Alternative to PC based Cnc controllers

[ZebethyalParticipant @zebethyal]

Posted by Muzzer on 07/10/2016 10:33:07:

Well those are the wrong crimps. The approved terminations would be "bootlace ferrule" crimps such as this from RS,

I agree with you entirely, and those are the ones I use, albeit from a far eastern source – the picture was an example to show the limited space.

With SmoothStepper being available from a number of UK sources, including some on the right hand side of the board, I would say that unfortunately this is another point against LinuxCNC.

Looks like if I decide on the MESA route it will be another holiday purchase to bring back in the suitcase, if I can acutally find some one with stock

[John Stevenson 1Participant @johnstevenson1]

Jat, Definitely an interesting concept but feel that you are at a halfway house stage and not meeting goals.

You say no PC needed but you need everything else like monitor etc.

If you went to a stand alone controller you wouldn't even need that.

But if you kept the PC then you could have your CAD?CAM system of choice on the same PC.

I'll grant that with a stand alone you don't get a CAD CAM but you don't have the clutter.

Seems to me like you have a foot in both camps but then don't know which way to step. I did mention that it's expensive to say you still need all the extra's and from looking at the kickstarter project it seems that I'm not the only one thinking this as projected figures are saying you won't make half of the goal.

[J A Harvey-SmithParticipant @jaharvey-smith]

Thanks Muzzer,

I was briefly clutching at straws, thinking I might donate a new controller for a couple of hundred to make my working day a bit more interesting and productive, but I'm not going to fork out on positioners to talk to 30+ year old obsolete analogue servo drives on top. A proper job could be done replacing servos and motors, and power supply – expensive items to suit this big machine – and a couple of hundred soon turns in to thousands – but not from my pocket. As you suspect, a very large piece of scrap.

[Ex contributorParticipant @mgnbuk]

The Chinese stand-alone control looks like it would do most of what I would want a turning control to do.

The area clearance & threading cycles seem to use the Fanuc 0T appproach, having the cycle parameters entered over two lines. I was a little amused to see that their diagrams for the cycles (and TNRC) appear to be "borrowed" directly from the genuine Fanuc manuals – that's one approach to "Fanuc compatibility" !

Their implementation of the G31 "Skip" function appears flawed and rather pointless without an equivalent to "Custom Macro B" (parametric programming). No dedicated high speed input(s) for probing & no ability to manipulate data in the program means no automatic tool offset setting or part probing routines & possibly dubious repeatabilty.

I am suprised to see no "Control operational" (or Watchdog) output (same goes for the Massa here). I would not be happy to fit a control that had no form of internal hardware & software monitoring to any machine in an industrial or educational environment (you are a braver man than me if that is what you are proposing, John). I appreciate that these are "open loop" controls (no position feedback from the axes) & may be less likely to run away if a fault developed, but even Mach 3 had the "charge pump" arrangement to drop the drives if there was a computer glitch.

I will report back on the Chinese USB board when it arrives. I had seen the 25 line demo limitation (and the release code cost is more than €69, as 22% Slovenian Vat has to be added to that). While it is, in effect, a GRBL on steroids, it looks like it should be possible to program straightforward 2 1/2 D milling without having to go down the CAM route that GRBL would require, as GRBL doesn't support tool radius comp.

As it stands at the moment, the Massa is too expensive (for me) for what it offers – I look at it on the basis that the functionality is what it ships with now, as promises of future functionality are just that & may or may not come to pass. Going to a subscription model to retain the functionality on a month-by-month basis to fund (and maybe improve) the functionality would kill it completely for me. The genuine Planet CNC 4 axis board with spindle control sub-board & software licence is around £280 inc. Vat delivered from Zapp Automation – my opinion is that when Massa reaches a similar level of functionality, it should be much nearer that pricing than it is at present to be sucessful. SWMBO would take a lot of convincicng to allow me to drop in excess of a week's gross salary on a circuit board !

Haven't looked very deeply at Linuc CNC – both the desktops I tried didn't do very well on the latency / jitter front, so I got no further, though I may try the DAK Engineering TurboCNC Dos solution on one of those.

Nigel B

[MuzzerParticipant @muzzer]

Posted by Nigel B on 07/10/2016 13:47:57:

Haven't looked very deeply at Linuc CNC – both the desktops I tried didn't do very well on the latency / jitter front, so I got no further, though I may try the DAK Engineering TurboCNC Dos solution on one of those.

Nigel B

The concept of using an FPGA to generate the drive signals avoids the need for good latency which you would otherwise need if you use the parallel port or USB. That's the basis of the Mesa cards. You'll notice that the Chinese controllers also use FPGAs. Unless you are making a hobby CNC machine, that approach is almost certainly required.

Jat – what have you got in your controller? – a microcontroller and FPGA or just a DSP? I can't make out any part numbers and there aren't many views of the PCBA. I can see a bit of a large QFP device but not much more.

Murray

[Another JohnSParticipant @anotherjohns]

Posted by Zebethyal on 07/10/2016 12:54:20:

With SmoothStepper being available from a number of UK sources, including some on the right hand side of the board, I would say that unfortunately this is another point against LinuxCNC.

Looks like if I decide on the MESA route it will be another holiday purchase to bring back in the suitcase, if I can acutally find some one with stock

Just FYI:

The last Mesa product I purchased (5i25, 7i76) came from http://www.mesaus.com, and was shipped internationally as requested and arrived very promptly. No personal interest in the company, just passing along my experience.

(ship date was 29 August 2016, so not too long ago)

John.

[Raglan LittlejohnParticipant @raglanlittlejohn]

John,

I am also looking into purchasing some Mesa boards, so thanks for the link http://www.mesaus.com. Their site has a simple explanation of what the Mesa cards do ie they list stepper solutions in one box, then servo solutions in another box. They also show where you plug the card in eg PCI Bus/5i25/7i76. I've found it hard to find simple details like this on these cards. I wonder if the lack of basic info is due to the large number of possible combinations of control available?. Please could you advise if your 5i25, 7i76 came with the correct firmware, firmware seems to be a possible problem area.

John.

[Another JohnSParticipant @anotherjohns]

Posted by Raglan Littlejohn on 07/10/2016 15:47:16:

Please could you advise if your 5i25, 7i76 came with the correct firmware, firmware seems to be a possible problem area.

John – yes, it came with the correct firmware.

Flashing new firmware (which I have done, a while ago) is actually not as hard as I had imagined.

I have (Mesa card-wise) one machine with a 5i25 connecting to a 7i76, another connected to a Gecko G540, and this third one will be a lathe, 5i25 connecting to a 7i76 once again.

What is not obvious is that one can connect, say, two G540s, so one computer can control two bits of hardware, either two mills, or…

I've never bothered, the computers are co-located to the machines so each machine/monitor/mouse/trackball/MPG is a package.

I copy files to machines over the network; in fact, I have controlled the machines remotely by exporting the LinuxCNC window over the network to my main computer in my office.

John.

[Raglan LittlejohnParticipant @raglanlittlejohn]

John,

Thanks for the update on the firmware. I've just realised http://www.mesaus.com is run by a prominent member of the Linuxcnc forum, so support for the firmware will be good. The 5i25/7i76 seems a good combination for me, I can start with that for step/dir set ups, then replace the 7i76 with a 7i77 if I want to change to a servo set up.

John.

[John Stevenson 1Participant @johnstevenson1]

I have a brand new 5i25 and a 7i76 plus the little daughter card that fits the 7i76 to allow encoder hand wheels to be fitted.

Imported from the States from Mesa and all import duties, handling and VAT paid, will sell for the price of the boards.

Never been fitted or messed with. PM me if interested.

[sam sokolikParticipant @samsokolik60334]

Yes – you would need a breakout board of some kind. I was just comparing bare bones smoothstepper to a similar mesa product. (both would require a bob)

I have used both the mesa daughter boards and generic bobs with mesa – obviously the mesa daughter boards have a lot more functionality but cost a bit more.

I have used quite a few of the mesa daughter boards and think they work great. This is the lasted conversion of a matsuura from the mid 80's. We re-used the servo, servo drives, spindle and spindle drive. We got extra servo drives from ebay in case of failure – if the spindle drive fails we will probably replace it with a normal vfd.

 

(this was early on in the conversion – the estop was just sitting on the table and fell off the vice at the end of the video and activated..  

 

 

Posted by Zebethyal on 07/10/2016 09:28:21:

@sam

You say that 5i25/7i76 is an over the top combination and go on to mention that a 7i92 is all that you need, yet this is the combination most mentioned anywhere I look for information on what Mesa boards to use.

I have re-read the description and manual of the 7i92 and yes, it would appear that it can be used stand-alone parallel port replacement – it would still need some form of breakout board even if it is a basic $4.00 Chinese one, since most home-brew conversions aren't parallel port ready

This also re-affirms my earlier point about it being difficult for someone new to work out what Mesa cards they need – no guidance on Mesa's own site, the LinuxCNC Wiki is amazingly vague on the subject, merely mentioning a large number of possibilities that should work and doesn't even mention the 7i92 card!

If I specifically search for the 7i92 card, I see very few posts about it, and many of those I do find are from the LinuxCNC forum which seem to be cries for help with using one – hardly a great advert.

To buy one I would need to order from the US, not necessarily an issue, but Mesa quote 6-8 week lead times, EUsurplus have no stock, and I have yet to find a UK supplier.

I like the idea of this board in that it de-couples from the required PC, making some form of laptop more of an option, or a mini PC that can fit behind the monitor.

One thing I am not so keen on with the Mesa breakout boards is that their screw terminals are too close to each other to use crimped ferrules, and pretty awful from a strain relief point of view – 90 degree plug in screw terminals would be a better option in that regard.

Edited By Zebethyal on 07/10/2016 09:33:53

 

Edited By sam sokolik on 08/10/2016 03:18:49

[blowlampParticipant @blowlamp]

Some pictures to show a few test threads done with a PlanetCNC controller running on a Denford Starturn 8 lathe of 1985 vintage and were generated via the lathe wizard in the software. Both pieces are 1.5mm pitch, one at 19mm diameter and the other at 16mm.

I did video the process, but the frame rate is very slow and doesn't do justice to the smoothness of it all. In reality, the movements are very similar to those in Steve Blackmore's video of his dedicated lathe controller, shown earlier in this discussion. I'll try to redo the recording with a better camera, but what was interesting to me at the time, was that I was able to cut these threads whilst recording the camera to the same computer without a hiccup.

Setting up the controller software was quite straightforward except for one thing, which was that I found it necessary to enter exactly twice as many pulses-per-rev for the spindle encoder than the number of slots within it – mine has 100 slots, but this caused a specified 1mm pitch thread to be cut at 2mm pitch – maybe because channel A+B count 100 slots each per rev?

 

 

Martin.

 

 

Edited By blowlamp on 08/10/2016 23:27:05

[Anonymous]

Pretty darn impressive threading.

Andrew

[John Stevenson 1Participant @johnstevenson1]

Martin, which card did you use please, the 4 axis or the 9 axis ?

[blowlampParticipant @blowlamp]

Andrew. Yes, being brass helps, but still not bad at all for a small lathe, I'm very pleased

John. this is the Mk3/4 board, so just 4 axis.

Martin.

[sam sokolikParticipant @samsokolik60334]

This looks promising..  It is called 'NativeCAM'  for linuxcnc.  It uses the linuxcnc preview to show actual stock and such.  Pretty neat.

**LINK**

The developer made some videos.

**LINK**

It is based on some previous work (it is really new – released last week)

sam

Edited By sam sokolik on 09/10/2016 19:30:01

Edited By sam sokolik on 09/10/2016 19:31:44

[John Stevenson 1Participant @johnstevenson1]

Sam,

Confirms what I have been saying all along.

I looked at the first link and 6 pages on the forum between very experienced Linux guys and it took 6 pages for one guy to get it working, plus loads and loads of code. Don't know about the others, possibly given up ?

[sam sokolikParticipant @samsokolik60334]

wow – really? He released it yesterday. Yesterday! I think it says a lot that it is to 6 pages – people are testing and working out the bugs. Did you look at the videos to see how powerful it is?

sam

Posted by John Stevenson on 10/10/2016 00:59:45:

Sam,

Confirms what I have been saying all along.

I looked at the first link and 6 pages on the forum between very experienced Linux guys and it took 6 pages for one guy to get it working, plus loads and loads of code. Don't know about the others, possibly given up ?

[Michael HornerParticipant @michaelhorner54327]

– people are testing and working out the bugs.

Hi Sam

Isn't this exactly what JS is talking about, it didn't work straight out of the box! Worked for one guy but not another.

Cheers Michael.

[blowlampParticipant @blowlamp]

I captured a couple of threading videos on my phone and uploaded them to vidme.

The first video is the thread cutting and the second one is a dummy run without cutting tool and me just playing with the lathe RPM to show how the feedrate varies with it.

 

 

 

 

Martin.

 

Edited By blowlamp on 10/10/2016 16:09:48

[John Stevenson 1Participant @johnstevenson1]

Impressive Martin.

Looks like this is the way to go for a cost effective PC route where both software and hardware comes from the same stable.

Couple of things I can't work out from their web site. The 3/4 board is 119 Euro plus VAT, software is free but you need a 69 Euro plus VAT, controller licence. If you buy two boards, one for mill and one for lathe do you need two 69 Euro licences or will one do if the boards are genuine ?

Price wise that adds up to 243.02 Euro given that Slovenia VAT is 22% plus postage and converted at today's rate works out to £219.03

Forget the PC, monitor etc as these are needed by all systems this works out to a bit more than a Mach4 license but Mach4 can't stand on its own feed and the cheapest option is a Pokeys CNC57 so cost wise Planet CNC wins.

Now Linux CNC will do this using the parallel port IF you can get it up and running but from my point of view I can't support it to sell Linux CNC to a total beginner plus as I have said before, they wouldn't buy it because of the screens.

If you factor in Mesa boards that Planet CNC still wins cost wise.

[blowlampParticipant @blowlamp]

Posted by John Stevenson on 10/10/2016 20:51:14:

Impressive Martin.

Looks like this is the way to go for a cost effective PC route where both software and hardware comes from the same stable.

Couple of things I can't work out from their web site. The 3/4 board is 119 Euro plus VAT, software is free but you need a 69 Euro plus VAT, controller licence. If you buy two boards, one for mill and one for lathe do you need two 69 Euro licences or will one do if the boards are genuine ?

Price wise that adds up to 243.02 Euro given that Slovenia VAT is 22% plus postage and converted at today's rate works out to £219.03

Forget the PC, monitor etc as these are needed by all systems this works out to a bit more than a Mach4 license but Mach4 can't stand on its own feed and the cheapest option is a Pokeys CNC57 so cost wise Planet CNC wins.

Now Linux CNC will do this using the parallel port IF you can get it up and running but from my point of view I can't support it to sell Linux CNC to a total beginner plus as I have said before, they wouldn't buy it because of the screens.

If you factor in Mesa boards that Planet CNC still wins cost wise.

It was a new concept to me too, but yes, you need a licence per controller. I think this came about when their hardware started being copied and sold cheaply whilst rather cheekily relying on PlanetCNC's free software to drive it. I just decided to lump the price of the licence onto the hardware and forget about it as a separate purchase.

A plus side is that the software & licence can be put on as many computers as you like, so moving between machines is a doddle, if that's what you want to do. Once you've configured all your machine's software, switching between them takes less than 10 seconds.

Martin.

[sam sokolikParticipant @samsokolik60334]

John, Does this help at all? (sorry about my voice – I am fighting a cold)

[Russell EberhardtParticipant @russelleberhardt48058]

Somewhat off topic but this thread seems to have partly turned into a LinuxCNC vs Mach 3 argument.

As a casual user I use both Mach 3 and LinuxCNC on my little mill. I could be described as a Linux fan as I have Linux installed as the default OS on all my (and the wife's) computers. However for running straightforward Gcode on the mill I do prefer Mach 3. For me the interface seems more user friendly.

As far as installation and setup of the two programs is concerned I think LinuxCNC is easier. To install Mach 3 you first have to find an old copy of a Windows operating system, install it and register it. Then you can install Mach 3 much the same as any other software on Windows.

To install LinuxCNC you just have to download the live disk and burn it to a dvd, insert it in your PC, restart and follow the onscreen prompts.

In both cases you then have to tell the program about your machine, what are the connections, maximum velocities, etc., make sure the movement directions are right, are there limit and homiing switches, etc. Not much in it as the main difficulty is deciding what your settings should be but with LinuxCNC there is a setup wizard that is easier to follow as a beginner.

Just my few centimes d'Euro worth.

Russell.

[John Stevenson 1Participant @johnstevenson1]

Posted by Russell Eberhardt on 12/10/2016 15:11:13:

As far as installation and setup of the two programs is concerned I think LinuxCNC is easier. To install Mach 3 you first have to find an old copy of a Windows operating system, install it and register it. Then you can install Mach 3 much the same as any other software on Windows.

Russell.

Not actually correct as Mach will run on W8, W8.1 and W10 if using a USB breakout card.

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