12V electrical connectors - replacing lost screws.

[Phil-B259]

Hi, anyone got a solution to replacing the tiny screws in the lego 12V / 4.5V connectors to hold the wires? I have several connectors with pins but no screws!

I'm thinking some small grub screws like the type linked to bellow might work but am not sure what size would be best as its not clear exactly what size screw Lego used though I understand from Bricklink they might be 3.2mm long.

 

M1.6 M2 M2.5 M3 M4 M5 A2 Stainless Grub Screws Cup Point Hex Socket Set Screw | eBay

 

 

[LEGO Train 12 Volts]

I'm very curious to know if there is a solution ... I too find myself with a series of lost screws 

[supertruper1988]

What I do is take the part I need a screw for and head on over to the local hardware store and check the various sizes they have. Usually a range of screw types in many sizes can be bought from the bolt bins for pennies. if they dont have exactly what you are after then at least you will know the size and thread pitch. 

[Toastie]

@LEGO Train 12 Volts and @Phil-B259,

do you have any of these screws? If so, take a good resolution photograph, with some calibration device visible (ruler ...). Then zoom in and guess length, diameter and pitch. Well, this is what I would do.

A caliper helps as well ...

Best
Thorsten

[Phil-B259]

Yes, I do have a few complete 12v connectors (but not a caliper) and should be able to work out the key dimensions.

However it seemed a sensible idea to ask on here too - as I can't believe I am the only person who has lost them over the years given how tiny they are and how easy it is for them to become lose.

[Jeroen vW]

Well i also have some connectors and a caliper :). It seems to me they are M2 with a tap of 3 mm. I tested it with a set of small screws i have. I used M2 length 4 mm (the black one) and they work perfectly.

So the scrub screws you suggested should work too. Just pick M2 with a length of 3 or 4 mm.

Another observation i have is, that the connectors (the metal part) are very similar to the miniature bananaplugs of 2,6 mm.

Like these: https://eshop.microrama.eu/en/test-benches/400-2-6-mm-male-banana-plug-set-of-6.html  Maybe they could be used to replace a missing inner connector.

 

Kind regards

Jeroen

 

 

[Toastie]

1 hour ago, Jeroen vW said:

It seems to me they are M2 with a tap of 3 mm.

That sounds good! Was about to say yesterday (and then decided not to) - the 12V train stuff was a rather European made line, wasn't it? I forgot. But if so: Europeans like the M-line of screws ...

For all of you really wanting to dig deep on what "M2" means and never dared to ask: https://en.wikipedia.org/wiki/ISO_metric_screw_thread

With regard to the M2 screws sitting inside that miniature banana plug: Here's all about that: https://asset.re-in.de/add/160267/c1/-/de/000730572DS01/DA_Kahlert-Licht-Miniatur-Bananenstecker-Stecker-gerade-Stift-2.6mm-Schwarz.pdf

It is in bloody German though ... it says they are of size M 2x3. It also says the plugs have a diameter of 2.8 mm within the document and 2.6 mm when you order it (https://www.voelkner.de/products/89270/Kahlert-Licht-Miniatur-Bananenstecker-Stecker-gerade-Stift-2.6mm-Schwarz.html?ref=43&utm_source=google&utm_medium=organic&utm_campaign=fpla&gclid=Cj0KCQjwkIGKBhCxARIsAINMioI0u_brbc-gqWwd6EgUmJOM08yRSZ3V5FbhRRZki50nbipSRPl66RAaAgfBEALw_wcB). I believe the sockets don't care that much about the 0.2 mm.

And there are about 100k other companies selling these, I believe.

Happy reading!

Best
Thorsten

 

[LEGO Train 12 Volts]

Wow @Jeroen vW and @Toastie this is simple precise and effective! 

How did I not start from a measurement with the caliper?

[Andy Glascott]

8 hours ago, Toastie said:

That sounds good! Was about to say yesterday (and then decided not to) - the 12V train stuff was a rather European made line, wasn't it? I forgot. But if so: Europeans like the M-line of screws ...

12v may indeed have been a European thing but this European brought a significant amount to the US when he moved  and then bought up most of the straight 12v track that was available on Bricklink at the time….. 

So far I haven’t lost enough of those pesky screws to need to replace them, but that day will come….

[Toastie]

37 minutes ago, Andy Glascott said:

So far I haven’t lost enough of those pesky screws to need to replace them, but that day will come

and then you simply order all the M2x3 screws available on this side of the pond - and even go bananas on the plugs no, wait, I meant order the banana plugs.

Good to know all these details - 12V for ever.

Best
Thorsten 

 

[Paperinik77pk]

I found some years ago some good plugs that could be used for replacing Lego ones (at least internally to train and buildings) so to keep the good original ones for external connections (e.g. points, signals...).

These were brown an were very similar to blue plugs of the blue era and fitted the 4,5v battery perfectly. 

I think I've still some of them in the basement. If I succeed to find them again,  I'll post a photo. I've never found them again nor online or in any shop.