Making Round forms on a metal lathe

My original plan was to make two or three tangent cuts then smooth the peice via lathe filing

although it would be good practice for lathe filing my overall goal is to learn ways and means to do projects that i can also use on aluminum steel and stainless.

Because my goal is learn> On Thu, 28 Sep 2006 07:36:44 +0000, Harold and Susan Vordos wrote: >

Reply to
Brent
Loading thread data ...

Sorry Jeff , I should have put gadgetbuilder.com It's a great tool.

Ron.

Reply to
Salamanda

*****GLOOM***** - thanks Harold. I still dont understand much of what you are saying, but will dig out the textbooks and try and figure it out (dont speak Engineering fluently yet, its a new language to me...)

I am doing a trades course, but its a weird way of teaching - (showing my age, again) - you are given a heap of theory prac. books to fill in by finding the answer in the text book. This may work for some, but not me - I need to "see" whats being taught, in front of me, and then ask "Why is it done this way" - at the moment, trying to tie in theory with practice. And yes, the instructor (when you can get him) will answer questions, but sometimes I dont know the questions to ask...(yes, I know, that doesnt make much sense.)

My school text book is big and thick with Lots of Pictures of Big Industrial Machines - theres an assumption you have a basic knowledge of the trade - which is reasonable, its an apprentice course. Thank God the kids in my class are tolerant and helpful of the token " Old Fart".....actually,its been a real eye opener - a good bunch of people who will go on to be decent citizens, - we are so accustomed to seeing the stuff-ups and disasters on the evening news.

The only time there is a group lesson is when someone does something wrong and we get a lesson on how NOT to do it.....and a lecture on how much the broken tool cost....or how close someone came to serious injury....

But I will get there, - thanks Harold for answering my questions (and the other people as well - much appreciated). Was it Gunner a few days ago said that this is a truly infuriating occupation - so much effort needed to get some basic competence in the field?

And I am getting there, albeit slowly - understanding more of whats being discussed here, texts are starting to make more sense. And, starting to be able to work to tolerance consistently most of the time (oh, ok - 4 out of five times, better than a few months ago..)

Andrew VK3BFA.

Reply to
Andrew VK3BFA

S>> On Thu, 28 Sep 2006 07:36:44 +0000, Harold and Susan Vordos wrote: >>

Reply to
Eric R Snow

==================== What you are describing is the result of administration efforts to "get by on the cheap," stressing efficiency over effectiveness, with the primary goal of meeting standardized [paper] test requirements.

It has been known at least from the work of John Dewey in the early 20's [American educator 1859-1952] and possibly as far back as John Amos Comenius (1592-1670) that most people learn far more/better from observation and imitation [AKA "monkey see-monkey do"] than they do from any form of the traditional academic/lecture format [AKA "sage on the stage"] which was originally developed before the advent of the printing press, because the handwritten books were too expensive for student use.

While it is a truism, it is never the less true that: I hear and I forget; I see and I remember; I do and I understand.

I have instructed beginning and intermediate machining classes, and have found that the best combination from both an effectiveness [students can actually do machining] and efficiency [amount of material covered and number of students instructed] is video tapes of actual machining operations that the students can watch at home, class discussion of the tapes including the "why" as well as the "how," and as much hands-on chip-making time as possible in class, preferably on student selected projects, or simple tools they can use, such as pump staffs.

These video tape series tend to be a somewhat expensive for the individual but in the United States there are companies that rent the tapes. Most likely there will be similar companies in Australia. Another possibility is to get the school to buy the set, or to get several of your friends to share the cost.

The series that I like are from the American Gunsmithing Institute cover general turret [Bridgeport] milling and typical engine lathe operation. They also have a number of firearms specific videos on action tuning, specific weapon disassembly/maintenance, etc. which most likely will be of little use in Australia.

See:

formatting link
{lathes}
formatting link
{turret mill}
formatting link
{general shop info}
formatting link
{package deal all three}
formatting link
{videos only no books}

Unka George (George McDuffee) ............................. I sincerely believe . . . banking establishments are more dangerous than standing armies, and that the principle of spending money to be paid by posterity, under the name of funding, is but swindling futurity on a large scale. Thomas Jefferson (1743?1826), U.S. president. Letter, 28 May 1816, to political philosopher and Senator John Taylor

Reply to
F. George McDuffee

Interesting observations! I teach at a dental school and I get the students when they are beginning to learn how to use high and low speed drills. At the same time they are indoctrinated into the intellectual side of anatomy physiology and material sciences. The big learning curve is training the eye to see and the brain to control the hand and to vizualize. Any suggestions on what teaching methods are "foolproof" would be appreciated.

Charles Friedman DDS Ventura by the Sea Woodturner Deep drawer on the press Metal spinner

6th childhood

. This may work for some, but not

Reply to
Charles Friedman

A similar phrase got used a lot in some of the circles I hung with.

See one, Do one, Show one.

You see it to get the idea, you do it to learn it, and you show it to the next person, thus fulfilling the first step for him or her and firmly planting the knowledge in yourself.

Cheers Trevor Jones

Reply to
Trevor Jones

==================== I can see at least half a dozen dissertations, 10 or more books, and a ton of monographs/journal articles in your question.

If I had an answer to this (and not even a "good" answer, or

*THE* answer) I would be on my way to Stockholm to pick-up my special Nobel Prize. ASAIK there are no "foolproof" or even "fool resistant" methods. Even Harvard Medical produces a few duds that somehow manage to slip through the final performance test called "internship."

I do have some observations limited to your particular area.

First, you need to determine what characteristics your students must have to be good dentists, other than they want to make a lot of money and have Mondays off. Then you need to prioritize these traits. While some minimum IQ or "smarts" is necessary, given that most dentists do not do research work, ultra-high academic [as you may be aware, there are other IQs] IQs are not particularly important, and in fact may be counter productive.

From my understanding of Dentistry, (having had my teeth worked on occasionally) outstanding hand-eye coordination is an essential requirement, as is an exceptional micro-kinesthetic sense that allows micromanipulation with minimal visual clues/feedback.

A separate but co-equal requirement is an excellent spatial sense of how various small 3D objects/surfaces will relate when rotated and translated.

These are psychomotor skills that can and must be developed, but to be developed, an underlying talent or capacity must pre-exist.

If you do not currently use the existing tests for these characteristics/abilities for screening applicants, it would be helpful. Indeed, you may find it helpful to develop additional tests stressing micromanipulation.

Assuming that you have weeded out the totally maladroit and the spastic, then the key is practice, practice, practice.

Because there is only 24 hours in the day, overemphasis on intellectual/academic topics and GPA may well interfere with acquiring, improving and retaining the necessary foundational psychomotor skills. It is at this point an unusually high academic IQ may be a problem, in that there is little intellectual challenge in practice, practice, practice.

It can be helpful to use the practice time to create items of interest to the students, and to engage the students in friendly competition, such as who can grind the smallest "DDS" on a simulated tooth hidden from view in a simulated mouth.

Do you have milestones established, for example that at the end of week three the student will demonstrate their ability to drill a hole in, or polish, a simulated tooth with limited access/visibility.

Are your students encouraged to stop by the lab and use the equipment outside of class time, possibly on their own projects? These might include a charm for their girlfriend's bracelet, or tie tack for their boy friend.

Some of the finest home shop machinists and model makers I have seen have been dentists.

Unka George (George McDuffee) ............................. I sincerely believe . . . banking establishments are more dangerous than standing armies, and that the principle of spending money to be paid by posterity, under the name of funding, is but swindling futurity on a large scale. Thomas Jefferson (1743?1826), U.S. president. Letter, 28 May 1816, to political philosopher and Senator John Taylor

Reply to
F. George McDuffee

The other way to do this I've seen still involves holding the file backwards, with the handle pointing away, but the lathe runs forwards. The trick is to hold the file _under_ the part and press up... I end up doing most of my filing this way. --Glenn Lyford

Reply to
glyford

That works too. I just can see better when the file is on top. ERS

Reply to
Eric R Snow

I dont think i can make my lathe turn backwards with the current motor fitted on it and if there is anything i know form an electronics background its not to fiddle with the insides of motors you NEED that are older than you =)

If a replacement were handy that would be different but my lathe only spins one way for now

Thanks for the filing advice.

I th> >

Reply to
Brent

Look at a few small jewelers lathes. They use hand held tools similar to a wood lathe.

Reply to
Ron Thompson

Do not despair. Some of us don't grasp the concept initially----but unless you're hopeless, the light will come on and things will make sense. Cutting tools, in particular, are very simple to grind, but you must first understand why they cut. Once that's entrenched in your head, and you understand how clearance and rake affect performance, it's dead easy to design tools for specific chores.

snip great report of class, methods, people and progress----

That's a common complaint I have----along with the related lack of respect for those that have paid dues to achieve a level of competence by a select few that don't understand that making chips isn't the same as making parts. Nothing sorts them out quicker than building a part to prints specs, which will be inspected by an unbiased inspector that's looking for nothing more than good and proper work. Some folks can't put it together.

Exactly! One does not eat an elephant in one gulp----it's done a bite at a time----and suddenly the elephant is gone. You'll do fine, Andrew. Have patience, and do your best. What's important is your attitude. If you care, and choose to learn good and proper procedures, you will. If, on the other hand, you choose to use every dodge one can fathom to avoid the learning curve, that's likely to be the outcome as well. You have a choice of becoming a good machinist, or a good bullshit artist that claims he can, but can't.

You mentioned being an old fart, Andrew. How old? I believe I mentioned somewhere that I turned 67 in July. I feel every one of those years.

Harold

Reply to
Harold and Susan Vordos

My dental school is one of those that is research based. The students are very bright and they are motivated by the good life style. They intellectually get it most of the time, but the link from the mind to the hand needs lots of practice to function well.

There is as much feedback as there is in working on a manual machine and stopping for measurements periodically. Not as satisfying as a DRO.

I am open to any interesting ideas on developing a feeling for 3-D.

I agree, there is no substitute.

I think that the problem here is one of frustration. But I thought that all of those hours spent mastering video games would come in handy here. Or does that only work for fighter pilots?

There is plenty of free access to to the lab and faculty.

My own experience is that sometimes an instructor can help you with a set up or introduce you to a tool or hold down device that you did not know about. Otherwise I play with feed speed and nature of cutting tool. Go with what works, but try to understand it.

Charles Friedman DDS Ventura by the Sea

Reply to
Charles Friedman

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.