On 11/04/2011 08:32 AM, Viesturs Lācis wrote: > 2011/11/4 Les Newell<[email protected]>: >> In general wood dust does not affect computers that much. I have seen >> machines with piles of dust inside, still working fine day in day out. >> Heat is an issue so do as much as possible to keep it cool. Possibly fit >> an over sized CPU cooler. > > The thing is that machine works correctly for 40-50 mins, then > malfunctions begin to appear - it does not run a file, when button is > pressed and some other. Or it ruins a part, just as if motor had lost > steps, but the trick is that next part if good without rehoming or any > other activity taken - just change material and run the file.
If the OS is not crashing then your problems are elsewhere as others have suggested. Depending on your motherboard, it's components temperature can be monitored with utilities like digitemp fancontrol hddtemp lm-sensors. I cannot tell how well they work with RT kernel and EMC as I haven't tried it. I put a thermometer with memory for high and low records in areas of interest many times. It helped me relate server crashes to environment temperatures. You might put such a thermometer in the control box for 24 hours to see what the extremes are. Temperature logger would be even better. You may want to check in Arduino world for such a sensor/shield solution. > And the more machine is running the more often these malfunctions > appear. That tells me that some parts in machine are overheating and > thus not functioning properly. I would like to blame the dust that > gets in all the narrow places on the boards and disturb normal heat > dissipation. > It's possible you have a poor connection somewhere. Connectors are metal which expands and contracts with a temperature and also act as "unwanted vibration sensors". Check the connections first. It's also possible you have a component with a cold solder joint which also reacts to temperature and vibration. That would explain why your CNC system resumes working without errors at some point. Is it possible that the problem appears when the machine (tool, router etc.) is in a particular position? That could indicate a broken cable, more likely on older machines. To troubleshot such problems I use a screwdriver handle or some other insulated material and tap on different components or wiggle the wires to see if that triggers a problem. You might want to check screws that hold wires in connectors or terminal blocks. They tend to get lose or corrode sometimes. While wood is not causing electric problems most of the time, it's dust could bring moisture into the box that would cause connection problems or corrosion. And let's not forget grounding again. Make sure all is well grounded all the time. > >> If you want to enclose the computer in a box, fit a fan on the side >> pushing air into the box. In other words the box becomes slightly >> pressurized. That stops dust from creeping in through cracks or door >> seals. Filter the air coming in with an air filter from an older car, >> the type that is just a big round ring that sits in a frying pan shaped >> housing. Clamp it to the side of your box with a round disc of wood or >> metal. You will have to replace the filter fairly regularly but they are >> quite cheap. > > That is why I would like to put them in totally sealed box. > In that case I could implement water cooling for PC components. I like this idea but you need to monitor/check plumbing every once in a while which in my experience almost never happens. All equipment I ever supported in industrial environment come with instructions for regular maintenance. Some even include nice log books or sheets to keep track of it. I've seen empty pages too many times so that needs to be taken into consideration. Another option is to use heat-pipes which are frequently used to cool components inside sealed boxes in industrial and military systems. Search for "DIY heat-pipes" Heat-pipes are not going to cool every component of course, just those that touch it directly. Trouble is that they need to be custom made most of the time. Let me give you one link http://www.silentmods.com/section2/item230/ > What should I do about monitor? > Modern industrial monitors work well in wide temp range but cost more. Use either that or check how they solve this problem as others have suggested. Google "heat exchanger design" for tons of links. >> Many bigger commercial machines use air to air heat exchangers so the >> clean air inside the box and dirty air outside never mix. > > Any idea, how to do that in a cost-effective way? > > Viesturs See above. -- Rafael ------------------------------------------------------------------------------ RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
