Somewhat related to metalworking

This is somewhat related to metalworking... And surely more related
to it than most of the @#$%^ some of you keep posting.
Thank God for Agent and it's ignore function I've finally found a way
to ignore most of those threads.
Now... That having been said, and the fact that I lost access for 2
months again and came back on a different newsreader only receiving
minimal mention, I'd like to describe a scenario I had to quote
today...
Ten 0.1562" holes drilled in thin material.
Each hole drilled by its own small drill (our 1000 series unit).
Each 1000 series unit spun and stroked by an air motor.
So far, no problem!
Challenge - The customer wants me to give him the option to start all
the drills with a single start button. The air motors must kick in
only on the downward stroke and must turn off when the drills are
stroking home (note, not when they ARE home, when they are on their
way home...)
However, the customer also wants the ability to turn off each and
every drill individually. When a drill is off, the customer does not
want the motor spinning.
Difficulty - The air motors suck up enough air that they can not be
run off the same valve as the stroke of the drill is.
We figured it out, but figured you'all might enjoy the brain teaser in
pneumatics logic.
Why is it metalworking related? Well, the 0.1562" holes, of course!
They are being drilled in aluminum with zero collant. Thankfully, the
material is 0.060" thick and the hole does not need to be burr free.
Reply to
Joe "Dufu"
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Individual electric 3 way valves. By allowing it to vent to air when turned off the spindle should stop much faster. Add a manual valve to each OR an individual electric switch. Switches are probably cheaper. Get fancy and wire up a control panel with an LED for each one that is turned on in the same array pattern as the air spindles. Don't know enough about your feed setup, but if this is something like banks of drills with each bank processing a single part then maybe you can have a simple mechanical interlink between banks that allows you to not even feed those that are not actually processing a part.

Reply to
Bob La Londe
The addition of spring activated solenoid valves and a PLC make this easier, that's for sure.
But see if you can solve it with pneumatic logic only...
If you do, I'll tell you about the more complex nine drill set-up we had a month ago and even show you photos. :)
Reply to
Joe "Dufu"
Or use a PLC to do the hard work.
Gunner
"The socialist movement takes great pains to circulate frequently new labels for its ideally constructed state. Each worn-out label is replaced by another which raises hopes of an ultimate solution of the insoluble basic problem of Socialism, until it becomes obvious that nothing has been changed but the name. The most recent slogan is "State Capitalism."[Fascism] It is not commonly realized that this covers nothing more than what used to be called Planned Economy and State Socialism, and that State Capitalism, Planned Economy, and State Socialism diverge only in non-essentials from the "classic" ideal of egalitarian Socialism. - Ludwig von Mises (1922)
Reply to
Gunner Asch
but...why would you?
Gunner
"The socialist movement takes great pains to circulate frequently new labels for its ideally constructed state. Each worn-out label is replaced by another which raises hopes of an ultimate solution of the insoluble basic problem of Socialism, until it becomes obvious that nothing has been changed but the name. The most recent slogan is "State Capitalism."[Fascism] It is not commonly realized that this covers nothing more than what used to be called Planned Economy and State Socialism, and that State Capitalism, Planned Economy, and State Socialism diverge only in non-essentials from the "classic" ideal of egalitarian Socialism. - Ludwig von Mises (1922)
Reply to
Gunner Asch
Perhaps lower cost & simplicity, improved reliability & serviceability. Also only a single energy source connection.
Reply to
Glenn B
Lower cost? Hardly. Hooking up all that pastic tubing takes time. Simplicity? ROFLMAO!!! Improved reliabiltity and serviceability?
Never worked on complicated pneumatic logic before..have you?
As for "single energy source connection...are we talking about that 10hp 3ph Ingersol Rand air compressor in the basement? Or simply plugging the plug into the wall?
"The socialist movement takes great pains to circulate frequently new labels for its ideally constructed state. Each worn-out label is replaced by another which raises hopes of an ultimate solution of the insoluble basic problem of Socialism, until it becomes obvious that nothing has been changed but the name. The most recent slogan is "State Capitalism."[Fascism] It is not commonly realized that this covers nothing more than what used to be called Planned Economy and State Socialism, and that State Capitalism, Planned Economy, and State Socialism diverge only in non-essentials from the "classic" ideal of egalitarian Socialism. - Ludwig von Mises (1922)
Reply to
Gunner Asch
Because the customer demands it. Logical reasons would include a situation whree they are drilling out a container filled with hydrogen gas and the "pneumatic" part of it is run on an inert gas, etc.
All types of other examples abound. ...Most of which are based on the customer's preferences and not necessarily mine.
Reply to
Joe "Dufu"
Time delay pneumatic relays, I'm not sure exactly what you call them. We use them on certain machine resets to activate two cylinders at different times on the same circuit. they will turn off a circuit after a preset delay too. I assume the time of the cycle doesn't vary much so the drills stop on the up-stroke.
Reply to
Tom Gardner
Reduced noise for one. Also, the cost savings on the air might just add up.
Reply to
Tom Gardner
I don't think it's that complex, I think it can all be done without electrics or electronics.
Reply to
Tom Gardner
Valve (gang valve if necessary) provides mass air to the entire assembly. The quills are fed by a spring retracted pneumatic cylinder with some form of control valve to control speed. A manual valve allows you to turn off air to the feed quill piston and the spindle. When you cut main air all engaged spindles stop turning and retract. Air pressure has to be fairly strictly regulated once you dial it all in. Timing could be another issue.
Pneumatics isn't really my thing, and I when you say "pneumatic logic only" I don't know how much mechanical control is allowed.
Reply to
Bob La Londe
I considered explosion proof environment as a possible reason. See my other reply. Mechanical ball valves are cheap (relatively) so simply installing a valve to shut off all air to each spindle and quill as described in my other reply is easy enough.
Reply to
Bob La Londe
Alternatively the quill feed piston could be bidirectional and you could employ a 3 way gang valve. When your main gang valve is engaged it feeds air to the feed the piston and to the spindles. When the valve is reversed it cuts air from the spindle and forces the piston to retract. Cutting air to individual drill heads as described before still works, and if any quills experience creep they are forced back each time the valve is reversed. Spring assist for retraction is still an option.

Reply to
Bob La Londe
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Dashpots.
Enjoy, DoN.
Reply to
DoN. Nichols
We call them pneumatic timers and reverse timers.
Standard waits anywhere from nil to X before it sends air through and reverse sends air anywhere from nil to X.
Reply to
Joe "Dufu"
Are those the same as they had on '50s and '60s auto carburetors? (That word brought back some deep old memories.)
Are the valved mechanisms which slow metal bandsaws during cutting called dashpots, too? Or is there another name for those?
Reply to
Larry Jaques
The items on the bandsaws are usually called "feed controls" in my indutry. The #1 manufacturer being Deschner and their prodict is amazingly well made.
However, Band saws usually use a much less precise and durable item because it's just not that critical in that scenario.
The deschner product I use can handle up to 1200 lbs. of thrust if I remember correctly. ...Not exactly something a band saw would normally see.
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If you call them for any reason, please tell them Joe from AutoDrill sent you. I won't get anything out of it other than a cute conversation the next time I call them.
Reply to
Joe "Dufu"
So, I am curious. How did you do it?
Reply to
Bob La Londe
No I haven't - that obvious is it! :)
I would have thought once set up a purely pneumatic system with no electronics would be much more reliable.
I'd imagine most if not all workshops would have shop air plumbed throughout.
Reply to
Glenn B

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