How does a fully configured Linuxcnc system compare to industrial controls.

I have only ever used linuxcnc or similar on cnc machines and really don't know how well they compare to "real" industrial controls.  I'm getting a Fadal with the older 88 controller, and will upgrade to the 527 control or linuxcnc it.  Since this is no longer a hobby, but how I make a living (design/ prototyping/ machining), I value my time highly.  For the cost of the 527 plus upgrades, I could pay myself for quite a few hours configuring linuxcnc.  Regardless, I will run the machine for a while on the original control to get it mechanically proven out and gain some experience.  

Pros

• I know linuxcnc will handle motion control and servo interface well.  
• I like the G64 approach to controlling the machine path, this just makes a lot of sense to me. 
• is very fast in processing lines of code.  Seems like a huge advantage for 3d or mulitiaxis simultaneous motion.  
• I love having the graphics on the screen, this has saved my butt on a few occasions as I can jog around obstacles and see if there is going to be a crash, or visually check if the quick hand programming I just did rapids into the part (caught this one last night!) 
• being able to select a path on the screen and see what line of code it is, helps a ton when manually editing a large file. 
• Freedom to make it as I want it. with no additional cost for simple addons like 4th axis, etc... 
• built in scope is awesome tool.

Cons

• No Tool management systems I am aware of
  • current tool hours 
  • tool wear compensation
• I have read g41/g42 programming has issues, and have experienced a bit of strange behavior in the past while using this.  I really don't use this much for what I do but think this would be more important coupled with tool wear as I understand it is done with some industrial controls. 
• Can be time consuming to figure out implementation of new feature or function, this seems to be less of a concern the more experience I gain with it. 
• Conversational?  I know you guys are working on some macros that look awesome, maybe this is equal, but I am just ignorant of what is out there. 

I'd really like to hear from the community opinions how Linuxcnc compares currently to the industrial controls. 

 

Dbsharp wrote:

Since this is no longer a hobby, but how I make a living (design/ prototyping/ machining), I value my time highly.  
 

There's not even a question that a Linuxcnc retrofit is NOT the way to go for a business. It's inevitable that things go bad, and when they do if you are the only one in the world who knows how a system is designed and programmed (and you did document your design thoroughly, right?) your business comes to a screeching halt for a day (?), a week (?), a month (?) while you have to figure out the solution. I don't mean your machine is down, but you are the one fixing the machine so emails aren't being answered, product isn't being packaged, etc, so you are hit on both fronts of your time being lost. Having 3rd party support is essential, that is why you are able to buy a machine from a builder that has been out of business for 20 years and those machines haven't become orphans.

There are two completely different scenarios that you are describing: designing/configuring a CNC control and using a CNC control. Re designing/configuring a CNC control, that no MTB except Tormach uses Linuxcnc is a huge flag that the alternatives are a better option for industry. Linuxcnc is adequate, but many features are simply not developed enough or simply missing. Tool life management as you mentioned is a big one but the trajectory planner is probably the biggest limitation for high speed machining. Being limited to 9 work coordinates is another issue for a segment of milling shops (with another segment never using more than G54). 5 axis... 

Re using a CNC control, if a user has to get into configuration files for day to day operation, you already have a major breakdown in the user experience. The reliability and ease of navigation are the metrics that matter here, the control is only the conduit through which you make parts. 

Tool wear compensation is possible with remap code.

For building custom CNC machines or automation I use LCNC almost exclusively since no other software tool can get the job done as well as fast and as easily. For high volume CNC machining I can typically build a better and faster specialized machine for higher throughput of factory parts. Businesses are happy since I am making them more $$$ faster than with standard CNC machines.

I was at a recent trade show where Siemens rep was trying to sell me on using their controls. They said that they have the parts and software to build the most accurate typical CNC machines possible. They did not know what to say when I asked them about integrating something as simple as a laser galvo or as complex as an inkjet printhead assembly. They only offer a limited range of motors and controls that they do understand and tweak very well. They just can't adapt quickly and easily to anything outside of what they typically offer. Ask any of the industrial control vendors how long it will take to get their controls to run a DLP/LCD/SLA printer, CNC glass-working lathe, multi-axis inkjet printer, sand casting printer, DNA synthesizer, etc etc. I can do in days what they will take months or years to do. As far as reliability goes if you use good parts and properly wire and assemble the machines they last a long time.

I always spend time talking to the CNC control vendors at the shows to find out if they have anything to make my job easier than using LCNC. So far I have not found anything. But I have only been using LCNC for about 17 years and designing machines for over 40. Maybe some day I will.

Dbsharp wrote:

I have only ever used linuxcnc or similar on cnc machines and really don't know how well they compare to "real" industrial controls.  I'm getting a Fadal with the older 88 controller, and will upgrade to the 527 control or linuxcnc it.  Since this is no longer a hobby, but how I make a living (design/ prototyping/ machining), I value my time highly.  For the cost of the 527 plus upgrades, I could pay myself for quite a few hours configuring linuxcnc.

• • • 
      I'd really like to hear from the community opinions how Linuxcnc compares currently to the industrial controls. 
      
      

My Fagor 8055TC is linuxcnc, I also heard Hydenhain uses it, if that is true. I just finished a Fadal VMC conversion, which was already converted once to an obscure control. I scratch build common rail Diesel test equipment, and we make our own user interfaces and code the microcontrollers, wire up everything, build the entire machine. Unfortunately most of that does not translate to linuxcnc. We did however manage to implement timed events and write some of our sub-routines in C for the gearchange and mpg.

IT IS NOT for the FAINT of heart though, I am 9 weeks into my conversion and finally found out tonight how to use the Hal scope to set my PID correctly with NO overshoots, and no following error, well not much of one that is. We use PID on our CR test benches, and we also have a chart/scope to tune those in with no overshoots, so I understand what I need to see.

Documentation is an issue, not that there isn't any, you will simply find it all overwhelming and find that simple things like compiling files and what M64/M65 really do that is so simple will simply drive you nuts, because little bits you need are well just not in simple terms.

I spent countless hours in Fadal wiring schematics trying to find out all the connections for things like the 1100-1 J1 connector pinout, then searching for parts like a brekout board to din cable for it, J9-12 connectors and pinouts. Toolchanger will cause some headaches, RS274NGC will be a great enemy until you befriend it.

Reality, is this it was not necessarily hard but required perseverance, and some help from the guys on this forum, and mucho document searching.

Link to my conversion with the toolchange operational:

Thanks for all the replies. 

msrdiesel, If I choose this route I would love to see your setup as reference, if you want to share it. I just jumped into the "RS274NGC" section to setup a router to measure its tools automatically... things didn't quite work with the toolchange.ngc reference code I found here so I re-wrote it (and will post it once cleaned up).

footpetaljones, I am interested in learning more about the trajectory planner issue.  I get what you say about others following the work and having employees not be able to work on something, but since I am a single man operation and will probably remain that way for a while, I am not sure that matters much to me.  This is why I picked the Fadal, because I can do all the fixing myself cheaply.  I make most of my money on engineering, and often dont make as much on machining jobs I pick up, but I really enjoy the shop time and having the capability opens doors for design projects. 

Bari,
I have been doing mostly consumer good engineering, but have been looking to branch out into this area.  I have an EE I work with on a lot of projects who has done lots of firmware, automation, and controls. Between the two of us, I think there isn't much we couldn't do. I'm interested to hear how would you appoach this today if you were starting out? 

Regardless, I will run the machine for a while on the original control to get it mechanically proven out and gain some experience.

Dont fix what isnt broken. As a regular joe blow fanuc cnc/robot guy, the biggest linuxcnc pros that impact me on a regular basis
- file size over 512kb
- python interpreter (too bad mastercam doesnt post python code though)
- freedom

pros for fanuc cnc on a daily basis
- gui, they arent nice but they take care of business, easy to navigate in a way
- lack of freedom , makes thing easier in the jail known as work
- lack of accountability in exchange for money, "just call fanuc"
- all that other shit that money gets you, its so much easier and nicer than linuxcnc most of the time

So it depends on what your doing. For me, at my job, it wouldnt be an advantage. But my job is to be just another cog in the machine. If I were one of those people with freedom, I might think differently.

When Im home from work, its a different story. Nothing will do but linuxcnc, as it is the only thing that can do what I want.

footpetaljones wrote:

20 years and those machines haven't become orphans

Tech Support for my 20 year old machines
- ebay
- "man thats old, there's no one that worked here that long ago"
- " thats really old, I can source you a replacement [entire machine] "

My take. I have Lcnc on both my lathes, a larger Cincinnati and a Hardinge Hnc. They both had dead controls, they both make good parts. The Lcnc works as well or better then the original control. That being said, it is a ton of work and a HUGE learning curve to get the machines reliable. I have an old Matsuura with an Alzheimer’s Yasnac control , it’s gonna get a retro this year. That being said also, it’s gonna be proved on the bench before one wire is removed from a functioning machine I use it daily to make my living. I have two other mills, Tree’s with Dynapath controls. They are weird, but they work.

As for your Fadal, I owned a Fadal for 25 years. The control is easy, it always works. Lcnc has a few short comings, mostly in the tool table, it’s awful. I would look into the NexGen control , David Decaussin, who was the D in Fadal sells it. The control is based on a Galil card. It’s fast and bolt on. He is a nice guy.

Don’t get me wrong, I do like the Lcnc . The learning curve was s steep and until you get it down , it’s a struggle. For making a living and having only one machine , stick with an OEM that bolts on. If you used say, a Mitsubishi, you would have similar issues.

Get a cheap machine with a brain dead control and figure it out in spare time. If you use this Fadal to feed your self, go for bolt on reliability.