Crane Grabber Machine

[markymark]

Hi Guys,
Yes my son has discovered the joy of these amusement grabber type machines. We all know the type I'm on about, where the operator fixes the torque of the claws so even on a perfect clutch of a cuddly toy the thing drops it before it gets to the dispenser!!!!

But having looked on the web these are expensive £300 - £400 for ex-arcade machines. So unless one of the members on this forum know a bloke down the pub who knows a bloke at work who knows someone who is closing down an arcade and wants to get rid of some cranky old non working rusty grabber machine, mechanical or electronic, then let me know... In the meantime, I'll maybe consider building one!!!!!!!!

Does anyone know if instructions exist or if anyone has some pictures of how the claw works. Not being an electrical engineer, I guess I'll have to make the grabber/claw mechanical, like the old fashioned Meccano toy cranes from the 70s!
Any offers of pointing me in the right direction would be great.
Thanks.

[slotalot]

Does anyone know if instructions exist or if anyone has some pictures of how the claw works.

This is a photo of a Bryans mechanical claw, it will give you some idea of how it works. You pull string "A" to close the claw, and you pull strings "B" to let it open. I hope this helps??? There are full plans for a crane in the pennymachines archive. Good luck with your project.
Crane grab 1
Crane grab 2
Crane grab 3

[andydotp]

From memory I seem to recall that one of the three claws is set to Not Grab, ie it just limply falls down to appear as if it does and that's why most prizes fall out.
Simple, clever and the players would never guess!
Right old bunch of scoundrels machine designers weren't (aren't) they!
a dot p.

[markymark]

Thanks for the picture. I think I got it now. Just ordered some electric motors, and the joystick and buttons. Next... the wood, the paint, the glass, and not forgetting the fluffy cuddly toys. This is gonna be a long long project... not forgetting the wiring, which I don't have a clue at this stage. Any more help appreciated.

Oh, and why is it when you look to buy something there's never any for sale, but when you're not interested in buying, the whole world seems to be selling grabber machines... Bah!!!!!!!!

[slotalot]

A bit more info here
http://www.patentgenius.com/patent/7080840.html

http://www.twobits.com/craneins.pdf

http://www.instructables.com/id/Build-a-big-crane-game/

[badpenny]

Hey markymark .............

How many grabbers do you need, I've just checked eBay and if you ignore the toy ones there are currently 7 on offer

Own up chap - you just want to build one don't you?
Best of luck and keep us informed won't you?
By the way, you say you've ordered the motors, what are they? and where from?

Regards,
Badpenny

[markymark]

lol... yes but have you seen the prices... OK I admit if it was a one arm bandit I'd happily spend triple on it.. however, I know what my son is like, after a few weeks he'll be bored with it and on to something else, like Nurf Guns!!!!
Besides one thing that scares me about buying one of these modern machines (apart from the fact he wants it in his bedroom.. you guys can just picture me trying to push one of those grabbers up a flight of stairs!!! - and once in there he won't be able to move, its the size of a box room!! Bless Him!!).

But going back to my worry, these things are all circuit boards and chips.. if something goes wrong, how can I fix it, or locate a dealer with spares... Give me a good old fashioned mechanical device anyday.. cogs, chains, springs and linkages!

In answer to your question... yes I probably will build one, as I've now got that "bug" of trying to achieve a simpler version. The motors (I bought 3) are for model racing cars because they have a high torque so should be able to pull and grab things. I also ordered a joystick (from ebay). Want to keep the wiring down to a minimum. Just in the process of working out a simple method of moving the grabber back and forth, left to right.
Oh and the main reason.. gonna make it a table top size and slightly smaller than commercial ones. No doubt, by the time Im finished building it my boy would have moved on to something else.. so keep watching ebay, it'll probably end up there..

[badpenny]

Buy him the Nerf Gun and let him acquire his own funds to buy a Grabber.

[markymark]

Now there's an idea!!!