Copyright (C) 1986-2011 by Daniel H. Hudgins, All Rights Reserved.

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This Web site is dedicated to the thousands of "users" of my programs, those who have helped test my programs over the last 25 or so years, and especially those who shared their experiences with me.

You must read this notice: This is a licensed Web site (HTML document and associated files). You must read and agree to be legally bound in contract by the Terms of Use and conditions given in the End User License Agreement ("EULA"), Legal Notices, Instructions, Warnings, Disclaimers, and all other text in "SECTION: 0" of "This Web Site" (HTML document and associated files) before reading or using any of the information, software programs, and or files, contained in, linked to, and or associated with, "This Web Site" (HTML document and associated files). Any use or "Beta Testing" of "This Web Site" constitutes your acknowledgment of your full agreement with the current End User License Agreement ("EULA") and your decision to have this current license supersede all prior and contemporaneous agreements and understandings. Information and files in "This Web Site" (HTML document and associated files) have been placed here so that long time users of "The Author's" programs DANCAD3D.COM (tm) , DANCAD87.EXE (tm), DANCINEL.EXE (tm), DANCINES.EXE (tm) , DANCAM.EXE (tm) , or DANPLOT.EXE (tm) could help proofread the text of the documentation files or screens displayed, and also help test data files, example files, and or any software programs that might be made available from time to time, to aid "The Author" in finding mistakes, bugs, and other errors, omissions, defects, mistakes, and faults. Everything in "This Web Site" (HTML document and associated files) is "Beta Test", "Beta Code", Experimental, Preliminary, requires proofreading, or is being evaluated for possible revision, and is NOT warranted to be free of defect. To help "The Author" report any bugs, foul-ups, defects, or mistakes that you find, see "SECTION: 8" for instructions. "This Web Site" (HTML document and associated files) and all other files and programs by Daniel H. Hudgins are made available "AS IS" without warranty of any kind express, expressed, or implied. All offers and specifications are subject to change or discontinuation without notice of any kind. Please look over "SECTION: 8" of "This Web Site" before contacting "The Author."

SECTION: 7.20 is for some "general" discussion about Metalworking, see also the program files in the current distribution of my programs, the other parts of this HTML documentation, and the current On-Line version of this Web site for information more specifically about my programs. Any comparisons of my programs or methods to some others is only given as a vague generality of my opinion and is not intended as a recommendation or reference to any particular products, or methods, always make your own evaluations and comparisons before taking any action.

The illustrations in the sections and sub-sections of SECTION: 7.20 are not intended to be examples of recommended or proper practice, and in some cases may illustrate methods that you yourself would not apply as shown. The variety of illustrations, showing both practical and discouraged practices, has been included to provide illumination of the general metalworking principles discussed in these sections, and other parts of the documentation, in order to help the reader understand some of the many issues relating to the practical matter of producing parts of usable quality by manual, semi-manual, semi-automated, or fully automated machine operation, and how CAD and CAM software, such as my programs that are described in this Web site, might be of assistance to that end.

A couple of the photos in subsections of SECTION: 7.20 where taken using a Sears (tm) Craftsman (tm) Atlas (tm) type lathe, the others were taken while using a ShopTask (tm) model 17-20 type 3-in-1 multi-purpose combination mill, drill, and lathe. When a manual machine tool is retrofit for computer control you need to consider how safety shields should be added, and where the emergency power cutoff switches should be placed.

Be sure to watch all of the video clips linked to in SECTION: 4, in order to see my CAM program DANCAM.EXE (tm) being used to automatically make a part under a form of Computer Numerical Control a.k.a. CNC, and to also see other narrated lessons on how to use my CAD program DANCAD3D.COM (tm) for related tasks.

When making parts, whether by manual or automated means it is frequently necessary to make flat surfaces on a part. In a vertical milling machine you can use the bottom or side of an end mill to make flat surfaces by facing them. A fly cutter can also be used to make flat surfaces in the way the bottom of an end mill is used.

Under computer control my program DANCAM.EXE (tm) might be used with a round bottom end mill to move the cutter up and down while machining surfaces so that they can have sculpted 3D contours. The [W]eave, [B]etweens, and [A]ssemble commands in DANCAD3D.COM (tm)'s drawing editor might be used to create tool path files for contoured surfaces. Contoured surfaces might also be made in DANCAD3D.COM (tm) from equations programed into CAD Macro files, or from scanned images or artwork saved as BMP files.

A vice can be used to hold a block for facing one surface with the bottom of an end mill. In this case the block was not high enough to extend above the top of the vice's jaws, so some un-sharpened tool bits where placed under the block as spacers to raise the work-piece above the top of the vice's jaws.

It is best to face all of one surface at the same time without having to change the tool height. If I had clamped the part and did one half, then rotated the part and faced the remainder there would always be some un- evenness of the surface since the machine's table and other parts are probably never absolutely true.

If this was the first surface that was being faced, it would be extra important that it be done in a single operation, since the factory side on the bottom would probably not be flat enough to allow the part to be re-clamped.

Some of my users have told me that they sometimes use double sided sticky tape or glue to hold parts so that the full surface on one side can be machined in a single operation. The vice can be adjusted with the employment of a dial gauge to make it square to the machine's dovetails, but if you glue the part down it would be hard to get it into alignment with the machine unless you use some kind of fixture that is already aligned to the machine.

When making parts using machine automation, i.e. CAM software, the tool path can be rotated before machining to compensate for the part being stuck down cockeyed.

The problem here was that I needed to face a small odd shaped part. Since the end mill had to go over all of the part's surface the vice's jaws could not touch the sides of the part. I used some un-sharpened tool bits to act as spacers on the sides of the part so that the end mill would clear the faces of the vice's jaws.

Under computer control, i.e. CAM, it might have been possible to hold the part against the jaws of the vice, then cut within 0.01 inch of the vice's jaws. When the part was removed the thin piece sticking up on the edges could be knocked off with a fine tooth file while making the bevel on the edges.

When using a four flute end mill the end mill should be lowered when the end mill is past the end of the plate, then brought forward to cut along the length of the edge. If you lower the end mill while it is in contact with the plate you will probably get a mark deeper than the rest of the faced surface.

In this photo you see the end mill being held in an end mill holder, which is a better method of holding end mills since drill chucks may not be designed to take the side loads that end mills produce while cutting. Sometimes I use the drill chuck to hold the end mill in order to adjust the tool height without having to put the work-piece up on the "1-2-3" blocks, and such, which works all right for me in non-critical work in aluminum if light cuts are made.

When designing tool paths for used in DANCAM.EXE (tm) have the tool move out into the air past the end of the plate, move down, then move along the plate's edge at a fixed height. The final cuts should be made without the tool moving down at all, just have the tool move back and forth past both ends of the plate's edge's ends.

A fly cutter is sometimes used to face the edge of wider plates, the fly cutter acts like the bottom of a large radius "one flute" end mill. Making several passes with an end mill may result in a flatter surface than using a fly cutter though since the larger radius of the fly cutter amplifies the deflection error of the vertical mill's spindle.

In cases where it is not practical to stand the plate on its edge, you can use the side of an end mill to face the edge of a plate. The surface flatness and smoothness are generally not as good as using the bottom of the end mill, but the plate can be clamped, or held in a vice, flat down on its larger side, and may be more stable lying down rather than standing up on its thin edge.

Since the spindle in the vertical mill, and with it the end mill, will deflect somewhat under the force of cutting, the final cuts should be made with little or no feed into the tool, and when the tool is lowered so that the work will be feed into the tool, the tool should be in the air past the end of the plate.

If you start the end mill in from the edge of the plate you can cut-off a portion of the plate, while you face the edge you want to make, e.g. rather than milling off all of the extra material. You should be careful as the cut-off portion is about to come free, you may want to use a hacksaw for the last bit of cutting in order to remove the cut- off portion, rather than having the machine cut all the way through with the end mill, to keep the cut-off portion from falling off or flying off and damaging something or someone.

You can face part of the surface of a part. You can make a wide slot, i.e. a channel that reduces the width or thickness along the length of the part, or you can make a pocket or recess which is a channel that is a faced area that does not extend to the edge of the part.

Under computer control, i.e. CNC, a program like my DANCAM.EXE (tm) program might be used to make channels, pockets, and recesses that have round bottoms or radiused depth in their corners, in addition to the usual flat bottomed cuts.

An island is the reverse of a pocket, where the part is faced everywhere except for a portion of its surface. It is sometimes possible to flip or mirror a portion of a tool path in order to convert pockets into islands and vice versa.

Slots are like long narrow pockets that go all the way through the part. Under computer control you can use an end mill to make round holes or long slots of different widths without changing the radius of the end mill used, i.e. by having the end mill move around in different size quasi-circles or quasi-ovals.

When you need to go all the way through a part you can put spacers under the part. "1-2-3" blocks are normally used as spacers under parts, but since I was making the slots close to end of this piece there was probably not enough room for using "1-2-3" blocks, so I used some un-sharpened tool bits as spacers.

Under computer control you might be able to cut very close to the table height, but 0.005 inch or so short of the surface of the machine's table and not use spacers. Then when the part is un-clamped use a small needle file to remove the thin "skin" over the slot or hole.

The Fly-Cutter makes a wide cut to make a smooth surface, but the Mill spindle RPM needs to be slower than when using a smaller radius End-Mill type cutter.

The Fly-Cutter makes a wide cut to make a smooth surface, but the Mill spindle RPM needs to be slower than when using a smaller radius End-Mill type cutter.

The Fly-Cutter makes a wide cut to make a smooth surface, but the Mill spindle RPM needs to be slower than when using a smaller radius End-Mill type cutter.

Note the scratch lines that are used to see how deep to cut. The scratch lines are made with the hardened jaws of the dial calipers after the outside faces of the plate are faced flat. You set and lock the dial calipers to the distance you want the depth of the channel to be, hang the top jaw of the dial calipers on the face edge of the plate and then pull the lower jaw point along the side of the plate pressing it onto the edge of the plate to make the cutting depth limit scratch line.

The Fly-Cutter makes a wide cut to make a smooth surface, but the Mill spindle RPM needs to be slower than when using a smaller radius End- Mill type cutter.