X/Y 4-pin connectors
Hi! The small, white, plastic 4-pin X/Y connector plugs original to my K40 arent narrow enough to fit the 2 side-by-side slots on the mini gerbil...what kind/type of connectors should I look for to replace the K40 ones?
Hi Thom,
Do you have a v1.1B or a v2.0 Mini Gerbil board?
While there's not exactly a generous amount of room to insert the standard K40 plugs, as far as we know there's always been enough room to insert them as needed. I do accept that K40's come from a variety of factories and occasionally they use parts that are different to the others.
Can you show a photo of the X and Y plugs with insufficient room, positioned just above the relevant K40 socket? If they are really are a different kind, then I'll review some plug catalogues and work out something to get you up and running.
To answer your question specifically: to connect to the X and Y headers, you can use a 0.1" 4 pin header such as this https://www.ebay.com.au/p/22016647474
It can often be more convenient to simply use jumper cables (as long as you ensure the wire order is correct). Search for female to male jumper wires like this https://www.ebay.com.au/itm/40pcs-10CM-Male-To-Female-Jumper-Wire-Ribbon-Cable-for-Arduino-MTC-H1/402635395927?hash=item5dbef09357:g:C-YAAOSwjVVVngmj
Cheers
Dan
Hi Dan
Here's a (terrible) photo of the K40 header. I got some Molex KK 254 headers, now my main concern is making sure the pin order is correct. The leads are marked on the K40 board, so tracing them from there shouldn't be a big deal, what order should they go on the minigerbil side? 
Hi Thom,
I've listed a few different Q&A below, hope they help:
Q which way round does the motor plug go?
A it's not critical - try it one way and if everything moves in the expected direction, leave it. If not, try reversing it. You can also reverse in the $ settings as a backup plan.
Q what is the correct sequence of the wires within the X and Y 4 pin motor plugs?
A the first two wires should be either end of one stepper motor coil, the next two wires should be either end of the second motor coil. In other words, the coils should be connected as side by side terminals in the 4 pin plug (AABB), not interleaved (ABAB). You may need a multimeter or some online research to determine your coil wiring. If you don't get the result you want, just reverse the plug and the direction will reverse.
Q what else can go wrong?
A I recently had a customer whose system didn't work, turned out to be one of his stepper motor cables was accidentally grounded due to wire impacted by a screw - so watch out for this!
Thank you! That makes me feel a lot better 🙂