Colchester gear: $800!!!!!!

Yep! I agree fully. I'm not fond of being screwed and often do things for myself instead of reaching for my wallet. It's worse than just the money in some instances, too. Poor workmanship and unreliable people that don't follow through. I know I can trust myself, although I may be slower than tar on a cold day when doing things I've never done before. Still, I get it done.

Cutting a spur gear is no big deal--indexing is probably the most difficult part. The last one I made I was fortunate in that I could do it with an indexing head. That's not always the case.

Harold

Yes

Index head or rotary table?

Yes

If so, what's preventing you from making the gears you need for the Tray-Top??

Time

I am of the mind set that I can do almost anything in my shop, but I am always a little short on time.

Using a similar

I wanted to do metric threading to do a "free" job for a friend. I do have plans to make the two gears one day, but first I need to make a 127 hole indexing plate for my dividing head. And I might even have to make a raiser block for the indexing head).

Has anyone ever noticed that one simple project is actually a series of increasing difficult ones?

Vince

Proctologically Violated©® wrote:

Thats Cornells Law.

Gunner

"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.

Think of it as having your older brother knock the s*it out of you for torturing the cat." Gunner

IME, a lot of the common wear parts are actually pretty reasonable from Clausing, but maybe that's because they sell enough of them to keep the cost down while still making a decent profit. They're manual proces are also pretty reasonable (

CTRS - Cascading Tool Requirement Syndrome.

It's not as bad as RCTRS - Recursive Cascading Tool Requirement Syndrome, where tool "A" is needed to make tool "B", but tool "B" is needed to make the tool "A".

Understood! :-)

And if you think it's slipping away quickly now, wait until you retire.

Harold

One other not insignificant bonus is what a person learns by tackling anything new . The knowledge has to have a value . That and the feeling that you beat the system , every small bit helps ;-) Ken Cutt

I couldn't have said it better. Tackling the difficult is something I always encourage. Think about running a lathe. Some folks are intimidated by hand grinding toolbits, so much so that they turn to insert carbide tooling in order to avoid the learning curve. Truly a sad thing, for they're cheating themselves from the one skill that's essential to machining, the ability to generate cutting tools, and to know when they aren't proper, and why. I can't think of one thing that will set a person free more than that ability, when manual machining is involved.

I rarely allow myself to be in a position where I'm at the mercy of others. In order to live that life style, you must have incredible will power and confidence. I have both, and they've served me well. Too bad I didn't have the foresight to get an education, so they could have served me even better. sigh!~

Ah well, life has been good, and I can't complain.

Harold

Harold and Susan Vordos wrote: Too bad I didn't

Harold,

Though others got the assembly line style of education, I rather think you got just as good if not better and more practical, though seldom recognized as such, an education. You just assembled yours in smaller bites and spread it out over many more years. Never denigrate what has shown itself to be of value. Got mine the same way.

George Vigneron

In case anyone wants to try it, I suggest the book "gears and gear cutting" by ivan law. Good intro to involute and cycloid gears both inch and metric as well as how to cut.

See:

You can buy in the US from Powells see

also see

I have had good luck using 6061 T6 aluminium and formica/micarta for change gears. This appears to be very light duty/intermitant use, esp. for the home shop machininst.

There is another way to do this. there are several sets of gears within the normal range of the dividing heads that will give a very close approximation of 1.27:1 which are close enough for reasonable length threads. I can dig this out if you are interested.

see our website at

Biggest advantage of using the fistures/gages is repeatability. Our first term students were able to get "line out" fit on even acme thread tools after a few tries.

Don't have any pictures on the site but we used a 19.95 harbor freight pencil air grinder with the appropriate tools. Works real well for sharpening taps. For boring we found grinding "hook" in the tool was better than grinding half of the tool away to get it on center [of the boring bar].

George,

True, I suppose. Problem is it's hard to sell the school of hard knocks to a prospective employer, very unlike conditions when I was a young lad. I started my machining career in a missile facility, in which several of the engineers had no degree, but could do the work. I'm of the opinion that such people would find it impossible to find employment in that capacity in today's environment.

The place I feel I'm woefully lacking is in general education. I'm not well rounded, and I feel it shows. I was a bit of a mule as a kid, paying attention only to things that interested me. As a result, I've never learned the art of learning about things that may have an affect on my life, but I find boring. Politics, for one. Had I been "forced" to learn to learn, maybe I'd be better rounded. The forcing didn't work in my early school years--at which time I did nothing. I have no recollection of hauling books home. I was tested when I was in the 5th grade because the teacher felt I wasn't able to learn. The results were shocking----for I was found to be performing at a 9th grade level. I was lucky. I could pretty much sleep through my classes and still get passing grades (note I didn't say good grades). Only when I got into high school and could choose things that held my interest did I do good, and then only in the classes I chose. Truth be known, in my case, it's a personal problem that resulted in my poor education. I fault only myself, not the system.

But then, as I said, life is good! :-)

Harold

While it may be "close", I'm of the opinion that such threads are a horrible compromise. Under loading, only a tiny proportion of the thread is in intimate contact, with the balance of them in clear air. If you horse the fastener, you get a cascading collapse of the thread, possibly leading to complete failure. I recommend against such threads if there's a load involved, or if failure can result in injury or damage.

Harold

Thanks for the offer, but I bought a DRO last year and making a 127 hole plate will be easy with it. Well, almost easy, the automatic bolt hole function only goes up to 99 holes. I'll generate a table in excel and manual make the plate. I thought of making two rows so the holes are not two close together.

Vince

F. George McDuffee wrote:

You may have an unexpected problem since 127 is an odd number and can not be evenly divided into two circles. One circle will have a wide gap and the other will have two holes 360/127 degrees apart. It seems to me like the thing to do is just make the hole circle as large as possible. Don Young

Well there is one huge compensating factor the world has given to those not too timid to ask . The Internet and the forums , such as this one . As long as one is willing to ask for help the world is full of people of all skills more than willing to pass on what they can . Nothing is ever asked in return . Wow imagine that . Think about it , in a world that at times seems driven by " Whats in it for ME !!! " . Here is so much precious experience given , without strings . Kinda makes a person think that way way out there you can see the faint glimmer of light at what the world may become . I could not list all the people here that have helped me learn . I sure have been a big winner overall but the sweetest part is it ain't over yet . Ken Cutt

It does happen occasionally. My father was an engineer at Lockheed but didn't have a college degree. I have a friend that became an engineer at an elevator company five or ten years ago with no college education. He started at the bottom and worked his way up. He's now a trouble shooter that gets the jobs no one can solve. I don't think a college trained engineer could do what he does because they wouldn't have the hands on experience from assembly to repair that he does. He's well paid and he really enjoys solving the hard problems. All that you could ask for in a job. Karl