Is a DNC-only machine livable

[wehnelt]

Hi All,

I'm looking at a Makino KE-55 for my home shop, but the memory is absolutely tiny. Small enough that DNCing is my only option. What are the drawbacks to DNCing all my programs? If I have a laptop next to the machine with a serial port and fusion 360 installed, it seems like it's fairly low friction -- I just post and DNC right from the laptop. What might I be missing for what makes this annoying and potentially a dealbreaker?

Best wishes,
Evan

 

[DouglasJRizzo]

If that's a Fanuc based control, the memory can be expanded.
If you're in a home shop and you need to drip feed everything, it sounds like your programs are enormous.
There's ups and downs to DNC a machine, and it can be rather balky.
Perhaps streamline your programming a little?

 

[wehnelt]

It's a Fanuc 20FA control. I think it's a relatively obscure control, probably making memory upgrades difficult. On this machine I think it usually has 32 - 128 kb or so. I was also told "320 meters of tape." I imagine it'd be plenty if I was hand-programming but Fusion 360 isn't trying to generate the most efficient code. Adaptive clearing is pretty complex.

 

[dandrummerman21]

Generally, DNC isn't great for the type of toolpath you are probably generating. it may stutter and hang.

IDK about 20FA, I have a note about 20MA that suggests 160 meters of tape for part program storage, which is about 64KB. 320M is 128KB.

0m (not to be confused with 0im) controls also have a 320M/128KB memory limit, maybe less for 0ma.

With a machine like that, you would be better to stick to traditional toolpaths, or only use adaptive type toolpaths for cutting small sections. Could also increase tool size which allows you to increase radial stepover, might cause smaller program sizes.

 

[wehnelt]

I was informed that the absolute max that the 20FA can hold is 256 KB, where half of that can be allocated to FACT, the conversational programming system. So it isn't really upgradable, either.

 

[e30ryan]

How many lines of code are your programs? Can you increase the smoothing/tolerance to generate more arcs instead of tiny G01 moves?

 

[Stirling]

+1 on smoothing/tolerance settings do cut code size drastically. It outputs far less positional points.

Doc and woc increases will also cut down cold size as there is simply less moves to make

 

[Garwood]

What is the 20FA related to? Is it similar to the 16/18/21 controls?

If the control is similar- Like the main board and connectors are interchangeable, I'd look at swapping the control to a better supported mainstream Fanuc control.

Sounds complicated, but Fanuc was really good about interchangeability back then. Controls from the same era would often swap physically and run the same parameters.

 

[Mtndew]

If that's a Fanuc based control, the memory can be expanded.

Yeah but they want your first born for adding 2 megs of storage.

OP, you can drip feed, but the one big con is that you can't restart in the middle of a program.
I think that Cimco DNCMax might allow this? It's been a long time since I used that software but it's pretty versatile.

 

[DouglasJRizzo]

Yeah but they want your first born for adding 2 megs of storage.

OP, you can drip feed, but the one big con is that you can't restart in the middle of a program.
I think that Cimco DNCMax might allow this? It's been a long time since I used that software but it's pretty versatile.

Possibly, I've never tried it tho.

 

[Garwood]

Yeah but they want your first born for adding 2 megs of storage.

That's why I suggest a control swap. Get a control from a machine headed to the scrapper or off Ebay. There's frequently deals on that stuff. A 16/18/21 will typically have a good size memory.

Small memory isn't that bad though. I had a mill with a pretty small Fanuc 6 memory when I started out. I upgraded it to 256K for free and never filled it up after that.

 

[dandrummerman21]

If the control is similar- Like the main board and connectors are interchangeable, I'd look at swapping the control to a better supported mainstream Fanuc control.

I wouldn't. I'd just get something that already has more memory, or at minimum has memory upgrades you can easily find.

 

[Aejgx6]

Meh, it's a good starting point. If you do it all day you will soon get tired of dnc. I don't get the cutter life I expect. Dripping seems to cause alot of dwell time and air cutting.

If you take the time to learn how to upgrade fanucs you would be wasting your time running one. From a technical standpoint it is very doable. . It is mostly plug and play stuff with alot of ladder work. No way to tell what features are included when you buy a control headed to scrap, so be prepared to pay for all them features you need. That's no exactly true but close enough for day to day knowledge. I've considered and researched retrofitting several times. In the end its cheaper to buy what you need instead of trying to cobble crap together.

 

[Aejgx6]

Ya it's livable. I dnc one machine. Works fine. I probably waste 10-20min a day with dnc and alot of steps and turns. It physically wears on you.

 

[jhov]

It's doable, but your program density is limited by transfer speeds. What baud rate does your control support? I exclusively drip feed my Brother S2B at 19200 and it can run adaptive toolpaths at less than ideal speeds with some smoothing enabled. Anything slower would not really be workable. Some controls can drip feed at 115200 or more and are much more suitable.

You can also buy drip feed units to put on the machine that will store g-code files and drip feed to the machine so you don't have to keep a computer near by. Many of these devices have networking so you can just send the files from a computer to the machine over wifi or wired network. If you're handy and can code in C, you can make one of these for about $10 in parts.

 

[Ox]

I was informed that the absolute max that the 20FA can hold is 256 KB, where half of that can be allocated to FACT, the conversational programming system. So it isn't really upgradable, either.

Delete the conversational part if possible / if you don't use it.
I deleted C.A.P. from an 18T years ago, but now I don't know how to doo it anymore, and I have 2 others that I would like to delete it from. It opens up a LOT of storage if dumped!


------------------

Think Snow Eh!
Ox

 

[William Lynn]

My old shop has a KE 55 and was hooked up to a dedicated PC via serial cable for drip feeding. I never ran it that way but others did. I don't recall any complaints. Note the KE 55 is not a powerhouse and would stall if taking too heavy of a cut, mostly in Z when drilling.

 

[mhajicek]

One major downside to drip feeding over serial is that a serial connection can occasionally miss, or misread, a character. If this is one in a thousand, you might never see it loading programs, but you definitely will drip feeding for every cycle.

 

[Cole2534]

Would a Calmotion box ease your troubles? I think you could do one of these - Drip box with 4gb storage - so at least you could hold programs on the machine (kinda) rather than dripping straight from your PC.

Baud rate may still be an issue, better use of programming tools can help in that arena.

 

[Vancbiker]

One major downside to drip feeding over serial is that a serial connection can occasionally miss, or misread, a character. If this is one in a thousand, you might never see it loading programs, but you definitely will drip feeding for every cycle.

Is this based on some bad experiences???? I’ve drip fed my Mori with Mitsu control whenever programs get too big for over 10 years now and never had data loss. Some programs as large as 4 meg though most in the .5 to 1.5 meg range. I do use hardware handshaking though as I feel it more trustworthy than XON/XOFF.