Happy Birthday, Son. Here’s Your Very Own Claw Machine

mrclawIf [Will Baden] is in the running for Father of the Year, he’s a shoe-in. His son requested a robot-themed birthday party, so [Will] did what any superhero father would do and built him a toy claw machine.

[Will] harvested many of the parts from copy machines: both the 5V and 24V power supplies, the limit switches, 2/3 of the motors, and the 24V solenoid coil in the claw. The carriage is from a commercial printer. He made many of the mounts, including the ones holding the 3 stepper motors from Pololu.

A PIC16F870 is running the show. [Will] programmed it in assembly using Timer2 for stepper pulsing and RB0 interrupt to drop the claw when the button is pushed. He also added a WDT to get out of code trouble if needed. The claw’s solenoid is driven by a ULN2001A Darlington array. [Will] put a kickback diode on the coil so the pulses don’t go farther than they need to. He formed the fingers of the claw by bending pieces of brake line.

Not your kind of claw? Check out these incredible Wolverine claws!

[Thanks, Will]

32 thoughts on “Happy Birthday, Son. Here’s Your Very Own Claw Machine

  1. Wow. Pic and assembly? Going old school there. Great build very smooth on the motion and the claw has trouble grabbing toys just like the real thing (sorry, couldn’t resist).

    Kristina, have we considered doing the “Hack-a-day awards” at the end of the year? We could track the coolest projects and post a recap in December. I nominate this one for the “Hack-a-day ‘My dad is geekier than your dad!'” category.

        1. You shouldn’t bother. They have a computer controlling them, specifically the power going to the claw. There’s a counter, and only 1 out of X times does the claw actually maintain power on it’s way to the chute. So only 1 out of X goes can possibly win, skill or not. X is a number you set on the machine’s control panel.

          So what I’m saying is, skill doesn’t matter, they’re a total scam, and yes it DID drop your prize on purpose! But in such a cleverly engineered way as to leave some room for doubt in your mind.

          1. A year or so ago, I was talking to a man maintaining a claw and other vending machines at Wal-Mart. In the conversation he mentioned that in order to get the Wal-Mart concession they have to guarantee a certain [number/percentage] of “wins” on the machines and get audited to make sure those goals are happening.

      1. I wonder how many others are thinking future 3D printer parts?
        I was also thinking what IF you could make a freehand printer out of it later.
        ” Silly Sand” for a medium perhaps?
        ah but the pesky problem of grit in Everything, eh.
        What about Modeling Clay?
        Heat & squirt it like the plastic stock.
        Or if Legos didn’t need the assembly force
        You could use it like a Pick-n-Place unit
        How about stacking blocks?
        Is there any use in working with kids in a “therapeutic”
        Forgive me for sort of spit-balling here,
        But this thing and other peoples comments
        just gave my brain a nudge.
        i guess that’s why I keep reading things here.

        1. Repurpose, I will :) I am going through multiple ideas of what I will convert this into when the birthday party is over. Now only to convince my son that those ideas would be cooler than a claw machine. . .

    1. Bne, I wish I could of found a gutted claw machine. But I could not locate one at a reasonable price. The majority of the cost is in the clear panels and aluminum angle. . . the other parts are from scrap/extras box and just needed some imagination to utilize.

  2. I recognize that PSU unit! It’s from an old xerox copier right? I remember trying to use one of those damn things for one of my projects and the voltage regulator blew up in my face :(

      1. i have 3 printer carriages and a box of motors, as well as about 15 linear shafts of different sizes from an old copy machine. since this doesn’t need the precision of a CNC, i figure the steppers might be overkill. the joystick could send temporary power to the DC motors already connected to the printer carriages to move them little by little before it falls. my 3d printer should be able to handle the claws and anything else needed to keep it together. then it’s really just powering it, controlling it, and enclosing it.

          1. a build log of the printer or claw machine? i haven’t started anything with the claw machine other than look through some parts last night. i don’t think i have much posted about the printer, nothing recent at least.

            i wonder what else you could re-purpose to make scoops.. maybe cut some triangles out of old milk gallon bottles and use zip ties to secure them to the brake line fingers?

          2. Are you having problems with the claw, or just don’t like how it looks? You could use metal coathangers, wood, or all sorts of tech scrap to make a stronger one. If it’s just a cosmetic issue, I think it looks good as it is.

          3. Using a scoop style claw would let us put smaller prizes (candy) inside. I might convert it to that style yet. Maybe create different claws for different prizes. . . hmm yet some more ideas to repurpose. Hackaday’s community is going to be bad influence on me. :)

          4. Repurposing a “lift-crane scoop”(i dont like the wording but a google search seems to imply that it is acceptable english) or something similiar from a toy truck/crane/tractor/etc could be the way to go (either the grabber or scooper model could work i think, either have their individual charm. the hook (with a intriquate pulley system is probably overkill and would require the ‘gift’ to have a hole of some kind))

            If you have kids of that age then you likely have a few broken toys that might fit the description.

            In case i am not being entirely clear:
            Grabber: http://images-en.busytrade.com/19366000/motor-hydraulic-dual-scoop-grabs.jpg
            Scooper: http://images.stockfreeimages.com/603/sfi/free_6030769.jpg
            hook: http://us.123rf.com/400wm/400/400/kokandr/kokandr1205/kokandr120500108/13767534-lifting-tap-with-lifted-by-dart-mobile-heavy-lifting-crane.jpg

            But I see no problems with it as it is. I love those things myself but rarely use them
            (due to to cost/benefit. Might aswell buy a softtoy while the kids arent looking, then claim you won it – that way you get the right one and dont have to spend hours arguing that the one the kid really wants is _impossible_ to get :-) But popping a few coins in for the the fun, accepting it as a loss upfront can be fun occasionally.

  3. Great job. I found this looking for inspiration for an overhead gantry crane for my sons whole room. The terminology is claw for what it is now and grapple(like grappling hook) bucket for candy or aggregate product. I just rebuilt from top to bottom an orange peel grappler for work, have to be precise so all the arms aligned at the same length snd time. So mabay find a hard rubber ball(racket or squash) and cut triangle shaped segments, then flatten the brake line claws at even intervals for pop-rivets or whatever hardware suits your fancy.

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