Hey John,
attaching the magnet probe to the rail should in no case trigger a motor error.
I agree. Support has asked me take the rail a part.
Hey John,
besides cables being pinched between rail and end cap making a short this way it is also possible that a crimped wire became loose from its pin at the connector that is inside the rail.
Hey John,
when I looked at the video describing this (Support : How to Access the inner tube motor wire), it was clear that of course you donât have the rails lying around like this, but that you have an assembled, working machine. I just had the thought that if there is ever any concern about the cables inside the rail, it would be good when planning a table for the Onefinity CNC to have a service hole under each front foot which would allow access to the screw that loosens the end cap (which allows to remove the cable then).
And my second thought is, why donât they have light at their film set? (Or at least why doesnât someone click on the brightening/contrast button in their post-production software?)
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Lol I thought about drilling a hole thru the bottom my table as it is only a temporary table but I am not confident in my drill stops and I am concerned I would plunge it into the bolt making the problem worse.
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Hey John,
May I recommend you these ingenious Star-M Depth stops 
:
The plastic cap rotates freely and stops rotating when you reach desired depth. I use a set of them, from 3 mm (=approx. 1/8âł) drill diameter upwards. Picture shows â 15 mm drill (=approx 19/32âł).
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Hey John,
according to the motor error appearing when attaching the ground probe to rail, and according to your resistance measurements, this is exactly what is expected to see. These blank wires short one or more stepper cables to the rail. It is similar to the image Darren posted the other day. This is an assembly fault.
So did I.
Onefinity has a replacement in the mail. I am surprised the red wire even functioned with how it is pinched.
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Hey John,
so now next challenge is to achieve what they didnât achieve at the factory: To get the cable into the tube without pinching it again! I think the cause of this issue is that the cables are rigid, and the tube is small, so what shall the cable do when you push it? Everyone already pulled a cable, but did you ever try to push a cable?
If you donât plan anything special then it will kink because of its overlength compared to rail tube, but where will it kink? Well, without further ado it will again crease at the inner edge of the end caps. I havenât tried it, but I donât think itâs that easy.
I thought to myself, how would you have to do it so that it doesnât bend and get stuck at the front? Exactly, you would have to give it a helical shape, and this before you even put it in.
By wrapping it, somewhere further back a few inches, around a cylindrical object, maybe like this:
You remove the cylindrical object after that of course, itâs just to give the cables a little helical shape. It is shown a little exaggerated, you donât want to create an electrical coil, but you have to ensure there is a predetermined position where the overlength of the cable will go when you slide it into the rail.
And then, when doing this, additionally it would be best to put the front end of the cable in a small tube about 3-4 inches long so that it cannot kink at the front under any circumstances, and put the end caps around the connector only at the last moment. The small tube would have to be larger than the connector so that it can be slipped over it, but small enough to be inserted into the rail tube as an insertion aid which you remove in the last moment. Or even let it remain in there.
What do you think of it? Can you report how it goes when you try to install the replacement cable?
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So it wasnât much of an issue to reinstall the cable. It had an enough stiffness that I was able to gently feed it thru the back to front. Then I just snapped back on the cap piece and gently pulled on the wires in the back as reinserted the cap.
The wires are pretty precise length so there would likely not have been sufficient length to wrap it around a tube.
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Hey John,
thank you for reporting this. Is the new cable shorter than the older one?
I donât thinks so.
If I had to guess what happened originally, I would say that the wire was put in the tubes before the black end supports were put on or that the end supports with the wire was assembled than the tube was slid on over the wire but that is purely conjecture.
Hey John,
since it is already the second time I see this issue in the forum (with wires pinched inside the hollow shaft and thereby an electrical short of stepper) it is possible that a number of machines were affected from this assembly fault. I am sure that the manufacturer has given some thought in the meantime to how to find a remedy for assembly process, either by better training assembly personnel or by introducing the use of some insertion aid in assembly process. I think that if I were the manufacturer, this issue would have alarmed and concerned me a lot.
We donât know how many machines were delivered with this assembly fault. But I did not yet mount my machine, so of course I think better to check if one is affected by this issue before assembling it, than after :-). Would not sleep well if I didnât check it as a first step before assembling.
Also I want to see how difficult it is to install the cable in real. My thoughts that I described above on how this issue could be prevented at the factory are only theory. If I find a good idea on how to prevent this issue during assembly, Iâll share it with the manufacturer of course
I didnât mean to wrap it around a tube and to install it with it, what I meant is, before inserting the cable into the tube, just to create a flexure in the cable at an other location, that would act as a predetermined flexion point where it would bend the cable overlength, rather than having the flexion point being directly at the end cap (where is the danger of the cable being pinched between cap and steel hollow shaft)
Take a small piece of paper towel or cloth or some soft foam that will fit inside the tube. Not tight but just enough to cover the opening. Tie a string on to the plug, then stuff it in the end of the tube where you want to start pulling wire from. Go to the other end and use your shop vac to suck it through, have the dead end tied down or you will lose it. Itâs only ~4 feet so it will happen in a split second. If youâre not careful youâll pull it all through. Donât put the vac hose completely over the tube, use partial vacuum to control the force.
The same method is used to run a pull string through conduit. That string is then used to pull a rope through if needed for larger cables.
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Hey Bob,
this reminds me the âWool thread vacuum cleaner methodâ that I use to put a new light cord into a bicycle frame after an *diot pulled the cord out all the way without tying the new one to it 
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Was that person someone you know well but have never met face to face?
A push rod certainly works for this application since it is such a short run.
Hey Bob,
Of course not, Iâm too smart
Seriously, in this case it really didnât happen to me. When I was a child we had our complete electricity renewed in our house and I observed well the electricians. They tied the new cables to the old ones and when they pulled them out, the new cables were in place instantly. When you observe this as a child, the thing with the light cable pulled out of the bicycle frame seems not to happen to you
Not on the bicycle, entry point of the light cord is on the front end of down tube, near head tube, and exit point is at the end of chain stay - it has to pass bottom bracket tube
Wool thread vacuum cleaner method works nicely for this
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With regard to the push rod I was talking about fishing cable through a straight tube such as on the Onefinity not bicycle frames.
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The Star-M Drill Stops are also available from Taylor Toolworks.
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