2019-11-28

Shit week (or two)

Some times things go wrong, it happens, but if I did not know better I would say some deity was out to get me the last couple of weeks!

  • My 3D printer started playing up, but in a subtle way. It was printing some parts slightly too narrow, which is crazy. I spent ages on this as the lid of a case did not fit on the base properly. They are a tight fit, but this was just too tight and meant it cracked the edge of the lid. I adjusted tolerances in the design, printed loads of tests, and finally the lid fitted the base just, but no idea why.
  • I then put the lid on the widget I was making which has an OLED display. This is glass, and has a very thin bit at the edge. Well, the lid is carefully designed to leave a small amount of space around this, but it printed wrong didn't it! So fitting it cracked the display.
  • So I had to remove the display from the base board, and it is fitted with square pins which are a bugger to desolder, so I cut them. But the cutting caused the pins to tilt enough to rip the tracks off the main board. So I had to make a new main board.
  • The 3D printing got worse, now it was clearly squashing the design at a particular point, but only some of the time!
  • It turns out it would print sensibly to start and then get worse, but also a small print would be fine (it broke as specific points on the X axis) all of which caused confusion as I would think I had found the cause (e.g. the X axis rails were slightly skewed) because a small test print (after tinkering) would seem to have fixed it.
  • I tried all sorts, and eventually ordered a new stepper motor. The one from Amazon was wrong current, so did not work, but I found that the original stepper motor was actually slipping on the flat edge of the spindle, only at certain points and only when it warmed up. All this, wasting nearly a whole week, because of a loose grub screw. Oddly Lulzbot totally failed to answer support emails (apart from a e-ticket number) which is really bad of them.

  • So, re-installed original stepper motor, tightened, applied thread lock, and bingo, working perfectly again, phew. Back in business.
  • I then tried to mill a new board on my milling machine. I have done a lot of these, and I am using a simple bed-levelling program I wrote to measure the corners and adjust the cut over the board to allow fine tracks to be reliably printed. But this one new board (which was bigger than previous ones, and has some long straight cuts) was not cutting correctly - turns out I had a bug in my code that got the Z level wrong (was for previous point not current point) causing some tracks to cut at wrong depth. Just enough to not show up most of the time, but create duff boards several times.
  • So I was improving the code, and making it probe several times for each point and more slowly, and so on....
  • And just then the main milling motor on my milling machine stopped working. It would spin up slowly and then grind to a halt.
  • I tried on a bench supply and it is fine, so clearly the power supply not the motor.
  • I ordered a 48V 3A power supply, and that was not beefy enough to run it.
  • I ordered a nice 10A bench supply, which I am waiting for now - will it work - I'll add a PS to this post later today :-)
  • In the mean time, with 3D printing working, I had managed to make one working PCB, so made a case for the latest widget and it did not fit. For some reason I had made a silly mistake in measuring the parts, which took my about 6 attempts (at over an hour per print) to get right - this is crazy.
  • However, the slightly wrong print (due to design, not printer, this time) meant the button cell battery holder moved, pulling tracks off the board, shorting it, and that took me ages to debug as the GPS refused to work with no backup battery.
  • I set up the Quectel M95 mobile module, and surprise surprise all of the commands I need are different to the SIM800 module I was using. Arrrg! Thankfully they have a good manual. So new GPS tracker working well.
  • Then something else stopped working on the board - I don't know what yet - I need to use my magnifying glasses to work on this board, and guess what, they just snapped.
  • And in the middle of this, other issues, involving someone having unexpected hospital visits (which have turned out fine, phew).
It has been a shitty couple of weeks really.
It can only get better :-)

P.S. And not the plastic cover thing on end of my glasses has come off so I stabbed myself putting them on.

P.P.S. the cheapest, unbranded, iffy looking DC power supply I have seen, from Amazon... Actually has a CE mark, but not sure I'll ever leave it unattended. But it works - yay!

4 comments:

  1. I've gone through times like this with my printers!

    I think Lulzbot had a significant staff reduction in October, it might explain why they are slow to respond.

    ReplyDelete
  2. https://hackaday.com/2019/11/12/the-past-present-and-uncertain-future-of-lulzbot/

    ReplyDelete
  3. Be careful with the CE mark, there is a China Export mark that many places use that happens (coincidentally I'm sure) to look just like the certification mark.

    ReplyDelete
  4. In one week last month one of my ADSL routers died of sheer old age (thankfully I have two), I blew up my backup firewall through accidentally plugging the wrong PSU into it, and someone rammed a car into my front garden wall, demolishing it, and buggered off without so much as a sorry.

    Some weeks are weeks like that. (Though this one was definitely karmic payback for getting a lovely gadget.)

    ReplyDelete

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