[scratch_6057]

Just curious does this exist, does it exist at a hobbyist /small shop level?

Does anyone make a “Black Box Device” that for lack of a better term
(or knowing what I’m talking about) I’ll call a “Electronic Punched Tape
Recorder / Player” or “EPTRP”

I’ll briefly describe what it is and does:
In a hypothetical situation you have a file containing proven G-Code for a part.
You need to produce these parts in quantities ranging in the hundreds.
Instead of dedicating a computer driving a CNC system to the task for
endless hours, you download the G-Code into the “EPTRP” just as you would
to a CNC system, only there is no mechanical movement, so the time factor
is minimal. The “EPTRP” has recorded the voltage level signals along with
marking and recording time slices. The “EPTRP” now knows what signals to
send and when, so it is hooked to the CNC system in place of a computer and
runs the system for a large number of identical parts. After each part is
finished, the “EPTRP” could beep / flash indicating that it is ready for
a finished part to be removed and a new “blank” inserted. One button would
start the milling process on the new blank. The device might have a power
switch, a program / run switch, a mill next part or go button and the all
important E-STOP.

[MetLHead]

http://www.grecosystems.com/products/minifile.html

Is this what you're after?

Scott

[One of Many]

Unless you already have a tape system that needs some type of interface. There is little need to store it on tape if you have a PC already on the CNC like most hobby mills do. I see no benefit considering the PC is running anyways. Unless of course it has a conflict with Free Cell.....

Since it would take a microprocessor type of system to make this work, it would be "Rube Goldberg like" these days, to create an external storage medium that can be done simpler in electronics without it.

DC

[kdoney]

I've never seen such a thing but I believe it is possible to record signals and replay them on demand without a microprocessor. Adjustments would not be possible at runtime of course. What are you going to do with the controller that was originally on this machine? Move it to another machine while this one is working? If you are building your own special purpose machines I can see some value in recording signals instead of having a general purpose computer. If the signals are very sophisticated and the controller very expensive then eliminating that cost in cloned operations or complete systems would have an advantage. That is what ASIC's are all about. G-code running systems though are not candidates I wouldn't think. Although some manufacturers make you believe it's still the 60's when it comes to computing power, we are already living with your toothbrush having a microprocessor to tell you to brush more or buy a new head.

[scratch_6057]

MetLHead
Yes the “Minifile” is something of what I had in mind
But I was actually thinking of something a little less
Elaborate. Just looking at some of the features and capabilities
My Guess would be a price somewhere on the high side of 50K

One Of Many:
No preexisting tape system, I was only using the term
“Punched Tape” in order to more clearly convey what
I was thinking about. You are correct when you mention
a Micro, something along the lines of a midrange Microchip
or Atmel with a large Eeprom for storage. I wouldn’t even
begin to think about such a design without one.

kdoney:
Well I guess it COULD be done without a Micro but I wouldn’t
want to be the one doing the design. Something like a DTMF
(“Dual Tone Multi Frequency” or “Telephone Tone”) chip provides
if I recall, sixteen distinguishable tones so STEP, DIRECTION
(requires 2 forward and backward) , ON-OFF. For 3 or 4 Axis,
NO I don’t want to design it ! ! ! Radio Shack YEARS ago had a
Computer called a CoCO that used a DTMF scheme to record
programs to audio cassette tape before they had disk drive add ons.

When you said “What are you going to do with the controller that
was originally on this machine? Move it to another machine while
this one is working?” You actually hit the WHY reasoning right
square on the head. Recall I had stated a quanity run of HUNDREDS
But also after YEARS in IT and Networking Services I’ve lost
count of the number of times I have seen EXPENSIVE computers
“Hink-Up” or freeze when doing simple repetitive tasks. As far
as G-code running systems being candidates for ASIC's, remember
that I said or implied that the G-code was PROVEN.
That having been said remember that once the code makes its way out of a
processor it is no longer code but voltage signals. A stepper Motor Driver
is looking for voltage levels it doesn’t care where they come from.

ALL:
Don’t get too overly concerned or twisted over this I think it could make
for interesting design discussion and I was curious as to whether such a
system existed. As far as I’m concerned at this point it is all a
hypothetical situation.

[CJL5585]

Just curious does this exist, does it exist at a hobbyist /small shop level?

Does anyone make a “Black Box Device” that for lack of a better term
(or knowing what I’m talking about) I’ll call a “Electronic Punched Tape
Recorder / Player” or “EPTRP”

What you are describing is about 40 year old technology which is almost non-existant these days.

You might be able to find one on a junked machine that works. By the way they are called "A Punched tape reader".

Interfacing one to a machine would be a daunting task even with schematics of the machine and reader.

Jerry

[One of Many]

ALL:
Don’t get too overly concerned or twisted over this I think it could make
for interesting design discussion and I was curious as to whether such a
system existed. As far as I’m concerned at this point it is all a
hypothetical situation.

I kind of thought this to be a hypothetic proposition.

I can possibly see this as a crude 2 axis stereo or quadraphonic 4 axis stepper controller. It would still need something to convert the signal to a digital format from the analog tape pulses, not voltage input, but frequency to stepping controller driver(s). Control the tape speed for feed rates? Base Speed, Step and direction would be already formatted on the recording. IF sync can be maintained between multiple channels. Ta heck with re-inventing the wheel when the axel could be made out of magnetic flux too! :banana:


Getting a recording is only a small portion of this challenge. Recording could be done on a full system to prove it runs as expected. Then move it off to a dumb terminal system that will just copy the path as original. If the tolerances weren't to critical, this may be functional.

A microcontroller does seem like the simplest way. Yet, if you can store it digitally so much easier, I don't see what benefit the recording tape is going to gain. Drip feed from a disk makes more sense. Just buffer the incoming serial shifting pulse stream. I suppose that could be done with tape to get flow control.


I'd doubt this to be realistic for servo systems which do use analog voltages. No servo amp would take this analog input and make use of it to maintain a consistant linear path velocity using stretchable tape? A home hobbyist is highly unlikely to make an analog converter from discrete semiconductors to drive servos direct with any kind of repeatability. Teddy Ruxpin style precision?

The backup systems are just that. They are nothing more than a disk drive to store programs. Many of the NC punch tape converters were just another medium to store a string of canned cycle moves. Certainly not cheap. Some did do G-code, but both still had controllers.

DC

[txcowdog]

Older embroidery machines use exactly that to drive servo motors moving the fabric in both X & Y directions. Most of the old systems have been replaced with floppy drives which do the same thing. I guess you could modify an old tape unit to your needs. Seems like a lot of trouble considering a computer powerful enough to run MACH3 is under $200 (2.2ghz AMD with 128MB ram etc.) Why take all the time and expense to make the modifications to a tape reader to save buying a $200 computer?

[greybeard]

Scratch, I expect by now you wonder where the discussion might be going considering how simply your original question was.
I need exactly such a black box for what my cnc set up will eventually be used for - single product.
To start with I shall use one of my pc's, but as I started my electronic life trained with punched tape, and then oversaw the Uk army convert to all electronic versions, I'm well positioned to consider just the sort of idea you have.
In spite of most people wanting to just answer every problem by throwing money at it, I have very little to spare. Fortunately my memory is still pretty good, I have a large imagination, and don't consider thinking time wasted.
When I get up and running, I'll post.
John

[scratch_6057]

One Of Many said
“I don't see what benefit the recording tape is going to gain. Drip feed from a disk makes more sense.”

In MY world I would completely forget about using tape or any type of magnetic storage outside the original HD inside the computer. Once the signals and timing were recorded to EEProm Memory inside the “Black Box” then NO tape or disk would be involved. Yes, I did mention the DTMF to tape system, BUT that was only to show how it COULD done, NOT that it should be done that way. Tape schemes for any data storage are older than DINOSAUR BONES.

One Of Many said
”I'd doubt this to be realistic for servo systems which do use analog voltages. No servo amp would take this analog input and make use of it to maintain a consistant linear path velocity using stretchable tape? A home hobbyist is highly unlikely to make an analog converter from discrete semiconductors to drive servos direct with any kind of repeatability. Teddy Ruxpin style precision?

I agree with him 100% on the “stretchable tape” issue too many weak points in any tape system, I personally don’t care for any type of magnetic disk recording interface WAY too much “EMF” floating around in a shop with motors running and it’s all just waiting to attack your disk and scramble your data.

His “Teddy Ruxpin” brought to mind the world of “ANAMATRONICS” do a Google search for ”anamatronics” and “servo controller”, then add to that search “analog” and you end up finding things like http://www.milinst.com/animatronics/1_965inst.pdf now to get analog add something like
http://www.milinst.com/animatronics/1_905.pdf and you’ll probably have to amplify / buffer that output but it looks like its there.

One Of Many said
“A home hobbyist is highly unlikely to make an analog converter from discrete semiconductors to drive servos direct with any kind of repeatability.”

I Highly disagree with this statement, if you are going to make that statement hold true then a statement such as

“A home hobbyist is highly unlikely to make a CNC system from discrete semiconductors and mechanical parts that will produce accurate parts with any kind of repeatability. “

would be just as valid of a statement. Never under estimate what a home shop hobbyist will do or is capable of doing, (some of the BEST Beer I ever drank came from home brewers) Apple Computer started in a garage, and if I’m not mistaken so did Microsoft at some level.

As an example of what people can and will do with electronics on a hobbyist level take a look at
http://www.seattlerobotics.org/
http://www.seattlerobotics.org/encoder/index.html
http://www.wa4dsy.net/robot/

Once again I’m not writing to make anyone mad or upset, just a interesting discussion that can hopefully help educate people to things they did not know were around and get the creative juices flowing.

Share your knowledge

Mike_L

[Geof]

As someone who has hundreds of G code programs that are proved out to work and who makes parts in the tens of hundreds I can attest that what you are discussing does exist; it is called a CNC machine, it stores the program and makes the parts over and over again.

[One of Many]

One Of Many said
“I don't see what benefit the recording tape is going to gain. Drip feed from a disk makes more sense.”

In MY world I would completely forget about using tape or any type of magnetic storage outside the original HD inside the computer. Once the signals and timing were recorded to EEProm Memory inside the “Black Box” then NO tape or disk would be involved. Yes, I did mention the DTMF to tape system, BUT that was only to show how it COULD done, NOT that it should be done that way. Tape schemes for any data storage are older than DINOSAUR BONES.

One Of Many said
”I'd doubt this to be realistic for servo systems which do use analog voltages. No servo amp would take this analog input and make use of it to maintain a consistant linear path velocity using stretchable tape? A home hobbyist is highly unlikely to make an analog converter from discrete semiconductors to drive servos direct with any kind of repeatability. Teddy Ruxpin style precision?

I agree with him 100% on the “stretchable tape” issue too many weak points in any tape system, I personally don’t care for any type of magnetic disk recording interface WAY too much “EMF” floating around in a shop with motors running and it’s all just waiting to attack your disk and scramble your data.

His “Teddy Ruxpin” brought to mind the world of “ANAMATRONICS” do a Google search for ”anamatronics” and “servo controller”, then add to that search “analog” and you end up finding things like http://www.milinst.com/animatronics/1_965inst.pdf now to get analog add something like
http://www.milinst.com/animatronics/1_905.pdf and you’ll probably have to amplify / buffer that output but it looks like its there.

One Of Many said
“A home hobbyist is highly unlikely to make an analog converter from discrete semiconductors to drive servos direct with any kind of repeatability.”

I Highly disagree with this statement, if you are going to make that statement hold true then a statement such as

“A home hobbyist is highly unlikely to make a CNC system from discrete semiconductors and mechanical parts that will produce accurate parts with any kind of repeatability. “

would be just as valid of a statement. Never under estimate what a home shop hobbyist will do or is capable of doing, (some of the BEST Beer I ever drank came from home brewers) Apple Computer started in a garage, and if I’m not mistaken so did Microsoft at some level.

As an example of what people can and will do with electronics on a hobbyist level take a look at
http://www.seattlerobotics.org/
http://www.seattlerobotics.org/encoder/index.html
http://www.wa4dsy.net/robot/

Once again I’m not writing to make anyone mad or upset, just a interesting discussion that can hopefully help educate people to things they did not know were around and get the creative juices flowing.

Share your knowledge

Mike_L

Mike,

No irritation or upset from my end. I joined this discussion to offer opinion on a recorder. Which at first glance was extrapolated from the tape statements as a viable way to record voltage signals. This direction has changed to a digital format. To that end makes a lot more sense. It also allows the data to be stored and used with greater flexability and integrity. The primary goal being able to put it in a format that the driving system can react to without a whole bunch of excess brain power.

You highly disagree with my comments on discrete semiconductors to read a tape to direct servo control, was taken somewhat out of context? But, then sommerize it in the same terms it was offered in for the discussion at hand within that paragraph. That exact system existed in the Teddy Ruxpin controller on the second channel of the tape. Obviously not an accurate system for cutting precision parts to which you concurr. Again.....at first glance this was my take on what you were looking for per your original post. In that respect, my other statements of a home hobby shop attempting this approach as flawed from the start. That is not to discount their talents, just to opine on what the expected out come might be for the effort of using magnetic tape, analog signals etc.

It sounds like you have a better grasp on this than what I read into(concluded) from the original question.

DC

[Phooey]

Im wondering if someone could let me know how this would save time or money. I have heard mention of such a thing before, and also of stand alone controllers of various types, and am confused by both- doesn't this just remove the advantage of upgrading to PC in the first place? Freeing up the computer only makes sense if you can't get a computer for 100 bucks anyway- why are we always trying to save computers- they are cheap and easy to put together. Am i missing the point?

[scratch_6057]

DC,
Yea after re-reading your statement regarding the abilities of the
home hobbyist, I must conclude that I did take the statement out
of context, sorry about that, when taken in conjunction with the
rest of that paragraph you are correct. The FAULT lays not in
the capabilities of the person performing the work but in the
inclusion of the (any) tape recording system.

( Sidenote: I remember seeing a system portrayed as a
Computer Data Backup Solution that used audio output and a
VHS video recorder. It wasn’t long at all before that system
started showing up all over the surplus market at DEEP discounts)

I guess I could have made things a lot clearer if I had used the
word DIGITAL liberally in my original post. Digital is absolutely
the way to go, using EEProm for small “canned cycle” storage and
most likely “Flash Cards” (like a digital camera) for storing multiple
“Programs” (1 on each card) and interchangeability.

(I really don’t like using the term "PROGRAM" in this context,
might lead people to think we are talking about a G-Code interpreter
inside a microprocessor, NOT what I am thinking about at all.
Anyone have suggestion on what other term we might use when referring
To the stored digital voltage levels and time slices? )

Mike_L