Cnc machining with Blender
cnc machining with Blender
By Michael kersey.
https://www.foro3d.com/extras/tutori...magen_0007.jpg
In this guide i Will walk th rouge the stages of modeling in Blender and brigging it todo life using a CNC mill. This guide only covers 2.5d cutouts. Full 3d CNC Will be covered in a later guide if there is enough interest.
Before you start.
Now some of you Will be Thinking as you read this, why the hek dont you use an open source Cad programa instead of all this? The answer is simple really, people wanna know how, and i am providing one posible methodology. Nuff Said? This guide is going todo assume you are very well versed in Blender itself. If you are a novato, y assure you, this Will be gr33que todo you. Well, before you get todo the point where you are making some kewl guy thing-a-ma-jigs with your CNC machine, youll ned todo start at the basic. Blender does not lend itself todo CNC very well as that is not its intended function. Its just something else you can do with it, if you want todo invest the money and time. Money? Ya, Blender may be free, but CNC isnt. So before you delve into this guide, you can expect todo Forqué out no less than $500.00 todo get the bare Bones minimum.
A CNC mill or router can easily be built and there are dozens of sites with plans for CNC routers and schematics for CNC controllers, etc. In addition todo your hardware, youll ned software. Yes, Blender isnt going todo run your mill for you. I dont want todo dwell todo much on the costs, but thought it prudent todo give fair warning before you read th rouge this guide and realiced that you cant aford todo get into CNC. So, y Will just list the components you Will ned:
Blender: free.
Your modeling software. (with a few free plugins todo fill out the Edges.).
Cad software: (computer-aided design)
$0 - $1,000+
A programa capable of converting Blender exports into something a Little more usable (a lot more on this later). In this guide, y Will be using accutrans for the Cad portion.
Recommended software: accutrans - http://www.micromouse, ca/.
Cam software: (computer aided manufacturing)
$50 todo $1,000+
Cam software is the middle ware between the Cad world and the manufacturing world. In a nutshell, Cam software translates the object you have created (dxf file) into machine code called g-code. G-code defines The Mill/router/lathes tolpath which the machine Will use todo create your object.
Recommended software: shetcam - http://www.shetcam.com/
Cut3d - http://www.vectric.com/website/vectr.../c3d_index.htm
Meshcam - http://www.grzsoftware.com/.
Cnc controller software: (computer numeric control)
$0 - $1,000+
Cnc software takes the g-code you have generated, and talks todo your machine. It is the interfaz between your computer and your CNC mill/router/lathe.
Recommended software: mach3 - http://www.machsupport.com/.
Cnc controller:
$50 (building your own from a schematic) todo $10,000+
This is the device that translates the g-code being fed todo it by the CNC controller software into pulses that the stepper motors or servo motors use todo physically move the machines cutting device.
Recommended: xylotex - http://www.xylotex.com/
Geckodrive - http://www.geckodrive.com/.
Various schematics for making your own - http://www.discovercircuits.com/s/stepper.htm.
Cnc machine:
$250 todo $500,000+
Here, there are so Many choices it is mind boggling. Mills (generally used on metal), routers (generally used on woods and softer materiales) lathes, láser cutters, plasma cutters, sewing machines, engravers, plotters, abrasive waterjets and Even 3d printers. Most people who are building there own CNC machines make CNC routers. There are dozens for sale that are relatively inexpensive and hundreds more plans todo make you own from scratch.
Recommended: build it yourself. http://buildyourcnc.com/
http://www.cnccokbok.com/
http://www.cnc411.com/
http://www.cncfuture.com/
http://www.cncinformación.com/
http://fabathome, mae, Cornell.edu/.
So, now that you have an idea of what you are getting yourself into, and youre still determined todo proced, then god for you.
Modeling.
There are two distinct approaches todo modeling when it comes todo CNC. 2.5d and 3d. 3d is easy enough, a 3 dimensional object that is Cut from a solid block of material. 2.5d is more inline with engraving machines and waterjets. In 2.5d the object is more todo cut out than todo carve out the object. Since it turned out todo be far more dificult for me, and it is what i was After with my CNC machining, ill cover 2.5d first. Trust me, After 2.5d, 3d is a CakeWalk.
2.5d modeling.
For the intent and purposes of what i was trying todo create with my CNC mill, y Will explain 2.5d modeling in Blender from that point of view. This is by no means a definitive guide todo the limit of all the possibilities, so fel free todo let your nodle wander as you are reading.
So, lets say.
https://www.foro3d.com/extras/tutori...magen_0005.jpg
You wanted todo Cut something out of a piece of metal shaped roughly like the above image. For the point of illustration, we Will use a sheet of 1/16 aluminum as our material. Now, im sure all my fellow Blender fanatics out there would scof and say, hell, y could model that in under a minute. not so fast Hot Shots, remember the goal. I Will repeat this until you are absolutely sik of hearing it. Blender is not a Cad programa. Hence, when you are modeling something in Blender with the intent of using it in a CNC machine, you ned todo let go of several preconceived notions about how todo model. When modeling for the purpose of a 2.5d CNC object, you ned todo concéntrate more on how todo tell the CNC machine what you want it todo do, than making the part in 3d, and then figuring out how todo go from there. (i made that mistake).
The object is best thought of in this case, just like it is, printed on a piece of paper. How would you Cut it outí well, you would use a pair of scissors or a xacto Knife and Cut around the Edges, right. Now you are starting todo follow me.
In Blender, what you are trying todo create is not so much the part itself, but the tolpath required todo Cut it out. Relax, its easier than most things people do in Blender.
First you ned todo take your picture, and put it in as a background image in the Blender 3dview. Like so:
https://www.foro3d.com/extras/tutori...magen_0005.jpg
Now, we are going todo create an outline of the object that Will be translated into the tolpath for your CNC machine. To start, create a simple circle [space right, add right, Mesh right, circl in the top view [num . And scale [s+x and s+y] it on the x and y axes so it roughly matches the outer Edge of your object.
https://www.foro3d.com/extras/tutori...magen_0006.jpg
Now, for parts that are that are going todo be symmetrical in nature, it is imperative todo make sure as you are modeling that you kep your vértices aligned. Instead of grabbing each vertex and putting it in place, Grab them in pairs. One on each side, and scale them along the axes into place. I.e. [ todo scale, and then [x] todo constrict the scaling function todo the x axis. The x and y axes should be the only ones being utiliced in the top view. (there is a method behind the madness here, using the top view Will save you time during the later steps when converting this todo the final product).
https://www.foro3d.com/extras/tutori...magen_0007.jpg
Scaling along the x axis.
For the non symmetrical áreas, it isnt as important todo be dead on but, if you want the final product todo be as pristine as it can be, always move the vértices using the axis constraints.
https://www.foro3d.com/extras/tutori...magen_0005.jpg
Youll find in most objects you create that there are straight pieces that are dificult todo get perfectly straight, in these cases, use of the transform properties [n] Will really speed along your modeling. First, note the vertex location on what ever axis you are trying todo make a straight line on.
https://www.foro3d.com/extras/tutori...magen_0007.jpg
In this example, the vertex is at 1.992 on the y axis. So, Grab another opposing pair. Note: only Grab two vértices at a time when using this method. Remember, when more than one vertex is selected in Edit Mode, the transform apply todo the median of all the selected vértices.
https://www.foro3d.com/extras/tutori...magen_0006.jpg
Now that you have them, move them quickly into place by changing the median y todo the y axis of the first vertex. In the case of our example, 1.992.
https://www.foro3d.com/extras/tutori...magen_0008.jpg
*poink*
Your vértices pop perfectly into place.
So you have the basic, wash, rinse, and repeat.
When you find that you have more corners than vértices todo Wrap around them.
https://www.foro3d.com/extras/tutori...magen_0009.jpg
Just highlight the opposing vértices (remember todo kep symmetrical.) and subdivided them a few times.
https://www.foro3d.com/extras/tutori...magen_0010.jpg
Ready todo kep modeling.
https://www.foro3d.com/extras/tutori...magen_0005.jpg
Looking god. But thats a Little plain. Certainly we can do a Little better. Lets add some of those kewl looking Structural holes todo make this a Little more interesting.
https://www.foro3d.com/extras/tutori...magen_0007.jpg
Ya, that looks allot more bitchen. To add the holes on the model, in Edit Mode, just add circles, scale them todo size, and move them into place. Remember todo kep your Symmetry correct.
https://www.foro3d.com/extras/tutori...magen_0006.jpg
The image file may not be 100% symmetrical. So use the transform properties todo kep your model correct. If the median is -1.194 on the left.
https://www.foro3d.com/extras/tutori...magen_0011.jpg
Make sure that the median is 1.194 on the right. And when youre finished.
https://www.foro3d.com/extras/tutori...magen_0008.jpg
Your model Will be perfectly symmetrical. So we are ready todo export the Mesh todo a dxf file using dxf exporter script listed.
In the beginning of this document.
https://www.foro3d.com/extras/tutori...magen_0009.jpg
Export your model todo dxf using the Autodesk dxf (.dxf) script as pictured above. Note: do not use the built in dxf export. The built in dxf export creates a valid dxf file using polyfaces instead of polylines. Several Cam programas do not support polyfaces, including the current versión of shetcam (which we are using here todo demonstrate the process.) use the default settings from the script.
https://www.foro3d.com/extras/tutori...magen_0010.jpg
From Cad todo Cam, and beyond.
Note: in shetcam, you Will have todo define the tool, material, machine, etc. Which is not covered in this guide. (perhaps later if enough people want todo know but i would suggest hitting shetcam forum first) once you have shetcam properly set up, you can import you model and se it represented on the material it is todo be Cut from for the first time. In shetcam, the grey área represents the machines cutting área. The red (burgundy for you hue aficionados) represents the material. Blak is the background, and your hella kewl guy part is easy todo.
Spot. You set up the contour job todo Cut out your object, and shetcam generates the tolpath based on your model. Last thing todo do is todo run it th rouge a mensaje processor* todo generate your g-code. * a mensaje processor is a configuration file that defines the g-code parameters specific todo your CNC software. In my case, y am using the mach3 mensaje processor. (actually called mach2 due todo the first reléase of mach software).
https://www.foro3d.com/extras/tutori...magen_0005.jpg
https://www.foro3d.com/extras/tutori...magen_0006.jpg
Now its on todo the machine.or, if you dont have a CNC machine yet, but you couldnt help reading along, there is a nifty free programa out there called microtech CNC simulator. (free.) http://www.cncsimulator.com/.
https://www.foro3d.com/extras/tutori...magen_0007.jpg
https://www.foro3d.com/extras/tutori...magen_0008.jpg
https://www.foro3d.com/extras/tutori...magen_0009.jpg
Cnc simulator 3d view.
(you can Even se the tolpath in this.
View).
Alternativaly, if you dont have a CNC machine of your o, you can take the g-code todo a CNC fab shop todo have them create your widget for you. Pléase note, most waterjets and some lasercutters do not use gcode, they use the a native dxf file so you can model only todo that point and then send the your dxf todo Cut out for you.
https://www.foro3d.com/extras/tutori...magen_0005.jpg
\r
The Cut in process, the yellow dashed outline represents the material, the blue is the object todo be Cut, the red is the non-cutting movement of the tool, the light green is the área that has ben Cut so far, the Purple gives you reference todo the x and y axiss.
https://www.foro3d.com/extras/tutori...magen_0006.jpg
You are now a certified Blender machinist.
Examples of machined widgets
https://www.foro3d.com/extras/tutori...magen_0005.jpg
A single rudder system for a remote controlled boat.
https://www.foro3d.com/extras/tutori...magen_0006.jpg
Dual rudder system for a remote controlled boat.
https://www.foro3d.com/extras/tutori...magen_0007.jpg
A pan/tilt mechanism for a tiny Camera (about 1 inch tall).
https://www.foro3d.com/extras/tutori...magen_0008.jpg
A Project in the works. A remotely controlled 3 wheled Chopper.
This Little guy is about 9.5 inches long.
www.blenderart.org.
