Boring a hole on my milling machine - cheap boring head woes

[PStechPaul]

I have considered taking courses at the local community college. But their machine tool classes are in seven parts and a total cost of $7000, and that's more than I'm willing to spend. It is a total of six months of training. Probably well worth it if I were to look for a job in a machine shop or plan to perform machining work for hire, but not for occasional/hobby work. And I could buy some nice machines for that money! See page 55:
http://www.ccbcmd.edu/media/ceed/flexifall.pdf

The book I have, "Technology of Machine Tools", seems to be a comprehensive high school or trade school level textbook, and it covers pretty much all the basics and some advanced subjects, even for 1969. But it does not really go into some of the techniques and tooling discussed here and on similar forums. I think I'm doing OK by doing some prior research, asking questions before major projects, performing the techniques on the equipment I have, and discussing the results. I'm careful and I work slow, so I don't usually engage in dangerous behavior. If I was able to survive the experience of machining the tricky part with an end mill in a drill chuck as shown above, I think I can proceed safely with the knowledge and experience I have gained without personal assistance. Of course, if someone cares to stop by and provide some hands-on assistance, I'd be delighted.

[Rosco-P]

$7000 may be a little steep, but if it's your hobby, your passion? Not much diffferent than the old car hobby, flying, diving, caving, etc. Many on this board probably own well in excess of that ammount in machines, tooling, measuring instruments, support equipment, stock, etc.

No other schools? No county or regional vocation school with an adult night class in machining?

The book I have, "Technology of Machine Tools", seems to be a comprehensive high school or trade school level textbook, and it covers pretty much all the basics and some advanced subjects, even for 1969. But it does not really go into some of the techniques and tooling discussed here and on similar forums.

Buy another book. Or two or three. Some of the books that were published in the 1920's-40's have the cleverest setups. They got the job done with a minimum of machines and tooling.

[outback]

Slight thread drift here - can you guys explain how to initially set the cutting diameter a boring head? Do you just make an initial cut, measure, and adjust from there, or do you find "zero" somehow with a dial indicator, and adjust the boring head to the desired radius?

Best to have the machine spindle centered to the hole. Start with the boring tool set smaller than the hole. Then, very carefully using the spindle quil, move the boring bar up and down. With each stroke adjust the boring head so the boring bar moves toward the side of the hole. Eventually, the boring bar will make a scratch on the side of the hole. That is your starting point. You should be able to enlarge the hole diameter by .050 to .060 per pass. When the hole is about .030 oversized take smaller passes like .015, .010, .003 the about .002 for a finish pass.

Be certain all the springback in the boring bar has been accounted for or the hole could end up oversized.
Jim

[PStechPaul]

I have searched for other venues in the Baltimore vicinity, and came up with not much. Some possibilities:

http://www.cams-club.org/resources/index.html (Chesapeake Area Metalworking Society)

There are some courses at Montgomery College (about a 1-1/2 hour drive). Seniors pay only a $104 or so fee:
http://aceitoc.montgomerycollege.edu...elistings.aspx

I called someone at CCBC and there may be a short term summer course from June 16 to July 19, so I need to have them call me back with details. I agree that it is a good idea to get some formal training. Having some of the machines at home should help, but I'm sure the school will have much better tools and I can see how to set things up and perform operations properly. Then I might see what else I may need to adapt to what I have or what I can get to do things better.

I searched deeper and found several courses that would be more appropriate and much less costly:
http://catalog.ccbcmd.edu/search_adv...D=machine+tool

CAMM111, CAMM112, and CAMM152. I'd also like to learn welding, and they have two classes for that.

Thanks.