It seems rare to look at this forum page and not see questions about “disconnects.” Is this a major issue with all consumer grade CNC machines? Are the electronics on Shapeoko CNC machines more prone to this? Isn’t there a way to sell these machines so that this issue has been worked out for new users? I dealt with this intermittently for a year before I seem to have finally solved the problem. This must be the most common source of frustration with these machines. Is this just an unavoidable part of CNC at these price points that can’t be solved ahead of time?
1 Like
I think the short answer is that all usb connected machines are more susceptible to static than anyone would like.
I don’t think there is a universal fix for this issue that can be applied at the factory to preempt issues in all cases.
The extent of the issue depends on a boat load of factors such as what you are cutting, what kind of extraction you are using, and the general environment the machine is in.
See this thread for more details:
There may also be some perception bias when it comes to these issues. I don’t know how many machines C3D sells, but I imagine it’s a large enough number that there’s bound to be a couple of issues at any given time. We’re also only going to see reports of “issues” not necessarily reports of “everything works great!” (Though I do see those as well)
Just my thoughts as an outsider looking in 
1 Like
People who don’t have this problem don’t post about cuts going uninterrupted.
We have a blog post on it:
https://carbide3d.com/blog/dust-collection-disconnects/
and folks have discussed it rather thoroughly:
4 Likes
I’ve often wondered about this. C3D machines & ecosystem is great in so many ways so it’s too bad that this comes up. I feel bad for any new user that gets a machine they are excited to use and then have to wade through this issue.
Could C3D add more grounded or shielded components to their system at purchase so the user doesn’t have to troubleshoot on their own?
Has there been any discussion of using a controller or connection method that is not USB dependent, e.g. Ethernet, standalone, parallel port, etc.?
I did a google search on “CNC disconnect problem” and from the looks of the search results it is not a something that only impacts C3D machines. Also keep in mind the numerous reasons for disconnects… everything from user “error”, static, MS Windows settings, loose connections, faulty USB cables and connections… the list goes on.
While I know there are legitimate issues, IMHO some people are too quick to blame the machine without thoroughly investigating the cause of the issue. Proof of that statement can be seen in the last replys from the original post where the user shares what really happened and how they fixed it.
Once again I step down from my soapbox… 
3 Likes
The environment you live in has a lot to do with static. If you live in the Arizona desert it is very dry and static is inevitable. If you live on the beach the chances of static are greatly diminished. However living at the beach you can still generate static with your dust collection system running. Moving air with plastic hoses will generate static anywhere. So grounding is very important. Since I own a Shapeoko I cannot speak to other OEM machines getting disconnects but I am sure they get them if prevention is not used. I live in East Texas and the humidity is over 70% all the time. So static is not a big issue. I use static resistant dust collection hoses to keep the static at a minimum. If you are lucky enough to have an air conditioned shop the humidity is much lower then the outside. My shop is not climate controlled so whatever the humidity is outside it pretty much the same in the shop.
Bottom line is it is relatively simple and cheap to protect yourself from static and you should protect your machine from static. When you start moving air you generate static.
1 Like
I think that the frustration is that it is an issue that a new buyer has to slog through on their own (ie. the weekly disconnect posts here on the forum). None of this info was included with the original owners manuals. For me it was at least a 6-12 month process which included about 90% my own research and legwork and about 10% help from the customer support people. Each time I read all the posts on the forum and one by one upgraded my machine with star grounding, anti-static hoses, upgraded USB cables, new grounding wire on my machine, measuring resistance to ground throughout the machine, etc… I made the following post at one time that solved about 90% of my disconnects. It then took a couple other fixes to get me now up to about 98% success. I learned most of this the hard way which is still a sore spot in my mind. I am not the only one based on the weekly posts here that never end. I just wondered if this is common to all CNC machines.
1 Like
We have pretty good anecdotal data on this, because we’ve been selling machines for over a decade.
First, many of the modern/current “disconnects” are not a disconnect- new users see any error, and they call it a “disconnect.” If I happen to be helping out in the support queue, I won’t accept that a disconnect happened until I see a photo or it’s otherwise very clear that the correct pop-up occurred. (You may have seen me asking for a screenshot in a forum thread)
Overall, real disconnects are way down for us, thanks to a combination of changes to the electronics and machines over time, and people are accepting that a vacuum system must be grounded. And, we’ve generally become better at troubleshooting on this.
It’s almost completely avoidable with the right vacuum system and grounding. Unfortunately, that’s not necessarily cheap, so people tend to favor a progressive application of best practices to minimize cost.
There is no way to say this without offending people, so I apologize in advance. There’s a lot of bad information on this forum and every other forum. Most is created by people trying to figure things out, and you end up with a lot of voodoo that may or may not be helpful.
You also have threads about older machines or older software, with solutions to problems that no longer exist, even if the symptoms are the same. (This is a big reason why we auto-lock threads after a period of time, and why I try to go back and delete old threads with info that is no longer relevant if it’s leading people astray.)
We keep tabs on the larger CNC router community. I think I can say this generally:
- Static problems happen on every machine to some degree or another.
- Some dry environments are absolutely brutal, and others have zero problems, even with zero precautions taken.
- Some people have “special” electrical wiring in their walls (something ain’t right in some way) that seems to almost amplify any other problem.
- Even minimal grounding and precautions eliminate the vast majority of the problems.
Take that all for whatever it’s worth.
11 Likes
Here is an example of what seems to me to be a design error. When I simply placed my multimeter on many parts of the machine including the XZ axis assembly where the vacuum hose and router are attached, there were many parts with no continuity to ground at all or high resistance readings of 30-50 ohms. There was nowhere for built up static charges to be released. I was able to run new grounding wires down the axis to fairly simply correct this to now establish much better grounding as I documented in my link above. Why isn’t this fairly inexpensive extra step taken on new machines? Again, this is just an example that makes me question the frequent disconnect problems on the forum. Otherwise I am very happy with my machine.
I forget what versions/revisons of the machine added grounding wires, but I don’t think 30-50 ohms is a problem for ESD. The static discharge hoses have much much higher resistances, which is not a problem because the voltages involved are high and the total charge is relatively low.
1 Like
I’ve owned a Sherline CNC mill for approximately 15 years and have never had a problem with static discharge. The computer case also has the drive boards for the stepper motors in it. The power cables run out to the stepper motors. The C3D machines have the whole system attached to the machine itself. Two other things that are different and to consider is I’ve only cut ferrous metal on the machine and some acrylic. The machine is also not in an enclosure which the C3D Nomad 3 is. This may also be the cause of a “disconnect”. Cutting wood on the Sherline has not been done much so I have to ask, could it be the material being cut?
Not saying this could be the cause. Just throwing some ideas from a guy who’s also run industrial size CNC machines,
Bernd
My first ever CNC machine was an Sherline. It was a fun machine and I sometimes think of getting another for the nostalgia.
Ultimately yes, the material is part of the equation, because you typically run a dust collector with wood. The vacuum system is where the ESD comes from.
2 Likes
The linear bearings do not pass electricity well.
I ran a ground wire from the z transom to the grounding block to resolve it.
1 Like
I honestly have not had a static grounding issue on a Shapeoko in years. I’m currently running 4 of them and none have had an issue.
One note: many “disconnects” are because the PC puts the USB port to sleep to “save power”. Turn that off in the power settings and that solves a bunch of “disconnects”
3 Likes
It’s a usb issue more than anything. Industrial machines don’t use a usb interface.
My s3xxl stopped having disconnects after I grounded the machine and the dust collector.
My S5 machines have never had a static disconnect I’ve been running them for a couple years now. And in full disclosure. My dust collection system isn’t grounded. I get shocked touching my cnc dust hose drops all the time. Still no disconnects.
Like others have said. People only post problems.
Im a master tech at. New car dealer for my day job. O only see problems. I struggle to talk about the good in anything because of ti.
2 Likes
I think this was the main problem for me that caused the majority of my problems. I just don’t understand why I had to discover and solve this problem myself on a fairly expensive machine.
Of the first 20 topics on this forum this morning, 2 of them are from customers struggling with disconnects. (ie. 10% of the topics). That seems very typical on this forum.
Since adding that ground, all of my disconnects have been USB related.
I am using an old laptop and the physical connection is a bit suspect.
I had disconnect issues when I first started using my Shapeoko 5 pro. Installing separate
(isolated) power ckts to feed the machine solved my problem. I am assuming that noise from other things on the ckt. caused noise problems that interrupted the processor or the PC that I use to run the CNC. I had the same issue with my cnc plasma and ckt. isolation resolved it, also.
1 Like
How I seem to have solved this (so far)…
I had a few disconnects pretty quickly once I got past simple/learning cuts that took 30 minutes or less. After a few google searches I wrapped the last 3 feet of my 3” ribbed vacuum hose with simple solid bus wire I had, making a loop every 2” or so before bending and twisting 2” further up the hose away from the connection hose attachment point. I then ran the bus wire along the hose, without wrapping it but just zip tying it to the hose which is flexible suspended and supported over the cnc table, to a point where I could branch off and connect the bus wire under the screw head of a metal wall outlet cover on a grounded metal outlet box (ie not a modern blue plastic box). Some article I found suggested this type of setup best I recall.
I also experimented with sending the bus wire across the diameter of the hose just above where it connected to the dust boot on the cnc.
I’ve had no disconnects on cuts as long as 2-3 hours now.
There’s no ground loop since the hose ground isn’t in contact with the cnc. As I said, this seems to have solved my disconnects.
This was all over the last several months during the dry brutal cold winter where my basement workshop was often as cold as about 50° and very dry.
Your mileage may vary…
I was having the same problem with my 3XL. I grounded the gantry and haven’t had an issue since.