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3 axis CNC - rotary work holder?

Joined
Mar 22, 2019
Background
Not experienced with production machining.

Current situation
About to buy a mill, trying to get a little more educated as to options.

Question
The major parts to be produced are:
  • Aluminium.
  • Require machining from at least 3 of 6 faces.
  • Likely be produced in batches of 8, 16 or 32.
  • Likely be from bar stock, pre-cut to length.

Not having experience, I have been thinking about work holding and need advice.

I am aware:
  • From other equipment that it is typically possible to use GCode ("M-codes" or similar) to flip relays to toggle the state of external subsystems, including work holding systems.
  • There are pneumatically driven work holding systems, some of which support rotation.
  • Machining many parts concurrently in batches amortizes the overhead of an operator-executed manual re-orientation operation across the total number of parts and thus reduces the impact substantially. However, I would really prefer not to have an operator present at all, if possible.

What I would like to ask is are there pneumatically driven work holding systems that also provide workpiece rotation around axes other than Z?
  • Ideally I would like to reduce the number of manual re-orientations to zero for 3-face milling, and 1 for 6-face milling.
  • At a minimum, I would like to reduce the number of manual re-orientations to 1 for 3-face milling.

What solutions are you aware of and am I completely off the wall with this line of thinking?

Those I am aware of:
  • Rotary vise. Exist? Viable? How would this work when finally disconnecting the workpiece from bar stock? Recommendations?
  • External robot arm or gantry. Undesirable due to cost, space, initial setup time, lack of reconfigurability, etc.
  • Design a custom overhead robot to descend, release the workpiece, pick it up, re-orient it 90 degrees, and replace it on the new face, then retract to allow for continued milling. This would be triggered for all parts via an MCode.
  • Pay someone to do the manual re-orientation including the mistakes, safety issues, reliability issues, and ongoing costs associated with humans.

Thanks for your consideration.
 
Thanks Vancbiker! I have found some others in that same category.

I can see mounting this sort of device inside of a mill along the X or Y axis should not be hard, by using some sort of endpiece, stop or clamp.

However I am unsure, being inexperienced at machining, how to go at the overall machining process-wise, in terms of reducing the bar stock to multiple disconnected finished pieces.

Obviously mounting one bar is faster than mounting a bunch of smaller pieces, and also guarantees identical alignment to the face.

This supports the idea of milling multiple pieces along a longer bar before splitting it in pieces.

However, this raises the question of how to actually split the pieces in the end. I could keep them together during machining, perhaps reducing the material, then actually cut them apart as a subsequent (offline) operation but this would presumably require a secondary finishing operation (eg. grinding) which seems wasteful and inefficient.

If there are any recommendations for books to read on this sort of basic machining question then I am all ears. I guess a lot of people learn on the job, but no doubt someone has written this stuff down at some point!
 
Background
Not experienced with production machining.

Current situation
About to buy a mill, trying to get a little more educated as to options.

Question
The major parts to be produced are:
  • Aluminium.
  • Require machining from at least 3 of 6 faces.
  • Likely be produced in batches of 8, 16 or 32.
  • Likely be from bar stock, pre-cut to length.

Not having experience, I have been thinking about work holding and need advice.

I am aware:
  • From other equipment that it is typically possible to use GCode ("M-codes" or similar) to flip relays to toggle the state of external subsystems, including work holding systems.
  • There are pneumatically driven work holding systems, some of which support rotation.
  • Machining many parts concurrently in batches amortizes the overhead of an operator-executed manual re-orientation operation across the total number of parts and thus reduces the impact substantially. However, I would really prefer not to have an operator present at all, if possible.

What I would like to ask is are there pneumatically driven work holding systems that also provide workpiece rotation around axes other than Z?
  • Ideally I would like to reduce the number of manual re-orientations to zero for 3-face milling, and 1 for 6-face milling.
  • At a minimum, I would like to reduce the number of manual re-orientations to 1 for 3-face milling.

What solutions are you aware of and am I completely off the wall with this line of thinking?

Those I am aware of:
  • Rotary vise. Exist? Viable? How would this work when finally disconnecting the workpiece from bar stock? Recommendations?
  • External robot arm or gantry. Undesirable due to cost, space, initial setup time, lack of reconfigurability, etc.
  • Design a custom overhead robot to descend, release the workpiece, pick it up, re-orient it 90 degrees, and replace it on the new face, then retract to allow for continued milling. This would be triggered for all parts via an MCode.
  • Pay someone to do the manual re-orientation including the mistakes, safety issues, reliability issues, and ongoing costs associated with humans.

Thanks for your consideration.

What work will you be stealing from the USofA or your country of origin ?

How many jobs ?
 
What work will you be stealing from the USofA or your country of origin ?

How many jobs ?

First, employment is not a zero-sum game. Just because work exists somewhere does not mean it does not exist somewhere else.

Second, I am an entrepreneur. That means I create new products from scratch creating new employment where no jobs previously existed.

Third, it is not possible to innovate in the domain I am working in western countries. It would be insanely slow and expensive due to supply chain and cost issues, as well as regulatory issues.

Fourth, the product I am producing is not primarily targeting western markets, it primarily targets East Asian markets.

Fifth, this represents ideally zero production jobs because, as stated, it is one job on one mill and I am going for as close as possible to full automation.

Finally, I do not appreciate your tone.
 
If you're that green to manufacturing just send it over to my shop in Zhongshan or Foshan. Machining is not just something you pick up from a book and automated machining takes many years of hands on. By the time you buy a cheap Chinese mill and tool it up you're gonna be about 300,000 RMB out of pocket then still have to invest in the automation part plus learn how it works. Not to mention setting up your Chinese W.O.F.E. business licenses, Insurances, Taxes. And just remember, every employee you have no matter if they only work half a day and you get rid of them you must pay one month salary and tax.

We have a bullet proof NDA that would hold up in any court in China. An employee confidentiality agreement that scares even the foreign employees. A no Camera/Cell Phone workplace, even potential customers coming for a tour have to sign a confidentiality form as well as surrender their cell phones.

I try to keep as much money as possible flowing back to USA of Europe by buying my machines and tooling abroad rather than in china (Kinda like how Chinese companies in other countries work). If you’re needing fixturing I have one of the best guys in the county that strictly designs and builds automated fixturing.

If you invest in a machine in china and slam the spindle into a vice and need warranty work you can forget it (It is inevitable you will have several crashes, we all have. It's just up to old man Murphy to decide how bad it will be). Nearly a decade of managing and owning shops in china and not once have I ever seen a Chinese supplier honor a warranty.

The offers on the table and my email and website is in my profile if you want to inquire.
 
Cheers, emailed you. Nearby, let's beer.
That's a good idea, cuz you'e not going to get a wofe these days for anything under $30,000 (usd, not oz). That's not counting registered capital. And you're not renting, registering with the tax department, getting a bank account, getting electric service or even a phone without a license. From the description, you're not going to be able to work or stay in China, either. You're a long ways off from worrying about automation.

They are not interested in small foreign operations.
 








 
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