Knob strength on hardware

Discussion in 'MASCHINE Area' started by ashleyisas hamed, Mar 10, 2019.

  1. BigPictureSound

    BigPictureSound NI Product Owner

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    I saw someone replace one on an Electron, I am guessing they are also soldered on four points in the MK3. I called in to the company I got it from today, and I am thankfully still covered by NI's warranty until September, and AMS for another year. It would be cool if the next iteration of the Maschine has Pots you can easily snap out, like on the OP1.
     
  2. D-One

    D-One Moderator Moderator

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    Not me. I read in a djtechtools thread that the solder used requires higher temps than normal to desolver/remove that kind of scared me since I only have basic soldering skills.

    I think all recent NI hardware uses the same encoders so I opened my M32 to see if there's any serial, 0B20K 8J2 ... not much luck other than confirming it is 20k, 4 Pins +2 side pins (which are connected to something, so it's not just to hold it in place, disregard this statement if its something stupid to say lol)


    [​IMG]

    [​IMG]
     

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  3. RobLo

    RobLo NI Product Owner

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    I'm assuming they use lead-free which is a pain to resolder...but since they are still thru hole encoders it's less of a risk. I've lifted pads and vias before but usually on cheaply fabbed pcb's
     
  4. René must be Unique

    René must be Unique NI Product Owner

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    A trick that is widely used is the following.
    First solder the component that you want to remove with lead-containing solder.
    After this you can remove the component with a lower temperature.

    René
     
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  5. CPAF

    CPAF NI Product Owner

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    such an annoyance yeah - i had my MK3 sent in, and they replaced the whole board where the potentiometers are on. But, you know, a couple of days later I already felt the same two knobs giving in, and getting loose.

    It is such a shame! I also have very different resistance on my KKs61 mk2 --> as far as I've seen on the forums and elsewhere it is quite a common problem, I think NI really should look into this! I love the hardware otherwise! :)
     
  6. D-One

    D-One Moderator Moderator

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    This is exactly why I dont send in mine, it's completely useless if the pots are replaced with the same model... not to mention ill be a while without my controller and have to deal with the hassle of shipping it.
     
  7. D-One

    D-One Moderator Moderator

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    Well, the topic is the different "strength" encoders, having it repaired by NI won't fix that.
    If they fail completely then sending it to warranty will fix that specific problem and therefore is the wise course of action, even if out of warranty it will probably be cheaper, faster and less of a hassle than experimenting with encoders we arent 100% sure will work.
     
  8. Drachenkatze

    Drachenkatze NI Product Owner

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    351
    I haven't read the thread completely, but I have seen that there were several mentions of encoders.

    On the MK1, they weren't encoders but rather endless pots. I assume from the pictures it's the same thing with MK3. These endless pots are a PITA to source, but luckily I was sent replacement ones for my MK1 9 years back by NI. I don't think they'll do it these days :(

    If they're pots and not encoders, you just measure the resistance. However, without a datasheet you'd actually have to figure out the pin assignments.
     
  9. Michael Arthur Holloway

    Michael Arthur Holloway NI Product Owner

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    129
    Two of my encoders on my Mk3 have far less resistance than all the others. From reading this forum (both this thread and others) I've gathered this is a very, very common situation. It's the most annoying thing about the hardware, which otherwise I think was put together very nicely. The two knobs aren't broken, they work fine for changing parameter values, recording automation, etc, it just *feels* annoying that they have such light resistance and move so fast compared to the other ones, which all provide a 'normal' (to my feeling, anyway) sense of resistance.
     
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  10. D-One

    D-One Moderator Moderator

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    In my little eletronics knowledge: A regular potentiometer is finite, meaning it has an endpoint in both sides whether its a knob or a fader, an "endless potentiometer" is an encoder.

    The models prior to MK3 dont have the "strength issue", maybe because they aren't as specialized and arent "touch capacitative", you find them more easily out there... mcp-stuff.com sells them.

    They are confirmed to be 20k so what would you want to measure? Physical size?
     
    Last edited: Jun 21, 2019
  11. Drachenkatze

    Drachenkatze NI Product Owner

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    351
    tl;dr: Endless (or 360°) potentiometers = analog, encoders = digital

    Verbose:
    An encoder is typically a mechanical switch in a rotary form, it encodes movement into a set of pulses, hence encoder. Other types include magnetic and optical encoders, but these are mostly used in conjunction with motors and rarely found as input devices.

    Incremental encoders are the ones found on most electronics devices (that's where the typical indents come from). The huge advantage and the reason for their popularity is that you don't need an ADC as opposed to an endless potentiometer. Digital inputs are enough and one could use microcontroller interrupts to free up clock cycles to do other things.

    Here's a diagram of how the pulses look like:
    [​IMG]
    The disadvantage is that you'd need to implement velocity control in software, and some poor software implementations of reading the encoder causes the values to go backwards if you turn an encoder too fast. Also it's not possible to determinate the absolute position of an encoder, whereas with endless (or 360°) potentiometers you always have a known value at a certain position.

    There are also encoders which support absolute positions, but I have never seen them used in any electronics device as an input control and I'm not even sure if they exist in a potentiometer-like form.

    When I took apart my Maschine MK1, I was surprised to find an endless pot and until today I'm still a bit puzzled on the decision making process why to use an endless potentiometer in that application.
     
    Last edited: Jun 21, 2019
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  12. D-One

    D-One Moderator Moderator

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    Ohh. I had it all wrong then, thanks.
    So, it is most likely an analog endless pot but there's no guarantee, correct? I am wondering if it's worth connecting the pins from the board to an Arduino to read the values and confirm it. I wouldn't mind doing it if helps somehow track finding a working replacement model.
     
  13. Drachenkatze

    Drachenkatze NI Product Owner

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    351
    Well the photo in the thread above looks very much like the spare one I was sent by NI many years back.

    B20K is also a giveaway that it's a potentiometer: B usually means linear and 20K is the resistance code. But I just remembered that there was something interesting in the way the resistance worked, let me pull the spare out and do some measurements. Maybe I can provide some additional clues.
     
  14. D-One

    D-One Moderator Moderator

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    Ohh cool, thanks! Yours is red instead of green, like this one right?
    https://www.mpcstuff.com/native-instruments-maschine-rotary-pot-used/
     
  15. Drachenkatze

    Drachenkatze NI Product Owner

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    No, it's green and is manufactured by Alpha. I entered the part into my database on Jun 30 2011, but I think I received the part well before that date. I'm also about to void the warranty sticker on my MK3 :p I'm curious if they implemented the touch feature using the same pot.
     
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  16. Drachenkatze

    Drachenkatze NI Product Owner

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    I can confirm that they're still using the pots in the MK3, however, they don't seem to be from Alpha anymore.
     
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  17. BigPictureSound

    BigPictureSound NI Product Owner

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    180
    This is exactly how I feel! I recently contacted support to replace my less than a year old unit with loose knobs and one of the conditions stated that “if they are unable to repair they will send me a “factory re-furbished” (used) unit as a replacement. I never buy refurbished gear as it is usually just a quick visual inspection, and frankly I found the offer less than desirable.

    My unit is in mint condition and it seems likely it will be impossible to get back a unit of similar condition, and especially with all 8 knobs behaving flawlessly.
     
  18. Drachenkatze

    Drachenkatze NI Product Owner

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    351
    I'm wondering: Are the pots getting harder to turn or the other way around?

    I haven't noticed this yet, so I have to ask. If they're becoming harder to turn, maybe some dust got into them, at least that's the only conclusion I come to at the moment. As a very last cause of action prior replacing them you can try contact cleaner, but to be honest you can get very mixed results from working flawlessly to making it worse.

    If they become easier to turn, maybe the wipers inside the pot have worn out. In that case I can only recommend a replacement. Opening the pot is a delicate process.

    I'm currently working on a Maschine MK3 teardown video. I hope I feel confident to actually upload it to YouTube, but if I do, it'll contain quite some info on how to replace the pots.
     
  19. BigPictureSound

    BigPictureSound NI Product Owner

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    180
    For myself, the pots are getting easier to turn with slight wobble on X and Y axis. Mostly noticeable on the far right knob used to cycle between presets. I’ve started using the 3D knob for this to lessen the wear.
     
  20. D-One

    D-One Moderator Moderator

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    Yeah.. It gets lighter and easier to turn over time. Oddly enough the looser one i have is from a knob i dont use very often at all (4th), it pretty much has zero friction/resistance (not sure whats the appropriate term)
    Opening a pot sounds like a nightmare.