PID -Hardware needed for a software fix

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This topic contains 463 replies, has 28 voices, and was last updated by  John 2 months, 1 week ago.

Viewing 30 posts - 301 through 330 (of 464 total)
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  • #61115

    Johnny
    Participant

    Somehow even just touching it with the negative lead of my multi meter kills the noise completely.

     

    That sir, is what is called a result! Keep up the good work.

    1 user thanked author for this post.
    #61145

    Jason Dentler
    Participant

    Somehow even just touching it with the negative lead of my multi meter kills the noise completely.

    Breakthrough! Your machines are safe, for now.

    #61147

    Ryan
    Keymaster

    Well I really like my multimeter and I’m not giving it to you guys so it’s not a good enough fix. I’ve been too busy to do any more testing yet today so that’s a bummer. Soon.

    Also looks like I am good to go with the dimmers now.

    #61148

    Jeffeb3
    Participant

    Also looks like I am good to go with the dimmers now.

    They all come with a disclaimer, “do not eat”.

    #61151

    Ryan
    Keymaster

    Pretty much.

    #61167

    Bill
    Participant

    I just had to type “oscilloscope” into Wish.com and the first one listed comes with a case for $17 plus shipping. 🙂

    #61190

    Ryan
    Keymaster

    Sweet maybe you all can teach me how to use one.

    #61194

    Geoffrey
    Participant

    I just had to type “oscilloscope” into Wish.com and the first one listed comes with a case for $17 plus shipping. ?

    Since it’s on Wish, it’ll only take 6 months to arrive, and it will be a plastic telescope.

    1 user thanked author for this post.
    #61227

    Bill
    Participant

    I’ve had pretty good luck on Wish, though I do tend to stay away from $1 Windows laptops… I’ve had a few gotchas and have always been refunded quickly.

    #61268

    Ryan
    Keymaster

    Not sure the scope was a necessity but because of it I do believe I found the issue because of it.

    Yesterday I learned what a decoupling /bypass capacitor does, it cleans up a funky power supply. Seems like I should have heard of that before. I have some caps on order, the 3 I had all work but I would like to see if it can be better.

    I swear I tried a capacitor but the guess and check method with liver current is a bit sketchy so, lesson learned, new tool earned.

    I do not know all the proper terms (yet) but it seems to reduce the noise by a factor of 10, from mV to μV. That should do it as it is on par with the better PS now….but it might get better. I am seeing that two different sizes can help each clean out some different frequencies. I do seem to have two vary different frequencies in there. I am looking for some calculators or something but I guess a 0.1μF and a 10μF together really might do the dead. I only have a 22 and 33, both work so fingers crossed.

    So as frustrating as it is I have learned a ton along this journey and I think it is worth it so far. Along that same note still fiddling with the product insurance. So the logo prototype boards should be available soon.

    #61269

    Geoffrey
    Participant

    I swear I tried a capacitor but the guess and check method with liver current is a bit sketchy so, lesson learned, new tool earned.

    Liver current… nom nom.

    #61270

    Ryan
    Keymaster

    Liver currents…the worst kind.

    #61272

    Jeffeb3
    Participant

    What about a software solution? 😉

    #61284

    Ryan
    Keymaster

    What about a software solution? ?

    Soon.

    #61348

    Ryan
    Keymaster

    Okay, it might be time for a software fix… I am getting the same issue on both power supplies.

    #61351

    Ryan
    Keymaster

    DUDE!!!

    I think I got it, I think I actually got it. Instead of filtering the High frequencies off the power…which wasn’t the problem…filter them off the signal! 0.1μF Cap on the signal to ground looks pretty good in the scope and flawless PID control!!!!!!!!!!!

    I am going to try a few different values but that should be quick.

    1 user thanked author for this post.
    #61352

    Ryan
    Keymaster

    No other caps work, I think a little smaller might even be better. This just works up to 30k I doubt it can handle higher, too smooth.

    Messing with trigger size now that I can see the actual effect…

    DS1Z_QuickPrint1
    IMG_20180609_160103
    12000 RPM (200Hz) …keeping notes, 1/60HZ=1RPM

     

    DS1Z_QuickPrint2
    IMG_20180609_160241

    #61358

    Ryan
    Keymaster

    Something fishy at high speed, smaller cap is needed I think. Need to look up some frequency charts or something.

    #61359

    Jeffeb3
    Participant

    Those plots look great! That’s an intersting idea making it smaller. I looked at mine and I can’t believe you got all that to fit. I cant wait to try it.

    #61360

    Jeffeb3
    Participant

    Did you scope the signal going to the dimmer?

    #61363

    Ryan
    Keymaster

    Did you scope the signal going to the dimmer?

    Not yet, ran to Fry’s to grab tiny caps.

    #61364

    David Walling
    Participant

    DUDE!!!

    I think I got it, I think I actually got it. Instead of filtering the High frequencies off the power…which wasn’t the problem…filter them off the signal! 0.1μF Cap on the signal to ground looks pretty good in the scope and flawless PID control!!!!!!!!!!!

    I am going to try a few different values but that should be quick.

     

    This was what I was referring to with the 5v regulator powering the LED. When you were talking about putting a capacitor on, I also thought you were referring to the output to the LED. Sorry I didn’t make that more clear or we might have figured this out a few days ago 🙁

    #61365

    Ryan
    Keymaster

    I also thought you were referring to the output to the LED. Sorry I didn’t make that more clear or we might have figured this out a few days ago ?

    No worries, I did try that as well, no go. This is a cap on the signal pin, It was a last ditch effort before I actually listened to heffe and did the software fix.

     

    Blamo, the math seems more complicated than I am willing to do on a Saturday night for frequency on caps and I didn’t see a chart. So I went for brute force. All 3 of these work all the way up to full speed and look good doing it.

    DS1Z_QuickPrint1-1
    0.0068uF

     

    DS1Z_QuickPrint2-1
    0.01uF

     

    DS1Z_QuickPrint3
    0.047uF starting to round at the bottom, too much.

     

    DS1Z_QuickPrint4
    This is the 0.047uF at ≈27000RPM. The larger cap squished the graph at full speed.

    #61372

    Jeffeb3
    Participant

    That is a sweet scope. I am now jealous…

    #61375

    Ryan
    Keymaster

    I am getting a little more familiar with it. I can see using it a little more often than I expected.

    Can’t figure out the PWM reading yet.

    #61390

    BT
    Participant

    Adding the capacitor to the signal line does make sense – I suspect the dimmer is switching between line and neutral which would create some high frequency noise on the analog common unless you filter it.

    1 user thanked author for this post.
    #61428

    Jeffeb3
    Participant

    I cannot believe all this stuff fits in there.

    1) great CAD, to make something to nearly perfect dimensions and is still easy to print.

    2) great ideas to figure out how to fit it all in there.

    IMG_20180610_130522

    #61431

    Ryan
    Keymaster

    Thanks.

    I am pretty sure we can actually mount this externally now…but I’ll try it later. As for the mark, nothing stick on, it gets too hot and they all come off. What I find really works well is a full single smooth coat of white out. This needs to be very thin and smooth or you will hit the printed part. Then color half with a sharpie or whiteboard marker, deep black. I even colored all of the shaft pocket black. this gives a nice flat matte black, real good contrast.

    Working on a PCB, sketches first, fun, never tried this before. I have done a bunch of component placement stuff but with 4+ layer board routing is not even a factor. Single layer is like building a maze. I can stick with bread board for a while longer but I really want to make a PCB on the CNC, my fun for the day. (…I really should get to the LowRider, tons of emails for parts….yikes, bad business on my part).

     

     

    #61433

    Jeffeb3
    Participant

    You can always cheat and add a wire for a 1.1 layer board. 🙂

    If you’re using your cnc, then you should challenge yourself and do a two layer. That will test your abilities. Time to make a jig!

    #61434

    Ryan
    Keymaster

    If I can get clean traces, two sided is up next for sure. Sadly it is not going to happen today, forgot I don’t have a tiny PCB drills…so proto board first I guess. If I can’t get clean traces, then break out that 0.3mm pen again, plot the traces and try some acid dripping.

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