Tabletop Mill/Lathe Combo

From ProtoLab Wiki
Tabletop Mill/Lathe combo in the Grainger Makerspace

The Tabletop Mill/Lathe is a machine used for machining different materials with extreme accuracy. Materials typically used in these machines are softer metals and plastics such as aluminum, POM, and Wax.

General Stats:
Price : The cost of the material used. Check out the price sheet here!
Maximum bed size for Milling: TBD
Maximum bed size for Lathing: TBD




Safety Instructions


  • No attempt should be made to operate the mill/lathe until you understand the proper procedures for its use and have been cleared by a staff member to use it.
  • Dress appropriately. Remove all watches and jewelry. Safety glasses or goggles are required for operation of this machine.
  • Plan your work out thoroughly before starting.
  • Know were the location of the OFF switch is.
  • Be sure the work and holding device are firmly attached.
  • Never walk away from the machine while it is turned on.
  • If someone approaches you while on the machine - shut down before directing your attention towards that person.
  • For the lathe: turn the chuck by hand with the lathe turned OFF to be sure that no part of the lathe is in the path, and there is no danger of striking any part of the lathe.
  • Always remove the chuck key from the chuck immediately after use and before operating the lathe. Make it a habit to never let go of the chuck key until it is out of the chuck and back in its holder.
  • Keep the machine clear of tools. Tools must not be placed on the ways of the mill/lathe.
  • Stop the machine before making any measurements, adjustments, or cleaning.
  • Chips are sharp. Do not attempt to remove them with your hand when they become “stringy” and build up on the tool post or workpiece. Stop the machine and remove them with pliers.
  • Stop the mill/lathe immediately if any odd noise or vibration develops while you are operating it. If you can not locate the source of the trouble, get help from a staff member. Under no circumstance should the lathe be operated until the problem has been addressed and corrected.
  • Use care when cleaning the lathe. Chips sometimes get caught in recesses. Remove them with a brush or short stick. Never use a floor brush to clean the machine. Use only a dedicated brush, compressed air, or a rag.



Operating the Mill


Pic of Bed, Pic of head, Pic of handles. (Maybe Gif of them moving instead of pictures)

To use the mill, first understand the components of a mill and how they move.

The bed on the Idea Shop's machine moves in the X and Y axis, and the head moves in the Z axis. With these 3 degrees of motion, you can move the bed to adjust where the cutting head is removing material. Both X and Y axis have dials on the handles to correlate the linear movement of the bed with the rotational movement of the handle. This lets you cut material with a precision of .001". The Z-axis has a drawbar similar to the drill press which allows precise movement. These 3 axis combined allow you to cut channels, precise holes, and more complex geometry out of softer metals and plastics such as aluminum, POM, and Wax.

Setting Up the Machine

Now that we understand the basics, we can learn more about the machine. First, we need to fasten the piece you want to cut to the bed. This can be accomplished with a vice attached to the bed or clamping the piece directly to the bed. After the piece is secured, we need to insert a cutting tool into the head so we can zero the machine to the material. Either secure the drill chuck collet into the head and fasten tools with that, or use a collet meant for the selected endmill to fasten it into the machine. To secure the collets, slide them up into the spindle, and twist the drawbar at the top to pull the collet up and tighten both it, and the tool it is holding.

Zeroing the Machine

Next, zero the X and Y axis to one of the corners on your workpiece. Move the cutting tool to the edge of your workpiece in either the X or Y axis, take a piece of paper and move the cutting tool towards the work piece. Start moving the cutting head into position while moving the paper, and stop when the cutting head grabs the paper. Now turn the dial on your handle to 0. You have now found the edge of the material! Next bring the tool above the material and move the tool half of the tool diameter into your workpiece. The center of the tool should now be right over the edge of your material. Reset the dial on the handle to 0.

Do these steps for both the X and Y axis.

To find the Z axis zero is very similar, but easier. Get a piece of paper, and bring the cutting head close to the material. Move the paper underneath the material and slowly bring the handle down until the cutting head grabs the paper. (setting Z zero will have to wait until the shop opens)

Beginning the Cut, Adjustment and Calculation of Cutting Speeds

Now that you have zero-ed your workpiece, you can begin cutting. Using the dials on the handles, you can fine-tune where the head is moving, but keep track of how many rotations are made, each rotation is (.2" or .25" ?). When cutting, listen to the noises the machine makes while cutting. If the machine is chattering or squeaking, stop what you are doing. If the machine is chattering, lower the speed at which you are cutting material. Different bits like to spin at different speeds, and the rate that you cut the material also changes. Use this simple calculation for determining how fast to move the cutting head.

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<math>|\text{Cutting Feed} = \frac{\text{Tool DIA}*\text{RPM}}{3.82}</math>

The cutting feed variable is in Inches per Minute. Try to get close to this number when turning the axis handles. It will cut nicer, leave a smooth surface finish, and make the cutting tools last longer. If you hear high-pitched squealing or whining, try to use some cutting fluid or oil to lubricate the cutting tool. This allows it to slide through and cut the material without too much friction.


Using the Lathe


Foam Placeholder Image

Components of the Lathe

To use the lathe, first, understand the components of a lathe and how they move. Pic of chuck, Pic of cutting head, Pic of handles. (Maybe Gif of them moving instead of pictures.)

This machine has 3 axes of motion: a rotating axis, and an X and Y axis for cutting. With these 3 axes of motion, while the 3rd axis is rotating, the X and Y axis can be moved to cut the selected material into varying circular geometry. Similar to the mill, both X and Y axis have dials on the handles to correlate the linear movement of the cutting tool with the rotational movement of the handle. This lets you cut material with a precision of .002". The 3rd axis has a dial to tune the speed of cutting. These 3 axis combined can allow you to cut shafts, bushings, and more complex geometry out of softer metals and plastics such as aluminum, POM, and Wax.

Now that we understand the basics, we can learn more about the machine. First, we need to fasten the piece you want into the chuck. This can be accomplished by loosening the chuck with the key, sliding your workpiece inside (with at least a 1" section inside the grip) and tightening the chuck. Make sure to remove the key from the chuck before turning the machine on. Once the piece is fastened, now you can spin up the machine and start cutting. For setting the handles to zero on the lathe, set and lock the cutting tool in position. (explain how to lock the cutting tools into position) Now move the cutting tool until you just barely cut into the material, and set the dial to 0. Do the same for both X and Y axis.



Cleaning the Machine


  • Please sweep up any metal shavings. Plastic or wax materials are okay to vacuum.
  • Wipe any leftover oil or residue off of the machine.
  • Reset the machine to how you found it. Remove any tools, and move the cutting tools away from the lathe chuck.

Location


Location of the Mill/Lathe Combo in the Idea Shop Maker Space