More Automated Wire Cutting

[MC] realized he had forgotten about an order for 2000 cut wires that was now due in a few days. Rather than dropping everything to complete the task, he whipped up this machine to cut the wires for him. A PIC 16F628 board drives a couple of battery-powered drill motors. One of them powers two lawnmower wheels for the feed, and the other turns a pin that squeezes the wire cutters. It’s not as advanced as the cutter/stripper from last year, but it gets the job done.

After the break you can see it does what is intended. The final product took about $80 and 12 hours of his time to build.  [MC’s] planned improvements include more accurate wire measurement, plus an LCD and button based user interface.


33 thoughts on “More Automated Wire Cutting

  1. 12 hours is 21.6 seconds / wire. Not bad if you count in the fun of building it vs tediousness of cutting the wires directly ; Not exactly a time saver but at least not a waste of time.

  2. I’d only impressed if they were stripped, bundled and labelled.

    Kidding! Kidding !

    Great job! There’s something elegantly “Golbergian” about that cutter wheel.

  3. In the Event HAD is keeping track or or counting, I liked this. Keep posting similar if you find them.

    @Chris. Evidently this job order didn’t require the wire ends to be stripped. I that he has aready built a machine that cuts and strip wire, he should build a machine that’s more adaptable wire type and job needs. When he is not rushed to meet a deadline, than gain that might me when he is more creative. I wouldn’t know. As long as he and those expecting the wire on time are happy, that’s all that matters.

  4. I would call this capital equipment, and even though he could maybe work faster by hand, now he can set it to working while he’s doing something else. It’s his robotic slave! I love it.

  5. @rallen:

    You’d be surprised how often people think that if a person can do it faster than a machine, there’s no reason to have a machine do it. Complete nonsense, since a machine can of course do it unattended. A longer job with no work on a human’s part is almost always better than a quicker job you have to pay someone to do.

  6. @tyco. That’s as maybe but it would only take an hour to manually cut that many wires. Even if it took 2 hours you have still saved 10 hours making this. I’d say it’s worth doing if it saves time in the long run. That might take a few orders to accomplish.

  7. @ tyco,

    You speak like all other companies. Yeah it is cheaper to have a bot do it, than a human. No labor costs, no medical coverage, no striking, no slacking on the job. But you also realize with every robot created to do a humans job, that is 1 less job for us.

    I understand this a automated wire-cutter and I dont know why he would hire a person just to cut wires. But I was talking about in the masses.

    Plus if it was faster in the long run to cut it by hand (Which it would of been), then he would of been $80 richer, and still have it done on time. If it took him 12 hours to build it, and you figured that into man hours for cutting the wires. That means for a 12 hour period he would of had to cut a wire every 21 sec.

    He already took the time to build the machine, why not just cut the wires now. And take the time to build a machine that can do more. He wasted 12hours of his time with this.

    Great build though.

  8. I’m impressed… So what if it’s slow, sometimes the result isn’t important… The fact is he now has his own wire cutting machine which he can look at and think “I made that!” and when he’s got a few hours he can make improvements if he feels the need…. $80 well spent!

  9. I don’t think he wasted his time at all. Next time someone orders cut wires, he’ll already have this machine ready to rock.

    Also, while it’s logically true that each robot doing a job displaces a human, it’s also true that each robot built is going to require maintenance, parts and programming. That should generate at least as many jobs as it displaces; they’ll just be more skilled jobs. I think most people would agree that the move toward a service-based economy in the Western world means fewer low-skill jobs and more high-skill jobs. Good or bad, that’s the reality. Now if only we could get kids to realize this before they drop out of school…

    And finally, on the topic: I like this simple, solid build. It’s clean and it gets the job done. Could be faster, but that’s what tweaking is for.

  10. If robots replace humans for tasks like cutting wires that’s a good thing. Think of the life times that are wasted doing mundane crap like this. If the tedious stuff was all done by robots that would only leave the fun stuff for humans to do (until they take over that is). The problem is not the machines, it’s the economics. As we invent ourselves out of mundane jobs we also have to invent economic systems that don’t rely on payinghumans to do robot’s work.

  11. Brilliant!

    If there’s an LCD screen with length options I hope there’s one option that’s simply labelled “this long” because of the amount of times I’ve been asked to make a cable with plug X on one end and plug Y on the other and the length isn’t mentioned or just “this long”…

    Hmm, maybe we (the internet collective) should try and find out what “this long” actually is in cm/inch by everyone inputting their measurement of “this long” into a simple database to find out the average.

  12. Not a waste at all… he spent 12+ hours doing something creative that he enjoyed, AND it freed him from the mindless drudgery of “measure, cut… measure, cut…, measure…”. He “spent” less than $7/hr and probably got lots of enjoyment from the puzzle. If it was JUST about the Benjamins, I would not spend ANY time doing Sudoku, surfing Hack-a-day, watching TV, etc. Cookies? There’s no profit in that! If you want to whine about putting humans out of work, then wallow in automated, self-check-out kiosks at the FoodMart, or robots in the auto industry. Heck, whine about the 25 cent sneakers that sell for $100+ AND the factories that used to employ families for generations, now out-sourced. Aw heck, just whine.

    I would like to see close-ups of the drill-to-wheel interface… from the vid, it looks like a simple friction fit. What’s controlling the rotations or measuring the length? Where’s my Captain’s Wafers?

  13. @Patrick – you hit the nail on the head.
    I tossed the idea of doing them by hand (I’ve done it before) – as I assemble custom embedded controllers for an order.
    I just didn’t look forward to sitting at a bench, for a couple of man-hours (imn reality more real-world hours!) to get the result – and as you guessed – I have it again for next time.
    Averyone’s comments are valid – I wanted to do somtehing creative other than cut wires on a cold winter weekend, and this was it.
    And yes – there are a lot of things I learned which will make the next iteration somewhat faster and more elegant!
    Cheers for the feedback, and all power to the ‘real’ hackers of the world!

    P.S. ‘This Long’ is directly proportional the length of wet string when it has dried out.

  14. I guess im pamperd. With all the automatic wire cutters at work, i dont think i need to cut a wire by hand again. Even connector crimpers….ahh automation is the life. Plus i put workers out of a job daily with automated fixtures. I kind of feel bad about it. not too much though. Because, even though a machine is automatic doesn’t mean you dont need someone to start and stop the thing. Circuit boards aren’t going to jump into the BON (bed of nails) fixtures and run there test…..

    Anyways, faster would of been nice. more voltage to the motors or different gearing maybe.

  15. I’ve been wanting to build something like this for awhile now, just keep not having time for it.

    I was planning to use a PIC to control the feed, probably using steppers, with an LCD to help the user select the wire length (1 inch or more, in .100″ increments), and select if they want one or both ends stripped (thermal stripper), with an output bin so they’re sort of bundled. I was planning something a lot smaller though, designed for 22ga AWG solid core, basically for jumper wires.

    This build might inspire me to actually get started. :)

  16. For anyone that’s going to attempt this…

    The things to look out for are :-
    – Slip between the motors and driven surfaces.
    – Slip between the tyres and the wire.
    – Sufficient torque to operate the cutters.
    – having a big enough DC supply to sustain the motor load current over a long period.

    In the next iteration, I’ll probably add a spring-loaded idler to measure the feed, and a shear type cutter (possibly double-headed to cut on both the up and down phases of the blade).
    – or go to the moving V-blade style of cutter used in pro cut & strip machines.
    … and yes – I will finish the job and put an LCD GUI on the rig. Time won out on this build!

    Hmmm – those $1500 built & tested units are starting to look pretty good!

  17. Wow-this is excellent for what it does. The surplus electronics place I worked had a half-ton machine rusting on the back dock, from a Magnavox plant in TN that was dedicated to this exact task in high speed (it cut and stripped narrow gage wire for board stuffing at high speed) this is not bad at all for something that fits on the work bench.

  18. For the next iteration you should use a disc cutter like you see on the ends of extrusion machines. Where one edge of the cutter is the wire guide and the other is a plate with N holes drilled in it that line up with the guide, then when the wire is at the appropriate length the disc rotates N/360* to cut the wire and line up the next hole.

  19. @MC

    There are motors with quadrane encoders built into them. Instead of adding another pulley that may have slop directly mount to the output of the motor.

    For your drive wheel a V groove would be best. If those wheels are solid rubber or plastic a heated razer blade will do the trick. Hold it in one position and allow the mechanism to rotate so you can concentrate on keeping it at the same position.

    You may want to consider 2 Idlers. One on the entrance and one on the exit. Mount them so that the wire will be forced to make a hump shape which should reduce slip.

    If you find you need more torque gears always help.

    The power supply is a tricky one. My projects use motorcycle batteries and car batteries but you probably want a power supply off of the mains. Only readily available / cheap supply that I can think of would be pc power supplies. Get several of them and wire them in parallel.

  20. Thanks @DRAKE – all valid suggestions

    QUAD Encoders on feed motor shaft – unfortunately does not give closed-loop feedback on what the wire is actally doing. slip etc is not accounted for.

    V-groove – already in the unit you are watching.

    2 Idlers – not sure how that can reduce slip?

    Gears always help – very true. Add cost & complexity – and reduce speed, but always worth considering to get the result.

    Power supply – I originally used a small battery bank with a constant charger – but after about 20 minutes operation the voltage began to drop to the extent that the motors labored during the heavy load periods – and of course lost some feed length (aargh!) As this was a quickie solution – instead of building feedback on the wire feed length, I simply stuffed a 7.2V 20A mains supply on the job. Problem solved – but solution noted, and next iteration will have closed loop feedback on the wire drive!

    Cheers & thanks

  21. @MC

    I use motor controllers with built in closed loop via quad or potentiometer.

    Set up parameters (eg pulse per revolution or delta resistance per revolution) then send it commands to go a set distance.

    The two pulleys would be one on each side. Same diameter but put in such a way that the wire must go down a bit then back up over the pulley then back down. This will increase the surface area the wire comes in contact with increasing the friction and decreasing the slip.

    Another thing comes to mind would be some of the non-slip material used on shelves may help.

  22. The guy is thinking too complex.

    I would have taken a piece of wood, hammered two nails into it at the specified distance, and spun the wire from the spool on the nails a hundred times.

    Then all you need is strong cutters to clip the wires all at once. You only need to repeat the process ten times because each time produces 200 pieces of wire. The whole job would have been over in less than half an hour.

  23. @Einomies: I like the way you think, but I’d also hate to see the end result. Wires would all be +/-5mm or more, and skewed end cuts… need to be re-trimmed again to length for square ends and eventually termination.
    Although a machete might be able to make cleaner cuts across the 200 pieces than hand cutters. May be worth considering instead of shear cutter blades!

  24. Is there any companies that actually make a wire cutter with an integrated microcontroller? I have been searching for so long, I need something that would attach to a gantry type positioning system. Any resources would be greatly appreciated!

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