Josh

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the basic shaft od (outside diameter) profile is turned on a lathe between centers. The shaft is then taken to a mill where it can be inserted into a made fixture for mass production--or a rotary table. and the star to cam and star to cam pin profiles are milled with approperiate dia end mills . Rough milled parts are left about .010 oversized to allow for grinding. The part is then heat treated. After heat treatment, the shaft will be ground between centers on an od grinder. Then the star to cam and star to cam pin bearing surfaces are located back into a made fixture or rotary table and ground on a jig grinder. Finished part needs to be precision inspected. Tolorances for these parts is about + or - 0.0002 or so -- a quarter inch is 0.250 --so this shows you just how precise these parts are! Yes, I can make these parts--I just dont have my own shop! Fun projects. About 3 days work to make one star and cam (including heat treatment) So making one is expensive! Shops like LaVezzi have special set-ups and tools for mass production. This explanation is very basic, I have not discussed all of the tools and fixturing needed. These would have made excellent projects for my machine tool classes--we just did not have a jig grinder!

As for sprockets, LaVezzi has designed their own special tools and processes for making sprockets--these are their own patented secrets that they will not discuss--they do not give tours of their shop.

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But just for the record, The company would be called RCA

Josh

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Josh, have you seen the video tape PBS had about these old radio guys? The title was, "Empire of the Air". I have that, and if you would like to borrow it, I'll send it to you. I think it is out of print, and can't buy it anymore. It includes the history of all these guys from Marconi, Armstrong, Deforest, Sarnoff, and a few others.

One weird funky circuit RCA had was known as the "Syncro-Guide" Oscillator. It was used as the horizontal sweep circuit in the old RCA TV sets, and it was nothing more than a mdoified Series Hartley Oscillator.

I never ever did figure out how his horizontal drive circuit worked. And, I have heard many TV techs say, "Oh, those ***** syncro-guides - grrrrrrrrrrrrrr" And, I have said the same countless times.

Paul

Starwheels are another matter as they involve more operations, but are roughed out in a similar way as the cams are. After rough cut the star end is round rather than like a star. Next operation if memory serves me is to rough out the star radiuses first on CNC milling machines and to turn any oil spirals, etc into the shaft end, and then the stars go out for hardening and Black oxide for corrosion prevention. The black oxide also aids in visual checking during machining operations. They come back from heat treatment and are sent through a number of different grinding operations such as shaft diameter, star slot rough grind, etc. of which the final operation is a final grind on the slot. This is done in a soundproof booth(talk about working in a padded cell!) with an air bearing Studer grinder which is manually operated. On my last trip there were two of these rooms set up for this. On my last trip through there Al LaVezzi said that there were only two people that worked there that could do this final grind operation properly. The final slot grind operation is something that has to be heard and cannot be felt as in other grinnding operations and thats why the sound proof room. Even the grinder barely makes any noise of its own when its running.

After any part at LaVezzi is manufactured it goes into a temperature controled room for QC and each and every parts critical dimensions are checked to meet specification. Reject ratio is low due to the many long time employees experience in this type of manufacturing. Employee turn over is not something he worrys anout much.
They also make parts there for other companies such as Imax, Cinemeccannicca, Strong, and also movement parts for many motion picture camera manufacturers.
They do have a web site at http://www.lavezzi.com/
There is an on line slide show of the plant and some of the parts that they produce, however, one has to actually go there and see the operation to appreciate the craftsmanship that goes on there. Also, keep in mind that Motion Picture parts are only a small amount of what is produced there anymore. LaVezzi also makes many other parts such as medical items(many from from Titanium!), aerospace parts and anything else of a precision nature. All in all an amazing place to tour.
Mark @ GTS

It is absolutely amazing how much we take for granted. I bet no one will ever look at these parts in quite the same way again after reading your detailed description of LaVezzi operations in making these parts.

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Oscar Neundorfer
Chief Engineer
SMART Devices, Inc.

Just to give you a little background info about myself. I have been a licensed FAA Aircraft Mechanic since 1988 including both civilian and military service. I am currently completing my AAS in Machine Tool Technology CNC Option from Pima Community College (need to finish English 102 to graduate) and am working on a BS in Manufacturing Engineering Technology from AZ State University. Yes, I have job shop machining experience--not to mention my experience as a Projectionist. So I found your post about LaVezzi interesting.

I guess Mr. LaVezzi wants to ruin his expensive CNC machines--1" cuts!? And machines bursting into flames? I'm speechless! And needing to hear the gringing operation because feel does not cut it? This is what precision inspection equipment is used for during and after the machining and grinding processes!

As far as these guys taking such heavy cuts are concerned I'm quite sure that they know what they are doing with the lathes that perform this task. I can't remember the depth of cut exactly but it is very large. My last visit there was about 6 years ago and I'm sure those lathes are still humming along quite well today. These lathes also do alot of Titanium machining rough out for medical instruments so one could assume that they're made for this sort of work day in and day out. As I'm sure you kow, it all has to do with spindle speed and cutting tool feed plus proper lubrication of the cutting tool to clear away debris and keep the cutter cool. Any high quality lathe of sufficient size can do this if properly set up, day in and day out.

Will, Probably after you have about another 20 years experience in making ONLY presision parts you can then start to think about making parts like those that come out of LaVezzi. If you have the facility to do it in. Keep studying!
Mark @ GTS

If you are offering me a challenge about making these parts, then give me a copy of the prints! I'll take you up on it! There may be a few operations that I may not be able to do because I dont have the tools. I can present the challenge to my instructors and maybe I can use the shop!

Most of my classmates are/where people with a lot of experience behind them! They went back to school to get a little piece of paper so that they can get promoted at work!

About some of my instructors:

They are just not "schoolroom" instructors--all work in industry and teach as a side. If I spent the time here to tell you all their credentials, it would blow you away! Keep in mind that Tucson is very high in the aerospace industry. Several of my instructors were in charge of the tool room at Hughes Aircraft. One of these people was also a tool maker at Los Alamos! Several of these guys are injection mold makers. Several are also precision instrument makers at the University of AZ involved with NASA related projects! We have one injection mold shop in town that is known for taking on the difficult jobs in the country that no one else will touch!

As for me, ya, I am used to working with tolorances of 0.0000! And ya, I am good!

Another piece of info for you--if one decides to become a machinist, one will never stop learning! The worst machinists are those with egos who are know it alls!

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