Design to machining CNC

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wpala

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Hi
Looking to CNC my mill or Buy one , question is what programs are the easiest and cheapest to design the part and then just send it to machine ? or are there steps in between ? if someone can give me and idea of the work flow from design to a finish part, I'm very "green" in the CNC subject, will probably take some courses in CAD design programs but it seems there are are bunch of them now on the market would like some opinion on this
Thanks

Paul.W
 
Paul,

The typical workflow is to first design the part in a CAD program then, use the output of the CAD program as input to a CAM program to generate what is called G-code. The G-Code is then loaded into the software on the mill. The software on the mill (often times, people use a program called Mach 3) then controls the mill to make the part.

Learning a CAD program takes a little time and practice. There are some free share-ware programs but many do not have the feature to export the file for use by a CAM program. Also, the free share-ware programs have the usual problem of not being supported and often are not very mature and have too many bugs. CAD programs which have CNC file output capability can be expensive ranging from $1000 to $6000 with maintenance fees running between $300 to $1000 per year. I happen to use and like a program called Geomagic/Alibre. It is full scale, professional stuff and is at the lower end of the mentioned price ranges. There are others but, when selecting a CAD program, you need to stick with a company that will be in business for a while as, it takes between 6 months to a year to become proficient with any particular package. Other packages out there are TurboCad, RhinoCad, Solidworks, AutoCad... There are others but these are the more common ones that have a reputation and arent' going away anytime soon.

CAM: CAM programs generate a computer image of the part and machine and provide ways for you to set the tooling types, paths, speeds, ranges of motion etc. More often than not, they let you simulate the motions and preview all actions thus allowing you to minimize crashes. Likewise, they too have a learning curve and typically cost as much or slightly more than CAD programs. The more common packages are VisualMill (Mecsoft), SprutCam, BobCam and CamBam.

There are some CAM programs that "plugin" to your CAM program and the two software packages work from the same familiar working environment. For example VisualMill has a plugin for Alibre/Geomagic and all the screens work the same way as the ALibre CAD program.

The controller software -most commonly is Mach 3 and it allows you to (among other things) stop/start the machine in between sequences. Mach 3 is pretty inexpensive at about $300.

Right now, I'm in the market for a CAM program and I've selected the 4 axis version of VisualMill. Since I'm a licensed user with current maintenance on Alibre, the VisualMill software is $2500. It would otherwise cost a little more but the two companies have a partnership.

It just so happens, I like Geomagic/Alibre but, I'm also getting familiar with Solidworks; thus, I can only render opinions about those two programs. Be apprised, Swx is $6000 for the simplest package and it goes upward from there. I also played around with a demo version of TurboCad and found it very difficult to use. -Everyone is different about their preferences...

Of course, you could bypass all this and simply write G-code to control the mill directly. I wouldn't advise this anymore than I'd advise a person to write computer code in machine language or assembly language. -Just so happens, I still do a lot of machine and assembly language programming -and it is very, very time consuming...

Ray

EDIT: Most of the CAM programs mentioned above fall in the "Advanced Hobbyist and Low-End Professional" category. Those programs are designed for use on general purpose mills and lathes. There is a whole additional category of "High-End, Professional" software out there but the prices range in the 7 to 10 grand (and much higher) category.

Also, there might be cheaper ways to get into this but, I did not research them as, I'm mainly looking for professional-grade packages with name recognition that can be used on a resume and used in a professional setting.



wpala said:
Hi
Looking to CNC my mill or Buy one , question is what programs are the easiest and cheapest to design the part and then just send it to machine ? or are there steps in between ? if someone can give me and idea of the work flow from design to a finish part, I'm very "green" in the CNC subject, will probably take some courses in CAD design programs but it seems there are are bunch of them now on the market would like some opinion on this
Thanks

Paul.W
Click to expand...
 
Ray has a pretty decent rundown. I'll see if I can add anything.

I am also an Alibre user, and have the MECSoft CAM package (AlibreCAM). I like the drawing side more than I like the CAM side. I don't find the generated tooling paths from AlibreCAM to be particularly... sensical. The combination was not cheap. I also demoed a combined package from Dolphin. They have a demo you can try out, and they were nice and answered all the questions I had. I was more familiar with 3d cad systems though, so ultimately I went with Alibre.

I have also heard good things about CamBAM, though have not tried it out. Regardless of what you choose (and there are many options, from free to all way to the mid 5 digits) the steps remain the same, draw it, post it, cut it. The nice thing is that many software makers have demo versions so you can play around for a few weeks to see if things are going to work for you (you know, before you spend any $$).

Another thing to think about is, what sort of stuff are you going to cut. If you are doing mostly machine parts with simple radii and straight edges (2.5 axis milling), then you can get away with simpler software. If you are doing complex 3d shapes, the software will have to be more complex to keep up.

There is a sticky thread in this section called "Basic CNC" you might want to glance through it, we covered a lot of stuff there, some about machines, and some about software.
 
You could download the demo copies of 2.5D capable VCarve pro ($600 full license) and the 3D capable Aspire ($2K full license) - both software from Vectric. They are not CAD/CAM packages in the traditional sense but you can go from Vector drawing or imported DXF, apply the toolpath, and generate Gcode in minutes. They include the "CAD" and the "CAM". Tons of videos out there showing you how to do all of this plus a support forum. Every year or so they have a free point release and then after about the same time has passed a paid for full version upgrade.

I drew up a circle and wrapped a profile toolpath for an endmill around it and geneated fanuc gcode in about 30 seconds with Aspire yesterday. Then tested it on my recently retrofitted Ajax controlled Millport knee mill. The Centroid software loaded the vectric generated fanuc gcode it and ran it perfectly.

Also Centroid software has coversational part creation built in so you could use that to make parts and skip the CAD/CAM.

Centroid Software is a $500 and works with the Centroid and Ajax (DIY Centroid) controllers. These controllers will also run Mach which is $175.
 
You should also think about the type of CNC you are wanting to do - there is 2.5 D, 3 D, 4 axis, and others. 2.5 D works in a single plane - think of it as working with the left-right (X axis) and fore-aft (Y axis) and depth (Z axis). All cuts will be based on this. The Z axis is somewhat limited (more by the CAM software) to functions like drilling, profiling, and pockets. 3D adds the ability to load in a three dimensional object and convert it to more complex tool paths. 4 Axis adds a 4th axis, usually a rotary axis, that would allow machining of things like a splined shaft or fluted rifle barrel. As you might guess, the level of complexity goes up with each level. The other thing that was touched on, but not in enough detail is G code - it is not a hard fixed standard. For that reason, most CAM software has some sort of machine specific code generator, usually referred to as a Post Processor. If you use Mach3 to retrofit your mill, make sure that the CAM software you choose supports Mach 3 or you may have to write your own post processor. Even if it does, you may still have to modify some part of it, if your conversion does not match the setup the post processor was written for. Another CAM program that supposedly lets you draw your part from scratch and convert it to G code is BobCAD CAM. It can be a little intimidating and it lists for around $1200 right now, I think. The company I work for bought a copy of version 23 off ebay, which is perfectly legal, however, both you and the seller need to be aware that there is a $100 transfer fee to register the software. Make sure the seller is registered if you go that route. The current version is 26 (just released). If you buy an older version and register it, you become eligible for upgrade pricing, which cuts the price of the current version in half, so it can be worth buying an older version. We ended up buying version 25 when they offered it to us at $295 including the video training, so they can be very aggressive in their marketing. Let me finish up by saying that going CNC is a fairly complex process and you will invest a lot of time (and most likely money) learning it, to do it right.

Dan
 
One thing worth mentioning... If you download a demo version of a program, you will have to register first and most companies are pretty strict about limiting the demo to only 30 days. Most of the programs will lock themselves to your computer's disk ID or other identifier and each time you start it up, it will "phone home" to verify you are not cheating them. If you're first learning a CAD program, make sure you have time in your life to get the most out of those 30 days. If you're looking at a CAD/CAM package, see if you can download the CAD package first, learn it for a week or so then get the CAM package. Trying to learn CAD and CAM at the same time is a tall order. Also, it's probably sensible to only download one package at a time to get the most out of the 30 days. Learning/experimenting with two different vendor's packages at the same time might be self-defeating.

Some vendors will work with you on extending the 30 day trial period but you'll need to call a salesman and strike a deal. When I tried Alibre about a year ago, they gave me an extra couple weeks. -Don't know if they regularly do that or not but, I was indeed a serious customer and needed more time to evaluate.

Ray
 
FWIW, I'm also a Alibre/Geomagic user. I found it much easier to use than Solidworks. For CAM, I have been using CamBam. My current workflow is as follows:


  1. CAD parts and assemblies in Alibre/Geomagic.
  2. Verify that everything looks good and fits together.
  3. Open each part in Alibre. Then go New->Drawing, select 1:1, select the correct face, export to DXF
  4. Open CamBam, open the DXF file, save as a CamBam file, and then work on the CAM (profiles, drills, pocketing)
  5. Generate the .nc gcode from CamBam, simulate it in CutViewer
  6. If everything is ok, copy it to my network server
  7. Go to my CNC Mill, copy it from my network server, use MACH3 to open the .nc files and start cutting the part.

For simpler parts (rarely), I will sometimes do it directly in CamBam. However, I find that it usually only takes me 15 minutes to CAD a simple part in Alibre (I still like that original name over GeoMagic!!), so I usually CAD it first. I've also tried using VisualMill (Alibre CAM), but I found it... ummm.... let's just say it was a stubborn mule to work with.

Paul Tan.
 
Paul,

Good post.

Yes, I'm not crazy about the new name. Geomagic sounds like a ride at Disney World. Alibre had such a nice ring to it conotating debonair and clean. Not only that, it had about a decade of established name recognition.

A quick comment about Geomagic vs. Solidworks... I first evaluated Swx and had bad go of it using the online help and tutorials. I later tried Geomagic and it was very easy to learn. The quality of the manuals and tutorials in Geomagic was (in my opinion) top notch. In a few days, I was making drawings. We use Swx in the office and I transferred a license to my office computer and after learning Geomagic first, Swx was strikingly similar and much easier to use the second time around. Upon using Swx for a small project, I came to truly realize the tremendous value of Geomagic. It is 1/6 the cost and for basic CAD functionality, it seems to have at least 80% (conservatively) the functionality of Swx. Swx wins-out when you need to add advanced packages such as wiring/bundling management, stress analysis, thermodynamics etc... Geomagic has some extensions for stress analysis, advanced motion and rendering but Swx is king of the hill in that regard.

I haven't cut the check yet for VisualMill and based on your input, will take a second look at CamBam.

Ray


paulctan said:
FWIW, I'm also a Alibre/Geomagic user. I found it much easier to use than Solidworks. For CAM, I have been using CamBam. My current workflow is as follows:


  1. CAD parts and assemblies in Alibre/Geomagic.
  2. Verify that everything looks good and fits together.
  3. Open each part in Alibre. Then go New->Drawing, select 1:1, select the correct face, export to DXF
  4. Open CamBam, open the DXF file, save as a CamBam file, and then work on the CAM (profiles, drills, pocketing)
  5. Generate the .nc gcode from CamBam, simulate it in CutViewer
  6. If everything is ok, copy it to my network server
  7. Go to my CNC Mill, copy it from my network server, use MACH3 to open the .nc files and start cutting the part.

For simpler parts (rarely), I will sometimes do it directly in CamBam. However, I find that it usually only takes me 15 minutes to CAD a simple part in Alibre (I still like that original name over GeoMagic!!), so I usually CAD it first. I've also tried using VisualMill (Alibre CAM), but I found it... ummm.... let's just say it was a stubborn mule to work with.

Paul Tan.
Click to expand...
 
Last edited:
This is exactly what I was looking for thanks
I have read many post about Alibre and happy customers, I would love to learn and start using it, was wondering if there is a place in GTA that I could sit in the class and learn it?
I do much better in organize sessions then on my own you know you pay for something no excuses etc....
I'm very green when it comes to CAD programs I have a problem drawing in sketch up for God sake,
Anyway thank you for all the input I will try to contact Alibre and see if they have any authorized courses in GTA



Paul





paulctan said:
FWIW, I'm also a Alibre/Geomagic user. I found it much easier to use than Solidworks. For CAM, I have been using CamBam. My current workflow is as follows:


  1. CAD parts and assemblies in Alibre/Geomagic.
  2. Verify that everything looks good and fits together.
  3. Open each part in Alibre. Then go New->Drawing, select 1:1, select the correct face, export to DXF
  4. Open CamBam, open the DXF file, save as a CamBam file, and then work on the CAM (profiles, drills, pocketing)
  5. Generate the .nc gcode from CamBam, simulate it in CutViewer
  6. If everything is ok, copy it to my network server
  7. Go to my CNC Mill, copy it from my network server, use MACH3 to open the .nc files and start cutting the part.

For simpler parts (rarely), I will sometimes do it directly in CamBam. However, I find that it usually only takes me 15 minutes to CAD a simple part in Alibre (I still like that original name over GeoMagic!!), so I usually CAD it first. I've also tried using VisualMill (Alibre CAM), but I found it... ummm.... let's just say it was a stubborn mule to work with.

Paul Tan.
Click to expand...
 
Their main web site outlines several types of training. http://www.alibre.com/training_support/
Also, on the main website at the very top bar, look for a small "forum" selection. It will take you to the user forum which you can join even if you don't own the software. In that forum you can find several authorized training programs of varying types.

-No affiliation with any of this. Just a satisfied customer.

FWIW, you can purchase the video training set for about $150. It's very good -a purchase I do not regret and still refer to on occasion.

Ray


wpala said:
This is exactly what I was looking for thanks
I have read many post about Alibre and happy customers, I would love to learn and start using it, was wondering if there is a place in GTA that I could sit in the class and learn it?
I do much better in organize sessions then on my own you know you pay for something no excuses etc....
I'm very green when it comes to CAD programs I have a problem drawing in sketch up for God sake,
Anyway thank you for all the input I will try to contact Alibre and see if they have any authorized courses in GTA



Paul
Click to expand...
 
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