Hardware needed for a software fix

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This topic contains 26 replies, has 9 voices, and was last updated by  Dui, ni shuo de dui 1 month ago.

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  • #45352

    Ryan
    Keymaster

    So I use a speed control on both my machines and whenever chatter got nasty I would just move the speed a bit, with either my $20 660 controller or the speed control on the 611.

    Seeing AvE bust out this little hack made me realize what the heck was happening.

    So know we really need the PID speed controller so we can add in a non stable RPM so we can cut faster. Any EE’s out there have some ideas for the mains power control? The controller (arduino?) side will be easy, I think.

    2 users thanked author for this post.
    #45359

    Johnny
    Participant

    Its times like these I wish I had taken more meaningful classes in college.

    #45376

    Bill
    Participant

    Do you really need PID speed control, which is designed to keep speeds constant in the face of changing conditions? Or instead do you want speed control without PID, which would allow you to make small incremental changes at any time without the lag a PID is going to provide? If the goal is to provide a stable bit rotation speed, whether we’re in air, cutting a straight line or cutting corners or curves, then you want PID. If you want to reduce bit chatter then you want speed control without a PID, which seems like it’d be much easier to implement.

    #45378

    Ryan
    Keymaster

    Both.

    I want PID first and foremost, but with the ability to vary that constant speed at the push of a button or programmed in when needed within a very specific range. I vary the speed on almost every single cut I do, it does really work.

    Once we have control over the speed than we can really push the limits. This I think is by far the most lacking part of all small form factor cnc’s. We have no way to control chip load without it, so we play the guess and check game as we cut.

    The part I don’t understand is almost all the components I think go into this are super cheap.

    #45382

    David Walling
    Participant
    So I use a speed control on both my machines and whenever chatter got nasty I would just move the speed a bit, with either my $20 660 controller or the speed control on the 611. Seeing AvE bust out this little hack made me realize what the heck was happening. So know we really need the PID speed controller so we can add in a non stable RPM so we can cut faster. Any EE’s out there have some ideas for the mains power control? The controller (arduino?) side will be easy, I think.

    <iframe src=”https://www.youtube.com/embed/po5VUW3I8P8?feature=oembed&amp;wmode=opaque” name=”fitvid0″ width=”300″ height=”150″ frameborder=”0″ allowfullscreen=”allowfullscreen” data-mce-fragment=”1″></iframe>

     

    Yeah… switch to a brushless motor and use a real speed controller.

    #45383

    Ryan
    Keymaster

    That gets pricey real fast, that’s no fun.

    #45384

    Johnny
    Participant

    Ryan, out of curiosity what are you using for speed control on the 660?

    #45386

    Bill
    Participant

    So to run a PID on speed of the DW660 you have to have feedback that provides spindle speed. I see that as being a reflective tag on something spinning, like perhaps the collet nut? You then read that to feed it back to your PID. How would we mount the sensor? I have a little hand held tach, but I don’t have a way to pull that back out to an external PID.

    #45387

    Why not to use one of this sensor that we are using in 3d printers. Proximity sensor plus some Arduino. I don’t know how is with Your 660 or 661 but probably you can find way to connect it to it and read puls. that will be the cheapest solution I guess;P I have few sensors of that type so I will try to make something.

    #45395

    Ryan
    Keymaster
    Ryan, out of curiosity what are you using for speed control on the 660?

    I have this one and the one in the first link, depends on which machine, https://www.vicious1.com/speed-control/

     

    Bill, You can either place the optical sensor at the top of the dewalt or on the collet nut with a dab of white paint or some come with a reflective sticker. There are a few places to put the sensor, and actually a few ready made solutions out there but I am not happy with the price or the setup really. One of our members was working on it and even had boards made but then disappeared. I have seen a few solutions that are close and open source. I have actually emailed a few and asked for higher amp ratings but no reply. I will try to modify one but since I am not an EE I won’t sell them as I don’t want to be responsible for wrecking things. There are actually a few that just need to have a slightly higher amp rating in the $30 range that I will try to modify soon.

    Krzysztof, The rpms are so high I am fairly certain optical is the only way to detect it. I don’t know if a hall effect sensor can do 30k+. Wish I would have taken more EE classes. No better time to learn than now.

     

    #45431

    David Walling
    Participant

    Send the link to one of the $30 ones you’re looking at. If I have the time I might pick one up and help.

    #45438

    Ryan
    Keymaster

    I have this one coming, I think it is correct.

    https://www.tindie.com/products/bugrovs2012/pwm-ac-light-dimmer-module-50hz-60hz-/?pt=full_prod_search

    It says 5A so that is the 660 I believe, but hopefully a slightly bigger heat sink will work if the current one has issues. But I think at higher speeds it should be fine. The 611 needs to have the speed control bypassed I think. If this does work programming in soft start and different speeds should be easy enough. I have a handful of arduino micros and a few other tiny arduino’s, I have some optical sensors but should probably get the proper ones.

    I am hopeful but this is a long shot as far as I am concerned. Just having the ability to control an AC motor to me is the largest hurdle the rest seems fun.

     

    #45483

    Jeffeb3
    Participant

    I wonder if there’s a place higher in the dw660 where you could paint a shaft, drill the hole in the side for the led and light sensor. I don’t like messing near the collet.

    That light dimmer looks like a good fit.

    For sanity, would you build this as a separate Arduino? I think stuffing it into the ramps or Rambo would be a pain. But being able to set the speed in cam would be nice. Maybe the second Arduino would be a slave to the Marlin board. It could read ppm from a servo port.

    #45487

    thesfreader
    Participant
    Maybe the second Arduino would be a slave to the Marlin board. It could read ppm from a servo port.

    Or via I2C if a finer resolution is needed

    #45488

    Ryan
    Keymaster

    In my head I see it as separate, like the super pid but cheaper and tweak able. Get the desired rpm from the control board. After seeing AvE’s video putting on a button that will vary that rpm by 50-100, or whatever it may need,from the preset rpm. To get fancy a screen and a knob or some buttons for total rpm control.

    #46175

    Johnny
    Participant

    I think Ryan is trying to get me fired from work. Good thing I dont use the company computer often to look things up. I go to buy the speed controller he mentions above at Amazon and what do I see? “Customers who have bought this have also bought” and there is a picture of a big ol life like womans happy helper. Not exactly safe for work. Hahaha. Nice try Ryan, but not today!

    #46176

    Ryan
    Keymaster

    [email protected]!!! wtf is a “drildo”?

    Whatever “power tool” that is there are more of them buying speed controllers than MPCNC users are….and I sell a lot of MPCNC’s. I guess I need a new link, dang.

    #46180

    Jeffeb3
    Participant

    If you worked in the sex industry, it would be safe for work… *mind blown*

    #46191

    Barry
    Participant

    Damn, missed it.  I did a search for that part on amazon and just got a bunch of other speed controller boards on the “other customers bought” links.  Figured for sure I’d get something weird, I have a friend that does app security testing on IOT adult toys so I get linked to them on amazon every now and then.  Did you know there’s one with a freaking camera in it!!  That’s one POV I never really want to see.

    #46192

    Barry
    Participant
    If you worked in the sex industry, it would be safe for work… *mind blown*

    We had to go back to a client site to turn off the porn filter setting on their new firewall we installed.  Didn’t know this web design company did porn sites.  They were kind of pissed they couldn’t get to their sites!

    #46193

    Ryan
    Keymaster

    Oh dam, that’s too funny.

    The last place I worked we had a military project going and the industrial designers were having a hell of a time doing research, our firewall wouldn’t allow “gun” or “bullet” to come through. Too Strict. So they worked from there phones for a lot of it.

    #46222

    David Walling
    Participant

    My company blocks all the gun related stuff too. I guess it’s part of being owned by a company based out of California.

    They also ‘don’t allow’ guns in the office even though there’s no 30-06 or 30-07 signs on the door.

    #46229

    Johnny
    Participant

    Our company made sure to put up the 30.06 and 30.07 the very moment they could. We arent even supposed to carry pocket knives.

    #46356

    Ryan
    Keymaster

    Okay, it’s here. I hope to plug it in this weekend and see if I can melt it or at least make it bleed magic smoke. If not then hopefully we can do some cool stuff! I am soooo close to finished with a new set of MP3DP parts so hopefully I can wrap that up and cut the new parts with this little beast. Super clean, looks quality, fingers crossed.

     

    #46367

    Jeffeb3
    Participant

    Don’t touch it!

    New MP3DP parts? Way to bury the lead.

    #46371

    Ryan
    Keymaster

    It is tortuously slow going on the printer parts. Very subtle changes. I have been doing little things on it for months. Every time I try to do a major change I realize why I did it the way I originally did in the first place…Right now I am working on a new extruder mount, maybe move the XZ end stops, then that wraps it up. It isn’t very different but I couldn’t bring myself to build more of the same ones.

    #46380

    I’ve built something similar a while ago in order to control the speed of my DIY air purifier. I guess it would be the same principle here.

    Basically, you need to sense the zero crossings of the mains power, analyze it with an arduino and send it back to a triac. Then you can control the speed using PWM and program some speed variations in your code if you want.

    I made a schematics here and there are some explanations. Sorry, it’s all in French:

    https://www.bonjourchine.com/threads/purificateur-dair-filtre-hepa-a-pas-cher-en-diy.108474/page-8#post-524216

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