Introduction: A Smarter Way to Mill
Just because you have the best, most expensive state of the art tools doesn't make you rockstar. And just because you don't have access to the most expensive state of the art tools doesn't mean you can't be a rockstar.
Step 1: Standard Milling Is Stupid
Standard milling in a router takes too long and is too much lifting and glueing! Plus, it wastes a ton of material.
I had to make two MDF molds roughly the same size and shape, with slight variations. The first mold I made started with a standard laminated MDF stock in a big block. Cutting each slice took about an hour, and then the glueup which was another two hours and required lots of glue, clamping, and heavy lifting. The stock weighed about 70 pounds and so I needed to people to lift it to place it in the DMS 5-axis router. Then it took another 10 hours to mill start to finish!
Too much time.
I set out to find a way to make it easier, faster, and to use less material.
I wanted A SMARTER WAY TO MILL!
Step 2: Smarter Way to Mill
The general idea is to create your roughing pass as you cut your slices for gluing. This allows the following:
Hollow slices make for lighter parts
Parts can be nested and take up lass material
The roughing pass is already finished, reducing hours of mill time
Dowel registration possible for easier gluing, so you only need clamps for the Z axis
Less gluing, less glue and time
The photos in this section are of my second stock and final pass in the DMS router.
Step 3: Method One: 123D Make to Slices
This was a very easy way to create the cut files for your stacked slices. It took about ten minutes. I've written in text on each screenshot from here out, so refer to those for the next steps.
Step 4: Method Two: Do It All in Fusion 360 (or Inventor)
I used Fusion 360 to make my model, and I wanted a way to do it all under one program.
This method took more time than slicing in 123D Make, but you don't need to to convert the meshes in Meshmixer or fiddle around, its all ready to go in one program.
This process took about one hour, but still saved me a ton of time.
See the text on screenshots for the rest of the instructions for how to use Fusion to slice your model.
Step 5: Method Two, Part Two: Creating Offsets for Your Stock
After you slice your model its time to create offsets. The offsets will make your stock larger than the final piece, so that when you mill everything, the final piece matches your original model. For this i chose to make each slice one inch larger than the original, that way I had a little wiggle room in case I had stock registration issues when setting it up in the mill. There is a sweet spot between enough extra and too much. Remember, the goal is to reduce time in the mill, and if you have too much material, it will take a real rouging pass.
See the screenshots for directions.
Step 6: Method Two, Part Three: Creating Cut Files for Your Slices
The next steps can be used to create cut files for most cutting tools, including jigsaws, router tables, laser cutters, and waterjet machines.
Once you've exported your slices to drawings, save them out as a PDF or DWG and send them to your cutting machine. I didn't include it in the images, but after this step I nested the files manually in Illustrator and then used a 400 watt laser cutter to make each slice. Most important part in this step is to name each part and keep that name on your cutfiles. That was you can figure out what glues to what after you're finished cutting.
Step 7: Method Two Part Four: Make Your Stock
Next step is to make all those slices one piece to create the stock. Pretty simple, just join them all together and then make into a new component. Once I've finished this, I save out that file as a new one and get rid of any extra parts and pieces, that way the files is clean for exporting to the CAM program.
Once in CAM, you tell the setup which part is your stock and which one is your final piece.
This is many steps, but all in all it took me about two hours to complete, and compared to traditional milling from standard stock, I saved about 9 hours.
Step 8: Same As It Ever Was, Only Better
The rest is standard glue-up-type steps. . Since I used a laser to cut my parts, I needed to sand them before gluing. The dowels kept the x and y axis for the gluing, and it too less time, less muscle, and used less glue, too.
Step 9: Behold, Smarter Milling!
The idea of cutting and gluing up a roughing pass was a huge success.
I used the second method, which took a long time but was overall much better than Stupid Milling.
Overall I saved:
30% less material
50% the weight
30% less glue
and 75% less time
Step 10: Kudos
I was so excited about my new method that I told other artists about it at a meeting. After the meeting, fellow Artist in Residence Jeremy Magner asked me to explain my method in more detail. The next time I saw Jeremy, he had a piece loaded in the DMS all ready to go, and had used 123D make for the slicing. Impressive! It was Jeremy who showed me how to do it using 123D Make, and after going through the steps while writing this Instructable, its a much easier, faster method.
Check out his project by clicking this link.
7 years ago
Old machinist saying: "The mill is fine, but you make your money at the bandsaw."
7 years ago
Smart and helpful!
7 years ago
good thing to take advntage of the machine power! looks fun man!
7 years ago
Very helpful! I'll try this next time. I have a small home made CNC with limited rigidity so this should really help!