The Disconnect Problem

Posted on Jan 20, 2016 by Rob

We've been working with some of our customers to fix a problem on the Shapeoko 3 that has quickly gained a mythology that far surpasses its reality. We've tried to answer questions when they pop up in forums but we decided to post a more definitive statement here.

What is the "Disconnect Problem"

Over time we've seen that some users have problems with the Shapeoko disconnecting from the USB port, typically when the DeWalt trim router is turned off. Based on our data, this affects about 2% of the machines in the wild.

Every customer who emailed or called with a problem has been taken care of.

Why is there a problem?

The DeWalt is a relatively high-current motor and it generates electrical noise when it's running and when it's turned on and off. Depending on some variables such as your cable routing and the AC wiring where the Shapeoko 3 is located, this noise can end up in the Carbide Motion PCB and trigger a USB disconnect.

It's worth noting that we use the same PCB in the Nomad Pro and we haven't had a single disconnect problem. The electrical noise coming from the DeWalt spindle is the culprit.

We haven't had the problem occur in either of our shops on any of our Shapeoko machines. Because the problem is not reproducible to us, we’ve had to work with our customers to it has taken more time than we'd like to diagnose and troubleshoot the problem.

How common is the problem?

Based on our data, this affects about 2% of the Shapeoko 3's.

"Only 2%??? I read on the forum that everyone was having this problem!”

Nope, it's about 2% from our records and we have fixed every case we have been made aware of.

How do we fix it?

Sometimes it's as easy as changing outlets, or running the DeWalt cable on the other side of the machine. Often we'll send a USB isolator to the customer.

We've asked customers to trade boards with us but that never works- it's always dependent on the local AC wiring, a specific DeWalt, or the PC.

The most important thing is that all of the cases we're aware of have been fixed.

What's the long term fix?

We're just rolling out a third revision (V2.3) of the Carbide Motion PCB. This PCB includes even more ESD protection and additional layout changes to eliminate the problem. We've sent these out to a few customers that had the disconnect problem and this board has fixed it in every case. This will be the standard PCB in the very near future.

What if that doesn't work?

We have a fourth version of the PCB being made as a prototype right now (V2.4) that goes even further. We'll have that one on standby if we find a case that cannot be solved with V2.3.

What if I have the disconnect problem?

Get in touch and we'll fix it!

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