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I have a USB 3.0 micro cable in an assembly (below) where it attaches to a PCB on a sliding tray. Unfortunately, in the physical prototype, the cable is too stiff and causes the tray's stepper motor to struggle and stall.

Ultimately I will switch to an FPC-cable solution to address this properly. However, I was wondering if in the short term I could simply strip the PVC housing and shielding, and cut all USB 3.0-specific cables, leaving just the thin D+, D-, and 5V / GND wires. (The connection is to a raspberry pi which doesn't have USB 3.0 anyway).

Is it ok to cut the USB 3.0-specific wires and leave them floating? They have their own housing and are still pretty stiff even after the PVC is removed. I'd like to minimize the strain on the stepper as much as possible.

enter image description here

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Yes. It would be like they were never connected. You do compromise the effectiveness of the shield around the cables by cutting it though, so try to minimize that or ensure you tightly tape it back up.

But couldn't you use a 2.0 cable in the first place? The usb 3.0 micro b connector has two parts, a 2.0 micro b five pin part and a newer 3.0 only five pin part. A usb 2.0 micro b cable can plug into the corresponding side of the 3.0 micro b jack for 2.0 and power only access.

Photo illustration of USB 2 / 3 micro plug compatibility

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  • \$\begingroup\$ Thanks very much! No, I cannot use a 2.0 cable because the PCB is a vendor product and comes packaged with an SMT connector for USB 3.0 micro. \$\endgroup\$ – Ismail Degani Aug 8 '16 at 6:49
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    \$\begingroup\$ If it's a standard usb 3.0 micro b female connector, then you can plug in a 2.0 micro b male cable without issue. @Ismail \$\endgroup\$ – Passerby Aug 8 '16 at 6:50
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    \$\begingroup\$ @ismail blog.macsales.com/wp-content/uploads/2012/07/Cable-fit.jpg see? \$\endgroup\$ – Passerby Aug 8 '16 at 6:53
  • \$\begingroup\$ Wow, I did not know that! I just assumed the different shape meant they weren't compatible. Thanks, I will try that first!! \$\endgroup\$ – Ismail Degani Aug 8 '16 at 6:53

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