Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: bubba on July 10, 2008, 04:26:17 AM
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Which is giving the smoothest and most reliable operation, printer port or controller card?
Thanks,
Bubba
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Depends and no difinitive answer. Some people the parallel port will be enough but for others cards like the SmoothStepper is not only nice to have but actually essential.
Hood
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I find that LPY1 is more than adequate for my machine - although my requirements are relatively modest. I want to control spindle speed, which takes up two inputs (Ihave two spindles) and three outputs M3 M4 and my PWM. I want to control coolant, which takes up one more output, and I have three homing/positional switches. I might add a forth axis (rotary table)
My problem is that if I wanted anything else, the the LPT1 port cannot provide it.
I think therefore, if I was starting again from scratch, and had a modest budget, the the smooth stepper would be my choice a) for ease of connection - USB is the way ahead - and 2) it has more input and output capacity than I would think I would ever need - and 3)from what I understand it produces it's own stepper driver signals and therefore takes pressure off the computer, allowing it to do the computing - or allowing me to use a more modest computer - saving me some cash in the long term.
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Thanks for the response guys. I would still like to hear some more responses.
I have been using the galil card with a software called wingcnc for about 7 years
with very good results. But the software is very basic (no offsets g54 etc.)
And I could not see how a milling software would not run as good with out that $1000.00 +
controller card.
Which card seems to be the preferred and why?
I appreciate your feedback. I am setting up a second bridgeport series1 cnc machine, and this time
I really do not want to go thru 2 or 3 controller/ software before I am happy.
Thanks,
Bubba
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Bubba-
Having watched some hardware solutions that looked good on paper come and then go, I now take a pretty conservative approach.
At this point the broadest and most stable performance with Mach is still the PP solution. The SmoothStepper is looking pretty good, but there is still some functionality it doesn't support, so I'd call it in "Alpha" form at this point, close to being in "Beta" when it will have implemented all the functionality of the PP Mach version.
If you are building your machine now, I would definitely go with the PP solution. I use a SoundLogic breakout board with mine and it has worked well, but there are other breakout boards that also give good results.
The good news about the SmoothStepper is that is appears to be pretty easy to move to it from a PP machine, and if it gets to the point where it is really rock solid and is in wide use by the Mach user base, including the Mach developers, then I'll move to it also.
Paul T.
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Thanks Paul,
What type of machine are you running now on the pp ? (i assume this means printer port)
Do you have any knowledge of the G100?
I am like you very conservative about buying and trying new control/ software. Since 1997 I have
probably thru away $20,000 buying machines, controllers, and software which sounded real good on
paper and turned out to be junk in manufacturing.
Thanks,
Joe
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I would say the SS is a bit more than Alpha but thats just my opinion. It still has some issues and things that are not available yet but I have been using it on my mill for over 6 months now and its working well. The problems are that if you dont use breakout boards between your hardware and the SS you may suffer from noise which can trigger limits etc. This can be cured by attaching capacitors between the pins on the inputs to the SS and its 0V pins. Greg is working on digital filtering so hopefully that will not be needed shortly. If you are using a breakout board then the noise issue should not be a problem.
I also have a large lathe which at the moment is still using the parallel port (actually two PP) I have a SS waiting to put onto the lathe as soon as the Spindle Sync is completed and it will then allow me to get the full potential out of my lathe. At the moment I am limited to 3.5M/min as the parallel port cant put out a fast enough pulse rate for my setup (2000 line encoders) but this will be all in the past when I put the SS on it as I could if I was brave enough boost the rapid speed to 20M/min. The other main things that are not implemented yet on the SS are Backlash and Softlimits. I have tested a Beta plugin for the softlimits and its working reasonably well but just not totally perfect.
I think I would shy away from the G100, not had one myself but from what I hear they will not be any more development in the firmware of them and there are a lot of issues. Whether this is correct or not I cant say 100% but would advise you to do quite a bit of research before you get one.
Hood
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Joe-
I run Mach with a PP on a stripped down XP machine dedicated to Mach only. Its worked well for several years now on my BP sized mill. Its a little under the recommended min now at 667Mhz (it wasn't when I first set it up) but so far that hasn't been an issue, but I'm not running the latest release which apparently is a little more CPU hungry than earlier versions, I'm running a 3.02 version and also I run at the default 25khz kernal rate.
I would stay away from the G100, it looked promising when first introduced but it has a fundamental design bottleneck that limits performance for 3D machining and anything else that requires fast G code execution. I also don't think it acheived a large enough critical mass of users that the support for it will continue much longer, at least not at the priority level given to the PP Mach version.
Paul T.
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I would say the SS is a bit more than Alpha but thats just my opinion.
Hood, I agree with that (and was attempting to say the same thing in my post), the SS guys have clearly done a lot of hard work and are making good progress and it appears shortly they will be at Beta, ie all PP equivalent functions implemented but further testing needed.
I poked at the SS design a little bit a while ago regarding both 3D performance and absolute real time response (both important to good performance with Mach) and I liked the answers that came back, so it appears that a lot of thought went into the SS design. I'm hoping it both meets the design goals and gets heavily adopted by Mach users, if both those things happen it should have good long term success and I'll be popping for one also.
Paul T.
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Thanks Guys,
Much to learn before I take the next step it looks like.
I talked to Marris from Gecko today, and he told me with steppers unless I need to go faster than 300ipm (which I would never do on a Bridgeport)
that the G100 is not going to do anything that the printer port will not do. I would use a breakout board for sure. I do not want to have any noise
issues.
Are you guys happy with the performance of using the printer port? ( no lost steps, smooth motor function)
I have been using a g210 Gecko on my 4th axis for years, and have been happy.
I just recently started using a g210 on my Z axis. I had a Ahha board go bad, and as they are not around any more I decide to try a G210.
I am absolutely amazed of the performance! With the Ahha I was never able to reliably have more than 80ipm rapids on the Z without stalling.
With the Gecko I tested up to 190ipm before getting stalls frequently.
I ended up setting the rapids back to 100ipm for now.
Since the software I currently run wingcnc is a vectoring software all of my rapids were limited to the 80ipm before, this is a huge performance gain for me.
I want to switch to mach3, I am just trying to do my homework before I make the leap.
Thank you so much for your input !
Joe
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The printer port will do fine, some computers can have issues with the software pulse engine that Mach uses for the PP, these can often be sorted by doing optimisation steps. Computers to avoid if you are using the PP are Laptops and Desktops with onboard graphics. Some Laptops and desktops with onboard graphics work fine but they are definitely more problematic.
The SS will help (and already has) with these issues as it produces the pulse externally and really means any computer should be capable of running Mach.
All in all I would say you should be fine with the PP and my guess is you will see a vast improvement over what you have at the moment, especially if you use the Geckos as you have found out Mariss knows his stepper drives.
If the time comes when you find you need more than the PP can deliver then the SS should just be a direct conversion (take cables from PP and plug into SS)
Hood
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Thanks Hood,
You are absolutely correct about Marris. I have talked to him several times over the years. He is one of those super genius people.
What I really like about him is his patience, and ability to explain things in a way that us none electronic Gurus can understand.
What printer port breakout board seems to be working the best? I see several are available.
Thanks,
Joe
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I use PMDX 122 and CN CBuilding Blocks Acustep and like them both. The Acustep is no longer produced so its not an option but the good thing about it, and the reason I had it, was that it took the index pulse from an encoder and used it for homing.
The PMDX is a very nice board in my opinion and excellent quality at a reasonable price. Dont have any experience with any other breakouts simply because why change if you like what you have. I have heard good things about the Campbell boards so they might be worth a look as well.
Hood
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If you have settled on the Gecko's - and they are first class - then all I have as a breakout board is a non-powered Routout CNC board, which gives me the pins and the 0v from the LPT1.
I use Gecko 201's. These are internally opto isolated, so you don't need opto isolation again. The only thing you will have to provide is a 5V power feed to run the low voltage side of the Gecko's. I did this with a small phone charger type power unit, and a 5 volt regulator.
It will also provide any 5 volt feed you might need for your switches or relays for the spindle drive, limit switches etc,
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I picked Campbells SoundLogic combo board because on one board it had support for everything I needed, DC out to control VFD speed, MPG inputs and relays for my spindle and coolant.
The only rub was the documentation at the time was a little spotty and the speed control voltage isn't quite as solid as I would like it to be, but it works. I beileve they have reworked the speed control voltage and hopefully the documentation has improved.
My motor performance is very smooth and the only time I've lost steps is in a crash, but that's when you want to lose steps. I have a BP sized mill with big honkin' 42 size steppers. I use 60 ipm max on X,Y, 90 ipm on Z. I could probably bump my speed up with a higher supply voltage, I'm running about 2/3'rds of what the motors will take, but for what we use the machine for (prototypes, small production runs) we can live with the current speed.
Paul T.
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My mill had an Ahha board and the Artisan controller running it.
I switched to mach and the difference in performace is amazing, I'll admit that my Artisan control software wasn't setup to the optimum but just having constant velocity has helped a lot.
Artisan also had a problem with small curves, I had to alter the min curve setting and still had problems.
Steve
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Quote from Hood !"The problems are that if you dont use breakout boards between your hardware and the SS you may suffer from noise which can trigger limits etc. "
I have a IH mill that i setup with a combo board and had noise so bad i couldn't solve the problem and safely run the machine ! My ultimate solution was to revert back to the direct port wiring for the drivers and only left the vfd & coolant on board. This was the only way i could eliminate the noise problem. So, I guess i am the only opposition to the above statement ! The key to the whole thing is the system being wired up, and the board selection.
For the gent which run out of port pins, there are add in port cards too numerous to mention, for adding a port. The most critical point to keep in mind is the operating voltage of the board. Many run in the 3v range which "WON'T" work, It must be in the 5v range. I am using the one recomended by the previous IH owner and am having "NO" problems with it at all.
not opening my yapper in a long time i just thought i'd chime in and make some noise !
Cruiser
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Cruiser, not familiar with your setup but do you have a link to the breakout board you have? Did you try connecting capacitors between the Inputs and 0v on the SS?
Hood
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WOW, I never got any responces this quick when i was having nitemares over my system !
Hood ..... The board i used was (is) campbell combo board that i had now for close to two yrs. I never got any info about puting "anything at all" across "any" terminals to quench the noise issues. I feel that there is some anomoly dealing with the internal power supply that inter connected through the ground circuit which carried the elec noise back to my system which drove my system to epileptic phitts !(fits) I would have certainly tried it but right now i think i'll just leave it alone as it works clean and quiet. Although, other than the pain in the arsse of rewiring i'd be interested in knowing what and where or how to accomplish adding the appropriate caps to where etc ! If i "HAD" to rewire in the future then who knows !
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Not sure where you posted your nightmares, was it here or the SS forum? The SS forum has quite a bit of info about noise and capacitors etc.
I have the Beta SS on a coil winder I made and found that I sometimes suffered noise. I was using a breakout on Port 1 so couldnt understand. Didnt have anything connected to Port 2 butseems that Port2 may have been picking up noise, disabled the pins2-9 as Inputs option and the problem disapeared so maybe that was where your noise was coming in. Greg is working on digital filtering so I think that will probably cure the problem without having to resort to caps.
Hood
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Hey Guys,
Is anybody using the new Campbell combo board ?
I have tried to download the Pdf manual several times, and no luck it just will not transfer.
Since most people, also the guys from Gecko are telling me that I really do not need a controller card I am thinking
about going with this combo board.
I do not mind spending money on things, but I hate to spend money on things to find out they do not work well.
And then they are added to the useless shelf!
I( am looking at this board because I want to use a pendant for sure. I have been using a pendant for setup for so
long I would feel lost without it.
Thanks for your help.
Joe