[jeffofx]

I have a G540 running my nema 17 motors on my (Defunkt Viper Plasma company) system. the system came to me pre designed and ran great for about 100 hours You can fry an egg on the motors if they are left at idle too long. A couple of months ago my computer crashed and had to replaced it with a new one and all of a sudden the G540 will heat up and the output for triggering the plasma "on" stops working. I've tried switching between output 5 and 6 with same result. I hooked up a volt meter and watched the output voltage of the trigger wire in question drop below the point to where it wont trigger the relay anymore. While measuring the temperature rising on the G540. The Hypertherm Plasma works fine, I've replaced the power supply, the relay, the G540(TWICE) still with the same problem. I can only think that the motors may be causing the G540 to over heat even though they have never missed a beat, they have always and still do work. Any thoughts?? I was thinking of hacking the serial cable and finding the wire that triggers the G540 and drive a separate circuit outside of the G540. Anyone else heard of a similar problem? The tech at Gecko says my stuff is working great on the test bench.

[ger21]

Do you have a fan or heatsink on the G540?

[awerby]

Does the controller have any current-limiting resistors installed? By default, the G540 puts out 3.5 amps. With motors that small, they should be limited to a small fraction of that - what do the nameplates say?

[jeffofx]

After the problem started I then tried adding a fan to blow over the G540 with no help. I then tried blowing a can of air upside down over the "hot area" and the output stared to work again immediately until it heated up again, maybe a minute or so. So then I decided to drill a hole in the case to the G540 and blow compressed air directly into the G540 and that worked pretty good, giving me enough time to cut most everything I needed, but still not perfect. It still heats up

[jeffofx]

Does the controller have any current-limiting resistors installed? By default, the G540 puts out 3.5 amps. With motors that small, they should be limited to a small fraction of that - what do the nameplates say?

The system was pre designed and built by Viper Plasma. I'm pretty certain that there resistors at each motor. the motors have very little info on them. They only have a number SM57HT82-3504-01. And by the way the power supply is 48Volt

[ger21]

If it's an older G540, then the resistors should be at the G540 end, and not the motor end. Having them at the motor end will cause excess heat.

[jeffofx]

If it's an older G540, then the resistors should be at the G540 end, and not the motor end. Having them at the motor end will cause excess heat.

I'm not sure of the exact age of the G540's All three that I have are the same. The last one was purchased about 7 months ago.

[storm2313]

You require a heatsink in on the G540 if it's installed in an enclosed environment to increase the surface cooling area of the driver in the exact way a CPU is cooled in a PC. Gecko's site has an article called the heatsink experiment which covers how the G540 can overheat, and damage itself if not properly cooled. Please review it if you haven't already.http://www.geckodrive.com/g540-heatsinking

A fan should be used in conjunction with a heatsink to optimize cooling. This will provide you the best operating environment for the G540.

[Stotheh]

That article actually says that heat sinks have very little effect on the cooling of the g540. Having a fan blowing directly onto the g540 case back makes a huge difference to the running temp, adding a heat sink as well only improves the cooling by a couple of degrees.
The g540 on my lathe is running 5a motors (so it's putting out as much as it can, 3.5a) and it gets worryingly warm. Adding a couple of fans dropped the case temp by about 40 degrees C. The difference between too hot to touch and just warm.

If fan cooling isn't doing the job then there's something wrong.

[storm2313]

That article actually says that heat sinks have very little effect on the cooling of the g540. Having a fan blowing directly onto the g540 case back makes a huge difference to the running temp, adding a heat sink as well only improves the cooling by a couple of degrees.
The g540 on my lathe is running 5a motors (so it's putting out as much as it can, 3.5a) and it gets worryingly warm. Adding a couple of fans dropped the case temp by about 40 degrees C. The difference between too hot to touch and just warm.

If fan cooling isn't doing the job then there's something wrong.

Lets cover some basics to eliminate misconceptions in thermal dynamics. Heatsinks, and a fan are the proper way to drop the temperature on the G540, or any stepper drive. The reason heatsinks are utilized are they increase the cooling surface area, and add metalic density while the fan simply circulates air around the fins dropping the temperature even further. If you increase surface area, and density of a surface it becomes cooler, and actually harder to heat up in the first place. This is the exact principle used in PC cooling in every computer manufactured. A stepper driver, and computers CPU are extremely similar in they perform optimally when cooled using these methods.

I invite you to take a look at the included picture of Leadshine stepper drivers. Attachment 287236 They all have integrated heatsinks on the drives for the same reasons I wrote above.It has nothing to do with brand of the drives, or coincidence either

Gecko offers a large heatsink for it's individual drivers, here and as you can see not fans http://www.geckodrive.com/heatsink.html .

Please be very careful when posting what worked for your individual installation as although it may be working for you, doesn't mean it's the proper way to cool a stepper driver properly.

I encourage anyone reading this post to research through Google on the "heasinking process" to assure the information they are receiving is correct especially when it comes to possible drive damage. Overheating is very serious, and is VERY easy to eliminate with a basic understanding of thermal dynamics.

[123CNC]

I would have to agree with Stotheh on the data presented by Gecko's 3 different tests for G540 cooling. In there tests, forced convection had a larger notable change in temperature than the additional heatsink and fan. it would have been interesting if they had run one test of additional heatsink with no fan, just natural convection. I'm certain an added heatsink would help, although I would wager it would not make a very big difference with natural convection alone.

Storm, your comment "Please be very careful when posting what worked for your individual installation as although it may be working for you, doesn't mean it's the proper way to cool a stepper driver properly," may be viewed as more confusing than helpful. If any individual installation is working for a given environment, meaning it is maintaining temperature within a specified range, than it is 'proper.' If it works, however they achieved it, it is obeying the laws of thermodynamics. Whether it is the most efficient or elegant solution is a different discussion.

As Gecko points out the back mounted surface of the G540 is a heatsink and in their 3 runs was adequate to maintain the temperature below their design case temp of 85 C. As pointed out if the G540 has a high duty cycle near it's maximum output and or is mounted in an electrical enclosure, then the potential of overheating becomes a greater concern.

Just for clarification, 'metallic density' alone is not significant, the material choice should have a low thermal resistance or high conductance. A dense material with high thermal resistance, such as many ceramics, would be a poor choice. Although most metals will work to some degree, lead would be nearly 5 times less effective than aluminum, although a much greater density.

Yes, surface area can be important, as long as there is sufficient convection to fully use it.

There are three basic means of thermal transfer, conduction, convection, and radiation. The G540 in most applications the backplate is a sufficient heatsink to 'carry' the heat or thermal load via conductance out of the drive in an ambient environment to allow natural convection to 'carry' the heat up and away from the G540 housing. When the G540 is mounted in an enclosure, an additional thermal resistance is added by impeding the flow of the natural convection, therefore forced convection is recommended to introduce fresh cool air as well as forced removal or exhaust of the 'heated' air from the drive out the enclosure.

In jeffofx's case, it is unclear if his G540 is in an enclosure or not, although his attempts with compressed air (forced convection) helped, it was not a silver bullet. Which could be either insufficient delta T, insufficient flow on and around the backplate, or insufficient contact of the internal drives to the backplate/heatsink (although he mentioned Gecko had checked the hardware). It is also not mentioned what his environment temperature is like, obviously if his ambient temperature or enclosure temperature is seasonally higher, it will take more to help move the heat out of the drive and or enclosure.

Good Luck.

[storm2313]

I would have to agree with Stotheh on the data presented by Gecko's 3 different tests for G540 cooling. In there tests, forced convection had a larger notable change in temperature than the additional heatsink and fan. it would have been interesting if they had run one test of additional heatsink with no fan, just natural convection. I'm certain an added heatsink would help, although I would wager it would not make a very big difference with natural convection alone.

Storm, your comment "Please be very careful when posting what worked for your individual installation as although it may be working for you, doesn't mean it's the proper way to cool a stepper driver properly," may be viewed as more confusing than helpful. If any individual installation is working for a given environment, meaning it is maintaining temperature within a specified range, than it is 'proper.' If it works, however they achieved it, it is obeying the laws of thermodynamics. Whether it is the most efficient or elegant solution is a different discussion.

As Gecko points out the back mounted surface of the G540 is a heatsink and in their 3 runs was adequate to maintain the temperature below their design case temp of 85 C. As pointed out if the G540 has a high duty cycle near it's maximum output and or is mounted in an electrical enclosure, then the potential of overheating becomes a greater concern.

Just for clarification, 'metallic density' alone is not significant, the material choice should have a low thermal resistance or high conductance. A dense material with high thermal resistance, such as many ceramics, would be a poor choice. Although most metals will work to some degree, lead would be nearly 5 times less effective than aluminum, although a much greater density.

Yes, surface area can be important, as long as there is sufficient convection to fully use it.

There are three basic means of thermal transfer, conduction, convection, and radiation. The G540 in most applications the backplate is a sufficient heatsink to 'carry' the heat or thermal load via conductance out of the drive in an ambient environment to allow natural convection to 'carry' the heat up and away from the G540 housing. When the G540 is mounted in an enclosure, an additional thermal resistance is added by impeding the flow of the natural convection, therefore forced convection is recommended to introduce fresh cool air as well as forced removal or exhaust of the 'heated' air from the drive out the enclosure.

In jeffofx's case, it is unclear if his G540 is in an enclosure or not, although his attempts with compressed air (forced convection) helped, it was not a silver bullet. Which could be either insufficient delta T, insufficient flow on and around the backplate, or insufficient contact of the internal drives to the backplate/heatsink (although he mentioned Gecko had checked the hardware). It is also not mentioned what his environment temperature is like, obviously if his ambient temperature or enclosure temperature is seasonally higher, it will take more to help move the heat out of the drive and or enclosure.

Good Luck.

Interesting comment you wrote. " If any individual installation is working for a given environment, meaning it is maintaining temperature within a specified range, than it is 'proper.' If it works, however they achieved it, it is obeying the laws of thermodynamics. Whether it is the most efficient or elegant solution is a different discussion."

I think there are many practices that are done that complete the task, but to say its done properly is completely another story. You can solder a wire, and insulate the connection with electrical tape, and it would work, but heatshrink would be the proper insulation to use in the application. I believe you would agree, and can see my point as most would.

Lets talk about a few more interesting things you brought up. You wrote "As Gecko points out the back mounted surface of the G540 is a heatsink and in their 3 runs was adequate to maintain the temperature below their design case temp of 85 C. As pointed out if the G540 has a high duty cycle near it's maximum output and or is mounted in an electrical enclosure, then the potential of overheating becomes a greater concern."

The case of the G540 houses four individual G250 drives. Each of these drives put out an RMS rating of 2.47A or 9.88A total, or 7.41A on a 3 axis system . If you believe the G540's aluminum case is sufficient by itself to cool these drives mounted in an enclosure with a DC power supply excreating hot air for a duration of time reflects your heading for serious trouble. You use the term " adequate". This word is very dangerous especially considering it in conjunction with cooling.

This heatsinking artice never discusses the length of time the controller was operating at this temperature created by the fan which reflects your literally taking huge risk. The devils in the details when covering the variables in an experiment.

Please remember Gecko's warranty doesn't cover damage from overheating. Proceed with caution.

I build motion controllers, and use Gecko drives exclusively. I deal with these drives on a daily basis, and my customers who purchase my systems expect reliability, and not the freak issues associated with improper cooling. If they have a project to complete, and are looking to run for long hours the extra cost for integrating a cooling system will pay for itself literally immediately. Take a moment, and review my controllers. I practice what I preach with good reason. You can't hold Gecko liable for inadequate education of using there drivers in the event of a drive failure. I believe anyone taking the time to read this will see my point without your assumption of me generating confusion.

Here's my store to see my builds. I use a 65CFM cooling fan with 3 Thermalloy heatsinks Gecko G540 CNC Motion Control System 48V 10A 3 NEMA 23 300oz in 3 5A Motors | eBay

Anyone building a controller from scratch or purchasing a G540, or for that matter any stepper driver use proper cooling to protect your drivers, and components from heat damage. This includes utilizing heatsinks in conjunction with appropriate CFM cooling fans for proper heat dissipation.


If your spending the money it takes to complete a controller using superior drives like Gecko brand don't cut corners on protecting your system. The little extra money spent will be for piece of mind.

[123CNC]

storm,

Sorry that I did not make my self clear, in fact that was the only point I was trying to make, about trying to be more clear.

Let me take another stab, your statement of "Please be very careful when posting what worked for your individual installation as although it may be working for you, doesn't mean it's the proper way to cool a stepper driver properly," or simplified, although working it is not proper.

I whole heartedly disagree that one should be careful or not post what is working for them. There are many many ways to skin a cat, proper or improper are subjective terms, a skinned cat is a skinned cat. Many people find it useful and very helpful to learn by example, without getting into the physics, mathematics, or the 'nature' of things. The laws of thermodynamics are not constrained or hindered by proper or improper. You provide no empirical evidence that jeffofx NEEDS a heatsink and cooling fans. Everyone needs to evaluate their own situation as how best to meet their 'design' requirements, however whatever they do they just can't defy the thermodynamic laws as we know them.

To emphasis my point, do you have empirical data that supports your need of an additional heatsink in your installations? Without data one can debate ad nauseam on proper cooling.

Yes, my choice of terms, 'adequate' was intentional, perhaps a little over conservative. The Gecko tests did comment on test conditions including time. Most ran for nearly 40 minutes and were stopped when the temperature stabilized to within 1 degree. All of there data was below the design constraint of 85 C, therefore, truly more than adequate. So nothing dangerous in my language. In there tests, they never exceeded THEIR design constraint.

[storm2313]

storm,

Sorry that I did not make my self clear, in fact that was the only point I was trying to make, about trying to be more clear.

Let me take another stab, your statement of "Please be very careful when posting what worked for your individual installation as although it may be working for you, doesn't mean it's the proper way to cool a stepper driver properly," or simplified, although working it is not proper.

I whole heartedly disagree that one should be careful or not post what is working for them. There are many many ways to skin a cat, proper or improper are subjective terms, a skinned cat is a skinned cat. Many people find it useful and very helpful to learn by example, without getting into the physics, mathematics, or the 'nature' of things. The laws of thermodynamics are not constrained or hindered by proper or improper. You provide no empirical evidence that jeffofx NEEDS a heatsink and cooling fans. Everyone needs to evaluate their own situation as how best to meet their 'design' requirements, however whatever they do they just can't defy the thermodynamic laws as we know them.

To emphasis my point, do you have empirical data that supports your need of an additional heatsink in your installations? Without data one can debate ad nauseam on proper cooling.

Yes, my choice of terms, 'adequate' was intentional, perhaps a little over conservative. The Gecko tests did comment on test conditions including time. Most ran for nearly 40 minutes and were stopped when the temperature stabilized to within 1 degree. All of there data was below the design constraint of 85 C, therefore, truly more than adequate. So nothing dangerous in my language. In there tests, they never exceeded THEIR design constraint.

This is a real interesting debate especially when you wrote this. "You provide no empirical evidence that jeffofx NEEDS a heatsink and cooling fans. Everyone needs to evaluate their own situation as how best to meet their 'design' requirements, however whatever they do they just can't defy the thermodynamic laws as we know them."

The empirical evidence is damage I've seen others do to their systems from lack of knowledge from opinions given on this, and many other open forum venues. I hear things like " I didn't think the drive needed any extra cooling", or "I didn't feel they were worth the extra money"


A forum can provide a wealth of useful information pending your receiving facts, and not opinion from people with an extensive background in the specific field you require information about. Most all forums 98% of the time are opinion unless the question is a definitive yes, or no answer. Case in point defines this. You feel if an experiment is performed running a system for 40 minutes with only a fan is "adequate" as useful to base your own build on then so be it. I say for the other people out their putting their hard earned money out to build a system I would look at the factual past science of heat dissipation on stepper, and computer CPUs for a thorough understanding of what animal your dealing with. Google is your friend. Type in Gecko G540 heatsinking, and the results seem endless.

I agree there are many ways to skin a cat in certain various situations. I disagree completely that openly saying to the masses reading this "Your fine for not installing a heatsink do to you only requiring a fan to cool your drive" This information is incorrect, and can lead to possible drive damage in an enclosure, and I myself as a reseller have seen it.

Let me ask you this would you offer to replace someone's drive that followed your direction if the drive failed do to overheating? Would you put your money where your mouth is? I think we both know the answer.

I don't know anyone's individual installation when they purchase a DIY kit from me. The variables are huge. IE, where do they live? What temperature is the location they will keep their equipment in? How long will the system run before shutting down? What's their intended enclosure made out of? Is there holes in it for proper breathing, and hot air flow? What CFM fan will they use for proper heat dissipation? The list goes on. I hope anyone looking into building a controller does some research themselves to read the stories of past issues with overheating.

If I'm messaged before a kit is purchased I always discuss cooling solutions. Some people instantly understand the importance while others feel I'm trying to upsell them, or don't have the extra funds to complete the build properly.

The ones claiming they don't need to purchase a cooling solution typically understand first hand the issue when they install the driver in an enclosure, and I get a message like " The drive is to hot to touch is this normal"?

This last question I hope you have an answer for. If your so convinced on "If it works It's acceptable" thinking is correct. Why does Gecko write in the G251x drivers manual a warning stating if the drivers are used at above 3A that they require a proper heatsink to avoid damage?? Another interesting thing to point out is they say preferably with fins, and a fan as an option.

Understand the G251x drivers are the same as the G250 drives inside the G540 other than the screw terminal block, and basic mounting heatsink attached from Gecko. I included the direct snip from the instruction manual reflecting this for you, and others to review.
Attachment 287428

I hope everyone reading this realizes that because you can open your homes breaker box close your eyes, and start grabbing for wires, but never get shocked doesn't prove to be an adequate process to practice, or one to write about projecting this is the correct way to do this. Use Google, and find the correct answers. There out there.

[123CNC]

This is a real interesting debate especially when you wrote this. "You provide no empirical evidence that jeffofx NEEDS a heatsink and cooling fans. Everyone needs to evaluate their own situation as how best to meet their 'design' requirements, however whatever they do they just can't defy the thermodynamic laws as we know them."

The empirical evidence is damage I've seen others do to their systems from lack of knowledge from opinions given on this, and many other open forum venues. I hear things like " I didn't think the drive needed any extra cooling", or "I didn't feel they were worth the extra money"

Damage is indeed empirical evidence, the question remains, evidence to what? Something that has failed or is ‘not working’ is a single data point of evidence, it does not relay a lot of specific information. It certainly does not point to a root cause or provide a single or ‘proper’ solution.
Although you offer a plausible or possible solution, you offer NO evidence that it is THE solution for a particular user’s situation. You simply do not have enough information to make that claim. No one here knows the root cause, I’m not even sure if we clearly know the problem.

A forum can provide a wealth of useful information pending your receiving facts, and not opinion from people with an extensive background in the specific field you require information about. Most all forums 98% of the time are opinion unless the question is a definitive yes, or no answer. Case in point defines this. You feel if an experiment is performed running a system for 40 minutes with only a fan is "adequate" as useful to base your own build on then so be it.

It is not only adequate, it is empirical data that reduces the qualitative and subjective data and more precisely defines the conditions under which the input variables will very reliably produce a known outcome. What more can one ask for? It definitely reduces opinions or any tribal knowledge. The 40 minutes was more than adequate or sufficient, the data clearly shows that the system reached thermal equilibrium or steady state, as they had stated until the temperature remained within 1 degree. So 40 minutes or a billion minutes, the probability that the case temperature will be below 85 C is 99.7% or better.

I say for the other people out their putting their hard earned money out to build a system I would look at the factual past science of heat dissipation on stepper, and computer CPUs for a thorough understanding of what animal your dealing with.
Google is your friend. Type in Gecko G540 heatsinking, and the results seem endless.

By your own statistics, “Most all forums 98% of the time are opinion…,” therefore Google is definitely not your friend. Google will only result in fact 2% of the time. So the results may seem endless, but 98% can be thrown out based on ‘opinion.’ Even if one was to consider all of the Google results as good data, it would still remain meaningless without analysis and perspective. Additionally you are adding way too many variables to your argument when you start suggesting stepper drives, stepper motors, and CPU’s are similar animals. OK, similar like elephants have four legs, dogs have four legs, and hamsters have four legs.

I agree there are many ways to skin a cat in certain various situations. I disagree completely that openly saying to the masses reading this "Your fine for not installing a heatsink do to you only requiring a fan to cool your drive"

I certainly did not say that, nor did anyone else. A heatsink may be useful under certain circumstances, but certainly not under all circumstances. Gecko’s data very clearly demonstrates that the heatsink and fan combination they used under their tests conditions provided negligible difference compared to a CPU case fan alone. In fact, less than 1 degree C is likely much greater than their measurement error, in other words can likely be entirely ignored. Someone insisting that you must use a heatsink to someone who does not need a heatsink is an up sell.

This information is incorrect, and can lead to possible drive damage in an enclosure, and I myself as a reseller have seen it.

“In an enclosure” may indeed be the stumbling block for comprehension of the intended message. If one were to mount a G540 in an enclosure the size of a room, is a heatsink and fan required? Who knows, if 25 C then no, unknown temp. then certainly not enough information to make a very knowledgeable response. Therefore the better question is what are the environmental variables that add thermal resistance to the G540’s need to transfer heat away from it’s circuitry, especially those components that generate heat that is self destructive? It is also important to re-emphasize, how hard you are using the drive is the biggest contributing factor to the thermal load.

Let me ask you this would you offer to replace someone's drive that followed your direction if the drive failed do to overheating?

Absolutely, unequivocally, resounding YES! Given that someone does not alter the input variables or input state. This may be another stumbling block for some. Worded another way, if you change the problem, you have likely changed the solution. The inverse to this, one solution will not solve all problems.

Would you put your money where your mouth is? I think we both know the answer.

We both know the answer and everyone who reads this knows the answer, as I have not changed my message at all, YES.

I don't know anyone's individual installation when they purchase a DIY kit from me.

BINGO, BINGO, BINGO, you’ve hit the grand jackpot. That is why there is no one solution. No one can provide a solution to a multivariable problem with too many unknowns. They could take a wild guess, but they might not come close to hitting the broad side of a barn.

The variables are huge. IE, where do they live? What temperature is the location they will keep their equipment in? How long will the system run before shutting down? What's their intended enclosure made out of? Is there holes in it for proper breathing, and hot air flow? What CFM fan will they use for proper heat dissipation? The list goes on. I hope anyone looking into building a controller does some research themselves to read the stories of past issues with overheating.

If I'm messaged before a kit is purchased I always discuss cooling solutions. Some people instantly understand the importance while others feel I'm trying to upsell them, or don't have the extra funds to complete the build properly.

The ones claiming they don't need to purchase a cooling solution typically understand first hand the issue when they install the driver in an enclosure, and I get a message like " The drive is to hot to touch is this normal"?

This last question I hope you have an answer for. If your so convinced on "If it works It's acceptable" thinking is correct.

Perhaps now would be a good time to interject the intended message or meaning behind my choice of words. It is impossible for anyone to eliminate all misunderstanding, it is the nature of language and the nature of mankind. So I will try to add more context to reduce any ambiguity. Works = adequate = meets design requirements = does not fail = thermal demands met = laws of nature as we understand them remain intact. Does not work = inadequate = does not meet design requirements = failure = thermal demands unmet = laws of nature broken or no longer intact as we understood them. More simply, a category that works, and a category that does not work. Intuitively one would expect the greatest number of solutions to fall into the ‘does not work’ category. Within the it ‘works’ category there may be a great number of solutions, and one may choose to label individual or groups of solutions as the best, the worst, the OK, or the ‘proper’ solution. Those are all subjective and relative terms that really don’t add any value to whether it works or not. How can there be a ‘proper’ solution without a ‘proper’ problem?

Additionally, it is entirely possible that someone at some point may discover a ‘new’ solution or even redefine or improve on our understanding of the physical laws. After all, our understanding and definitions do not pre-date mankind. Arguably most new discoveries are found by accident or when one drops the constraints of what we think we know. That’s why it is great when people are allowed to share all ideas and solutions on an open forum. So still yes, if it works it is acceptable.

Why does Gecko write in the G251x drivers manual a warning stating if the drivers are used at above 3A that they require a proper heatsink to avoid damage??

Dealing with a single G251x driver is a different problem then the G540. A single driver or even multiple individual drives is a different environment or different input variables. By design, the G540 enclosure provides a heatsink to the internal G251x drives inside. In most cases this factory heatsink, the G540 enclosure or box, is adequate.

Another interesting thing to point out is they say preferably with fins, and a fan as an option.

This too makes total sense. As their own data demonstrates, when the G250/1x is mounted on a heatsink, much like the G540 case, it will provide adequate heat transfer for most situations. Fins, as you have previously mentioned in an earlier posts, increase the surface area which can improve the transfer from the conductive medium to the convective medium as well increase the radiant transfer. Of course there is a limit, at a point the size or surface area can exceed any practical benefit to heat transfer. A fan is an option in most cases. However, if you already have it on a primary heatsink, much like the G540 case, another heatsink will not likely add as much benefit as adding a fan, especially if your environment has a larger thermal resistance than most. Or if your heatsink already exceeds practical limits and you still have a thermal load problem, then forced convection must be considered.

Understand the G251x drivers are the same as the G250 drives inside the G540 other than the screw terminal block, and basic mounting heatsink attached from Gecko. I included the direct snip from the instruction manual reflecting this for you, and others to review.

I hope this is clear to everyone as well. The heat transfer problem for a G251x and a G540 are not the same. The G540 case provides a heatsink solution for most situations. The G251x may or may not need an additional solution, depends on the environment. One such environment variable is how long you push the driver at its upper end, where it approaches thermal self destruction, as Gecko clearly states pushing 3 A loads on the naked drive.

Another point to make here, is that if an end user finds themselves pushing the boundary of a system or component, one could address the resulting symptoms OR change the solution. A larger drive and or motors which try to keep the average use in the midband of output would be one such solution.

I hope everyone reading this realizes that because you can open your homes breaker box close your eyes, and start grabbing for wires, but never get shocked doesn't prove to be an adequate process to practice, or one to write about projecting this is the correct way to do this. Use Google, and find the correct answers. There out there.

Blindly poking around in an energized electrical cabinet, although a much higher risk for harm or death, in principle, is the same as relying on Google to provide one with the correct answers. There is a very high probability one will not be happy with the results, some claim 98% disappointment. Some common sense and some cognitive ability is still required of the user, in both cases

.

Perhaps I made a mistake in specifically quoting storm, as this may appear to him as a personal attack. It is not. A healthy debate is good, when it degenerates to arguments, not so good. As a matter of habit I address a user in a posted response to provide continuity and connection. Especially when the posting of responses are not necessarily in chronological order. I always try to answer as though thousands of people are asking the same question or making the same comment, I try to respond with a message that will benefit as many as possible and as congruous to as many people that would share or understand my view. In other words, nothing radical or earth shaking.

Let me try to get back to help the initial post and anyone else with a similar problem and in general how forums and language can help or hurt the situation.

I will use IP to denote Initial Post(er) and RP for responding post.
IP: I have a problem.

RP: Take 2 aspirin and call me in the morning. Get plenty of rest.

IP: No, My problem title is: G540 overheating. I have a G540 running my nema 17 motors on my (Defunkt ViperPlasma company) system. The system came to me pre designed and ran great for about 100 hours

RP: Ok, not a lot to go on. But interesting to note that in your title you think the device is overheating. So far we have no quantitative evidence that anything is overheating, but we will work with this statement as a ‘possible’ symptom of your problems. We know from Gecko user manuals and testing that if the drive is operated near its highest thermal demand, 3 A and greater and in an open ambient environment near 25 C, the probability of overheating is extremely low. The statement that it operated great for nearly 100 hours suggests during this time either the G540 was never above the 3 A output for very long or that all other input or environment variables were always within the design limits. It is unclear if the device is externally mounted or internally in an enclosure or control cabinet. At this point it might not be relevant, for 100 hours the system as provide by Viper Plasma worked (meaning did not fail, did not overheat, thermal demands were met). So what changed after 100 hours?

IP: You can fry an egg on the motors if they are left at idle too long.

RP: Ok, although still a qualitative response, much closer to quantitative. If you believe everything one finds with Google, an egg will fry at a temperature as low as between 55 C (130 F) and 70 C (158 F). From Gecko we find “The G540, being a stepper drive, is meant to get warm. While operating at its maximums the G540 can get up to 70C (158F) comfortably; heatsinking is mandatory if the temperature gets above that range.” First, there is not necessarily a one to one correlation between the temperature of the stepper motor and the temperature of the G540. But if we were to assume that in this case there is and the G540 is at or near this temperature, then we are in a gray area. Looking further into the Gecko data, “Please read the cited document if you have further Questions; ‘G540 Heatsink Experiment.” Here one finds the design threshold of 85C. The data also reveals that if the users ‘as installed’ G540 does not meet the thermal demands, one should expect thermal failure within 25 to 35 minutes OR LESS, not 100’s of hours. On a side note, the steppers at idle should not be drawing anywhere near the full output of the drive, it should be a small fraction. Second, if they are exceedingly hot they may indeed be drawing near their rated current even at idle. If the steppers current rating is not equal or greater than the drives output, a current limiting resistor is needed to add load to the drive, or current limit to the motor. Is our qualitative measure at the stepper motor good enough to assign a root cause to the problem or symptoms at the drive? It is uncertain, and we can only really expect a qualitative response, probably not. If one knew the real temperature at the back of the G540, we would have quantitative data to work with. The question remains, what happened after 100 hours?

IP: A couple of months ago my computer crashed and had to replaced it with a new one and all of a sudden the G540 will heat up and the output for triggering the plasma "on" stops working.

RP: Very interesting! A quick and intuitive response is that it is easy to see how a change in the computer, the control signal, or the input source to the drive and breakout board could be directly related to a change in an output response, e.g. “triggering the plasma ‘on’ stops working.” The baffling part is if there is any relationship with the new computer and hot steppers or an overheating G540, if it is overheating. There is no intuitive or immediate causal relationship, logic would lead one away from any cause and effect between them. Interesting. Where is the computer mounted or located? Where is it physically in relationship to the G540? Is the new computer adding thermal load to the system, is it blocking radiant or convective transfer? Has any of the wiring between the G540 and the computer changed when the new computer was installed?

IP: I've tried switching between output 5 and 6 with same result. I hooked up a volt meter and watched the output voltage of the trigger wire in question drop below the point to where it won’t trigger the relay anymore.

RP: Interesting as well. Thermal damage can be catastrophic, cumulative until catastrophic, or transient. It could result in partial or complete damage to the circuits. Later it is mentioned that some things still work, so we can rule out catastrophic damage at this point. A poor ground or EMI noise can also cause poor signal quality, in which case pull down/pull up resistor may be needed to ‘clean’ the signal to within an operable range. However, in this case it worked fine for 100 hours as installed. Were there any resistors previously used on these outputs or changed with the new PC? Has anything changed with respect to the G540’s ground? Has anything changed between the way the old computer’s power supply was grounded or not and the way the new computer is grounded or not? Have you measured the input voltage to the G540? Have you measured the input voltage or outputs over a time period to identify any transients? Have you followed Gecko’s recommendations for troubleshooting inputs/outputs?

From User Manual:
PROBLEM: INPUTS OR OUTPUTS NOT WORKING
SOLUTION: This problem is most often caused by a problem with the parallel port or the parallel cable. Use an ohmmeter to verify that your cable is a straight through cable and not a crossover or a printer cable. Next, go into BIOS and make sure that your parallel port is set to EPP or “Send/Receive” mode. If your parallel port is on your motherboard and is not a PCI card then the problem could be that it is incapable of EPP operation. Use a PCI parallel card and see if the problem persists.

IP: While measuring the temperature rising on the G540…

RP: Where was it measured, any data, any correlating time data, or any system state information to help analyze any possible correlations, e.g. system idle, ran at 50% output for 10 minutes, ran at 100% for 40 minutes, etc.

IP: The Hypertherm Plasma works fine, I've replaced the power supply, the relay, the G540(TWICE) still with the same problem.

RP: OK, was the new power supply identical to the old? Was the new ‘identical’ power supply wired ‘identical’ to the old? Between the old PC, new PC and old power supply, and new power supply were there any changes in the wiring or grounding of these components? Is it correct that both G540’s still work at some level, and they both exceed 70 C and or 85 C, and the outputs are non-operational? Have you bench tested either G540’s outputs 5 and 6?

IP: I can only think that the motors may be causing the G540 to overheat even though they have never missed a beat, they have always and still do work.

RP: OK, when you say ‘overheat’ are you using it in the sense that I interpret Gecko’s information as this will damage the drive, i.e. the G540 will fail and the steppers will no longer receive an output signal and will not work? Yet you mention ‘they have always and still do work.’ Either the G540 is not overheating, or Gecko is not implying that overheating will damage the stepper motor outputs? If the latter, than what symptoms would an overheated and damaged drive demonstrate?

IP: Any thoughts?? I was thinking of hacking the serial cable and finding the wire that triggers the G540 and drive a separate circuit outside of the G540. Anyone else heard of a similar problem? The tech at Gecko says my stuff is working great on the test bench.

RP: One could certainly circumvent the G540 for outputs, but how would that address an overheat condition, if there is one? The Gecko tech answers the previous question, “Have you bench tested either G540’s outputs 5 and 6?” They give it a clean bill of health. Your problem then has a very high probability that it lies outside of the G540 and that your system has not yet caused a catastrophic failure due to overheating. Most of your symptoms seem to point more towards your wiring (parallel cable or grounding) and less to any overheating or cooling problems. But let’s keep an open mind until a root cause or at least most probable cause has been found and a working solution is found. The Gecko tech has also confirmed with proper wiring, the outputs work fine, so why try to hack or go around them?

Without further information, one cannot determine the root cause. Without a root cause there is no proper solution. One might get lucky and throw a bunch of solutions at the problem and find a solution. In such a case the root cause may remain unknown and be masked by the lucky hit. In this case there is no way it may be claimed as the proper or best fix, because no causal relationship has been determined. However, if it works and you are happy that it works do you really care how proper it is?