Grayhound Skill Crane - potentiometer ratings question

[BeTheClaw.com]

Hi folks,

Does anyone know what ratings the thumbwheel pots should be on the old 2-button / 3-board Grayhound cranes? I have a modified crane, with a missing back pot. The front pot is 50k and even at max setting, the claw is a bit weak. The back pot has been replaced with a regular resistor. I'm trying to find out what rating the back pot needs to be, and whether the front 50k pot should be replaced as well.



Thanks in advance!

Allen Kevorkov
BeTheClaw.com

[lilshawn]

While I don't know about this particular machine, it looks good.

(i mean, it looks like it's supposed to.)

looks like your transformer there powers your claw...i would take a reading off that transformer then compare it to what is going out to the coil. if the output is considerably lower than the input, i'd suspect then something is amiss...likely that big old capacitor there is old and dry and it's dragging down the power.

[BeTheClaw.com]

Thanks... I actually tried getting a reading through the two white wires coming out of the plastic connector as mentioned in the manual, but it caused my whole machine to act really weird for a while, so I'm kinda scared to touch it again... 

The resistor labeled #2 is actually supposed to be a another thumbwheel potentiometer. Someone replaced it with a resistor, so it's no longer adjustable. I was just wondering what rating another pot would have to be if I replaced that resistor with another thumbwheel pot.  Not sure if I really need to do this, but it would be a nice to have an option to adjust it.

While I don't know about this particular machine, it looks good.

(i mean, it looks like it's supposed to.)

looks like your transformer there powers your claw...i would take a reading off that transformer then compare it to what is going out to the coil. if the output is considerably lower than the input, i'd suspect then something is amiss...likely that big old capacitor there is old and dry and it's dragging down the power.

[lilshawn]

well if that resistor is grey/red/orange it's 82k

if it's too weak, i'm pretty sure its supposed to be another 50k pot.

[BeTheClaw.com]

Good to know.. thanks! 

well if that resistor is grey/red/orange it's 82k

if it's too weak, i'm pretty sure its supposed to be another 50k pot.

[lilshawn]

to be sure, i'd have to see the backside of the board and see how everything is connected. you have a MOSFET there, so there is a possibility it's being used as a PWM switch to regulate the power output.

not the best way of doing it, but i suppose it works.

the modern equivelent is using a pot hooked to regulate the speed of a 555 timer. the 555 switches a transistor or MOSFET to regulate the claw strength via what is called "duty cycle". faster pulse means more power slower pulses means a weaker pull.

[BeTheClaw.com]

lilshawn,

Thanks for the info. I actually spoke with one of the Grayhound techs and he's sending me a replacement board with both original pots.

[lilshawn]

cool, glad you got sorted out.

be sure to post an update here with maybe a photo of the new board for prosperity's sake. nothing worse than finding a thread on a problem you have and they guy is all like "nevermind i fixed it" 

[BeTheClaw.com]

lol.. I hear ya. Actually, I misunderstood. He sent me the missing pot, rather than the whole board. However, looking at my board, it seems to be somehow different. If there was a pot in place of my current fixed resistor, there should've been 3 holes in the board, but there's only two. And there is another resistor soldered on the back of the board. So I'm not sure how exactly to go about soldering on the pot he sent me. I have asked for a quote on a new board. It might be easier just to swap it out rather than try to mess with this one and keep it as a spare. Here's my board...

Front


Back

[Metalman1661]

Looks like a replacement board might be the best way.

Can you let us know who you contacted regarding these Grayhound Skill Cranes?

[BeTheClaw.com]

Scott Holland is the son of Bob Holland, founder of Grayhound Electronics. He worked as a tech for Grayhound / United for many years and after the company closed, they asked him to continue running a service / repair shop for all their cranes, dating back to the old 3-board Grayhounds. I found him to be very nice, helpful, and generous, and would recommend to anyone who needs help with Grayhound, Talon, United, and a few other brands of cranes that were manufactured and/or supported by United. You can find his contact information at www.aslex.net. 

[Metalman1661]

Great, thanks for the info.

Question... did your Grayhound work before you investigated this fixed resistor problem?

[BeTheClaw.com]

Great, thanks for the info.

Question... did your Grayhound work before you investigated this fixed resistor problem?

Yes, it was fine, except the claw was weaker than I would've liked. I suspect that's due to the 2nd resistor being fixed and rated higher, so the claw wasn't getting as much juice as the original pot would've allowed.

[Metalman1661]

OK, gotcha.

Could you post pictures of your other boards in your machine for reference?

Also can you take pictures of your coin door and the wiring associated for reference?

Is your Grayhound the joystick or button type machine?

[BeTheClaw.com]

Sure.  It's button type, but I'm pretty sure it can be rewired for joystick and operation can be selected via dip switches.

[Metalman1661]

Any news on those pictures?

Your machine should have means for wiring it up for a joystick configuration. Definitely something worth doing.

Also im sure you already know this but I'm having trouble myself with my Grayhound Crane and I want to verify the wiring is correct. I am 99% sure it is but I just want to check it against a working machine.

Also I contacted Scott Holland and he provided me with some guidance. Do you know if he has replacement boards available for these machines?

Thanks for the help.

[BeTheClaw.com]

Any news on those pictures?

Your machine should have means for wiring it up for a joystick configuration. Definitely something worth doing.

Also im sure you already know this but I'm having trouble myself with my Grayhound Crane and I want to verify the wiring is correct. I am 99% sure it is but I just want to check it against a working machine.

Also I contacted Scott Holland and he provided me with some guidance. Do you know if he has replacement boards available for these machines?

Thanks for the help.

Sorry about that. Here are the pictures:

http://www.betheclaw.com/images/grayhound/wiring/1.jpg
http://www.betheclaw.com/images/grayhound/wiring/2.jpg
http://www.betheclaw.com/images/grayhound/wiring/3.jpg
http://www.betheclaw.com/images/grayhound/wiring/4.jpg
http://www.betheclaw.com/images/grayhound/wiring/5.jpg
http://www.betheclaw.com/images/grayhound/wiring/6.jpg
http://www.betheclaw.com/images/grayhound/wiring/7.jpg

Let me know if you need anything else. I'm glad you were able to talk to Scott. He seems like a genuinely nice man and very knowledgeable about these machines. Yes, he does have replacement boards and you may even be able to swap 3 boards with a single newer one (not the cheapest option, but I'm considering it).

I'll look into the joystick wiring option, although on this particular crane, the front door opens right above the button panel, so if there was a joystick sticking out the top, I wouldn't be able to open the door to access the play field. I'd have to figure something out about that. Maybe wiring 2 additional buttons for left and back, and a drop claw button instead of a joystick is a better option.

Allen K

[Metalman1661]

Great, thanks for the pictures.

My CPU board does not have sockets like yours does for the IC chips. That is a nice feature. I'm at the point now of changing all the IC's since I don't know what is wrong with my unit. I fear the actual programmed ROM has gone bad but I have no way of checking it against a working board. I purchased a full set of replacement IC chips including the Z80A CPU chip but don't really know which (if any) IC's are bad. We will see what happens when they get here.

The only IC's that are socketed on my board are the CPU and ROM chips. I will swap out the CPU chip when I get it to see if that fixes the problem. Its worth a shot. Bottom line is I would really need a working spare CPU board to test against. Just for reference below is what I am experiencing with my cabinet:

---> Power on, top fluorescent lights turn on, LCD 'plays' and 'time' panel goes to '00'. Crane does not home. Coin lockout switch and coin return light do not activate. Coin switch and dollar bill acceptor do not add credits. No revision codes show on startup and no error codes are being shown. Knowing this it doesn’t seem like the program is starting up.

Scott hasn’t responded to me in some days now so I do not know if he can actually send me a spare working CPU board to test things out. I guess we will have to wait and see.

The joystick hitting the front door would definitely be a problem. My door comes within millimeters of the joystick  but I guess that is the way they designed it. installing two more buttons and a third for the claw would be a solution. I can take pictures of my setup and share them with you. Maybe they will spark an idea.

Regarding this single board setup you mentioned. Do you know the exact make and model? Also will it work in a machine like ours?

Thanks again for the help.

[BeTheClaw.com]

Scott hasn’t responded to me in some days now so I do not know if he can actually send me a spare working CPU board to test things out. I guess we will have to wait and see.

Scott does respond to emails, but not every day. I talked to him on the phone as well. He said newer single boards from United Texitle cranes are apparently compatible with Grayhound. They are obviously used and run about $150 or thereabouts. A costlier option is an advanced microprocessor board from Jernie.com - those are $300 and take about a month to get. That would have very fancy features with payout percentages, sound, etc.

[Metalman1661]

OK I will wait and see what he says when he responds to my email. I may even call him just to get pricing on a couple options.

If I have no other option I may go with a new single board but we will see. I am still very determined to get this machine back up and running with its original parts haha.

Also to get back to the original topic of this thread, did u get your unit working properly? Where are you at with it?

[BeTheClaw.com]

Also to get back to the original topic of this thread, did u get your unit working properly? Where are you at with it?

I'm kinda in the same boat... waiting to hear from Scott, although I haven't quite decided if I want to replace just the claw board, all 3 with one newer board, or all three with the fancy Jernie one (not that I necessarily have money to blow). Having a single board would be nice, since that would give me 2 working sets for troubleshooting purposes. I'll let you know how it plays out. Please update us when you hear from Scott as well.

[Metalman1661]

I received this machine for free since it is pretty beat up and needs a lot of cosmetic work to get it looking back to how it originally was so I don’t plan on spending too much money on this to get it working. I just want to get what I have working but replacement boards will be the easiest option as it seems.

Did Scott quote you a price on replacement Grayhound boards?

Also as far as the crane power board with the fixed resister, he sent you a replacement 50K resistor right? there’s no way install this resister to your board?

[BeTheClaw.com]

Did Scott quote you a price on replacement Grayhound boards?

Also as far as the crane power board with the fixed resister, he sent you a replacement 50K resistor right? there’s no way install this resister to your board?

I believe he said replacement claw board is about $50 (used). There probably is a way to install it, but it seems that resistor wasn't the only thing modified on that board, and solder points are different, so just soldering the resistor on the board may short / fry something. I'd rather not take any chances. I could always mail the board to him, but in the end it may be cheaper just to buy another board and keep this one as a spare.

[Metalman1661]

O wow $50 is much more expensive then I was anticipating.

I can take a picture of the bottom of my board so you can see where the solder point go to and maybe you can rig it up so it will work.

Ill post that pic later when I get a chance to work on it again.

[BeTheClaw.com]

Actually, yes, if you wouldn't mind showing the bottom of the smaller claw board - that would be great. He might be willing to work out a deal with you if you have to replace it... maybe take yours as trade, not really sure. Worth asking.

Thanks!

[Metalman1661]

Here are the pictures.

I think if you attach the two outside leads of the variable resistor into the circuit where those fixed resistors are then connect the middle lead to either one of the outside leads it should be fine.

[BeTheClaw.com]

Thanks so much... I will take a look later tonight and see if I can make sense out of it. I'm a little worried I may mess it up, but maybe it's not too bad.

[BeTheClaw.com]

Here are the pictures.

I think if you attach the two outside leads of the variable resistor into the circuit where those fixed resistors are then connect the middle lead to either one of the outside leads it should be fine.

Oh boy... I compared the boards - maybe I'm a little unsavvy in the PCB department, but I couldn't make any sense out of this whatsoever. Looks like a bunch of stuff needs to be moved around and even new holes made in the board, and I seem to be missing one resistor that you have on your board. I think I'm just going to get another board from Scott... that way I don't risk messing something up.

[ed12]

hi
btw thats called a buck board
the 2 post's set a current b power
if your look's nothing like that ? then do not mess with it

ed

[Metalman1661]

So what's the deal betheclaw.com? Are you just gonna go with a replacement board from
Scott?

If so how much is he gonna charge you?

[BeTheClaw.com]

So what's the deal betheclaw.com? Are you just gonna go with a replacement board from
Scott?

If so how much is he gonna charge you?

I think it would make more sense to buy one complete board. Considering that as it is right now, everything works, for the most part, I don't desperately need to replace my existing board (although it would be nice to have more flexibility as far as claw strength is concerned). However, getting a single board would allow me to set aside the existing set of boards for a rainy day. I'm not in a big rush right now, but I will probably call him on Monday to get a quote.

The only issue I have right now is occasionally, the claw does not return to the left. Last night, after it started doing this, I put it in self-test mode and it worked perfectly, and was fine after that. I'm having trouble figuring out if it's a bad connection issue, or a relay acting up... it's intermittent and not frequent enough to affect play, but seems the easiest way to help isolate the issue is to replace all boards with one.

[Metalman1661]

Hmm sounds like a decent plan. I would do the same but I just want to get this thing running as is to see if it is worth fixing up.

Regarding the crane not moving left... I read in other threads that the intermittent crane not moving left can be caused from broken wires in the harness on the bridge. You can hook up a button that triggers left on the joystick for testing purposes and change the machine to joystick control. Then put it in self test and press left and move the wires around in the carriage and see if it breaks the connection. Or use a multimeter to test continuity.

It's worth a shot but takes a little more effort. I just want to get my crane working period haha. Well see what Scott says when/if he responds. Also keep in mind Monday is a holiday so he might not be working.

[BeTheClaw.com]

Oh yeah... I keep forgetting. Thanks, although he may not necessarily take a day off.

As for testing the left movement .. the only thing that makes me suspect a board / relay issue is that it immediately stopped after a self test. Almost like it reset itself. A wiring issue is likely to be less intermittent, I would think. But replacing the boards would help troubleshoot this.

P.s. I am also looking to get a set of larger claw fingers. I currently have fingers from the jewelry crane found in Sugarloaf machines at Walmarts, but would like to be able to use larger prizes. Will call Rainbow on Tuesday.

[Metalman1661]

True. It's worth a shot thought and it's fairly simple to test. You could eliminate the harness being the problem too.

I'm in the same boat, really need a spare board to test against.

Yeh larger claws would be good. What will those run you?

[BeTheClaw.com]

Yeh larger claws would be good. What will those run you?

Not cheap, I assure you... lol.  The jewelry claw fingers I have right now I bought from another manufacturer (ICE) and they cost me about $50 (well worth it for me). They don't offer the type of larger claw fingers I'm interested in, so I'll need to check with Rainbow. Hopefully not more than that, but very likely. I can always pick something up cheaper on Ebay, but I been keeping an eye on it and haven't come across anything in a while. There's a set of black fingers for $20, but they're not the kind I want. I make videos for hundreds of crane fans on YouTube showing people how to win stuff, etc.. make a little money on ads from Google, so I think it'll be worth the expense to allow me use larger plush (and for personal practice / entertainment as well).

[Metalman1661]

Definitely true.

Let us know is any testing was helpful with trying to solve the not going left issue.

Also have you tried to trace out the pics of my board I posted? You can definitely solder a variable resistor in there. Any luck?

[BeTheClaw.com]

Definitely true.

Let us know is any testing was helpful with trying to solve the not going left issue.

Also have you tried to trace out the pics of my board I posted? You can definitely solder a variable resistor in there. Any luck?

I did try, but it seems more modified / different from yours so I couldn't make much sense out of it...

[lilshawn]

pics

[BeTheClaw.com]

Thanks, I do have those diagrams, but I don't know what the symbols mean and since the board's soldering points have been modified on the back, I have no clue whar connects to what.

[BeTheClaw.com]

So what's the deal betheclaw.com? Are you just gonna go with a replacement board from
Scott?

If so how much is he gonna charge you?

It's not a huge priority right now, so I think I'm going to wait and see if he responds to me. I just bought a couple of new sets of claw fingers from Rainbow, so I can use larger plush in my machine, so that'll keep me entertained for a little while. I need to sell a couple of things before I spend more money