Wire harness issues - shorts in molex connectors

CNC Machines Shapeoko Pro
1

I have a shapeoko 3xxl pro I haven’t had a lot of time to use it. After initially building the machine and stirring with excitement - I got about three small projects into it I realized the machine, motors, belts, software - just about everything is really solid, well made and impressively well thought out and designed with good quality….but quickly found the downfall of the whole machine…the wire harnesses are much less to be desired.

My z axis and a few other connectors click with a short on occasion. With such a well made machine it is sad and disappointing to see the wires and connections be so problematic. I used a little piece of electrical tape to hold the harness connectors together which seem to work about 80% of the time on the next project or two, but with enough vibration the problem continues, especially on the z axis connector closest to the spindle. Often the molex connector gets pretty warm too. This then causes initialization and homing errors, loss of zero, lack of reacting to g_code commands and the machine doesn’t know the z axis hasn’t moved as instructed and the spindle not lifting when moving to a new path and just tearing through the material (Ouch) which then Leads me to stare at the progress when running a small job with my hand waiting to execute an emergency stop. Because of this I don’t use the machine very often due to trust issues, and sadly only have used the machine a couple of hours over the past year.

I tried working on the machine about a week ago once again and the z axis sank into my spoil board on a cut path about 15 minutes into the program and almost nailed the aluminum t track as I hit the stop luckily just in time.

Has anyone experienced this… and what was the fix? I found several “issue” videos ( with the exact issue I am experiencing) posted on YouTube, but never any solutions shown. I have read some have just soldered the wires and bypassed the connections - but some say it works great and others don’t recommend it.

I also have read that some of the molex connectors were bad a little over a year ago - how do I know if I got a bad set initially with my machine?

I have put off resolving this issue for way to long, haven’t found solutions to fix the issues, and just have’t really used the machine much at all since I got it and have had the issues. And advice would be greatly appreciated. I would honestly like to use this machine on a regular basis if I can make it run reliably.

Here is a link with a video I found that is having the same issue I am having…

2

The units are extremely solid, you’re right. Not a cheap feel to any of it.
Hundreds of parts and so much technology and thought put into it. Finding a small issue like yours can be definitely frustrating but also goes to show you, you really have to ‘find’ issues. Im sure from the youtube video posted that you can figure something simple to help your situation. Dont let a little thing like that stop you from using the unit. You can find many more issues actually trying to make things haha. So much to learn, hope you resolve your problem and get making things more regularly.
Be safe

3

Please let us know about this at support@carbide3d.com and we will so our best to look into this with you.

4

My fix for my Pro4 XXL that was having this problem was to cut out the connectors and splice the wires together.

5

That’s certainly one way to do it!
If the Molex connectors are done properly, they make solid connections. The most significant variable is how well the connector pins have been crimped onto each conductor - they can be just good enough to pass initial testing/inspection but then intermittently fail due to vibrations & bending stresses on the cable.
If the crimp is solid, it will just work.

6

If C3D will warranty then replace the connectors. If it is out of warranty then as @Steve.Mc said just cut the connectors out and splice the wires together.

So how to splice the wires together? Well you can use butt splices. You can cut and solder but be sure to buy heat shrink to insulate the wires. Butt splices work if you use the correct tool and crimp it hard enough. The solder works but how to physically join the wires is important otherwise you get a big blob.

One other wold be to buy some new connectors and crimp them in. You need the proper tool for crmping and strip your wire to the required length.

7

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.