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Thinking about pulling the trigger on one.

What is it?

I have been using one for about 4 years. I love it toward the end with the box close making sure I am not over finish sanding. It has been very reliable and they have made sure their new software works with the older probes

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But...what is it? Do I want one?

I believe Dave is talking about this and just has a typo in the subject:

http://www.magicprobe.net

Brad


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BTW - Being able to make a heat map of the top thickness is badass.


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Hmmm........

New username, same Pat Mac

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Pat

I've long wanted one, not yet been able to justify it.

Interesting. One could use it to measure film thicknessas well if 'before' measurements were taken...

On my wishlist for almost a year now. The list is shrinking quickly though. Hopefully I'll have one in a month or two.

There is an older version of this caliper (I forget the name) that used a magnet as well and a digital meter. It's about the same price but without the software interface. The software itself is worth about half the price of the unit IMO, especially in terms of record keeping and figuring out what works best with certain materials etc. Pretty cool little unit.

Finally! Something I need for Christmas. What Brad said! It would have been nice to have a reference library since day one. Not too late to start.

Thanks for the replies.


That's exactly what I need it for at the moment.





woops! Thanks Brad. Stay in school kids!



Justification skills are a must with this endeavor!

I have one and love it. I have an older version which hooks up to a simple meter that just gives the thickness read out. Doesn't look like they sell this unit any more. It was cheaper than this kind that hooks in the computer and uses software.

Wow, that is really cool!

New username, same Pat Mac

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Pat

Just a techno Hacklinger gage with one more decimal place. Topo map looks kinda nice, but unless you have a CNC, fairly useless. Doesn't take into account the stiffness of the wood to be much use, although I used the Hacklinger for years to study Loar F5's and other. Hacklingers were used for ages by violin builders, archtop builders and anyone that wanted to measure the thickness of their '37 Martin.

Hacklinger gauge is what I was thinking of earlier but couldn't think of the name. However, given that Hacklinger gauges are ~$300.00 and you have to stick your hand inside the box and place the magnet vs rolling it around while it enters data into your computer for you is easily worth the extra $50 at least to me. The contour map is handy for data collection and true it doesn't account for stiffness but if you keep deflection testing records that shouldn't really matter. The contour map is also a pretty cool thing to give to a client- the more information the better!

Sorry, sounds like you have used a Hacklinger a lot.
The little red "hockey puck" magnet will go over 1/4" braces and such. All you have to do is slip it into the sound hole. You can cover a whole guitar without worry.

Of course you should buy the latest gizmo. Someday soon, you will be able to buy the whole setup and run it all over your '37 Martin and it will CNC a top or back out for you likity-zip...

Yup, but unless you've got exactly the same piece of wood, the copy won't sound like the original, and maybe not even then....

The electronic one probably works sort of like a metal detector, sensing the chance in inductance in a coil based on the proximity of the iron in the magnet. That sort of contour map can be very helpful in a general way when you're trying to produce a particular sound, especially if you can look at a bunch of different instruments to find the common threads.

I have not, I cannot afford one at the moment (I have many other more pressing needs) but I had wanted one until I saw the magic probe. Like I said earlier it's only $50 bucks or so more so why not? I suppose if you already have a hacklinger it's probably not worth it, I get that. For someone like me with neither, the more technologically advanced version is more appealing. I don't really need one right now until I get to the finish sanding stage anyway, which should be sometime in January/Feb, just in time for the tax return

I have nothing against CNC, I actually just sold my small unit. However, snapping out a back/top isn't on the list of things that I've used it for.

What do you mean by finish sanding? Sanding to prep the wood for finish, or sanding the finish in prep of buffing?

When I used the term finish sanding I should have said prep sanding. Sanding getting ready to finish. I some time use a ROS and it can remove wood quickly.

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It sounds like a fun little gizmo. If I was at the point I could do "paint by numbers" guitar making it might be worth having. I wonder if you could use a light source and measure differences in luminosity within the top and match it against the thickness contour map. That might give a "map" of the density differences. The light source could be an LED in a magnetic housing that could be pulled around by another magnet outside the box attached to a high tech light meter. It would give you more information about the top, but I'm not sure what the value of it would be. Curiosity value if nothing else.
I'm still "measuring" things with the tips of my fingers.

Variations in the wood density alter the light transmission. Some folks use this in graduating the top: the idea is that you get the same amount of light coming through everywhere, so the denser areas end up thinner and not so stiff and heavy. It would be interesting to see if this actually equalizes the stiffness/mass and makes the vibration more uniform from point to point, as advertised. I'm skeptical.

By the same token, of course, uniform thickness overall results in variations in wood stiffness and mass from point to point too. This seems to be one reason why it's difficult (at least) to make 'identical' guitars that sound the same. The slight variations in wood density and stiffness from point to point alter the way the top vibrates at high frequencies, which is where normal hearing is most sensitive. Even when the low-end vibrations match up 'perfectly' the guitars sound different.