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Carvewright / Sears Compucarve...desktop Cnc?


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Yowza. Yeah, it would have to be pretty cheap... if the only thing to use it for is bridges and inlay work. Though, I disagree with your assessment of usefulness for inlay. Being able to cut the cavities is still a huge time-saver even without being able to cut the pearl. Alternatively, you could cut the pearl first and then make your inlay program based on the shapes. :D

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My first thought was that it would be great for making bodies complete with routes, carves, and angled mortises, depending on how easy/difficult it is to program. But then I read the fine print:

- maximum cutting depth of 1 inch, so it can't cut the full depth of the outline, cavities or mortises unless they are under 1", although I guess you could run a template following router bit along after you're done.

- according to the faq: "The accuracy of any single raster carving line is on the order of .005"-.010" in the y and Z and the step width is between .005" and .010" depending on the quality setting you choose." I'm not sure what they mean by the step width, but .010 doesn't seem very accurate. If you figure a mortise would be made of two lines, that means it could be up to .02" off.

Plus your workpiece needs to be 6" longer that the final product to reduce the risk of sniping.

I still think it's a pretty neat toy, though.

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Yowza. Yeah, it would have to be pretty cheap... if the only thing to use it for is bridges and inlay work. Though, I disagree with your assessment of usefulness for inlay. Being able to cut the cavities is still a huge time-saver even without being able to cut the pearl. Alternatively, you could cut the pearl first and then make your inlay program based on the shapes. :D

You can disagree with my assessment of its usefulness, but if the machine does not cut the pearl AND cut the routes for the inlay you lose the accuracy. I am not sure how much inlay you have cut, but cutting by hand is best fit by using the inlay itself to establish the routes(hand cut inlay is very close to pattern if cut very well, but not flawless). If it is capable of scanning the cut inlay accurately(without distortion) then you may be able to get it to work. Also, the machines accuracy(.005-.010") is pretty sketchy so it may not create very impressive results with detailed patterns.

That is just my take though, I could always be wrong.

Peace,Rich

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I haven't cut a lot. But I've cut enough to know that you're still gaining usefulness. Dare to compare: hand-cut pearl, traced on to wood, and then hand-cut cavities. How can that be more accurate than hand-cut pearl, followed by actual cut pearl transfered to a 'program' (or whatever the terminology is), and then cut into the fretboard automatically, based on that scan?

You're likely going to get more accurate results with the machine, and if not "more" accurate, you'll still be in the same ballpark while saving yourself some aggravation and fiddly work (by comparison, praying that your chisel or Dremel doesn't slip).

.005"-0.010" isn't precise enough for some fretwork, but it's plenty accurate for all but the most intricate inlay. Let's put that into plain english: "five-thousandths (one-two-hundredth) of an inch to one-hundredth of an inch". That's a barely-visible line, which I would be enormously pleased to achieve with hand-tools. More commonly, there will be even larger gaps than this, and the CA or epoxy will fill it in, leaving the appearance of invisibility. The crap-assed amateur inlay I've done had far, far larger gaps which still ended up looking "meh... acceptable". But that's a different story... because if you can achieve 0.010" accuracy, you're well beyond the "acceptable" range and well into the "sweet"!

All that said, it still hasn't even been assessed that the thing won't cut pearl. It well may. Though, I can't imagine it'll cut it without a godawful "burnt hair" stench and lots of harmful dust.

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Like I said Greg,

If it is capable of scanning the cut inlay accurately(without distortion) then you may be able to get it to work. Also, the machines accuracy(.005-.010") is pretty sketchy so it may not create very impressive results with detailed patterns.

If it can scan the cut inlay that would be a step in the right direction. The stepping accuracy though could be an issue. I understand how much 5 thousandths is(that if even all around the inlay could be fine). 10 thousandths is a piece of fine line binding, but again if it was even it could be acceptable. That is the stepping tolerance though +/- and if it was not even that would not look too hot(I am sure that would make sence to you).

I don't think this machine is a real good fit for guitar work. I would love to pick up a K2 one of these days. It is a lot of money and requires a good deal of learning to become proficient with one of these machines. If I am going to invest that much in a machine(the time learning how to use it well is probably the most expensive aspect to me personally). I am going to listen to the people that use them regularly. If they say it ain't gonna do the job or its limitaions make it pretty much useless. I will take there recomendations.

One day these are going to be a tool everyone has in their shop. The possibilities are really cool to me.

Peace, Rich

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Ah, OK. As you suspected, I didn't understand the difference between a simple "offset" tolerance (inventing terms is fun! :D ) and the stepping tolerance. Cheers.

No matter how you cut it (no pun intended), until you can enter actual CAD/CAM or other standard files, its usefulness is severely crippled.

Greg

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I've got a K2 3925 machine and it is repeatable to within about .002. This number includes all sources of error from all 3 axis. I highly recommend it...it is good for "slower" production work. The main limitation is the size of the spindle (which is a 3.25 HP porter cable router)..and the flexibility of the frame. Even so, it is definitely faster and more accurate than doing things by hand.

The compucarve thing is not geared towards inlay...or really any other parts of guitar making.

A machine like the compucarve is controlled via stepper motors whereas higher quality machines make use of servo motors. Stepper motors only move in certain increments..and when they wear out they miss steps. The machine controls position of the axis by counting how many pulses it sends to the motor. The servo motors on my K2 have optical encoders...they constantly feedback their position to the controller PC.

For anyone who is interested in getting into CNC, I highly recommend you download a copy of Rhino CAD software. If you get to the point where you are comfortable with CAD, then you are ready to go to CNC

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I've got a K2 3925 machine and it is repeatable to within about .002. This number includes all sources of error from all 3 axis. I highly recommend it...it is good for "slower" production work. The main limitation is the size of the spindle (which is a 3.25 HP porter cable router)..and the flexibility of the frame. Even so, it is definitely faster and more accurate than doing things by hand.

The compucarve thing is not geared towards inlay...or really any other parts of guitar making.

A machine like the compucarve is controlled via stepper motors whereas higher quality machines make use of servo motors. Stepper motors only move in certain increments..and when they wear out they miss steps. The machine controls position of the axis by counting how many pulses it sends to the motor. The servo motors on my K2 have optical encoders...they constantly feedback their position to the controller PC.

For anyone who is interested in getting into CNC, I highly recommend you download a copy of Rhino CAD software. If you get to the point where you are comfortable with CAD, then you are ready to go to CNC

I own a small CNC mill and hope to someday purchase a CNC router. I think the issue I would have is you are close in price to a real CNC router, real meaning 2" x 4" size table big enough to do most parts maybe even several parts at a time. Looks like you have to invest over 2K to start. The router is certainly a big one but my worry would be it looks looks like it will just fit a standard guitar body like a Les Paul or Strat. Forget about an Explorer or Flying V or any custom body sized over the max width of the unit.

Unless you are rich servos motors are for mass production; steppers are for us simple folk like most forum members and will work fine on any CNC router so that should make no difference. You dont get feedback from the motors but it works just fine if everything else has been set up properly. If you are doing this as a pro forget it, open your wallet and spend the big bucks.

I do like the probe so you can take a design and scan it into the machine, it will save you time learning several programs to get a part to cut. But I have already started that process and would personally look for a larger platform.

There is also a CNC forum out there CNCzone.com with a section on guitar building. I found this forum very helpful when I first started out. they will probably rip this machine up but try it maybe some does own one and it works.

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