Posts posted by scordatura
6 minutes ago, filimonovfineviolins said:
To this day people make mistakes with Perlman and Zukerman, such as Pinchas Perlman and Itzhak Zukerman.
This is quite a statement my friend. Know I know who I am dealing with LOL
I don't care moving on...
No Perlman. The reason being that was a selling point when I bought mine. "Perlman has one". It is a Vuilllaume made by Voirin. Perhaps he does not use it. Up to you mate.
I have also heard from a reliable source that Perlman owns/uses a Voirin.
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"!
12 minutes ago, Don Noon said:
The chiploads in the linked article are essentially the same as the chart I posted, which again gives recommended feed rates well above the capability of anything other than full-on industrial CNC machines.
Us common folks have to use lower feed rates. The fastest I have cut is 2500 mm/min (~100 in/min) out of the flat-out maximum travel speed of 4000 mm/min (157 IPM), and even that is less than half of the recommended feed rate in the article's example.
Yes the mega quick feed rates seem to be for commercial production setups that are cranking through milling. No doubt pro level machines that are beyond the reach for most of us. This why when I went from the guestimation formula to a more "evolved" calculation I thought the feed rates are just nuts. As someone I read put put it, when someone is hand routing, they are going by the sound and feel of the process to guide their feed rate not a calculation.
Interesting article on chip load:
Always go to the auction in person and/or have someone that has expertise go for you. Otherwise caveat emptor!
Spindle speeds during CAM seem to have two schools of thought. The fastest for the cleanest cut or slowest for heat and wear. I realize that the feed rate is the other variable and the two are interrelated. I find the calculators that are available (e.g.http://www.cutter-shop.com/information/speed-and-feeds-calculator.html) are fairly aggressive in terms of feed rate...My feeling is to have a higher spindle speed (mine goes to 21K) and slowish feed rate. That being said one is supposed to take into account the chip clearing rate for each bit. One can hear when the machine is cutting if everything sounds happy. Far less calculated but seems to verify if you are on the right direction. Thoughts?
2 hours ago, Marty Kasprzyk said:
There seems to have been at least four different ways of duplicating wood plate arch shapes that have been used:
1. Hand carving using arching templets as guides.
2. Duplicating router machines using patterns.
3. Pressing thin plates into molds.
4. CNC machining.
5. In the future we might see 3D printing if suitable materials/designs can be found
Each of these has some disadvantages so I make my plates flat.
I would also add carbon fiber which would be laying material in a mold. I have played the Luis and Clark instruments. They are good but for the discerning player have an unusual tonal characteristic.
Being a formula 1 fan, I am amazed what they and aerospace are doing with these materials. I also have a few carbon fiber bows that are pretty good. My favorite being the Rolland Spiccato.
53 minutes ago, David Burgess said:
"Recovery" can be quite a challenge. Recently, When I presented at a Michigan Violin Maker's meeting, some woman told me,
"From what I'd read, I thought you were going to be much bigger and badasser".
I responded, "What? Ya mean I'm not"?
Hey you are in good company. That is what Aaron Rodgers and Drew Brees hear when fans meet them.
29 minutes ago, David Burgess said:
I don't use any magnetized tool holders. Too many problems, including what Bill has mentioned. The strips you are seeing are Velcro. Yes, the Velcro can wear out in twenty years or so of intensive use, so might need to be replaced something like once per two decades.
Very cool idea as I have outgrown the number of slots on my wooden holder. I am verging on being a gouge and chisel junkie. They say the first step to recovery is recognizing the problem.
42 minutes ago, Bill Yacey said:
Micro fracture chips will stick to a magnetized edge and further hasten the destruction of a fine edge during use.
That is what I suspected.
We need a show us your “workbench” thread. David do you feel that the magnetic tool holders magnetize your gouges, chisels, etc.? I notice you are sticking them on the handles and not the tool.
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.
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:
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.
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.
I had a friend that owned a Storioni. It had one of the best E strings I have ever played. Everything was there--power, flexibility, color. Peter Prier (or someone in the shop) had to do a major restoration on the top as one of his children sat on it! Really cool violin.
1 hour ago, Three13 said:
I've found the folks at the Smithsonian to be a little easier to deal with - kudos for getting permission to scan it!
That is what I have heard. My next D.C. trip will be at the Smithsonian.
41 minutes ago, JohnCockburn said:
You must be a VIP if they let you do that!
No just persistent. When I visited the Library of Congress last summer, I was treated as a nobody!
18 minutes ago, Don Noon said:
If you loft using "rails" (as I did), I think the result is similar to the curve network.
I am going to do an A B comparison. My gut tells me that Rhino will have the edge on Fusion 360 when it comes to skinning from rails.
10 hours ago, Urban Luthier said:
Would you be able to share the STL file?
I'm sorry I cannot share.
Fusion 360 only has loft. Rhino has curve network. This video illustrates what I am talking about. We should probably move this to the CNC discussion so we do not clog Don's bench thread.
1 hour ago, Don Noon said:
I looked very carefully under glancing light at the parts that were milled from the model, and I could see no evidence of ripple from the model. Either it's just a rendering artifact, or something else that doesn't matter. I only care about the wood things.
I kind of like the corduroy effect of your milling. Reminds me of the pants I used to wear back in the day!
in The Pegbox
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...