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Michael Smith
01-09-2019, 03:36 PM
I'm thinking it's getting to be time to get a CNC before I get to stupid and old to figure out how to work it. I would like to do,

fingerboard slotting and marker channels
cut out inlays. This is where I have questions. I want to be able to make a drawing by hand, scan it and have the CNC cut out the parts. I don't want to lose too much artistic control. Is this doable? If not I don't really have much use for CNC. I don't want to have to make CAD drowings of things other than fingerboards and bridges etc. it would be nice to have it do slotted headstocks as well.

Can anyone suggest a unit that would work well for the above.

Allen
01-09-2019, 06:34 PM
There is no way that you are going to scan a drawing in and get the machine to cut it out. The files need to be in a format that the software can make use of. A picture isn't that.

The hardest part for most people that want to get into CNC is the software learning curve. It's absolutely huge if you aren't familiar with the concepts. And the time involved to learn, design your part and then program isn't for everyone. Most people new to the idea think that they are going to buy a machine and have it up and running within a few days. It just isn't so.

If it's going to be a one off type of thing for decorative inlay, then CNC isn't the tool in most cases. Though I have done it for a really complex and large inlay on fret board and peg head.

It excells in doing things that take an lot of time to do by hand and you do the similar thing all the time. And once you have it worked out, the accuracy is at a completly different level.

For instance today I did 5 fret boards from blanks to fully compound radius. 2 tenors, 1 concert and 2 sopranos. Cut to shape, added purfling lines, fret markers (mix of diamonds and dots) and blind fret slots cut. They just need frets installed. All the while I was also bracing backs, bending sides, and gluing in kerf linings.

I'd suggest you start by looking at Fusion360 from Autocad as your software for design and CAM. They offer it for free on a yearly basis to start ups and those on under $100K USD. It's hands down the best software out there and runs on both Windows and Mac OSX. The tutorials on their website and Youtube is all the instruction you will need.

Try and design a fret board. It'll be far more difficult than you might think. Especially if you want to put a compound radius on the top. I'm happy to help you out if you need.

If after that you think you want to get a machine, I can point you to ones that I would be looking at if I was in the market today.

Arcy
01-09-2019, 07:06 PM
There's a good Fusion360 Fretboard modeling tutorial at https://www.electricherald.com/fusion360-cnc-fretboard-model/ that walks through the basics of a straight radius guitar fretboard. Unfortunately the CNC I was hoping to use in the maker garage down the road is a bit too small for anything beyond a tenor fretboard (and might be a wee bit short on that too).

I've been playing with laser cut inlays, and in theory the 2D graphics are easy to do by drawing and scanning. In practice, getting the vectors sized right with the laser's kerf is defying me (I could simplify my figures, but... nah... that's ridiculous!). In the time I've spent fiddling with the patterns I could have cut more by scrollsaw than I'm likely to ever go through, especially since this is probably a one-off anyway. On the other hand, the saw's out in the cold and I can play laser games inside where it's warm, so I expect I will nail it before I get frustrated past the point I'm having fun.

Pete Howlett
01-10-2019, 10:30 AM
I couldn't get to grips with fusion. My CNC router came with an integrated package call Vectric Cut2D. I also use profcarve which is a 2D variant. I worked out that Fusion was far too powerful for my requirements.

You use a CNC to do repetitive tasks consistently. That isn't what you wanna is it? I spent a whole day on a complex inlay. When it's done it will be stunning, but moreimgportant, repeatable...

saltytri
01-10-2019, 10:47 AM
[QUOTE=Pete Howlett;2122643] repeatable /QUOTE]

Exactly. The 2D Vectric products are the bee's knees for doing things like fret slots and logo inlay. The time spent making files for tasks that are often repeated is soon paid back in full.

Timbuck
01-10-2019, 11:45 PM
While being a great fan of CNC machining (as most of you know I have built a few but dont use them) I feel that they shouldnt be used to replace art and skill but be used for their accuracy as in jig making etc: this image of an inlayed ukulele would have at one time made people gasp at its beauty and the skill of the inlay artist, and it would have been a one off ..but as it is produced by CNC it dosn't have that sort of appeal anymore and there are several more out there with the same inlay, done on the same machine with the same programming by a guy who never held a chisel or hand engraving tools...and it sells for less than $250
114699

Kevin Waldron
01-11-2019, 09:10 AM
Michael,

I'm going to answer a little differently that the others.......What your asking to do is doable for CNC and or Laser and there are several programs on the market that would allow you to do what your requesting.......but it is also usually a three step process in most cases.

If you want to free hand sketch then you will need to photograph the project so as to get the object into some kind of digitial file. Next step would be to convert from a JPG /Tiff to a usuable Vector file. You will need a program like CorelDraw (there are others I think Adobe Illustrator as well) which has an AutoTrace Function........ This would allow you to take your drawn images/photo's and convert them to vectors (basically a cad graphical line, arc, spline etc..... meshes will not work for what your wanting to do.... programs like Sketchup typically produces this kind of format.) Once you have this file then it can then be converted/exported to a DWG or DXF format (along with several other formats that Cad/Cam Programs can use). Aspire being one of many.....that would work well with inlays. (Aspire 9 also has a Bitmap to Vector tracing functions but personally find that Corel for me has been more effective) (Personally use Rhinoceros for drawing instruments into 2D and 3D and for most of my CNC work with RhinoCam as the Cam program in coordination with Rhino. By trade even though I have been in the Instrument business for more than 12 years... I'm a long time design building contractor/developer and use Vectorworks, TurboCad, FormZ, and Chief Architect for drawing.... so fairly familiar with most cad programs.) We use CorelDraw for laser work. And if we are trying to convert 3D scans we would use programs like Artec Studio. Programs like Rhinocerous have point cloud converters which will also work on laser scaned objects. For instance if you had an existing F-5 mandolin and you wanted to scan the top so that it could be cut in the future on the CNC you might use a point cloud from a laser scanner to do this kind of work.

As for Fusion...... my personal experience with Autocad .....and I've been using some parts of this compaines programs since 1982. My experience for me has been that its all been about the money...... This firm has purchased numerous small startup companies that had Cad products or add-ons for various cad programs (T-Splines- VSR Shape being two examples) and dissolved them in order to either incorporate technology or eliminate competition. In addition they no longer allow you to purchase their program but lease them for some period of time. While Fusion is now free user be ware......... somewhere in the future as people get committed it want be...... just my opinion.

Back on topic... if your doing one-up kinds of projects probably would not recommend CNC unless you had some inclination of repeating what your were going to do or you just liked messing with Cad. It is also possible to directly draw into many of the Cad programs with various tablets...... personally not an artist but this is doable for many.

My two cents. Have a good week-end.

DPO
01-11-2019, 09:29 AM
While being a great fan of CNC machining (as most of you know I have built a few but dont use them) I feel that they shouldnt be used to replace art and skill but be used for their accuracy as in jig making etc: this image of an inlayed ukulele would have at one time made people gasp at its beauty and the skill of the inlay artist, and it would have been a one off ..but as it is produced by CNC it dosn't have that sort of appeal anymore and there are several more out there with the same inlay, done on the same machine with the same programming by a guy who never held a chisel or hand engraving tools...and it sells for less than $250
114699

I agree completely.

Michael Smith
01-11-2019, 09:38 AM
Thanks to everyone. Really great information. I like Allen's suggestion to get a copy of Fusion 360 and try making a fretboard file to see what is involved in that part of the process. I take it if you can make the files in Fusion or simular programs you are half way there? From what Kevin says it is doable. I haven't used Illustrator for a decade but I used to know it pretty well. This could be a fun adventure!!.

I agree with what Ken is saying about the man V machine. But then Allen makes these beautiful instuments that are really unique and does so with a fair amout of CNC without losing the craftsmanly hand made character. My question is does the CNC inlay we see so mcuh of look cheap because it was done on CNC or is it because of the artwork itself. Maybe both. That is something I would like to explore.

Kevin Waldron
01-11-2019, 09:47 AM
Arcy,

Laser kerf is determined by your lens size for example with a 4.0 lens on the Universal lasers we have...the kerf size of .003" so either offset positive or negative .003" ....depending on what your cutting either the inlay or pocket. (for sure two distinct different drawings)......... if we were using the HPDFO lens a much less forgiving lens then the spot size would only be .00016" difference in pocket or inlay is almost none existent.

One other thing that you may not be taking into consideration is the hour glass cutting effect. Typically the cut will have a tapper either towards the lens or away from the lens depending on the focal point. You can't neglect this factor especially if your using a Chinese or equivalent laser with a water cooled tube.

Allen
01-11-2019, 06:25 PM
Kevin makes a good point about how a laser cuts. It will never be exactly perpendicular from top to bottom. You can use this to good effect much like you do with a scroll saw by keeping in mind that a tapered cut will help seat the inlay with no gap.

Allen
01-11-2019, 06:29 PM
. My question is does the CNC inlay we see so mcuh of look cheap because it was done on CNC or is it because of the artwork itself. Maybe both. That is something I would like to explore.

Probably a bit of both Micheal. It's easy to go overboard as in the example that Ken had.

I'm of the mind that less is more in my work. It is difficult to rein in clients desires for embelishment at times though. I have turned away work that was just way over the top for anything I wanted my name attached to.

Here's an example of some headplates I made yesterday. Still have to inlay names and cut some pearl for one. But this type of work is dead easy once you get your files made. Doing by other means......well you know how tediuos that would be.

114730

Timbuck
01-11-2019, 10:20 PM
It could be a good idea to put a few errors into the programming thus giving the work a more human touch like a slight oversized pocket here and there and little bit of thick and thin in the wording.....like they do with sequenced music these days especially on the drumming tracks giving it a more human style "laid back feel" and such to stop it sounding like a robot playing :).

Arcy
01-13-2019, 08:28 PM
if we were using the HPDFO lens a much less forgiving lens then the spot size would only be .00016" difference in pocket or inlay is almost none existent.
Thanks! I think the main problem I am having was on the software side, but with your suggestion here I may also be able to fix this on the hardware end and move from a GlowForge to a Universal with (I think) an HPDFO lens. I don't think the way I offset the kerf was correct and so it grew rather than offset. This worked great for simple convex patterns but not for complex ones where two pieces of inlay lock together with both convex and concave curves. Fiddling with that this weekend and adjusting the pattern some to compensate I got things much closer, but I'm still ending up with too-loose-gaps on one side and too-tight-to-fit on the other.

kkimura
01-14-2019, 02:36 AM
It could be a good idea to put a few errors into the programming thus giving the work a more human touch like a slight oversized pocket here and there and little bit of thick and thin in the wording.....like they do with sequenced music these days especially on the drumming tracks giving it a more human style "laid back feel" and such to stop it sounding like a robot playing :).

Interesting concept. A truly gifted programmer might be able to incorporate the building nuances of well known luthiers thus creating ukuleles as Stradivarius or Hauser might have built.

Pete Howlett
01-14-2019, 07:45 AM
You should have an 'offset' function on your laser program that compensates for the 'conical' cut. These people know a thing or two about it Aryma (http://www.aryma.co.uk/showcase/)