OSE Metal Fabrication Certification
The OSE Metal Fabrication Certificate is the first in OSE's line of certification based on well-defined criteria and testing. The basic test involves MIG welding, torching, grinding, drilling, marking, tool selection skills, and others. These skills are based on a generalized skill set indispensible to effective functioning in OSE build events.
The method of certification involves: (1) skills presentation by instructor; (2) hands-on practice by individuals; (3) Self-exam and documentation on wiki (see Fabrication Exams; (4) instructor-verified checklist of approved fabrication tasks.
Grading is based not on pass/fail basis, but on a method that fosters continuous improvement. As such, an Exam is simply a documentation of someone's skill set - and involves taking pictures and notes of a person's results based on well-defined tasks. These are documented on the wiki as the category Category:Metal Fabrication Certification.
In practice, the OSE Metal fabrication Certification involves the initiative of participants to self-document themselves after they received basic instruction and after they have practiced to obtain a basic level of comfort in a given task. This essentially results in a self-generated portfolio of work samples that correspond to one's skill level. A typical self-exam includes:
- Video yourself performing a specific, short task.
- Post your results to OSE Workshops Group on Facebook as a short video.
- Start your Work Log, put an entry named _______ Tools Exam corresponding to whatever tool you are testing yourself upon, and link to the OSE Facebook group the location of your video.
- Take a specific picture showing particular, requested features in that picture. Add this as a comment to the video you posted on the OSE Workshops Group
- On your Work Log, answer a list of exam questions that have been provided. This should take 15-30 minutes. The entire process should take about 30 minutes.
- After you have completed your exam, add your results to the Category:Metal Fabrication Certification.
See the Abrasive Tools Exam for a sample exam procedure.
What tools to use for cutting, drilling, holes, severing, measuring, bending, forming. Limits to bending metal. Limits to heat bending. Bending with a shop press. Deciding what tool to use for cutting shaft, thin tube, rebar, flats based on weight, length, precision requirement, speed of cut, temperature of cut, and purpose. Tolerancing of tubing holes. Cutting holes based on diameter, thickness of material, and speed.
Here is a good manual for using a bandsaw: http://www.lenoxtools.com/Guides/LENOX%20Guide%20to%20Band%20Sawing.pdf .
How do you know if you are using the right band speed? Look at the chips; check their shape and color. The goal is to achieve chips that are thin, tightly curled and warm to the touch. If the chips have changed from silver to golden brown, you are forcing the cut and generating too much heat. Blue chips indicate extreme heat and you will damage the blade quickly.
Lubrication is essential for long blade life and economical cutting. Properly applied to the shear zone, lubricant substantially reduces heat and produces good chip flow up the face of the tooth. Without lubrication, excessive friction can produce heat high enough to weld the chip to the tooth. This slows down the cutting action, requires more energy to shear the material and can cause tooth chipping or stripping which can destroy the blade.
A new band saw blade has razor sharp tooth tips. In order to withstand the cutting pressures used in band sawing, tooth tips should be honed to form a micro-fine radius. Failure to perform this honing will cause microscopic damage to the tips of the teeth, resulting in reduced blade life.
Reduce the feed force/rate to achieve a cutting rate 20% to 50% of normal (soft materials require a larger feed rate reduction than harder materials).
With each following cut, gradually increase feed rate/force until normal cutting rate is reached.
more info: http://www.supercutbandsaw.com/how_to_choose.html Cutting fluids. Feed rate. Blade alignment procedure. Throat thickness adjustment. Understanding Teeth Per Inch. Blade Selection. Clampgin a work piece. Clamping work pieces that are too short. Angled cuts. Cutting seam tubing. Number of teeth on metal. See Bandsaw Blade for information about blades. Bandsaw Exam.
Ironworker machine: Metal Shear, Punch, and Angle Cutter
Procedure for punching holes. Replacing dies. Understanding die size. Open center bidirectional hydraulic valves. Workpiece hold-down. Force amplification from blade gap and safety. Power Cube operation. Ironworker Exam.
Abrasive Cutting and Grinding
Using an abrasive cutoff saw. Cutting small diameter rounds rapidly. Cutting large-diameter rounds. Mounting new grinding wheels. Distinguishing when material gets cut-hardened. Grinder basics. Using cutoff wheels and grinding wheels. 5 and 15 amp grinders. Locking in a grinding wheel. Replacing motor brushes. Repairing a broken cord. Abrasive Tools Exam.
Eyewear. Gloves. Steel-toed boots. Welding helmets. Hard hats. Excess welding wire. Sharp corners. Heavy objects. Use of hoist. Fire extinguisher. First aid kit. Eyewash. Grinding safety. Welding fumes. Zinc plating and galvanized steel. Sound cues: metal squeaks and gas leaks. Safety Exam.
Ability to weld from sheet steel to 1/2" steel. Understanding wire feed speed and power settings, both high and low. Proper tension on MIG wire. Knowing when liner is clean. Understanding shielding gas flow. Keeping guard clean. Replacing tips. Keeping work area clean. Protective clothing. Turn-on and shutoff. Welding Exam.
Understanding proper gas pressure. Uderstanding tip size. Cutting straight lines. Cutting circles. Cutting 1" stock. Cutting sheet stock. Torching Exam
Understanding when metal is hot enough. Range of applications for brazing. Brazing Exam.
Using a correct reference point. Transfer punching. Using tracing paper to mark patterns. Using a speed square, level, carpenter's square, tape, and ruler. Match drilling. Measuring Exam.
Using a Milling Machine
X, Y, Z motion of slides. Using a milling bit. Milling keyways. Locating the top of a shaft. Using a mill as a drill. Feed rate. Cutting fluids. Proper workpiece fixation. Using a Digital Readout for distance measurement. Centering a hole on a shaft using the digital readout. Boring a hole to a precise diameter on a mill. Flycutting. Cutter diameter selection. Milling Exam.
Using calipers. Using a dial indicator.