Hi Team Laser,
I don’t know who to DM to ask this so posting here instead. Curious if the rotary cable has been rewired as decided in the committee meeting. Just checking before we head up to the space this week. If there’s anything we could help with just let us know. Thanks!
Thanks. No, there is no automatic tagging. Nor do we want it.
Is this wiring re-do something anyone can do? I don’t know much about electronics but I can put things back in place if it’s just a matter of removing a wire and reconnecting some ends on a new wire.
I think you misread; I meant the manually added tag the user put in the subject line of (at)team_laser. There is nothing automatic about that.
If it is solid wire instead of stranded, it will tend to break if flexed too much/often. It should not be difficult to replace with some stranded wire if an intermittent connection is the problem.
I threw that last part in there just in case there is a way to automatically tag the team with every thread started in the category.
Edit: on reading, I see you meant whether the tag in the title did anything. I am a member of the team and I got two notifications from you, not one from the OP and one from you like I would expect.
AFAIK Discourse doesn’t allow that, but users can follow a category and automatically get notified should they choose.
I set that with Metal for example, but we also have a lower post count average than a lot of other categories.
If I remember right the plan is to remake the cable with new wires and connector. It was discussed in the recent laser committee meeting. Maybe Andrew can clarify @sixvolts
We need a new cable made. The factory ones are flimsy an keep breaking.
So the rotary is still not working at this point? Any ETA on new cable for repair?
@Team_Laser Would it be ok for me to come up today and remake this cable? I have the skills and really need the rotary this week; have the means and motivation.
I think you can just do it. I don’t know how much ‘do-ocracy’ is still alive at DMS but I’d imagine this would be fine. I don’t see how replacing a wire would break anything so if it still doesn’t work they’d just take the wire out and put in a new one.
It would be really cool if you did. I need it this week too.
I spent a couple of hours looking at all three cables that we have. All three seem to use reasonably good stranded wire. None of them have a short or open. One of them was miswired; one had an obvious broken power conductor (GND); and one has no wiring issues. See below for a full summary of what I found. I’m going to say that the absolute problem here is not the cable at all. The problem that plagues us is the round DIN connector that connects to the Thunder laser. When I was testing each of these connectors I noticed that some of the barrels on the DIN side are larger than others (i.e. loose for what should be a good diameter fit). I suspect that these connectors are not rated for 1000s of insertions; if we are lucky they are rated for 100s. It might be worth working with someone to spec a new, high insertion connector and changing it on all the lasers and the rotary attachment. I’d be happy to swap them all out if someone could help me spec a good (i.e. high dollar) AMP connector.
I’m going to use the following three names:
I would love to test the restored cables but… all the lasers have been tied up for at least a couple of hours. I would try on Donner just to see if if can get good no-cut tests but I’m not going to risk the water leak. If someone trained in laser maintenance thinks I can use Donner for this purpose, is around at the space, and doesn’t mind supervising; I could give it a try.
I had a few hours of test time on the big Thunder. I also managed one test on Blitzen with the same results. TLDR; two of the cables seem to be fine but the stepper is ignoring the direction input. We seem to have lost a third stepper. Can someone order one or ask for a warranty replacement? IST57-10
Art let me use one of the meters from the ELab. With that in hand and some fine probes, I was able to prove that the cables are delivering the pulse and direction signals to the stepper but the stepper is ignoring the direction input. This stepper has an integrated controller so the signals are 5v or 0v. The PUL signal is a square wave pulse that is normally 5v and pulses to 0v for steps. It looks like 2.5v on the DC setting when stepping because of the square wave. The DIR input is 0v for one direction and 5v for the other. The actual direction is determined by S5. This makes it relatively easy to test those signals right at the connector on the stepper. I also retested the other two old steppers. Neither of those respond to the pulse and don’t move in either direction. The one cable I would avoid is the one ziptied to the stepper. The DIN connector on that is worn out which explains some of the “only works when I bend it just right” symptoms. The stepper motor will run on command from the laser in both directions by just flipping S5, the direction switch, back and forth. All three servo motors will self test with S6 so It really seems like just the signal inputs are bad. I suspect something with the lasers is damaging these servos. The Chinese manual I found had diagrams showing the controllers optoisolated inputs. These are basically resistors in series with a LED inside a chip. I suspect, but didn’t test, that the input LEDs have failed. That really requires over voltage or static discharge. A well designed optoisolated input should not be static sensitive but who knows with these. If there is some kind of overvoltage it is the fault of the Laser.