Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: c30232 on November 24, 2012, 03:46:59 PM
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Brief history: Circa 2002 I cobbled together a 3 axis ball screw desktop router for machining cast acrylic. It was assembled with parts inventory from a soon to be out of business machine manufacturer. The controller is PC based and runs DOS software through an undocumented proprietary 3 axis controller/driver. There were/are no manuals. Through a process of smokeless trial and error I was able to wire and configure the machine to run and it has done so for ten years. However, I am concerned that one day when it is need most the thing will just give up the ghost and we will be in a jamb. Therefore, I am attempting to establish a new control for it before that bad day arrives.
Immediate goal: 1) to cause an Oriental PH264-01 4V 1.1A stepper to twist. 2) Control a new plasma table.
Long term goal: 1) re-control the desktop router. 2) Re-control a Techono 2 axis stage. 3) Refit or re-control a Thermwood router.
Any guidance would be appreciated.
Problem of the day: the Stepper won’t twist!!! I purchased a TB6560 4 axis control/driver and 12V power supply off eBay. The selection was made because the item was cheap, within 10 miles, and could be retrieved immediately. The control package included Mach 3 and a license. The first install of Mach seemed okay but we discovered the absence of the proper communication port. I know nothing about this magic!!!
I have/had 3 industrial touch screen computers (Pentium III 1.26 GHz 512) that seemed perfect for the task. All three computers are identical, reformatted, and freshly installed with XP Pro. The install seemed okay but when an attempt was made to run the controller the system (computer) crashed and is now DOA. Really DOA!!! I am not sure whether the death is coincidental or incidental. No worries we have spares. The second attempt on the number two machine ended in an unrecoverable crash, however, it is not DOA. Third time is a charm . . . why not trash all three? Any comments on the DOA and crash would be appreciated.
The third computer and install seem okay. No crash yet. The controller does not seem DOA. Mach seems to do its thing. On my existing desktop the steppers will lock when power is applied to the controller/drive. This does not occur with the TB6560. Should it? Mach and the TB6560 seem to communicate at some level but will not twist the stepper. The step and direction pins as reported for/by TB6560 are not correct.
The step and direction for X are now set at 4 and 8. Jog does nothing but when the motor shaft is turned slightly by hand the jog will return the shaft a step to a lock condition. The stepper is a six wire that I believe is wired correctly.
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You have unfortunately jumped from one undocumented product to another, the Chinese TB boards are noptorious for their lack of documentation or if they do have some it is often incorrect.
Regarding Mach and the licence. First thing is the licence is very likely a pirate licence. Second is even if it is a legitimate licence they are non transferable so really you should be trying to set things up in Demo mode, ie delete the licence from the Mach folder.
Regarding your computer death, highly unlikely that could have been caused by connecting the TB board unless there are serious issues with it and it is sending high voltages into the port, even then I would expect the port to blow but the computer still be ok.
As you have no problems with the third computer then I would say its just all been coincidence.
What would I recommend, well probably nothing you want to hear ;D
Get rid of the TB board and buy something like a Gecko G540 or some other well known and proven board, many have had to do that and have not regretted doing so. What they have regretted is buying the TB in the first place and wasting money.
Of course this is just my opinion and observation but when I first started out I did similar, TB boards were not around then but I purchased cheap drives and breakouts from USA eBay, I had nothing but issues and problems and despair until I got a loan of a Gecko drive to test and the machine was transformed, it went from a very unstable 400mm/min to a very stable 4000mm/min, I immediately ordered some G201's and junked the rubbish I had been using, lesson learned for me, sadly I see it repeated time after time with new users :(
Hood
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Hood has beaten me to it ;D but as it was already compiled here is my take on the situation...
Whilst others have succeeded with using the TB6560 it is really not the best controller for the job. Just browsing this forum will show you the many problems some have experienced with this device and most of them have now moved on to something better, which works.
OK, it costs a bit more but bearing in mind the quality and support / backup that you will get I suggest that you consider something like the Gecko G540 http://www.geckodrive.com/catalogsearch/result/?q=540
Gecko really do have a wealth of experience and the information available on their website is second to none.
Having said that and returning to your TB6560 problem – yes, your steppers should lock when power is applied so the problem may be with your Mach3 setup. Check that your X,Y and Z axis are enabled (Config / Ports and Pins / Motor Outputs) and that you have the correct port #1 address enabled – typically 0x378 (Port Setup and Axis Selection).
You need to be a bit wary because there are many, lack of knowledge / experience, errors on this website but there is some useful information regarding the TB6560 here http://whatisacnc.com/driver-board/tb6560/
In addition, you will also need to verify that the Mach3 license you purchased is valid license@machsupport.com as there have been a lot of fake licenses sold with the TB6560 boards and (from personal evaluation) they just do not work properly.
Tweakie.
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Having said that and returning to your TB6560 problem – yes, your steppers should lock when power is applied so the problem may be with your Mach3 setup. Check that your X,Y and Z axis are enabled (Config / Ports and Pins / Motor Outputs) and that you have the correct port #1 address enabled – typically 0x378 (Port Setup and Axis Selection).
Unless the TB6560 has enable pins (I don't think it does), then the motors not locking up is a TB6560 problem, not a Mach3 problem.
To test this, unplug the parallel port and power up the TB6560. The motors should still lock up without PC control.
As the others have set, the TB6560 is a piece of garbage, and should only be considered if you have the smallest possible budget, and are willing to roll the dice, as they have an extremely high failure rate.
If you want to control a Plasma, you should look at the kits from www.candcnc.com Bring your wallet.
Retrofitting a Thermwood will probably be an extremely challenging and complex job, depending on how much of the stock functionality you need to retain.
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c30232,
I no longer reply to posts about problems with the TB6560 and echo the other replies.
Just wastes my time.
The last Chinese boards we tried to get working took 3 people hours of time and then the young lad spent hours getting all the pinouts right. The individual boards even had different pinouts. Documentation and fixes varied, the supplied documentation was junk, the drives were restrictive and didn't work right. Never again!
Hope you'll understand,
RICH
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Hood, Tweakie, and all
Thanks,
I have learned much in the past few days and you have confirmed what I was beginning to suspect. I have learned the basics of Mach and I shall toss the TB6560!
For the guys across the pond, the desktop I assembled was scheduled for Wadkin but they were in poor financial health at the time and had not paid for the machines being produced by a US company. I bought the machine partially completed for a discount of 70%. It has served well for a decade, however, I have learned as a result of the TB6560 that some of its ongoing issues may be in its controller. Like Hood’s referenced machine it moves along at just 150mm/min. Much faster and the motors stall, but except for rapid it is fast enough to push the 1 mm bit we use without breaking it. We use it as a 2 ½ axis machine so rapid is not needed much as it just travels a cutting path around to near home.
But again the pieces of the puzzle are starting to fit for the Wadkin as well. The Wadkin 250mm X 350mm sold for $10K in 2000 and that was less than others wanted for a similar product. The actual x,y, and z portion is well done but I am guessing now that they cheaped out on the controller. I will have more on that or its software later.
I will order a Gecko 540 and power supply on Monday. I have read on this forum, I believe, and elsewhere about power in volts required being several times greater than the rating of the motor. This is, as defined by the various writers, a concept that I can’t get my arms around. If I quadruple the power in volts to any other machine smoke will soon follow. What should I look for in the power supply for the G540? It will be driving 4 NEMA 23s but I do not have the exact rating yet. The steppers are installed but actual specs remain a secret to me. I will attempt to get the actual specs on Monday
The first task is to build the controls for a small plasma table. I believe we would enjoy a torch height control. Any thoughts on this and a recommended product? I assume it is compatible with Mach.
Mach v Wadkin. When I setup the Wadkin control there was an extensive calibration process. The process was related to the software and PC not the controller/driver/motors. I stumbled upon calibration process and learned the following:
1) Without running the calibration process the movement of the machine was random.
2) Not all PC’s are created equal. That is, the software would not work well on just any computer even though the specs were the same.
We found a computer that it liked and to date it still functions. A computer failure will be a disaster because I do not remember how to run the calibration. I am not sure what it was checking but the calibration took hours and hours to complete. Does Mach have any such calibration process? Again on the Wadkin a failure to calibrate the software v PC resulted in very poor accuracy. It is possible that my memory has failed and the calibration included the controller but I think it was limited to the PC.
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Most people use a 48V power supply rated between 7 and 10 amps with the G540.
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Regarding Mach setup, once you have it running sweet you can copy your profile file and save it on another computer just in case something goes wrong with your machines computer. If that happens all you need to do is install Mach on the new computer then place the saved xml file into the Mach folder and all your settings are back.
Hood
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Ger21
Candcnc may not be far from the dollar mark if you consider the THC and software bundle. The upside is that the pros will have done it. The downside is that we still won’t be able to fix our own machine. I will break out the calculator and delve. In part the project is to enlighten a young teenager. He is top of the class and claims to be headed for civil engineering. Based on his actions I think he would enjoy mechanical or electrical. Just want to expose him to something other than the books. The plasma is for use on the NASA moonbuggy competition build. They hand-jive the parts now and complain about second ops to clean the shake out of the part.
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Ger21
Is the 2010 screen your work?
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Yes, it is.
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ger21
Screenshot 2010 is well done and, in my opinion, very intuitive. Your zero feature would have saved me many frustrating hour while using the Wadkin. Just enough of a problem to be irritating but not some much as to toss more money at it. The cost feature ratio on cnc has certainly changed over the decade.
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I am now able to twist the stepper. The solution was, as you all noted, to place the TB6560 in the garbage can and replace it with a proper control. I purchased a Gecko Drive G540 and power supply from “danmauch” via eBay. I spent several days attempting to resolve the TB6560 with out success. I have 2 hours invested in the Gecko including a drive to town to acquire resistors and soldering the connections. I am sure I am not home free just yet, but the thing moves. Thanks for the sage advice.
The stepper does seem a bit hot after just a few minutes of twisting with no load . . .145 F and climbing. Any thoughts on that? The Gecko is hovering at 108 F. That’s just a 20 F rise from ambient.
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Q.) How hot is too hot for a step motor?
A.) The maximum heat for most steppers is around 100ºC (212ºF), but it is generally never good
to have the motor heat go above 85ºC (185ºF).
Q.) How should I heatsink my drive?
There is not drive-specific heatsink for any Geckodrive, and there are a variety of ways to
heatsink your drive. What you should do is ensure that your heatsink has fins to increase surface
area, and have air flowing over it. A good heatsink to use is a standard CPU heatsink with some
heatsink compound in between the drive’s plate and the finned aluminum heatsink. The method
to determining if it is being cooled adequately is to feel the drive while it is running. If it is
uncomfortable to the touch, then the electronics are uncomfortable as well.
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The stepper does seem a bit hot after just a few minutes of twisting with no load . . .145 F and climbing. Any thoughts on that? The Gecko is hovering at 108 F. That’s just a 20 F rise from ambient.
Getting maximum performance from steppers requires high voltage, which also causes hot motors. Make sure you have the proper size resistors, and have them wired correctly.
Gecko recommends having a fan blowing on the G540 to keep it cool.
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I have read of a few errors of loss of position due to an extremely hot environment for the G540. Definitely a fan and or heat sink.
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540 SPECIFICATIONS:
No heatsink needed below 40C ambient
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this is your main problem."I purchased a TB6560 4 axis control/driver and 12V power supply off eBay" piece of crap.
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The TB6560 is history. Ger21 is correct, current is the issue regarding heat. We reduced the current and heat was reduced accordingly. We determined there was no error in connections or the resistor sizing. The Gecko only saw a 20 F rise with the higher current and no rise with low current while the stepper saw a 90 F rise. This is all for education. When the final selections and assembly are made we will balance the current and ventilate the enclosures as required. I assume too that the machine will act somewhat as a sink for the stepper. The stepper did run noticeably better at the higher current . . . the truth is always in the middle.
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Thanks for all of the help. The table finally arrived and after some minor mods it is moving in a pleasing fashion. The motors turned out to be 276 oz 2.8 amp
Mach seems straight forward and easy to use. But I do have a few mysteries. The test pattern is parallel lines 15” long. The Z movement is up 1” then down to zero. Lazy Cam set a rapid out to 15” for each line which seemed good for a test pattern. Feed is 60 IPM with rapid at 200 IPM.
1) The Z while moving earthward 1 inch seems to pause or slow just before the end of cycle. I am not persuaded it is ramping down. It seems to pause and accelerate into position. It also seems that X is starting its move at the same time Z pauses. It is split second and hard to pinpoint. It would likely go unnoticed if a torch or router was running. However, there is a noticeable twitch on the DRO.
2) At the start of cycle the X ramps slowly but only on occasion. The rest of the time and throughout the run it accelerates quickly.
The repeatability at the end of 100 lines was +- .001” on X & Y. Z was better than ½ that. I have yet to determine if the move was actually 15”. There does not appear to be any lost steps.