Advice wanted: Bryans Gapwin screws & spring

[spanky]

Right, received a replacement pay cup from jingle, but am having trouble fitting it. I can't quite get all four screws in. I can't work out why, it's as if there's a tolarance problem.

As you can see, the screws aren't Pozidriv. In fact, they're really bolts, on the other side are square nuts.

Are these suitable screws? Are they original? Should I replace them with something else?

Question 2. The spring at the very bottom, responsible for firing the ball, has been overstretched and therefore its action is quite feeble. This often prevents the ball from being launched.

Are replacement springs available, if so has anyone got one? If not, should I get obtain one of a similar length?

[pennymachines]

The (round or square) coin cups on Bryans allwins are held in place with unslotted, dome headed, chromed coach bolts.

Yes, sounds like you need a new spring of the original length and gauge. Never used them but Ashfield Springs of Nottingham stock a range: https://www.ashfield-springs.com/shop/e ... ngs-3-10mm

[spanky]

Thanks, that all sounds very sensible.

However, coach bolts I have seen have a square bit behind the head to prevent them spinning. How does that work regarding the holes in the pay cup? Sorry for being thick.

[JC]

You're not being thick. From memory, I don't recall seeing coach bolts used with the later square (or rather, rectangular) cups. I think they were normally slotted pad-head machine screws, but would no doubt vary from machine to machine - example, the cross-headed screws on your machine look to be original.

[widget2k4]

I thought they all had these in them?

[JC]

No doubt some did, as I said, they will vary depending on the machine and maker.
The point I was making is that I don't recall ever seeing coach bolts (widget, your picture is of a machine screw, not a coach bolt).

[pennymachines]

The coach bolts were used on the round payout cup surrounds, which had square holes in them. The rectangular cups, with round screw holes, were used post-decimal when Mr Bryan could no longer source the round cups (or they were too pricey). Generally they avoided screw heads on the fronts of games (or filled and painted them) so as not to tempt naughty boys with screwdrivers.

[widget2k4]

All my square cups have four of those bolts in with no slot in to turn so couldn't be unscrewed. Never came across one yet with crosshead screws like the picture.

[spanky]

Hmm

Bit baffled now.

[pennymachines]

OK, so ideally you want Whitworth thread, unslotted, chromed, roundhead machine screws (similar to Widget's pic) of a gauge to fit though the holes, plus lock washers and nuts to match. I've cheated in the past by using easily obtained zink plated or stainless roundhead slotted machine screws, melting silver braze into the slots and buffing to a high shine.

[brigham]

Jamiesons also used those slotless machine screws. They're a pain in the neck to undo.
It seems the original hole in the wood was left slightly under-size, and gripped the screw while you tightened the nut.
You can sometimes get in with a junior hacksaw, to cut a slot in the inner end of the bolt. If you grip the exposed thread, you often flatten it, and the nut won't come over the flat bit.
I wonder what the original purpose of these screws was? Who would make a fastener with no provision to fasten it?

[pennymachines]

As I said, they were supposed to be hard to remove, at least from the front, to prevent kids nicking the payout cup.