Tuesday, 28 June 2011

Quiet week?

Well, no such thing as a quiet week really, but given we are not running the training course (not enough people booked) I actually have a clear diary for a change. Well, apart from a couple of conference calls.

Anyway, new logging stuff on firebricks seems to be going well. More to do, but this means that we are doing the last of the things the FB105 did which was web view and emailed logs. Probably going to make a factory release later this week.

Bandwidth on the broadband is going pretty well since we put a huge amount extra on the 21CN links. We coped with Wimbledon with no problems, which is good. I suspect we need to look at adjusting the GB per unit for evenings on 21CN in September though as evening traffic is getting disproportionate now. We'll see how that goes.

This morning I just got some new fireworks stepper motor controllers to try in the 3D printer. Lets hope I have the logic right now. I think I may take the afternoon off and have a play...

I have been pondering making proper electronics for the 3D printer and am trying to work out if we can make that commercially viable (selling the controller boards). Whilst this is all a bit of fun, obviously I needs to make money at the end of the day somehow.


  1. What can I say - it is looking a bit like my X stepper motor may be the issue now. The controllers are *NOT* catching fire now. I am 99% sure I know what to do now. Do not power 24V when steppers enabled. Simples.

    But a new X stepper motor?!?!

    And then, in the middle of lots of testing, the heat bed goes cold. I think the relay fried. FFS why me

    I can see why hobby electronics makes Kev cringe and it is starting to sound sensible to make proper electronics for this real soon!

  2. OMG! The problem all along for like the last week has been a loose grub screw on the belt drive on the X stepper.

    I have done all sorts to make it work with fuck all torque.

    So finally, X axis working. Hot bed died - but that was loose wire, so fine.

    Ready to go.

    And WTF - X axis stepper controller catches fire. Why why why?

    I have one spare.

  3. Why why why...

    I have put the Y controller in the X slot and put the spare in the Y controller.

    I carefully ensure the steppers were not enabled and connected 14V

    The then enabled the steppers

    The Y controller caught fire.

    I have no spares

    This is so fucking close.
    I don't know what to say.

  4. OK, of the old controllers that had not caught fire, I have tried three now, in the Y controller slot, and every single one has caught fire. quite impressively.

  5. The X, Z and E are all fine.
    How the hell does this happen.

    Once again, one more fucking thing.

  6. I tell you what makes no sense.

    All afternoon the stepper controllers have been fine - not even getting hot. No problem. The issue with X slipping has been there and I have tried all sorts to fix that.

    Then I find the cause - loose grub screw on the spindle on the X axis - yay!

    And then, steppers catching fire, not one but like 4 of them in a row.

    What makes no sense is the timing.

    The fixed grub screw cannot have any impact at all. And for 3 of the 4 controllers that caught fire it was not even on the same stepper, so no impact at all.

    So why fail just after I find the last remaining problem? Why?

    Why not before?

    Why not later when I have printed some stuff?

    Why the hell do the steppers start catching fire EXACTLY the very moment that I tighten a loose grub screw? Just to guarantee I still do not print any sensible ABS 3D stuff.


  7. Some theory on back EMF from me moving the stepper to work out why there was no torque may explain the timing. Either that or this shapercube is cursed.

    Well, we shall see - I have ten (yes ten!) stepper controllers on order at £10 each. I have a spare arduino controller board just in case. I'll have the camera focused on the board when I power up as it is quite impressive.

    This is all turning me in to an expert though I suppose.

    Tomorrow is the day I print something straight, from pink ABS!

    [P.S. I was congratualted on making a gay DALEK the other day ?!?]

  8. The world is awash with stepper motor controller/drivers - it seems most unlikely to me that you'll make a unique contibribution by designing yet another one.

    Are you sure none of the motor wiring's shorting to ground? I'd have thought that's a particular risk in home-made-moving-stuff-that-gets-hot. But a 10 quid motor controller's bound to be pretty fragile, I suppose.

  9. I think it's time to start diagnosing this electrically, not just swapping and hoping!

    Can you identify the route of the current that's causing the fry-ups? If so, bung a current-limiting resistor in there (a high-wattage one!) and measure the voltage across it. If you have a storage oscilloscope, that would do nicely! Then you can see what's happening without letting any more magic smoke out.

    If I had a storage 'scope I'd offer to help, but I haven't and I'm on the wrong side of the Pond at the moment anyway.


  10. To be honest it is a long long string of things and I am becoming the expert. It is amazing how many stumbling blocks there are. Some are just things I did not know and were not part of the kit (hot bed) and there are a lot of ways of doing it. Some are things that are bad in the design. The electronics are not ideal, and could be a lot better, so that means lots of things catch me out. Things like grub screws getting loose - well what can I say.

    What annoys the hell out of me is I have had this many weeks and on one afternoon I could print stuff, in PLA, and that was it. All the rest has been battling the latest "one more thing before it works right".

    I really do feel that it had no more to throw at me now.

    I'd like it to work whenever I want, for ABS and PLA, and just be a usable resource and fun. I can cope with the occasional tweak or niggle, but being all problem and no fun is, well, not fun.

    I bet there are people that would like some well made "bullet proof" electronics for a 3D printer and would pay for it.

    The stepper stuff is probably designed just well enough to work mostly. When I said on irc I fried 3 stepper controllers the comment was not "OMG that should not happen", it was "well that is more than I have". It is kind of telling.

    Watch this [3D] space.