Using JST SM connectors for 3D printer hotend and parts cooling fans

While setting up my Ender 5 Plus in the new shop, I ran into a problem. My first print started to clog after a few hours. Clogs aren’t unusual with 3D printers. But since I put a MicroSwiss all-metal hotend on this printer, I have rarely had clogs on it. While looking at the print, I noticed the hotend cooling fan was not running. That would definitely explain the clog. Without the hotend fan running, there will be some severe heat creep.

Luckily I had a spare fan on hand to quickly get the printer back up and going. Unfortunately, the hotend cooling fan has two wires that run to the printer’s motherboard. It seems like a waste to run the fan wires back to the motherboard. This can be especially a pain if proper cable management keeps wiring out of the way. So instead, I like to put JST SM connectors up by the hotend so fans can be quickly and easily replaced out.

The JST SM connectors are often used for situations such as this. This is because they are cheap and easy to crimp. Here is a picture of a JST SM kit I bought off Amazon (link at the end of the post).

JST SM connector kit.

There are plenty of videos about how to crimp JST SM connectors, but if anyone wants, I will take the time to make a video.

Below is a look at the JST SM connector hooked up to the hooted cooling fan. I was in a bit of a hurry, so I only put a connector on that fan.

JST SM connector used with the hotend cooling fan.

Usually, if I take the time to put connectors on one of the fans on my hotend, I will do the other fan (or fans). I didn’t do that in this case, but I will probably wish I had in the future when the parts cooling fan fails. Hotend and parts cooling fans fail often enough that I like making it a quick, easy process when they need to be replaced out.

I also typically put the female connector on the side of the power source. In this case, that means the female connector is on the side of the wires facing the motherboard. The theory behind this is that it is harder to short out the pins and cause sparks when the connectors are not together.

At the same time, I like to put the red wire on pin 1 for both the female and male connectors. That helps to ensure the polarity is kept correct.

I also like to leave enough room to work with the connectors efficiently. In this case, the wire coming from the fan sits on top of the fan housing.

Hopefully, this post will give some people an idea of how to use JST SM connectors to make fan replacement quick and easy. In the future, when I have to replace this fan out again, I’ll throw a male JST SM connector on a new fan and swap it out.

Parts used in this post

This section may contain affiliate links. To find out more information, please read my disclaimer.

JST SM kit with crimping tool (Amazon Affiliate Link):

Ender replacement fan set (Amazon Affiliate Link):

Ender 5 Plus (Amazon Affiliate Link):

Song of the Day – Tribute

Talking about fans got me thinking about another use of the word fan… and therefore to Tribute from Tenacious D.

Bonus Song – Immigrant Song

Took keep with Tenacious D, and Dave Grohl. Here is a live version of Immigrant Song with Foo Fighters and guests.

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