Copyright (C) 1986-2008 by Daniel H. Hudgins, All Rights Reserved.

No part of "This Web Site" (HTML document), including associated files, may be: distributed, sublicensed, transmitted, copied, archived, mirrored, modified, bundled, embedded, sold, given away, rented, loaned, or shared in any form without express written permission in a formal Vendor agreement contract dated and signed in ink obtained directly from Daniel H. Hudgins by registered postal mail. All agreements for permission to distribute expire after a period no greater than one year from the date of the signing of the agreement by Daniel H. Hudgins. See the current "EULA" for information regarding limited copying and storage for the purpose of "Beta Testing" "This Web Site."

To view or use the current version of this Web page you may need to reload or refresh the display of this page by your browser. Just clicking on the browser's [Reload] or [Refresh] icon may not be enough to insure that all of the page's most current contents have been cached and displayed. Some browsers may have additional commands to help display the page's most current contents such as: holding down the [Shift] key and clicking on the [Reload] icon, holding down the [Control] key and clicking on the [Refresh] icon, holding down the [Control] and [Shift] keys and clicking on the [Refresh] icon, pressing the [Control] and [F5] keys, pressing [Control] and the [R] key, or some other combination of keys or clicks. Check to see which commands your HTML browser uses to load the most current page contents into its cache and then to display them onto the screen.

This Web site is dedicated to the thousands of "users" of my programs, those who have helped test my programs over the last 22 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) , 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 read "SECTION: 8" of "This Web Site" (HTML document and associated files) before trying to contact "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 tap holes in the part so that threaded fasteners, e.g. screws, can be used to attach one part to another one. Clamping the part to be tapped can help reduce breakage of the taps by holding the work-piece stationary.

The large cylinder is being held by using one bolt and a long clamp touching the work-piece at two points. It is important that the clamps touch the work-piece so as to apply pressure at two points, in order to help avoid having the work-piece slip, shift, or rotate.

In this part the wall thickness of the cylinder was made thicker at the ends so that there would be enough metal to tap, and the in the center portion the wall was made thinner by using the boring bar in the lathe to remove metal from the inside, thereby lightening the component.

This photo shows the use of two clamps with their back ends supported on stepped blocks. The back end of the clamp should be slightly higher than the part in contact with the work-piece since you want the pressure to be downward on the work-piece, if the tip of the clamp was not in contact there would be side pressure against the work-piece.

In this close-up view you can better see the steps on the stepped blocks. The stepped blocks, clamps, bolts, nuts, and "T" nuts come as part of a clamping set. The back end of the clamps is also stepped, and the steps are made so as to interlock and hold when downward pressure is applied by tightening the nut. Since the clamps need to be adjusted to the height of the work-piece you should have a large supply of washers to put between the top of the clamp and the nut since the bolts or studs may not be threaded on their full length.