"Wireless" USB and disconnection issue

I’ve done it with a cheap bluetooth serial module. I wouldn’t recommend doing the same. It just couldn’t handle the data fast enough. It could’ve been the bluetooth on my cheap Acer tablet slowing things down, though.


Is there an inherent loss of speed? Are these devices rated based on throughput? Would you recommend one?

Thanks. Seems like an isolated USB might be the best place to start to solve the issue? Is it also important to keep the USB cable isolated from the other cables and vacuum hose? Any other easy things I should do that solves things for 80% of the people having this issue?

The isolator might work but the real problem is controlling static electricity. If the static discharges it be over 10,000 volts and causes microscopic damage to electronic components. The USB is usually grounded so it gets blamed but the real criminal is the static itself. Additionally many of the discharges are zapping the controller and the disconnect is a by product of the controller losing its mind.

So I would suggest you fix your static problem with grounding and so on. The Isolation of the usb cannot hurt but the real problem is static electric discharging. Since you live in Denmark I assume it is quite cold and that dries the humidity out substantially aggravating static electricity.


I’ve looked at a bit of posts in this community and a lot of people are talking about grounding things. I’m not sure how to do it on a practical level though?

Do you have any links to posts or guides about grounding for the Shapeoko? Is it just the machine itself or is it the vacuum? Any pictures?

Edit: @gdon_2003 I have my Shapeoko in an enclosure: Designing a soundproof'ish enclosure for my new SO3. Do you think it would help to put a glass of water or something like that in there to increase the humidity? Kind of like in a humidor (cigar box)?

A good post on this is:


Sometime ago I collected the tips that came up most frequently and captured it here at the time.

My “statistical” view on this from forum reports is that most (80%?) problems are adressed by

  1. grounding the dust collection hose, and the router body.
  2. more generally checking the grounding of the machine, using the thread Will linked for guidance.
  3. routing power cables away from signal wires when possible.
  4. USB tricks like the isolator, powered hubs, different ports at the computer.

There is no loss in speed, but there is a limit in speed/bandwidth to which an isolator is rated. The “USB” isolators that @holgersindbaek referenced are rated for USB 2.0 so up to 12Mbps. I honestly could not tell an excellent isolator from a poor one without trying them, they all use the same basic chips (e.g. the ADUM4160), but EMI devils tend to hide in the details (of the PCB design/routing).

I am not in a position to recommend any particular one, since I never used one on my Shapeoko. I think support should be able to provide a reference though


How exactly would you ground the vacuum and the machine when you live in an apartment in Europe? I that you’d wrap a cobber wire around the vacuum, but what would you attach it to? Would you buy a Schuko plug like this - https://www.av-connection.com/?PGr=1857 - and attach it to the third leg? Maybe attach it to the radiator?

Is it necessary to plug the vacuum, router and Shapeoko into different sockets or should it be fine if I attach the vacuum and router into one socket and the Shapeoko into another?

@LiamN is the grounding GrandMaster, he will probably have good tips and know of specific plugs you can use that expose the Earth wire (I don’t have any advice to provide, since I am ashamed to say that I never bothered to ground anything on my machine, because I never had to…).

Once you have a good place to pick-up a solid ground, and since priority #1 is the dust hose, I would definitely buy some length of antistatic hose (the ones with a copper wire embedded in the hose). I bought mine off a local reseller (and then never bothered to connect the copper wire to anything…I’m that lazy)

It…depends on how the circuits are wired, everyone’s setup is different. But if you can plug just the Shapeoko in a different outlet, it won’t hurt. There is no need to try and isolate the router from the vaccum, they are not sensitive to EMI anyway (not at the levels that are a problem for high-speed/low-voltage electronics like USB…)

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There’s two main options

  1. You can just use any plug that allows you to wire it up yourself and only use the ground pin, ignore the two power pins, this will get you the same ground that your power wiring is using, but do make sure you get the ground pin…
  2. You can buy an ‘antistatic’ plug with a built in resistor which will make it harder to create a ground loop by accident like this
    This is safer if you’re not familiar with wiring things up, personally I would only do this if I had a problem with option 1

As Julien says, an antistatic hose is the better bet. You can’t really ground something that is not conductive, that’s how we make capacitors. The plastic in the antistatic hoses is doped with something conductive so that the charge can leak away to the reinforcing wire. This wire is then the easy place to ground the hose.

I wouldn’t do anything to the vacuum unless I had to, they’re not designed to be grounded in most cases. Ground the hose to the Shapeoko and that should ensure the CNC isn’t getting static discharge noise.

After the hose, if you still have a problem, making sure your Z axis is grounded is also a good plan, that will also ground the outer metal shell of your router without you having to mess with the router.

It is good advice is to only do enough for your specific problem to go away :wink:

Yep, what he said :wink:



What type of plug do you have that your Shapeoko is plugged into. I did some research on Danish/European electrical connections and will write up my research but I need to know what type of plug you are using:

  • Type C - The standard European plug. Commonly used in Europe, South-America and Asia, but also in quite a few other countries. Plugs of type E and F will also fit in a type C outlet.
  • Type F - Used in almost all European countries and Russia. Also known as the Schuko plug. Plugs of type C and E will also fit in a type F socket.
  • Type E - Mainly used in France, Belgium, Poland, Slovakia and the Czech Republic. Plug types C and F also fit in a type E outlet.
  • Type K - From Danish origin, mainly used in Denmark and Greenland. Plugs of type C also fit into a type K socket, and there is unsafe compatibility with plugs of type E and F.

Please reply back about which type of plug you have.

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@gdon_2003 I’m using the first type (type C). Or more specifically, I’m using a plug with 2 outlets next to each other: https://www.greenline.dk/elartikler/lauritz-knudsen-fuga/stikkontakter/lk-fuga-dobbelt-stikkontakt. I’ve then put an extender - https://www.av-cables.dk/stikdaase-3-udtag-uden-jord/stikdaase-3-udtag-uden-jord-med-afbryder-hvid-1-m.html - in each plug so I can put the router and vacuum in one and the Shapeoko in the other. The reason I’m not using a grounded plug is that the only place I have one is in the kitchen. Do you think I’m doing something wrong there?

@Julien So you have a copper wire running through that hose and then the trick is to connect the copper wire (how do you do that without ruining the hose?) to another copper wire that you ground? I’ve read different things about the hoses. It seems some are with a wire and some without? Some say they work and some say they’re just junk?

@LiamN Thanks for the suggestions. I’m guessing you just connect the copper wire to the metal surface of the plug then? Problem is that I haven’t got a grounded plug near the Shapeoko (I live in an apartment). I’ve read somewhere that one can ground things to the radiator. Some say that it should be fine and some say that one absolutely shouldn’t do it. What do you think? It doesn’t seem to be that much current that’s generated, so I’m not sure what the damage could be?

From what I understand, you’d ground the vacuum hose to the Shapeoko? Which part of the Shapeoko? And then you’d ground the Shapeoko itself?

Edit 1: What do you guys say to the idea of putting a container with water in the enclosure? That should increase the humidity. Do you think that would have an effect?

Yes. You just strip the copper wire near the end of your hose (e.g. where you plug it into e.g. your cyclone dust separator), you just need a centimeter or so, so if you do that in the small length of hose that covers the cyclone intake anyway, there will be no harm to the useful part (and no air leak)

I’m sure there are fake antistatic hoses out there that won’t work, but if the description explicitly states it is antistatic, and you see the embedded copper wire, and it’s not dirt cheap, it is an indication that it’s legit. Anyway, it cannot be worse than a large length of regular non-conductive plastic hose

Does anybody have a convenient and simple way to generate static and directly it to the Shapeoko?

Reproducing things is always useful to help diagnose the issue and validate a solution. If we can generate a static discharge deliberately, we might able to find out the cause of an individual’s disconnection issues more scientifically.

Possibly: cut HDPE with no dust collection…cannot get a worse scenario than this


(and my machine did NOT disconnect during that cut…I’m lucky like that)


I love this picture. Reminds me of several black-goo creatures from sci-fi films.

EDIT: I also fancy a plate of spaghetti al nero di seppia now.

I have a regular old 30’ shop vac hose attached to an Oneida Cobra Vacuum. When I first hooked it up, the hose ended up covered in fine dust, stuck on by static. I KNOW it’s not supposed to work, but I took a long piece of copper ground wire, wrapped it around the OUTSIDE of the hose (photo below), and tied it off to a gas supply line that I knew was grounded. Everyone will tell you that this won’t work…but I don’t have any more static build up on that hose. I was prepared to run the wire through the hose, and was wondering the same thing about how to get it out of the hose without damaging the hose and losing suction…but I never had to deal with it. Maybe give that a try first? It worked for me and was really easy to do.

(BTW: Contrast the amount of dust on the hose in the background against the wall (which is not grounded) with the part in the front that is…)

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Ah, so the Shapeoko isn’t grounded either then.

You could certainly try just grounding the hose to a radiator yes, they are generally grounded reasonably well, although a safety inspector or a plumber might shout at you. Not much current, we’re just leaking away the static charge.

I’d just ground the hose first as it’s normally the major offender.

You could just put a humidifier in the room with it?

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The humidity in Copenhagen right now is 95%… any more humid and the walls will drip :slight_smile: