Basic Shop Processes and Safety
The vast majority of parts a student needs can be made using a combination of these basic shop processes at many of the many University fabrication facilities. This article will help you be aware of what each process can do and what basic design considerations your part should have to suit their capabilities and limitations. Incorporating advice on design-for-fabrication early in your project will spare you from many complications as you bring your plans into reality.
All of these processes are perfectly safe when safe practices are followed -- conversely, even a simple hand tool can be very dangerous when they are not. Ask a facility staff member to check your setup if you feel uncertain about the safety of your planned work.
"Chance takers are accident makers."
"As soon as you see a mistake and don't fix it, it becomes your mistake."
"Prepare and prevent, don't repair and repent."
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General Shop Guidelines
General Shop Safety
- Always have at least one other person present when working with machines, power tools or blades.
- Safety glasses must be worn at all times when around tools in use, even if you are not directly involved. Sunglasses are not substitutes for safety glasses.
- Only wear sport shoes or work boots. Sandals and other open-toe shoes offer no protection from falling objects and are prohibited.
- Do not wear loose clothing or jewelry. Tie back long hair.
- Do not use gloves when working with moving machinery (they can get caught and pull your hands in). Rags should never be placed near moving parts as well.
- Do not use compressed air to clean yourself, the contact pressure and flying debris can easily damage your eyes, ears, and skin. Use a brush or clothe instead.
- If you have not worked with a particular material before, ask a facility staff member to explain its processing requirements (appropriate tools, cutting rates, special reactivities, etc.).
- Do not enter a fabrication environment under the influence of drugs or alcohol, or when excessively tired or distracted. Being fully aware of your surroundings is critical to everyone's safety.
- Cell phone use is excessively distracting -- if you need to use your phone, stop what you are doing and move out of the fabrication environment.
- Arguments and horseplay are also excessively distracting. Save them for outside the fabrication environment.
If an accident happens:
- Turn off all machines and powered tools.
- If chemicals get in the eye(s), wash eye(s) for 15 minutes in an open flow of water before proceeding for medical treatment.
- Do not attempt to remove foreign objects from the eye or body yourself.
- Follow first-aid procedures and call for medical help.
- Right after the emergency has ended, report the incident to fabrication staff.
General Shop Etiquette
Being polite to your fabrication facility is critical to maintaining its availability for yourself and other students. Unlike being impolite to other people, being impolite to a fabrication facility has guaranteed disciplinary consequences not limited to revoking your access to UR facilities. Expect to spend 15-30 minutes at the end of your shop time cleaning up and reorganizing tools.
- If you break something, let facility staff know so it can be replaced/repaired. Breakage happens, just work on preventing it in the future.
- Report all accidents and malfunctioning tools to facility staff. Failing to report an incident (including giving false reports) puts others in danger, and disciplinary action not limited to revoking access to UR facilities may be taken as a result.
- Do not throw away anything if you are uncertain that it cannot be reused. If in doubt, ask a facility staff member.
- Put tools back to where they belong as soon as you are done using them. A cluttered workspace is a dangerous and inefficient workspace.
- Clean off machines and tools after use. Brush off large chips and use a vacuum for and dust. Do not use compressed air on dust! Airborne dust can be highly flammable.
- No eating or drinking in a shop environment. Eating shop debris is gross; getting food on tools is also gross.
General Cleaning
- Turn off powered tools before cleaning them.
- Remove all cutting tools, drill bits, end mills, and lathe tools before cleaning to avoid cuts.
- Put away all tools and other items around the shop. Keep the work area orderly.
- Brush and blow chips from the tools & chip pans. Do not blow/push chips towards machine bearings and ways!
- Recycle clean chips where possible.
- Vacuum or carefully brush dust. Do not use compressed air on dust, the dust-air mixture can be very flammable.
- Report missing, broken, or damaged tools to facility staff.
- Spend your last five minutes on general cleaning around the shop. We're all in this together!
Power Tool & Electrical Safety
Power tools are excellent for situations where flexible positioning or manipulation of the tool is useful and the accuracy of a machine is not. They are also available in many more facilities than machines. This articles defines power tools as being separate from machines (mill, lathe, drill press, etc.) in that power tools are portable and generally not as powerful. Examples include the power drill, Dremel tool, jig saw, heat gun, and angle grinder. "Powered" tool is a broader term referring to any tools that are powered by something other than the human operator's effort.
Power Tool Safety
- Use the proper tool for the job.
- Clamp or otherwise secure the workpiece such that you cannot move it with your greatest hand effort.
- Before use, turn on the tool and hold with a strong grip to test for proper function and to get a feel for its power output.
- Make sure all guards are in place -- ask a facility staff member before modifying a guard for extra usability.
- Keep cords and hoses routed behind you and away from heat, oil, and sharp edges while working.
- Wear proper apparel. Loose clothing, long hair, and jewelry can be caught in moving parts.
- Wear personal protective equipment, including safety glasses, work gloves, and hearing protection
- Double-check that the workpiece and tool bits are tightly secured before turning on the power.
Electrical Safety
- Make sure the tool is grounded if it needs to be i.e. if the tool's power cord has three prongs, use a three-pronged power outlet. Remember, the next-best path to ground is your body.
- If working outdoors with an electric tool, only use an outlet with GFCI protection.
- Never use electric tools in damp or wet locations. Use air-powered tools instead.
- Store tools in a dry place. Do not place tools on a wet surface, they can rust.
- Disconnect power cords by pulling on the plug. Never pull on the cord itself.
Drilling
Drilling is used to make holes. It is done using either a drill press (alternatively, a mill with a drill chuck) or a power drill. A drill press is a machine and gives you much more precision and power/leverage. A power drill is a power tool and gives you much more flexibility in drill-bit orientation.
Drill Bits
Drill Bit Types, Materials, and Finishes
Your project will likely only need HSS twist bits. These are available at almost every campus fabrication facility in standard increments. Some facilities also carry them in metric increments. Design your hole diameters based on what is available to you, if possible. Also, notice that drill bits cannot make flat hole-bottoms -- you need a mill and end mills for that.
Power Drill Use and Safety (Video)
Design for Drilling Holes Recommendations
Milling
Mills are used for removing material with high precision and accuracy along multiple axes. You can use a variety of cutting ends for shaping and making flat-bottom holes, and you can also attach a drill chuck to give your drilling the mill's high positioning accuracy.
End Mills and Cutters
The mill is a very diverse tool and has a diverse array of cutting ends (like drill bits for the drill press) to match. Square end mills with 3-5 flutes are most commonly used and are available at most campus machine shops in standard increments. Some facilities also carry them in metric increments. Design your part's milled features based on the increments available to you, if possible.
End Mill and Cutter Types, Materials, and Finishes
Design for Milling Recommendations
Lathing
Lathing creates features that span 360° around a cylindrical part by spinning the part and applying a cutting tool to it's surfaces. This includes making cuts to the outside of the part as well as cutting holes and threads at the center of the part. The simplicity of lathe setup and operation makes it an extremely accurate and time-efficient process. If you do not want a feature to go all the way around the part, consider milling or grinding instead. Alternatively, it may be a good idea to alter your part's design to allow for lathing.
Lathe Cutting Tool Types and Operations
Design for Lathing Recommendations
Lathe Parts and Safety
Due its high rotational momentum, the lathe is by far the most dangerous tool in the shop if safe practices are forgotten -- pay special attention when you use the lathe!
Lathe Parts and Safety (Video)
Band Saw
The band saw is machine that uses a long, continuous blade running in one direction to cut lines and curves in sheets and short blocks. The cutting is fast but not as precise nor as accurate as with milling or water-jet/laser cutting, so the band saw is recommended for basic needs as well as cutting pieces from large blocks of material before other fabrication processes are used.
Band Saw Blades
Changing the blade of a band saw is not usually done by a student (do not attempt unless specifically told to), but you can tell what type of material and curves you can cut with a band saw by looking at its blade. It's also important to know when the blade is damaged or too worn because these conditions can make your work difficult and dangerous -- remember, if you see a broken or malfunctioning tool you must report it to a fabrication staff member for the good of everyone. Most band saws on campus are fine for most non-metals and aluminum, but not for steels and harder materials.
Band Saw Blades and Checking for Damage