Erik do you have a schematic on how you hooked that switch up to the G540?
No, but I can throw something together this weekend.
Greatly appreciate it Erik. I’m about to pull the trigger and buy a G540 and would love the option to be able to do this to protect the G540.
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Instead of guessing I contacted several of the driver manufactures and asked them about this issue. One of them has already responded and mentioned something that no one has considered. Up until now we all assumed that just because there were diodes in place that the driver would be protected, but they said that’s NOT the case. Here is their response;
"It does use protective diodes but we would not recommend doing this…You would burn those diodes and then driver would not operate. "
I am still waiting on the response from Gecko, which makes one of the best drivers, if not the best driver for CNC machines, the aforementioned G540. I would be surprised if they didn’t say something similar.
Just like CNC machines, there are many different motor driver chip designs. Unless you are contacting the manufacturer of the driver chips that the X-carve uses then it is not relevant information.
The discussion here is about what the X-carve does, not some other machine.
If you want to expand the discussion to other machines then it would be helpful if you would be more specific. Like you are with the Gecko product.
Not that I advocate that anyone to do the same, but I move my machine around by hand quite frequently and have done so for years( gshield for most of that time but now tb6600). It is always a slow steady movement, never quick. I’ll let you guys know if I ever burn up a driver. 
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All of the companies that I contacted are used with the X-Carve. Gecko, TinyG (Synthetos), ETC, and I just contacted Warp9 Tech (SmoothStepper). The point here is that the stepper motor is more than capable of burning up the diodes, which would be the same thing as not having any diodes at all (not including the cost of going out and having to replace the driver). The response I’m waiting to hear from the most is Gecko. Hopefully today.
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Why did you change from the gshield?
Ya I went gecko some time back. I was just wondering if it was giving him any issues. You know other than a blown driver.
Don’t want to get in a whole new thing here, but the Y-motors could be wired in series to share, rather than split, the current.
Correct me if I’m wrong, but I think you totally missed my point.
Just because the driver chip on the X brand board has crappy diodes, doesn’t mean that Y brand driver chip also has crappy diodes.
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more power, extra driver for y axis(still haven’t rewired to utilize this), better cooling flexibility.
The gshield was working up until it was replaced.
Irregardless of which company makes the diodes, they will still function the same per sa. None of the brands that I contacted makes ‘crappy’ electronics. You’re probably referring to how the circuit the diodes reside in is designed (and responds) and that is why I am contacting the most well known brands. For example; Gecko got back to me and said that their circuit is specifically designed to act as a drain (like a lightning rod, only positive) and that the energy would be detected and would then be dissipated. I replied to their response to get a clarification from them. Will post their answer as soon as I hear back from them.
Right, if the steppers are wired in series they can be controlled by the same driver and can share the current. As @AngusMcleod mentioned, they’ll split the voltage (not as crucial as current).
Not true.
You obviously don’t know that the diodes in question are part of the silicon die that makes up the driver chip. You cannot buy these diodes separately, because they do not exist outside of the silicon chip.
I suppose that now you are going to try to tell me that it doesn’t matter who’s driver chip you use because they all work the same, per sa.
Your comment about the diodes is like saying it doesn’t matter who makes the CNC machine they all function the same.
And if you believe that you might want to read this thread.
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Why not?
No one is talking about buying diodes. They are called diodes and used in the circuit because they perform a specific function, that’s all I’m saying. To suggest otherwise would be disingenuous. If you’re suggesting that the diodes in question are bulletproof then please post your proof. What I’m saying is that any diode could be vulnerable and given the right set of circumstances could possibly be burned out. I would be more than happy to contact the driver chip manufactures regarding this.
Red Herring.
On a side note I did hear back from Gecko (in response to the clarification I sent them). They verified that their circuit is specifically designed to act as a drain, and any excess power would be pushed into the power supply’s filter capacitor. Their response was referring to the model G540. The only stipulation was that the stepper motor not be moved very fast, which is understandable. So if you’re using a G540 then you should be good to go. Having said that I’m still going to do the same as Erik did with my G540 and utilize a switch.
It doubles the impedance seen by the driver chip which reduces both torque and speed. Doubles back EMF due to rotation.
Could almost be eliminated by doubling the supply voltage.
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As an alternative to driving at half current, if you can increase the potential, it works. I’m not suggesting free energy. There are better solutions, no doubt.