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Fanuc 3M Limited Memory / Drip Feed Solution

WakelessFoil

Aluminum
Joined
Aug 18, 2020
I posted this to the CNCzone forum but I thought I should bring it up here since it seems like there's more activity here on PM.

We are searching for a solution to allow our vintage Fanuc 3M-A equipped milling machine to run more complex programs. From the factory the Fanuc 3 does not allow drip feeding or direct execution from the tape reader. To make things worse, the control only has 16 KB of internal memory (6 KB of which are eaten up by parameters), making this machine EXTREMELY limited.

We have talked to the people at Memex and Nexas up in Canada several times asking about their ROM upgrade and for a machine this old in a struggling machine shop, $1250 is a big deal. Last I called it sounded like they don't even carry the chips anymore, or maybe they are sitting in a box somewhere in the warehouse collecting dust unbeknownst to the receptionist?

If anyone has a clue where we can get our hands on these ROMs, new or used, you'd be a hero in our book. Maybe someone has recently decommissioned a Fanuc 3 equipped with the upgrade and is willing to read the ROMS for us or sell us the chips? We'd be happy to fairly compensate you.

If all else fails I had this idea to use a micro-controller and a modified version of DNC software to "simulate" the drip feed function that comes with the upgraded ROMs. This solution would be less elegant but simpler in design since it would interface with the control by directly controlling the panel via relays. I explain the details of this concept in the short video below.

VIDEO:

Has anyone heard of something like this? I am certain it will work if I can make all the I/O connections and get the Arduino to send text via serial.

Thanks!
Justin
 
Sounds like with a ton of work it might work.

Do you know any local Fanuc guru's? If so, ask one of them to look at the control and tell you if it's similar enough to a 6MB or 10M A or B to swap controls. Like just swap the main boards and load all the same parameters (except for the memory parameters of coarse).

I have a 6MB control you could have if you want to pay UPS. It's missing the memory board, but those are cheap. 6MB max memory is 256K plus it drip feeds.
 
We have an old Okuma mill with small memory. To run large files we have an ancient bit of software called Filesplitter.

You split the file into the max size the memory can run (in our case 54,000 bits) and you simple run 2, 3, 4 files. Have run up to 12 part files.

You simply start the first file, delete it from memory whilst running and load the second into memory. When the first one is finished, load the second into active memory and press run. Delete the second file and load the third. And so on. Each file ends with the tool at 50mm above the work.

You can greatly increase the volume of code on your file by removing the n line numbers and deleting empty spaces. Your NC editor will be able to do that.
 
Sounds like with a ton of work it might work.

Do you know any local Fanuc guru's? If so, ask one of them to look at the control and tell you if it's similar enough to a 6MB or 10M A or B to swap controls. Like just swap the main boards and load all the same parameters (except for the memory parameters of coarse).

I have a 6MB control you could have if you want to pay UPS. It's missing the memory board, but those are cheap. 6MB max memory is 256K plus it drip feeds.
I had not thought of this. The motherboards look very similiar. I will ask around to see if something like this has been done before and how easy it would be.

We may take you up on that offer. Thanks!
Justin
 
We have an old Okuma mill with small memory. To run large files we have an ancient bit of software called Filesplitter.

You split the file into the max size the memory can run (in our case 54,000 bits) and you simple run 2, 3, 4 files. Have run up to 12 part files.

You simply start the first file, delete it from memory whilst running and load the second into memory. When the first one is finished, load the second into active memory and press run. Delete the second file and load the third. And so on. Each file ends with the tool at 50mm above the work.

You can greatly increase the volume of code on your file by removing the n line numbers and deleting empty spaces. Your NC editor will be able to do that.
Memex wants to sell us a similar piece of software for $300. I'll have to look into Filesplitter. This could also be accomplished using a C++ program to read in data and split it into sequential text files. For my drip feeding idea, I really need it to include that spare signal (M17/18) at the end of each chunk.

This is the basis of my idea, except instead of the operator being forced to push the same buttons over and over like a monkey, we can create a robot that automatically performs the file splitting and handoff.

I have edited our Fusion post to shrink the file as much as possible, this includes eliminating the N numbers and getting rig of spaces between words.
 
We fitted our 6MB with a Memex board 512 k in 1990 and it still works fine. They told me that 512 k was the max for that control.
Unfortunately the 3M has a max of 32KB (I think?). We cant find any memory expansion boards for this machine. All for the 6M and up.
 
I had not thought of this. The motherboards look very similiar. I will ask around to see if something like this has been done before and how easy it would be.

We may take you up on that offer. Thanks!
Justin

I have swapped a Fanuc 10MB control for 10MD and it worked. They are different controls.

The Fanuc 3 was not very prolific. It came after the system 6, the same time as the 10. The thing is though, with all the rapid advancements in the 1980's and all the different builders doing different stuff Fanuc had to keep a very, very high level of interchangeability. Like various controls work with various different generations of drives and servos throughout the 1980's.

Anyway, I googled what a series 3 main board looks like and the series 3 board was apparently the same for 3T and 3M. They didn't make a specific T or M control board, the board did both. Anyway, the best pictures I could find online look nearly identical to the 6MB main board I have here. The plugs appear all the same size, color and in the same locations 3M VS 6MB.

In your shoes I'd try to get my hands a series 3 connection manual, series 3 parameter manual, 6MB connection manual and 6MB parameter manual. Those books would have the answers to the tough questions if you got stuck.

Then find a 6MB bubble board for 256K or an aftermarket memex/tulip board.

Tons of 6M parts out there. And dirt cheap today. They are 40 years old now. Most of the machines have long been replaced by machines 20 years newer and just aren't used anymore.
 
I posted this to the CNCzone forum but I thought I should bring it up here since it seems like there's more activity here on PM.

We are searching for a solution to allow our vintage Fanuc 3M-A equipped milling machine to run more complex programs. From the factory the Fanuc 3 does not allow drip feeding or direct execution from the tape reader. To make things worse, the control only has 16 KB of internal memory (6 KB of which are eaten up by parameters), making this machine EXTREMELY limited.

We have talked to the people at Memex and Nexas up in Canada several times asking about their ROM upgrade and for a machine this old in a struggling machine shop, $1250 is a big deal. Last I called it sounded like they don't even carry the chips anymore, or maybe they are sitting in a box somewhere in the warehouse collecting dust unbeknownst to the receptionist?

If anyone has a clue where we can get our hands on these ROMs, new or used, you'd be a hero in our book. Maybe someone has recently decommissioned a Fanuc 3 equipped with the upgrade and is willing to read the ROMS for us or sell us the chips? We'd be happy to fairly compensate you.

If all else fails I had this idea to use a micro-controller and a modified version of DNC software to "simulate" the drip feed function that comes with the upgraded ROMs. This solution would be less elegant but simpler in design since it would interface with the control by directly controlling the panel via relays. I explain the details of this concept in the short video below.

VIDEO:

Has anyone heard of something like this? I am certain it will work if I can make all the I/O connections and get the Arduino to send text via serial.

Thanks!
Justin
Hello Justin
I see this is a old thread but I have a Okada vm460 with a 3m control with the expanded ROM chips presently my machine is done with a electrical issue and someone made off with the manuals was not sure what your machine was or what you did to overcome your issue if you have a set of schematics for my machine would be exciting I can give you the part no's of chips but not sure where to buy
look forward to your reply
Thanks
 








 
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