scordatura Posted January 24, 2020 Report Share Posted January 24, 2020 I feel that it would be good to have a discussion regarding CAD/CAM software. There are a number of options out there. As I get deeper into this area two programs seem to be prominent. Rhino and Fusion 360. Fusion 360 - free for hobbyists and education Rhino 3D - 90 day free trial $995 to buy $495 for educators There is also VCarve pro that is free. Windows only. Even though I have only used it a bit, it does not seem to be as powerful as Fusion 360. For simple projects it seems like it would be fine. Fusion 360 seems to be the obvious choice due to it being free. There is something that Rhino has that is not in Fusion 360-- a curve network command. To me there is a difference between using loft with rails and the curve network. Modeling the surface for tops and backs can be challenging. The question is whether it is worth the expenditure. Link to comment Share on other sites More sharing options...
Geigenbauer Posted January 24, 2020 Report Share Posted January 24, 2020 This is a topic that I am also very interested in. Thank you for posting. I am new to the CAD/CAM world but here are my two cents based on limited experience thus far: Rhino: I have never used this software. V-Carve pro: I recently attended a Woodcraft class where this software was introduced. I am sure we only saw a few of its features I left with the feeling that this is a great and easy to use software for things like signs, simple furniture projects and maybe molds but I am not sure it is a good option for 3D models and complex surfaces. The same company makes a more professional software called Aspire. Not sure if this would be a better option. Fusion 360: I have put some time into trying to understand the software and practicing. I am attaching a picture of my very first rough attempt for creating a viola body. I think Fusion 360 is a professional and very powerful software, but you have to invest time into training/tutorials and practice. I will continue practicing and refining my skills. Link to comment Share on other sites More sharing options...
Michael_Molnar Posted January 24, 2020 Report Share Posted January 24, 2020 This is a great thread. I too wonder about the advantage of these expensive packages. It pretty much depends on the detail you want the CNC to achieve. If you are just hogging out a rough plate, there are very inexpensive programs for that. I know that Rhino is considered to be the “best” according the CAD designers. Fusion360 is very good too. It’s a matter of how much time and money you want to spend on this addition to your shop. Link to comment Share on other sites More sharing options...
Fiddlemaker5224 Posted January 25, 2020 Report Share Posted January 25, 2020 I currently have the Aspire v10 It is miles above V carve pro with many 3D options and you can add a 4th axis at a later time if desired.. One thing I like about the v carve and Aspire, is you can get the probe attachment. Then you can scan an existing violin viola or cello plate. With the scan cloud you produce, modeling the plates becomes a few hrs rather than days. One of the down sides is that modeling the inside of the plates with Aspire is not what I had hoped it would be. This still did not matter to me much as I always did the final shaping and graduation by hand. Link to comment Share on other sites More sharing options...
Geigenbauer Posted January 25, 2020 Report Share Posted January 25, 2020 I tried to capture the outside arching in Fusion 360 by placing the arching templates from the poster at the respective positions of the back. It worked pretty well but it took me a while to get this set up and scaled. Hope you can see this in the picture below. Link to comment Share on other sites More sharing options...
scordatura Posted January 25, 2020 Author Report Share Posted January 25, 2020 1 hour ago, Fiddlemaker5224 said: . One thing I like about the v carve and Aspire, is you can get the probe attachment. Just for the record you can also probe with Fusion 360. 45 minutes ago, Geigenbauer said: I tried to capture the outside arching in Fusion 360 by placing the arching templates from the poster at the respective positions of the back. It worked pretty well but it took me a while to get this set up and scaled. Hope you can see this in the picture below. That is how I am doing mine. I am matching arching templates as canvases perpendicular to the outline. Then creating new planes that have a 1 mm rise in the arching from the outline up. A topography or layer cake of sorts. This verifies that I am on the right track. Link to comment Share on other sites More sharing options...
scordatura Posted January 25, 2020 Author Report Share Posted January 25, 2020 2 hours ago, Michael_Molnar said: This is a great thread. I too wonder about the advantage of these expensive packages. It pretty much depends on the detail you want the CNC to achieve. It’s a matter of how much time and money you want to spend on this addition to your shop. Yes and yes. I am hooked on this stuff now. It comes from my days with Illustrator, photoshop, and all of my other digital endeavors. I feel that it will be time well spent. I also tend to be a perfectionist. Link to comment Share on other sites More sharing options...
Michael_Molnar Posted January 25, 2020 Report Share Posted January 25, 2020 How much longer will Fusion360 be free? What do you do when they shut that down? BTW, a few years ago I tried to get the academic discount for Rhino, but couldn’t because I was retired. Any other former teachers have success? I’m no longer interested, just curious. Link to comment Share on other sites More sharing options...
Urban Luthier Posted January 25, 2020 Report Share Posted January 25, 2020 Hi Mike, Likely free for non commercial use for some time to come. Licensing options here. PM me if you'd like more local colour. I'm ex ADSK (actually started at Alias). I've played with Fusion since the very beginning - Fab tool. But I will say (and Mike and Don will confirm) the effort for setting up a digital fab shop is extraordinary if you don't have a background in machinery and software. Much harder than working by hand! Chris Link to comment Share on other sites More sharing options...
scordatura Posted January 27, 2020 Author Report Share Posted January 27, 2020 Another element to add to the Rhino 3D story. There is no native CAM in Rhino. You need a plugin to run CAM. RhinoCAM is $1425. Ouch! FreeMill is free but is described as an "entry level" CAM engine. So my plan now is: Model in Rhino Export as .3dm from Rhino and Import into Fusion 360 for CAM. That is provided that the import goes smoothly. I am hoping that there are less steps and issues with working with .stl or .obj files. Converting meshes to a body is tricky. For those who do not know, it is difficult to select faces to generate cutting paths on .stl files. There are Mesh face limitations when converting to BRep in fusion. Sometimes converting to quads from triangles solves the problem but can lose the surface integrity. The other work around is to cut up the body into different pieces. Before you say just work in Fusion 360, at this point I am sold on the curve network command in Rhino. I might change my mind though as I just installed Rhino. I'm on the 90 day trial. When that is up, I am educating young musical minds so Rhino would be $150 for a single educator license. Fun isn't it. Most would just say " fool grab the hand tools"! Link to comment Share on other sites More sharing options...
HoGo Posted January 27, 2020 Report Share Posted January 27, 2020 On 1/25/2020 at 1:48 AM, Geigenbauer said: I tried to capture the outside arching in Fusion 360 by placing the arching templates from the poster at the respective positions of the back. It worked pretty well but it took me a while to get this set up and scaled. Hope you can see this in the picture below. That is similar to what I did for my first quick models (posted here on MN in one of the other CNC threads) but I used these curves to create whole new mesh with addition of topographic lines avery 2mm elevation. Worked quite acceptably for a 60 minute work (not counting creation of the simple crossections and drawing) Link to comment Share on other sites More sharing options...
Johnmasters Posted January 28, 2020 Report Share Posted January 28, 2020 This may be controversial, but I can't help but think that deciding where to place the line of inflections may be a fundamental consideration. I onder if the oldsters could have carved both an edge channel AND a channel to mark the inflection line, and this at a given elevation. Alternatively, this would not have had to be in a plane. Has anyone given thought to this? I visualize a minimal surface area for the entire plate for the given arch height, and I am not sure that the line of inflections can be easily deduced from the standard five cross arching templates. ATTENTION: Michael Molnar and David Burgess. Link to comment Share on other sites More sharing options...
HoGo Posted January 28, 2020 Report Share Posted January 28, 2020 8 hours ago, Johnmasters said: This may be controversial, but I can't help but think that deciding where to place the line of inflections may be a fundamental consideration. I onder if the oldsters could have carved both an edge channel AND a channel to mark the inflection line, and this at a given elevation. Alternatively, this would not have had to be in a plane. Has anyone given thought to this? I visualize a minimal surface area for the entire plate for the given arch height, and I am not sure that the line of inflections can be easily deduced from the standard five cross arching templates. ATTENTION: Michael Molnar and David Burgess. I think that it would be pretty hard to define exactly where the inflection is on relatively low smooth curve, perhaps better visible in c-bouts. When I finalize archings and trace pencil lines at given elevations to create map of the real thing to show spots that need attention few strokes of scraper can move those quite a bit. So unless the arching shapes are odd (sorry, but I consider the ones in picture above a bit odd with very wide channels and inflection almost half way up the arch) the exact place is matter of finalizing surfaces with hand tools. Giventhe arch crossections and long arch are decent you will get quite good generic representation of the model that can be finalized by hand (depending how much extra wood was left on the outside) Link to comment Share on other sites More sharing options...
scordatura Posted January 28, 2020 Author Report Share Posted January 28, 2020 41 minutes ago, HoGo said: sorry, but I consider the ones in picture above a bit odd with very wide channels and inflection almost half way up the arch I would suspect that the channel issues are due to the arching from an Andrea Guarneri (Comte Vitale) viola or similar instrument as the Andrea Guarneri violas are particularly revered. Definitely not Strad or del Gesu like. I could be wrong though... Link to comment Share on other sites More sharing options...
Don Noon Posted January 28, 2020 Report Share Posted January 28, 2020 10 hours ago, Johnmasters said: This may be controversial, but I can't help but think that deciding where to place the line of inflections may be a fundamental consideration. Has anyone given thought to this? 1 hour ago, HoGo said: I think that it would be pretty hard to define exactly where the inflection is on relatively low smooth curve, perhaps better visible in c-bouts. That is one of my main design criteria, and what I look for in good instruments. It's not that hard to find the inflection if you have a varnished instrument in your hand and have a localized light source overhead. Look at the reflections, and how they move when you tilt the instrument. In carving (or scraping), a glancing narrow-beam light source will find it. Link to comment Share on other sites More sharing options...
HoGo Posted January 28, 2020 Report Share Posted January 28, 2020 1 hour ago, HoGo said: I think that it would be pretty hard to define exactly where the inflection is on relatively low smooth curve, perhaps better visible in c-bouts. 17 minutes ago, Don Noon said: That is one of my main design criteria, and what I look for in good instruments. It's not that hard to find the inflection if you have a varnished instrument in your hand and have a localized light source overhead. Look at the reflections, and how they move when you tilt the instrument. In carving (or scraping), a glancing narrow-beam light source will find it. I had old distorted instruments in mind when typing. texture of varnish and wood would not make it easy to find it and I guess it would vary wildly around the instrument (the CT scans often show how different arch can be on bass side and treble side). But of course the main schools will have somewhat distinctive placings of the inflection (Amati vs Strad vs Guarneri vs. Stainer) Link to comment Share on other sites More sharing options...
scordatura Posted January 28, 2020 Author Report Share Posted January 28, 2020 10 minutes ago, HoGo said: I had old distorted instruments in mind when typing. texture of varnish and wood would not make it easy to find it and I guess it would vary wildly around the instrument (the CT scans often show how different arch can be on bass side and treble side). But of course the main schools will have somewhat distinctive placings of the inflection (Amati vs Strad vs Guarneri vs. Stainer) Yes this is the problem when working from CT scans. You have to do the arching correction which means bringing down the soundpost/treble side and then mirroring over to the bass side or the opposite if you work from the bass side. It depends on how tight (New York setup) the post has been and the vulnerability of the plates to distort. Splitting the difference between the high treble and low bass seems to make sense to me. Link to comment Share on other sites More sharing options...
Johnmasters Posted January 28, 2020 Report Share Posted January 28, 2020 6 hours ago, Don Noon said: That is one of my main design criteria, and what I look for in good instruments. It's not that hard to find the inflection if you have a varnished instrument in your hand and have a localized light source overhead. Look at the reflections, and how they move when you tilt the instrument. In carving (or scraping), a glancing narrow-beam light source will find it. My idea was to find where to DEFINE the inflection. That would help with the problem stated by HOGO. That was the whole idea, to place the arching by knowing where the inflection would be. Inside the channel, all curvature is positive. Outside it is negative (all saddle-points). It would have to be learned by experience. Continue strads f-hole channeling up and around. Notice that his f-hole channel seems to go above the top of the f-hole. Link to comment Share on other sites More sharing options...
David Burgess Posted January 28, 2020 Report Share Posted January 28, 2020 18 hours ago, Johnmasters said: This may be controversial, but I can't help but think that deciding where to place the line of inflections may be a fundamental consideration. I onder if the oldsters could have carved both an edge channel AND a channel to mark the inflection line, and this at a given elevation. Alternatively, this would not have had to be in a plane. Has anyone given thought to this? I visualize a minimal surface area for the entire plate for the given arch height, and I am not sure that the line of inflections can be easily deduced from the standard five cross arching templates. ATTENTION: Michael Molnar and David Burgess. John, that sounds like a very practical way to go about things. But if it was done that way on Strads etc., I'd expect that we would see some artifacts. There is also the possibility that we don't see things which we are not specifically looking for, and I haven't run across anyone yet who was looking for that, nor have I. I'll give it a go in the future. Link to comment Share on other sites More sharing options...
Michael_Molnar Posted January 28, 2020 Report Share Posted January 28, 2020 2 hours ago, Johnmasters said: Continue strads f-hole channeling up and around. Notice that his f-hole channel seems to go above the top of the f-hole. I agree. Link to comment Share on other sites More sharing options...
Michael_Molnar Posted January 28, 2020 Report Share Posted January 28, 2020 18 hours ago, Johnmasters said: This may be controversial, but I can't help but think that deciding where to place the line of inflections may be a fundamental consideration. I onder if the oldsters could have carved both an edge channel AND a channel to mark the inflection line, and this at a given elevation. Alternatively, this would not have had to be in a plane. Has anyone given thought to this? I visualize a minimal surface area for the entire plate for the given arch height, and I am not sure that the line of inflections can be easily deduced from the standard five cross arching templates. ATTENTION: Michael Molnar and David Burgess. I also agree that the 5 cross arch templates do not detect an important feature, namely infection patterns. Pay attention to Don’s use of light reflections and shadows. Remember my photo of the NY MMoA’s Strad? Now you can understand what I was looking for. Namely this: Link to comment Share on other sites More sharing options...
Geigenbauer Posted January 29, 2020 Report Share Posted January 29, 2020 I just came across this interesting discussion on the AUTODESK webpage. https://forums.autodesk.com/t5/fusion-360-design-validate/another-small-loft-problem/td-p/9201723 I found the video at the bottom of the page (posted by TrippyLighting) very interesting. He is demonstrating how he would approach a loft surface with few profiles. Also a lot of practical tips included. Link to comment Share on other sites More sharing options...
scordatura Posted January 29, 2020 Author Report Share Posted January 29, 2020 6 hours ago, Geigenbauer said: I just came across this interesting discussion on the AUTODESK webpage. https://forums.autodesk.com/t5/fusion-360-design-validate/another-small-loft-problem/td-p/9201723 I found the video at the bottom of the page (posted by TrippyLighting) very interesting. He is demonstrating how he would approach a loft surface with few profiles. Also a lot of practical tips included. There are some very good points in the video! The zebra contours is great for visualization. Link to comment Share on other sites More sharing options...
HoGo Posted January 29, 2020 Report Share Posted January 29, 2020 2 hours ago, scordatura said: There are some very good points in the video! The zebra contours is great for visualization. Zebra analysisi is available in RHino as well and it works great to find curvature continuity/tangency problems of your surfaces. I think some steps he did in the video are unecessary or at least could be worked out simplier in Rhino (all the stuff with pints and curves in the beginning including removal of the offset line). Perhaps Rhino has better/ more functions for surface creation but I've never worked in Fusion. Link to comment Share on other sites More sharing options...
HoGo Posted January 29, 2020 Report Share Posted January 29, 2020 12 hours ago, Michael_Molnar said: Namely this: Wasn't the fluting carved after the f holes were cut on nearly finished top? We cannot count that as inflection but rather cosmetic treat. I guess before fluting the f hole wing was convex or nearly flat and it looked better to them to carve it concave. Link to comment Share on other sites More sharing options...
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