Milling Basics & Workholding
This is the main benefit of high speed machining
What is faster material removal with less cutting force and better tool life?
This is the standard cutting ratio between radial depth of cut and axial depth of cut in HEM/HSM.
What is a small radial depth and a much larger axial depth?
This is the maximum length you should stick your workpiece out without a center, in general terms.
What is as short as possible, ideally minimal overhang
no more than 3x DIA
This code calls a sub-program
What is M98
This code group is used to set the origin for a part in a new location on the machine.
What are G54–G59
This is the best way to establish the work offset/origin for a cylindrical part on a mill
What is centering the part and using the center of the cylinder as the origin
This is the best way to deal with chip thinning when using HEM/HSM
What is increasing feed per tooth/feed rate to maintain proper chip load
This happens the farther out you place the part on the chuck jaws
What is less grip and more chance of deflection or pulling out
This code ends the sub-program and returns to the main program
What is M99?
This is the best way to establish a work offset on a machine if you want the most repeatable setup
probe
When clamping a part in a vise, this is where you should place it for the best gripping pressure
What is against the fixed jaw centered and as low as possible on the parallels
This is why climb milling is better than conventional milling on CNC
What is better surface finish, less tool wear, and more predictable cutting forces?
This is what you need to do when boring soft jaws with a backside to set the part against.
What is cut a groove in the back of jaws so the part seats consistently
Inside a sub-program, this work coordinate is typically used so the code can run from each offset
What is G54, or the active work offset being used by the main program?
This code is commonly used to call a probe macro subprogram.
What is G65?
This is what should be inside bored soft jaws on a lathe before the part is loaded
What is a close-fitting bore that matches the part’s diameter for support and repeatability
This is what feed per tooth is also called
What is chip load?
This is what a mandrel is for
What is supporting or holding a part by its bore for machining or inspection
This code lets you make one part, then shift all the tools down the Z axis to make a second part.
What is a work offset or G52 local shift, depending on how the machine is set up?
This is where you usually set the G54 X0 and Y0 on a 5-axis trunnion
What is the center of rotation
You are machining a round part in a vise and need a repeatable setup for several identical pieces. Explain the best workholding strategy and why it is better than indicating each part individually
What is using soft jaws or a dedicated fixture/collet setup for repeatability and faster changeover?
A 3-flute end mill is running at 2645 RPM with a .005 chip load. What is the feed rate in IPM?
What is 39.675 IPM
When using a tailstock, what major problem must you watch for, and why can it ruin the part
What is excessive pressure or misalignment, because it can bend the part, create taper, or damage the center
A 5-flute end mill is running at 4500 RPM with a .003 chip load. What is the feed rate in IPM?
What is 67.5 IPM
When running multiple parts in one setup, this is the main advantage of using multiple work offsets instead of redefining the whole program for each part
What is that you can reuse the same program and simply shift the origin to each part location