logo elektroda
logo elektroda
X
logo elektroda
Advanced Search
logo elektroda

Cable cutting machine

KamBys 3603 21
ADVERTISEMENT
Treść została przetłumaczona polish » english Zobacz oryginalną wersję tematu
Reply Cool? Ranking DIY | New topic
Notify about new articles
  • For my own purposes, I made a wire cutting machine to complement the electronic boards I offer for model railways. The premise was to cut the wires to a set length and quantity.

    Electronics .
    To speed up the build, instead of making a PCB I used off-the-shelf solutions: a CNC shield for an Arduino nano with two stepper motor controllers. To this attached after I2 a 16x2 display and a membrane keyboard (ready-made from Alliexpress).

    Mechanics .
    After reviewing similar solutions, I decided to feed the wire with the mechanics of an extruder from a 3D printer. As the kynar is thin and quite delicate, the drive had to be modified: the toothed roller has grinded teeth, and instead of a concave roller I put a bearing. To prevent the kynar from slipping off the rollers, I glued a truncated meat injection needle onto the input. On the exit, instead of a piece of bowden - a piece of pen nib. The last two modifications ensured stable guidance of the flexible cable.

    I carried out the cutting with scissors - a very important advantage of this solution is that after cutting you can continue with the closing movement of the pliers, unlike with typical clippers. There are Stanley clippers available, or replacement clippers that work with scissors, but I don't need to cut thicker wires, plus the scissors were easy to attach. Scissors without handles mounted in a 3D printed mount, the movable arm has a handle instead of a handle, which is articulated to a wheel attached to a stepper motor. The motor is arranged so that it can perform a full rotation freely. The whole, unlike the solution based on clippers, is not sensitive to the wear of the mechanism, its play, etc. (the scissors do not close at zero, they make a further movement, which will always eliminate tolerances, the influence of wear, etc.).
    Motor mounts from 3D print, Roller on kynar - 3D print reinforced with M3 pin. Display and keyboard in canopy 3D print, all encased in foamed PVC.

    Firmware .
    The display shows a menu where you select the variant to be cut, then the number of wires or sets per board. In the next step, the program moves the wire according to the preset length and then the stepper motor responsible for cutting performs a full rotation. The cycle repeats itself a pre-programmed number of times, and the start of the programme always begins by cutting the excess wire so that the first section is exactly the set length.
    The last menu item allows the length of the sections to be cut to be specified manually.

    What I would change .
    I would reverse the cutting motion - so that the movable arm cuts downwards rather than upwards - here I needed to eliminate the scattering of cut fragments by the canopy tray catching the tossed fragments.
    At the back of the case I would have given space for the power supply, so as to store the whole thing in a compact form.

    BOM
    Arduino Nano 10 zł
    CNC Shield 12 zł
    2x stepper motor controller 18 zł
    display 1602 with I2C expander 10 zł
    membrane keyboard 5 zł
    2x ENema17 stepper motor with cables 22 zł
    12 V power supply from demobilu
    scissors from demobilu
    M3 screws, washers, nuts from drawer
    2 sheets of foamed PVC 60 zł
    (prices from alliexpress, allegro)

    A video of how the device works:


    .

    Assembled device:
    Automated wire cutting machine with display and keypad. .

    Kynar feed drive:
    Wire cutting drive with visible extruder mechanism. .

    Cutting drive:
    View of the wire cutting mechanism with 3D printed components. Cutting drive.

    Entire mechanism:
    View of the mechanical construction of a wire cutting machine with green and red components. .

    Back of case
    Back of the wire cutting machine housing with visible electronic components.

    Cool? Ranking DIY
    Do you have a problem with Arduino? Ask question. Visit our forum Arduino.
    About Author
    KamBys
    Level 23  
    Offline 
    KamBys wrote 803 posts with rating 38, helped 32 times. Live in city tczew. Been with us since 2003 year.
  • ADVERTISEMENT
  • #2 21358432
    gulson
    System Administrator  
    Thank you for sharing an interesting design!
    Are you using the cut wires in any way more wholesale?
    Or is it more of a machine for the purpose of testing yourself and your capabilities?
    Has there been a dulling of the scissors situation yet?
    I like the offline module and the fact that it's completely independent of the computer, because now everything is connected to the computer and you have to pay extra for offline modules.
    Send me on Private Message the symbol of the Parcel Machine with the phone number, and I will send a small gift.
  • #3 21358601
    TechEkspert
    Editor  
    Very interesting! A lot of experience can be gained from such practical realisations, and in the future you can think, for example, about miniaturising solutions and increasing their durability when, after long-term use, you know which parts break down most quickly.

    With its work cycle and the sounds it generates, it reminds me of professional applicators for thermal transfer printers: https://www.elektroda.pl/rtvforum/topic4043396.html.
  • #4 21359071
    slaw0
    Level 15  
    Doesn't this feeder imprint teeth on the cable?
  • ADVERTISEMENT
  • #5 21359571
    KamBys
    Level 23  
    gulson wrote:
    Do you use the cut wires in any more wholesale way?
    Or is it more of a machine for the purpose of testing yourself and your capabilities?
    Has there already been a dulling of the scissors situation?
    .
    I cut about 100 pcs a week - the amount I use for my semi hobbyist production of electronics for models.
    This is perhaps not a prototype, but rather a one-off pilot series. As something comes out in the wash, an improved variant will be made.
    The scissors have not dulled, but the kynar is thin enough that there is little risk (up to now I have been cutting with scissors by hand anyway, out of convenience - but here the cut is always in the same place.

    slaw0 wrote:
    Doesn't this feeder imprint the serrations on the cable?
    .
    As I wrote, the sprocket has bevelled teeth, so they are not sharp and nothing is imprinted. On typical wires in "normal" insulation, even without blunting, nothing imprints.
  • #6 21360703
    michasinny
    Level 4  
    Hey.

    Super project and cool that you are sharing your knowledge with the rest of your colleagues.

    Thanks.
    Have a healthy and peaceful Christmas.

    Hi.
    Michael.
  • #7 21360744
    rb401
    Level 39  
    KamBys wrote:
    I cut about 100 pcs per week - the amount I use for my semi-hobby model electronics production
    .

    Your build is beautiful, carefully crafted and impressively worked. I like it very much.

    But somehow I don't see the practical sense of e.g. saving time or increasing production efficiency, with such a negligible load as you write.
    And there is also the issue, unfortunately, that your machine only cuts the kynar and does not, for example, strip the insulation from its ends. Which is a really important point, but also quite a technological challenge, especially with real kynar (PTFE, Kynar, tefzel, etc.).
    You can cut this hundred in ten minutes effortlessly with simpler methods. This is no problem at all. If you need thousands of pieces, using simple production aids like boards and nails is not some challenge requiring a complex machine either. So I don't have any objections to the design itself, but in the context of your application, this design, for me, is more of an art for art's sake.
    That's why I associate your project more with a modelling vibe, cool, but don't ask why practically. But I also understand that for the fun alone it was worth it. However, in terms of solving some technological problem in production, the value of the project is negligible (even more time lost in making the machine than saved in using it).

    This is how I feel, because I myself have done a lot of small batch production, where I needed to perform a few hundreds or even thousands of such simple actions a day, such as cutting wires, shirts to size, and these are only auxiliary to the main work. I experienced how important it is to choose the right tools, methods, auxiliary means, etc. in order to get the job done (and not to overdo it).

    For example, I used to cut heat shrink tubing into short lengths by the hundreds. And that's how I thought about a machine for this too, I even had the opportunity to work with such a professional machine a long time ago. And it was similar to yours from the principle of operation, because the motor pushed the shirt or cable and there were scissors. But it was a machine from the old days without a computer, i.e. mechanics alone. A stepless clutch between the feed mechanism and the scissors mechanism with a graduated knob. A mechanical counter for the number of cuts and that was it. It was fun to watch it work.
    There was also a machine for cutting kynar and stripping insulation on both sides, but I didn't get a chance to look at it.

    But in my production, the problem of the shirts ended up just with the visionless hand cutting machine. While watching the film, I had the top of the shirts cut precisely but effortlessly.
  • #8 21360822
    KamBys
    Level 23  
    rb401 wrote:
    But somehow I don't see the practical sense of e.g. saving time or increasing production efficiency, with such a light workload as you write.
    .
    Well, and I can see - as far as my case is concerned, it's quite a convenience for me, it takes me off a laborious, boring job that I simply don't like. And this is where the greatest added value lies - just like in real production - it's not only time that counts, but also the organisation of production where the worker is not assigned a sequence of tedious operations, because productivity drops. In my case, when it comes to time - production is after hours, an extra occupation, so the snapped time allows for more free time or the development of the offer.
    Let's take a more financial approach - the commitment to cutting at the moment has cut (estimate off the top of my head, but realistic) about 30 mins a week. This gives 25 h per year - the machine will amortise in under a year, including development time.
    It's also important to remember that, as with me and in real manufacturing (and I spent a dozen years working for a manufacturing company where, among other things, I managed the implementation and oversight of the production of their products), the most we gain is from a series of such inconspicuous optimisations that, over time, work like a snowball.
    Of course, I would gain much more from a pick and place machine, but here the build time is already such that I don't actually have that much time (and I prefer to enjoy peace and quiet and leisure time) to get it up and running, but maybe in time. ;) .
  • ADVERTISEMENT
  • #9 21360824
    clubber84
    Level 37  
    Hello.
    KamBys wrote:
    I accomplished the cutting with scissors
    .
    And this is where I see the first (quite serious) wear and tear in this razor - the cutting surfaces will quickly dull/chip in this one spot.
    I suggest using a guillotine-style cutting mechanism (up-and-down or right-left movement; the latter will be easier to use with the current blade drive solution) with blades adapted to the diameter of the wire, such as in the rod-cutting process in the metal industry or as in electricians' cutters.

    Regards
  • #10 21360835
    KamBys
    Level 23  
    clubber84 wrote:
    and here I see the first (quite serious) wear in this razor - the cutting surfaces quickly become dull/chipped in this one spot.
    .
    Nothing like this is occurring at the moment, and I used the scissors deliberately:
    - The kynar is thin, I don't cut anything thicker than that.
    - Typical knives for cutting in this type of machine: availability, cost, need to build your own drive - I rejected.
    - Typical cutters fall out, because they crimp and do not pass (description at the beginning), they remain this type: https://pl.aliexpress.com/item/10050061592670...ain.5.2c601c249JNaur&gatewayAdapt=glo2pol - I have, I bought, but I stayed with scissors - easy replacement, availability, etc., if there is a need to use them for thicker wires - I will use them, the drive is the same, to modify the attachment and transmission of the drive.
  • #11 21360849
    clubber84
    Level 37  
    And see, now I know you haven't explored the subject of cutting.
    I was writing about the guillotine mechanism, where nothing is clamped (it doesn't work like a sheet metal or paper cutter) just cooperates in one axis with a fit to the object being cut - that's how you cut non-plane shaped materials (round, triangular, square), not like paper/plate.

    Regards
  • #12 21360857
    KamBys
    Level 23  
    And you see, now I know that after 12 years the electrode does not fail. :D .
    I know perfectly well what you wrote about and I referred in the second dash to it.
  • #13 21360863
    clubber84
    Level 37  
    OK, in that case you used scissors because typical guillotine mechanisms were too expensive.
    But. In your scissors drive solution, a guillotine made of two stainless steel plates with a notch to match the diameter of the wire would also work - more durable, simpler and without destroying the scissors.

    By the way, congratulations on the workmanship and I'll ask some more:
    - How many prototypes were there before the final version was made?

    Regards.
  • #14 21360956
    TechEkspert
    Editor  
    Here https://www.elektroda.pl/rtvforum/topic4077229.html I have had the opportunity to test and pass on for testing wire cutting scissors, they have a serrated surface and I suspect are suitably hardened. Similar ones are used for cutting optical cables. Perhaps such equipment would have even greater durability?



    .
  • #15 21360977
    KamBys
    Level 23  
    clubber84 wrote:
    But... In your scissor drive solution, a guillotine made of two stainless steel plates with a notch to match the diameter of the wire would also work - more durable, simpler and without destroying the scissors.
    .
    I considered this, even drew the mechanism (prototypically I wanted to use blades from trapezoidal knives), but more time, complication of the system (ensuring free movement while pressing the blades against each other) led me to the current form.
    clubber84 wrote:
    By the way, congratulations on the workmanship and I'll ask some more:
    - How many prototypes were there before the final version was made?
    .
    Thanks. :)
    The prototype was not as such, but:
    - I ran the shift separately (this is where the need to use the injection needle as a guide came up).
    - There were 2 other variations of the drive ratio (length, shape).
    Then already assembled at the ready.
    TechEkspert wrote:
    Here https://www.elektroda.pl/rtvforum/topic4077229.html I had the opportunity to test and pass on for testing wire cutting scissors, they have a serrated surface and I suspect they are properly hardened.
    .
    Certainly - I have similar for cutting PCBs. This was decided by the easy availability of scissors at the Swedish market on J next door. ;) .
    A dilemma of sorts give something better, more expensive, less readily available, or accept the option of possible service. For myself I chose the second option, but if I had to give someone to service it - the first.
  • ADVERTISEMENT
  • #16 21361017
    clubber84
    Level 37  
    KamBys wrote:
    ensure free movement while pressing the blades together
    .
    With this cable cross section, the current solution (free arm on the wheel) would calmly suffice. One guillotine blade fixed, the other movable, on guides, coupled to the arm or to a scissor mechanism (as in the case of a construction boom):

    Diagram of a scissor mechanism with colorful arms. .

    Best regards and have a peaceful Christmas with your family.
  • #17 21361659
    rb401
    Level 39  
    KamBys wrote:
    Well, and I can see - as far as I'm concerned, it's quite a convenience for me, it takes me off a tedious, boring job that I just don't like.
    .

    I understand this aspect of weariness perfectly. But I still feel a serious dissonance between the number of cut episodes you write about and the reported tedium. I simply don't understand how one can get tired of cutting hundreds of kynarks into sections in repetitive groups of length and do it for as long as half an hour. Here, already in a simple approach using a little complex template and cutting by hand, if you take not one wire but pulled from several spools at once, let's say five kynars, the mountain of cut sections grows rapidly. With such quantities, this stage is a small time episode in the entire production, where later these kynars have to be processed further piece by piece. Although, for example, for stripping insulation in a group of several wires at once in one go, I have my methods and tools. Even so, for short lengths of kynar, somewhere between a few millimetres and a few centimetres, I use the technique of first stripping the insulation to size and only then cutting it into lengths.

    So I admire your determination to create this machine, but I still don't understand the problem this machine would take care of with the size of production you present.

    KamBys wrote:
    this type: https://pl.aliexpress.com/item...JNaur&gatewayAdapt=glo2pol - I have, I bought
    .

    Oh that's right. I see that somehow there has been a rash on Aliexpress of tools of this design (i.e. extractors with precisely spaced specifically shaped blades), mainly in the context of machining the ends of optical fibres. But the ones you bought look more versatile. And I have a question for you, how about the precision of manufacture and operation of the blades of the ones in the particular offer you show? Do they efficiently strip insulation from thin kynars?
  • #18 21361747
    KamBys
    Level 23  
    clubber84 wrote:
    With this cable cross-section, the current solution (free arm on a wheel) would calmly suffice. One guillotine blade fixed, the other movable, on guideways, coupled to the arm or to a scissor mechanism (as in the case of the constructional jacks):
    .
    Propulsion is not a problem, some issue (as I wrote) would be to build the mechanism so that the blades rub against each other to pick up the slack in between, while at the same time not providing much resistance to movement. Using scissors eliminates these issues, hence this decision

    rb401 wrote:
    But I still feel a serious dissonance between the amount of cutting you write about and the reported annoyance.
    .
    And very well - people are different :) It annoyed me, and building some simple gauge also takes time, and ended up the way it did. I got a bit more time, and eliminated the disliked thing.

    rb401 wrote:
    I have a question for you, how about the precision of the manufacture and operation of the blades of those in the acreage you show?
    .
    They cut, and that's about it - I haven't used them beyond a one-off test after opening the pack. I bought these as a spare, maybe if there is a more versatile design - these will allow isolation, but here the drive would have to be a servo (moving the wire front to back, closing to cut the insulation). I don't think they would be suitable for a kynar. If for my own purposes I need somewhere I either use a spearhead or scissors to pull it off. I haven't thought about automating the stripping of the kynar, there are probably some typical solutions to this problem - my first thought is to strip with, for example, a wheel with lots of teeth or (this is better) a descending knife with a stripper (it sticks out slightly below some "block"
  • #19 21361798
    jajacek44
    Level 25  
    In the manual wire preparation machine for mini-winding by O.K. Industries
    scissors were just used to cut the kynar.

    Cable cutting machine .
  • #20 21373529
    sukovenkoartem
    Level 3  
    >>21358409 >>21358409 I'll be honest, it's much more convenient to do it the traditional way.
  • #21 21383085
    KamBys
    Level 23  
    well, if you prefer to cut a few dozen cables to size by hand - then yes
  • #22 21387647
    Kiermasz
    Level 23  
    And I like this idea very much.
    There's an activity that's simply annoying and there's a technical soluuon.
    And it solves one fundamental problem of hand-cutting - there's no twiddling the guitar with the repetitive length of the wire.

    As for scissors, what's the problem? Here it's small batch production and the machine doesn't go 16h/d for the blade problem to be particularly noticeable.
    So when the time comes, we fire up the claw cutter, put on the rubber pick and simply sharpen :) .

    BTW.
    I personally hate drilling holes in PCBs. And I also solved this with a machine.
    Just a few clicks more and I get the gcode ready to machine from eagle. Just put the board in after etching, baseline and 30 minutes of life saved, comes out more evenly and there is no cleaning and no extra dust in the room :) .
Reply Cool? Ranking DIY | New topic
Notify about new articles
Report a violation of the law

Topic summary

A user designed a wire cutting machine for model railway electronics, utilizing an Arduino Nano with a CNC shield and stepper motor controllers. The machine employs a modified 3D printer extruder mechanism to feed kynar wire, featuring a toothed roller with ground teeth and a bearing to prevent slippage. The user reports cutting approximately 100 wires weekly, finding the machine reduces laborious tasks and improves efficiency. Discussions highlight the machine's design, potential wear on cutting surfaces, and suggestions for alternative cutting mechanisms, such as guillotine-style blades. The user emphasizes the convenience and time savings provided by the machine, despite some skepticism regarding its necessity for small-scale production.
Summary generated by the language model.
Popular Topics
ADVERTISEMENT