Make something big
DESIGN
For this assignment i decided to design a desk for my flatmate.
I did the design inRhino.I kept the joints simple.Press fit parts require filleted slots on inside corners. We did a test to see how the joints work and the tolerance of the machine. Before designing we need to take into consideration the diameter of the tool we are going to use and the size and thikness of oUr material material.
Cutter_TypesMILLING
/Software:
//Partworks 2d and 3d, design software
//Shopbot 3, control software
/Tools:
//ShopBot 3 axis CNC router
//End mill 6mm
//Drill
//Screws
/Material:
//Obs wood, 15mm
Shopbot TUTORIAL
MILLING PROCESS
//Firstly, we open the .dxf file in partworks 2d and 3d software.S et the size of the board and the thinkness of the material. Check the option "use XY origin offset" and set the units in "mm".
/Cutting parameters:
Pass Depth: determines how much deeper the tool goes with each pass.
Stepover: How much the tool will overlap on each pass when rastering a pocket.
Spindle speed: We’re using 12000 RPM. This is based on material, tool diameter, feed rate and number of flutes on the tool. Our material is OBS.
//For creating the Grooves in the main piece of the desk I use the "pocket toolpath".Under “Toolpath Operations” select “Create Pocket toolpath”. In this part of my desk I selected to do grooves instead of holes to keep the upper surface clean, without seeing the legs.
/Start Depth: 0” (starting on top of material)
/Cut depth: Choose a finished depth of cut. Make sure you don’t make the cut so deep as to make the remaining material. In my case 12mm.
/Select tool, end mill 6mm
/Machine Vectors: Inside
/Click Calculate. The program warns that our part will be cut through. Click OK.Previewing the Toolpaths we can see what our finished part should look like
/Under Toolpath Operations, Click Save Toolpath and name it
//For creating the holes for the press fit connections I use the "pocket toolpath". Under “Toolpath Operations” select “Create Pocket toolpath.”
/Start Depth: 0” (starting on top of material)
/Cut depth: The thickness of the material, plus some extra to make sure it goes through. In my case 16mm
/Select tool, end mill 6mm
/Machine Vectors: Inside
/Click Calculate. The program warns that our part will be cut through. Click OK.Previewing the Toolpaths we can see what our finished part should look like
/Under Toolpath Operations, Click Save Toolpath and name it
//Now we will generate the toolpath to cut the part out of the material. Select Your outer rectangle. Click “Profile Toolpath” Under the Toolpaths tab.
/Start Depth: 0”
/Cut Depth: The thickness of the material, plus some extra to make sure it goes through. In my case 16mm
/Select the tool, end mill 6mm
/Machine Vectors: Outside
/Click Calculate. The program warns that our part will be cut through. Click OK.Previewing the Toolpaths we can see what our finished part should look like
/Under Toolpath Operations, Click Save Toolpath and name it
//Now we need to set up the Shopbot
/We select the appropriate collet for our tool. Push it into the collet holder until it clicks
/Start to thread the collet holder onto the spindle. Insert the tool into the hole of the machine by pressing the green button.
/Turn on the control box
//Now we need to to fix material on the base of the CNC by using scews. We try to align the 0,0 point to the top-left corner of the CNC machine. Make sure to align your X and Y correctly. X axis is the long axes of the machine.
//Open the Shopbot 3, control software
/On the red Shopbot Position Window, locate the yellow “Show Keypad” button and click it. We can now jog manually using the keyboard. The arrow keys control X and Y, Pg Up and Pg Dn move Z. Move the tool to the bottom left corner and zero the x,y values.
/Set the Z origin the Zero Plate.Lower the tool until it is a few inches away from the material.Lay flat the metal plate on the material under the tool. Go to “Cuts” and run command “C2 - Zero Z axis w/ ZZero Plate.” Click OK. The machine automatically zeros the Z axis. Click OK and return the metal plate to its holder.
/Load the file and click "start". The screen now says Starting Router/Spindle. Start the spindle by hitting pressing the green button on the yellow control. After this click OK to begin cutting.
/Have your hand near the big red emergency stop button in case you need to stop the machine if something goes wrong
/If the milling finish,remove the screws, and vacuum up all scrap and dust created
Done!
TIPS:
|Press fit parts require filleted slots on inside corners
|Make sure the material is flat and well fixed on the bed of the machine
|Make sure to align your X and Y correctly
|Be sure you don’t put any screws where the material will be cut, this will probably break the tool
|Never leave the machine working alone
File: