As others have stated, run it out the opposite side of the machine. Good rule of thumb is to never run power and data wires near each other. If you have no other choice then always cross them at 90 degrees, not parallel to each other. On my machine I actually added a 3rd drag chain on the right hand side of the machine for the router cord, lighting power, etc… You may still have some areas where they will inevitably break these rules, but you wanna try to avoid those if possible or suffer the dreaded EMI disconnect gremlins! Don’t know which router you’re using, but my Dewalt came with a dongle on the end of the cord that “looks” like a ferrite donut, it isn’t, it’s an anti-theft doodad.
I appreciate all the input. Too bad, because it seems so convenient to run it through the drag chain. I’ll undo everything and go back to the original plan to hang it from above with enough slack to cover all corners.
I hate to be “that guy” but I have been running my router cord through the drag chain and off the same power strip as my computer and CNC control board with not a single disconnect for almost a year. Worth giving a shot. Maybe I just have really “clean”/stable power service to my house…
@Microwave_Monkey Did you do anything else to eliminate issues from EMI, or are you one of “those guys” that never had an issue? Where are you located? (humidity maybe?)
It doesn’t have anything to do with house power. The arcing of router brushes, which increases with increasing speeds and power, radiates electric fields. Router and HF spindle currents, which increase with router power, radiate magnetic fields. Both field types are parallel to the motor power cables, so wires parallel to them will pickup the most radiation. Separation helps because the intensity of the both fields decrease with distance. Convention shielding of the motor power cables helps reduce electric field radiation, but doesn’t affect magnetic field radiation, Magnetic field radiation can be reduced by twisting the motor power cables, but that doesn’t affect electric field radiation. The KISS and likely most effective approach is proper cable placement. Routing the motor power cable with the dust collector hose (and cooling water/air compressor hoses?) may not be “pretty” but it would be effective and minimize repeated flexing of things that don’t like that kind of treatment.
Thanks for the lesson @gmack. As I have stated before, I am not an educated man and my understanding of electrical engineering ends at what most of you would consider a prep-school level, at best. I understand it is less than ideal, but considering my planned upgrade path it will cease to be an issue very soon as my (eventual) spindle and its cooling tubes will be routed directly upward with my dust collection tube. Like I said, not trying to be that guy, just adding my two cents as not everyone has to deal with emi/rfi issues.
@neilferreri, I live in the southeast in an area that stays plenty wet. That being said, my shop is air conditioned and heated/humidity controlled to within “normal” conditions 24/7. I run the power for my 12v lighting, computer, router, and cnc control board through a surge protector found in the link below, my dust collector is on a different circuit. I am sure someone will tell me it doesn’t make a lick of difference, and I am happy to learn why.
Please understand that none of my posts are intended as insults or criticisms. I’m only trying to share information on what I know to reciprocate somewhat for what I’m learning on this forum from others.
@CrookedWoodTex Assuming you’re not just “pulling my chain”(?) the answer is yes, there are actually two EM fields. One is produced by the arcing brushes (containing negligible orthogonal magnetic field component) and the other (containing negligible electric field component) by the current. All four field components are parallel to the cable.
Well, my confusion comes because in my previous life creating very high magnetic fields in oil drilling pipes, etc. we dumped 10’s of thousands amps of current through a very large cable to get a “circular” field within the pipe for inspection purposes. So, when we described that action of the mag field we typically used either the “right-hand” or “left-hand” rule of current within a conductor vs. mag field created around the conductor.
Thus my confusion when you suggest that the mag field generated by the router power cord wires are “parallel” to the wires that generated them.
Yup - that’s why twisting wires helps reduce magnetic field generation and pickup. The fields produced by the opposite left-hand and right-hand current flow (thumb) directions cancel each other. There are formulas and tables (and probably apps these days) to predict how much suppression is achievable based on source frequency and number of wire turns per inch. The number of turns per inch in COTS shielded twisted pair cables isn’t sufficient to provide much suppression. We used to twist our own - which, even without shielding, likely provides better suppression for HF and BLDC spindle cables than COTS shielded cables.
The fields do radiate outward from the source cable (as they do from old school radio/TV transmitting antennas), but pickup of them is strongest when the other cable (receiving antenna) is parallel and close to the source cable.
I see how my reply could have come off snarky. In all seriousness, I am grateful to guy’s like you who share their knowledge. It has helped me immensely!
In your opinion, do you think the surge protector helps with emi/rfi reduction? Or is it ultimately down to the environment in which the machine is stored and operated?
@Microwave_Monkey My limited understanding is that surge protectors are primarily intended to protect equipment from utility over-voltages that can occur when power is restored after blackouts or brownouts and/or other unexpected utility power switching transients. Even though those processes are probably handled in a much more sophisticated manner these days, SDG&E still recommends unplugging sensitive equipment when power is lost and leaving it that way until power is fully restored. I usually do that if I can and fortunately it doesn’t happen here very often. So, surge protectors are cheap insurance for that purpose. I have UPSs on all three of my desktop computers that provide both surge and power loss protection (for as long as the batteries lasts).
Providing separate circuits for your high power equipment (dust collectors, routers, arc welders, etc.) is also wise because it minimizes how much they can disturb the power to your sensitive equipment. There are specs (at least in the EU) for how much disturbance power supplies and HF spindle VFDs can conduct back onto their power lines, but who knows if the Chinese manufacturers comply. Other 220Vac VFD manufacturers have power line filters on their inputs that should comply with those specs. They often also provide it as an option on there 115Vac powered VFDs. @wb9tpg would likely be fine using a single 220V circuit and panic switch for his 800 W HF Spindle upgrade if his VFD met the EU (and/or US?) power line disturbance specs.
Drill pipe had many different wall thicknesses, alloys and harnesses, and drill hole casing can be very heavy wall with larger diameters. Imagine being able to magnetize a 16" diameter pipe to a level where it will hold a wrench on an edge.
I’ve built lots of high current equipment where the power cables were run in very close proximity to control cables as designed by engineers.
Its the changes that get noticed; not the uniform conditions.
I can see how that would require a lot of current, but it wouldn’t work if the pipe was made of a non-magnetic material - like concrete (without rebar), copper/aluminum (like cable shields), or plastic (like modern pipes?). Those materials would not have a measurable impact on the propagation or effect of your magnetic fields.
Were your excitation currents DC or AC? If AC, what frequency? What frequency (or data rate) did the engineers for the control/sensor system use?
The stock Shapeoko does not have shielded cables and appears to be prone to EMI. Maybe the cases discussed are comparing different systems with different engineering specs, different environments. I know from my telecom days that EMI can be very hard to find the root cause and re-routing cables away from electrical conduits and/or using shielded cables usually resolved the issue. Why create the potential for trouble when it can be easily avoided.
Hey,
I was going to post another topic, but came across this discussion and looks like your the guy to ask this. Last night after having problems with disconnect when resurfacing my waste board. Never had an issue for about a month now,until last night. I have a Jet Dust collection system that I run thru 4" pvc piping to different stations in my shop, which I then built an outdoor enclosure for the bags, so it goes thru my wall and outside. There was a lot of static forming around the suckit boot,and was able to verify the disconnects with the vacuum system.
So to get rid of this I would run a copper wire thru the flex tube from the end that goes into the suckit, and then thru the pvc to the blower motor? I do not have any earth grounds. What size wire? Do I do the same to the shapeoko frame? Would running a wire into just the ground prong of a receptacle suffice? Or should I run one from my breaker box ground bar? Here is a pic of the setup running on the ceiling. Had to use my cheap shop vac to get thru the resurfacing and was wearing a mask, but can feel the after effect of the dust today, don’t want to do that again!
