Roto-Pool, Roto-Fruit, Rotolite, Electrodart, Bingola, etc.

[youngerap]

I showed this thread to my eldest son, who just happens to be an electrical engineer for one of our beloved utility companies. "See why I don't have any of these electrickery machines?", I asked. This is simply a foreign language to me except that, unlike communicating in a foreign land, shouting does not help. "This Operator Bell chap clearly served his time, Dad. And you are just a big girl". Nice.

[operator bell]

This Operator Bell chap clearly served his time, Dad.

I take that as a huge compliment

[slotsoffun]

I was wondering if I could do away with the electronic type thing, and maybe install a small motor with a cam fitted that turns to ring the bell then provides the power to the payout relay? Just an idea!!! Would look so much more interesting seeing something half mechanical controlling the bell and relay, rather than a solid state type device!
Just trying to thing of any way of doing the same, without these unreliable little bimetal switches!

Otherwise, I'll admit defeat and just ask the question... How do I connect the wires if I just remove both thermal switches, and live without the bell!!!!!

[slotalot]

one reason the bell/delay circuit is there, is to allow you time to look at the light display and see what you have won before the display steps on to the next position as the coin slide operates.
I have in the past managed to rewire the heater coil on the thermal units, but it is a VERY fiddly job to do..

[slotsoffun]

Slotalot, I think I may attempt what you did and fix the thermal thing... I've taken it apart, but just wondered if.. When I wind the thin wire around the bi metal strip does there have to be a certain number of winds? Also is it critical about the thickness of wire I use?

thanks

[slotalot]

Slotalot, I think I may attempt what you did and fix the thermal thing... I've taken it apart, but just wondered if.. When I wind the thin wire around the bi metal strip does there have to be a certain number of winds? Also is it critical about the thickness of wire I use?

thanks

What you need is Nichrome resistance wire and some heat proof tape for insulation, I cant remember the wire size of hand, just that it was as fine as a human hair..
I will have a look in the workshop tomorrow as I know I had some left over whether I can find it is an other story..

[slotalot]

OK, I have managed to find some nichrome wire & heatproof tape that should do the job,
Next question ? Are you going to Coventry ??

[operator bell]

slotalot, do you happen to know what wire gauge (thickness) your nichrome is? When these coils are switched into circuit they get 40-50 volts across them, so they need a respectable resistance, probably at least 1000 ohms. I have no idea what the resistance of the original coil was - perhaps somebody with an intact device could measure one, though you'd have to disconnect it from the circuit to measure it. Here's a table of resistance per foot for various gauges of nichrome -

If your wire thickness isn't in the table you can work it out - the resistance per foot doubles every three AWG numbers. So for 48AWG for example, go back by threes until you hit the table - 39AWG is three steps of 3 - then take that resistance and go forward again by threes doubling the resistance at each step. It's about 425 ohms/foot. I take it the wire is bare, not varnished, so the turns must not touch or they'll short out.

[slotalot]

slotalot, do you happen to know what wire gauge (thickness) your nichrome is? When these coils are switched into circuit they get 40-50 volts across them, so they need a respectable resistance, probably at least 1000 ohms. I have no idea what the resistance of the original coil was - perhaps somebody with an intact device could measure one, though you'd have to disconnect it from the circuit to measure it.

This why these "overload" units fail so fast, they were only ever made to run on 12 volts, they were designed as indicator flashers for cars, the resistance of these units is only 43 ohms when cold,
the wire I have is 42 SWG nichrome, it is not covered with any thing, and is a sod to wind without shorting the coils out, and you need a steady hand, patience and good eye sight all of which are failing in my case..

[slotsoffun]

After taking apart the thermal switch, I've decided to put it on hold for the moment. These things are so fiddly, what with my sausage like fingers and eyes refusing to focus close up now I'm in my 50s!!!
However, I picked up a cabinet without bits inside for free, and turns out the components I have are from a Roto-Fruit, but looks the same as the Roto Pool. Have started placing parts inside. Will post a picture once completed.
The machine works perfect, bell rings and pays out correctly.
Thanks for all help received from here.