I'm using OB Workbee, Blackbox controller and OpenBuilds Control software. No problems since I purchased in May 2020. I've used Easel and Vectric V-Carve without any issues. For the past week however, I cannot get my Z Axis to hold its place as it drops sveral mm on its own after jogging upwards. Even just the vibration of the router sets it of. I've exchanged the stepper motor with my Y axis and no change. I've checked all relevant wire connections. I' tried using the Easel and the Candle jogging features...same problem. Its like the stepper was'nt "locking or braking" in place after a raise signal. With G code loaded, it does the same thing, ruining a couple rather detailed signs I'd been working on. Any one out there with similar behaviour? Any suggestions?
I am having the same issue. Started yesterday. 01/11. The Z motor stutters when jogging. Sometimes goes up sometimes down. Not ever when I need it to do either. Switched motors no change checked connections no change unassembled and reassembed entire wire assembly, no change checked wires for contitunity, no problems swapped motor control wire positions on black box. Z for X , Press the X control and Z axis stutters Press the Z control and X works fine. Tried using a different GRBL controller and same issue. $1=255 Is this a problem at the Black box? Is there a way to reflash or reset the box to factory settinings? Thanks Jason
Ok so figured out my problem. Somewhere in 8 feet of the yellow wire for the z axis motor there is a short. After dissasembly and rechecking for continuity the yellow started showing an issue. used a jumber cable to bypass the yellow and all is working great. Will put in a warranty tag and see if I can get a new cable assembly.
sounds like a wiring issue. during use, the motors vibrate, and so does the router, so grub screws, motor mount screws etc can easily come loose, check them all. Also, wires can get dry joints causing a partial connection. since you swapped motors and the one attached to Z still does it, it is not the motor, great! so, check wires, all connections to Z, the pins on the Muscle board where Z connects, move the Z current adjuster (power off) back and forth a few times before putting it back where it was. Remember the wires flex when the machine moves, that will cause fatigue cracking at some point, look especially where the radius of flex is small. (this is why cable chains exist, they keep the flex radius large, though they do work best with wire designed for cable chains)
When you've replaced it, spend some time looking for strain points and add some strain relief to your wiring. Use Flexible Corrugated Tubing and Drag Chain Cable Carrier to make sure the cables all have generous radii, no tight bends, nothing can pull and tug on them, securely cable tied to prevent damage etc. Do all you can to prevent unnecessary strain to the cables. The store will probably replace it for you, but keep in mind the wire was fine, something happened to it - if you don't address that cause, a replacement will not last long either
I had the same problem but eventually all four wires failed. I just replaced the cable two days ago but today I had another Z failure and I am worried I have another cable failing. Did you fix your issue and if you did what did you do?
How is your wire routing, strain relief, etc. Cable breaking over and over indicates they may be put under undue stresses. Cable management (decent radii, cable tied safely out of the way, use corrugated covers and cable chains etc) protect cabling as it gets moved around a lot
After having all four wires fail with my first Z cable I used speaker wire. I had to spot tie it to the outside of the track but it still made all the turns as if it was inside the track. Never had another failure. Last week I got tired of this wire hanging on the track so I had Openbuilds customer service send me out new cables. Three days ago I replaced both the Z and the X for the X cable started to fail. I took the tracks off and opened them completely up so I could lay each cable. I made sure the cable did not overlap and was free to move within the track. I am pretty sure the cables were not stressed anywhere from the stepper to the BlackBox. I thought maybe the first failure was a defective cable for all four wires failed. But now I am seeing the same failures with the new cables so I am very concerned the problem is systemic meaning the cable design or tolerances are not adequate for the job. I run my machine two to three hours a day and I make large cutting boards so the Z cable is flexed a lot. Because this is affecting my business I cannot take the time to replace these wires and the worse part destroying bits and cutting boards. I am going to find a cable that is a larger gauge and is more flexible. I know the speaker wire worked for it never failed but it was too thick to fit in the track. I will let you know what my results are.
It may not be the cable itself, easy to assemble the terminal with wire outside the cage that lifts up when you tighten it, etc. Lots of opportunities for mistakes, a little post mortem may just prevent a repeat incident
Peter- I have had three failures with three different cables. To make sure it was the cable and not the connector I removed the connector and metered each wire end to end. The first cable that failed started getting opens. It started with the yellow wire, I bypassed the wire with speaker wire and it worked again. About an hour later the green wire opened (and destroyed a cutting board). Again I bypassed with some speaker wire and I was working again. This time I figure I would just run the machine without cutting anything. Glad I did for in less than 30 minutes the blue and red wires opened. I bypassed both with speaker wire and everything worked fine. Actually, I ran the machine for over two weeks with no failures. Last week I got my first failure with the X axis cable. It was the yellow wire and it did not completely open but must of been down to the last strain for the wire showed very high resistance when I metered it. The resistance was so high the stepper misstepped (and screwed up a cutting board that at least I could fix it). That is when I got the new cable from Openbuilds and replace both Z and X cables. After a day that is when I had the z cable fail again ( and destroy a cutting board). This time I am replacing both the z and x cables with straight highly flexible, stranded wire that is not in a cable but just wire. This way if there is a failure I can just replace the wire and not have to change a complete cable. I highly recommend that Openbuilds looks at the cables they are using. They might be OK for someone who only uses their machine a few times a month but for us that make a living with the machine and run it at least 2 to 4 hours a day, I would upgrade the x and Z cables.
Igus make great shielded continuous flex machine cable in a variety of gauges and conductors. ChainFlex control cable, I think they call it. Not cheap, couldn't realistically be included in a hobby duty machine kit like these, but not prohibitively expensive as an upgrade if you buy direct from Igus (pretty expensive through resellers!). I'm using a 16/4 line for a 2.2kW spindle, where shielding is paramount, but it doesn't hurt even on stepper cables.
Great information. Very much appreciate your help. I just tried to order the cables. They have to call me back tomorrow with a quote. They do ship same day 2nd day air so should have it later in the week. I'll get back and tell everyone how it went. Thanks to Rob Taylor I found these videos and the company Igus. I never knew that there was a company that specializes in cables for CNC and Robotics. Here is just one video I found educational -
Realized I was ordering the wrong cables. After reading the requirements I finally ordered two cables. The model is CF880-05-04, 20 gauge (they do not have a 22 gauge) with 4 wires. One 13 feet to replace the Z cable and one 7 feet to replace the X cable. My cost was $16.90 and that included 2nd day air delivery. I will give you the full review when I get them.
no mate, I don't think that is right, it should read "because this affects my business I MUST take the time to get this right and order cable chain rated cables for all axes" Yes, there are specially made cables for cable chains that have proven flexibility for years of cable chain service. Also google 'how to use cable chains' and you will find advice from cable chain manufacturers about how to place and fit the chains and cables. Do what they say, no shortcuts, then your business will not have downtime in the future. I encourage you (everyone here!) to listen to these guys Business of Machining In the last year they have addressed this sort of maintenance and reliability consideration from several angles.
LOL!!! For the kicks I googled the term 'how to use cable chains' and I got...are you ready...pages and pages on how to install snow chains on tires! Yes, thems the breaks you get when you live in Canada!
oh dear. Reminds me of the time I was reminiscing about vising the butcher with my mother when I was about 5, and the paper and hairy string they used to wrap the meat. Do NOT google 'hairy string'....ok, you will, but don't do it with your daughter looking over your shoulder....
Yep, another regular BoM listener here, of course. It's my sports- lots of yelling at the headphones/speakers. "That's already a THING, it's called ____!" I think they’re more of a general polymer development company. I have some round stock of iGlide which is like Teflon or something, that may actually be what they’re more widely known for.
