M-F jumpers for PCB pins

I have some G-scale model train locomotives. I want to use some wires to make a test setup to go between the “decoders” and the “baseboards”.

The decoders have pins about 1mm diameter that go into sockets on the baseboard. These pins are slightly wider that the normal Arduino breadboard pins, which seem to be about 0.7mm diameter. In any case, the F sockets from the Arduino kits are too small to accept the pins and the M pins are loose in the sockets.

I found the following on this site that look very similar to the pins on the board:

Can someone recommend some M-F jumper wires that are compatible with pins & sockets based around this size pin?


Hi Andrew, Welcome to the Forum!

This is a tricky one. I don’t have an immediate suggestion from our range. While you could buy a bunch of crimped connectors of different sizes and with a lot of luck, have one work, I’d say a better option would be to identify the connectors on your board. Without more info about them, I’d say this guide may be a good first point to check:

After that, attaching a photo to a forum post of the two devices you’re looking to connect will get us a lot closer to recommending some appropriate parts for you.

The pins you linked are designed to be soldered into a PCB, so your end goal may just be to design a simple PCB to act as your adapter. Let me know if this appeals to you, as I’ve gone down this path before and can share the basics.



Hi Andrew,

Welcome :smiley:

I have a few options that spring to mind

Another good question is, how much current will be flowing through the connections? If its only say a signal (<20 mA) then you should be able to get started with some alligator clips and we can figure out the connector while you figure out your setup.

You could also grab some of the pins, solder some jumper wire to one end and go from there.

Sacrificing a couple jumper wires might be a quick and easy route to get some readings. You can see from this close up that there isnt anything that will stop the crimp connector being bent open.

These connectors live inside most if not all of the square jumpers, might be worth a shot!



Hi Andrew, is it a Loksound?

I just searched for Arduino socket in Amazon (US site), and came up with this one.

Check the third image with specs. On the bottom left is the size of the holes of the female to female (socket to socket) connector board for Arduino. Looks like it might fit (1.02mm). Attached the image, don’t know if it can be zoomed here, can zoom on Amazon though.


Actually, it’s an old LGB 55020/55021 interface. You can see a compatible card here: Massoth eMotion L. Note the 10 pins sticking up out of the PCB - that’s the interface I’m trying to patch into. Matching sockets exist on the locomotive board for the pins to slide into.

Input is up to 24v and 2A. Output is up to 500mA.

The “DuPont” style connectors are a little too small, but those crimp pins look like they might fit OK. I might just grab a pack of these pre-crimped wires, but if someone can confirm that they are a little bit large to comfortably fit a DuPont connector that would be appreciated.


The attached photo is the female socket of a Dupont connector. It fits over a 0.8mm (measured with a Vernier) thick safety pin. The depth of field is not great, but, the socket can be expanded a bit with a suitable pointed tool (a scriber comes to the mind). It would fit over a 1mm pin.

Hope this helps.