knife (alternatively you could make the outside cut with the marker then an inside cut with the marker the way Roger and other do). If you reduce your edge thickness to 4mm, make the platform 9mm in the upper and lower bouts and only 7mm in the c's to prevent cutting into your arching. One advantage of this method is that it lets you make some mistakes at the top (the surface of the platform) since this gets cut away after.The flute then cut way is the way that Davide Sora does it in his videos. Davide does make it look easy, but i suspect there is less room for error.(when i say 4mm edges, 4.5mm corners, I mean the height of the purfling platform before inserting the purfling)
MAG-ic Probe Digital Thickness Gauge
in The Pegbox
Hi, to complement the iOS version I made last year, I've just finished the Android version for those interested in an App they can use on their phones: