arch profile guage

[actonern]

Those of you who are interested in copying arches of STRAD poster instruments can quickly check the progress of your work by using this device.

http://www.leevalley.com/en/wood/page.aspx?p=32522&cat=1,42936,42958&ap=1

Just a suggestion...

Best regards,

Ernie

[Oded Kishony]

I use a profile gauge whenever I'm carving an arch. I print a set of profiles using a curtate cycloid program and as I'm carving I lay the gauge on the paper and alter the arch to match the curves of the printed line. One advantage to doing it this way rather than making templates is that it trains my eye to recognize the arch. I found that following a template does not give me as good a result.

I think that 'eye training' is an under appreciated part of learning to be a violinmaker these days.

Oded

[JohnCockburn]

Think this one's a better bet, ern:

profile gauge

I think this is the type Roger Hargrave et al use to measure arching profiles on old instruments (but taken to bits and the pins all polished up and the ends rounded so they slide easier and don't damage the instrument).

Maybe someone like Neil or Bruce could confirm/deny/expand.

[actonern]

I like "yours" better... the pins are narrower and so can take a more accurate read in areas like the mid bouts where the arch is changing shape fast longitudinally... the one I showed won't take as accurate a read.

E

[catnip]

Here is my large profile gauge that I made using two aluminum bars and the pins from two small gauges. I use it to record and measure the longitudinal arches of the top and back. It is too big for cross arches.

[Anders Buen]

I use a profile gauge whenever I'm carving an arch. I print a set of profiles using a curtate cycloid program and as I'm carving I lay the gauge on the paper and alter the arch to match the curves of the printed line. One advantage to doing it this way rather than making templates is that it trains my eye to recognize the arch. I found that following a template does not give me as good a result.

I think that 'eye training' is an under appreciated part of learning to be a violinmaker these days.

Oded

And then you make the arch irregular and off the cycloid again when you "voice" the instrument from the outside?

[Bill Yacey]

I use the red plastic one. I chose it over the steel pin type because the steel pin type took considerable pressure against the wood to move the pins to fit the contour, increasing the chance of dimpling the varnish and wood.

The plastic one is slightly coarser with the bigger pins, but it's easy enough to "connect the dots" on a tight radius curve.

[Melvin Goldsmith]

Just a caution...

.... in case anyone ever considers it.....these types of gauge should never actually be directly applied to the surface of an instrument when recording archings because they will invariably leave a mark.

If I am taking an arch profile from an instrument I trim a piece of soft card to fit the profile ( it's quicker than it sounds)

For making I use the plastic type and find it invaluable. (I agree with Oded re eye training)

[JohnCockburn]

I use the red plastic one. I chose it over the steel pin type because the steel pin type took considerable pressure against the wood to move the pins to fit the contour, increasing the chance of dimpling the varnish and wood.

The plastic one is slightly coarser with the bigger pins, but it's easy enough to "connect the dots" on a tight radius curve.

yeah, like i say, you need to modify the metal ones to make the pins slide easier (and round the ends)

[Bacon]

"Just a caution...

.... in case anyone ever considers it.....these types of gauge should never actually be directly applied to the surface of an instrument when recording archings because they will invariably leave a mark. "

That would be my armchair observation as well. I have been using one (polished stainless) for many years, with great caution, and having scanned the top for marks and have found none. However mostly it is used for 'in the white' work. I think if the PVC one shown earlier was sharpened to more of a point it would be usable.

[Melvin Goldsmith]

Bacon

Sorry not to be more clear. Fine to use them on an instrument you are making on the white wood. Not fine to use them on a Strad to record the archings!

And not advisable to even try to check the archings on ones own finished work as they do have a tendency to leave a trail on a varnished surface.

[Oded Kishony]

And then you make the arch irregular and off the cycloid again when you "voice" the instrument from the outside?

Hi Anders,

Usually the amount of wood I remove is not noticeable, however, if I did feel that I needed to remove more wood I wouldn't hesitate, after all I'd rather have a great sounding violin than flawlessly shaped arching ;-)

Oded

[COB3]

The plastic one is 10" long, compared to 7" on the steel one.

Here is one you can double up and get 12" (they overlap and hook together) for eight bucks total, not counting shipping:

http://www.harborfreight.com/6-inch-contour-gauge-907.html

[Bacon]

Bacon

Sorry not to be more clear. Fine to use them on an instrument you are making on the white wood. Not fine to use them on a Strad to record the archings!

And not advisable to even try to check the archings on ones own finished work as they do have a tendency to leave a trail on a varnished surface.

Melving,

I guess I wasn't clear, I'm not finding marks on finished work. I agree it is not advisable for someone who is not using the utmost of care, this should be true of using any metal measuring device to finished wood. With this type of tool the trick to 'clean' use is lubricated low friction pins. I use a dry graphite product. Even the pvc item can dent a soft finish if carelessly used. I also find a flexible drafting curve tool quite practical with little possibility of damage. I can't find the one I use online but google images will show many. They are soft metal cores coated in nonabrasive flexible plastic.

[robertdo]

I like "yours" better... the pins are narrower and so can take a more accurate read in areas like the mid bouts where the arch is changing shape fast longitudinally... the one I showed won't take as accurate a read.

E

I have both and the plastic one is quite precise too. With the iron one it can be indeed quite hard to move all the pikes. I also got the plastic one very cheap compared with the price you indicated.

[NewNewbie]

The plastic one is 10" long, compared to 7" on the steel one.

Here is one you can double up and get 12" (they overlap and hook together) for eight bucks total, not counting shipping:

http://www.harborfreight.com/6-inch-contour-gauge-907.html

Interesting post! Thanks!!!

It looks like you connect these gauges in the middle.

Dick Tools has them as well.