General > General Technical Chat
Connector for slightly bigger wire than will fit in JST SM
(1/2) > >>
davethomaspilot:
The insulation on the wires is too big to fit in the JST SM contacts. 

Wire size (insulation) is 2 mm diameter.  It just won't fit.

First, does it really matter?  Crimps seem really strong--I can't pull the wire out of the crimp.

If it does, can some one recommend a slightly larger connector that's easy to crimp?  1.5 amps, low voltage rating.

Just two wires--application is for adding a crimp connector to the 12V side of a 12V to 5V DC/DC. 



thm_w:
Does it matter for hobby use? no.

What AWG wire, you don't have anything thinner? The SM contact is rated 28-22 AWG.

https://www.jst.com/wp-content/uploads/2021/03/eSM.pdf
davethomaspilot:
Don't know wire gauge, except it's about .95 mm diameter.  19 or 20 AWG.  Can't change it--the DC/DC convertors I have on hand have the wires.

Not quite hobby--I'm making 10 assemblies that cost around $1K each.  They will be used only once or twice a year, but will be expected to last at least 10 years.

The crimp on the wire is really good--it's just that the insulation won't fit under the outer crimp.  Thinking about it, I wouldn't think the extra mechanical strength provided by getting the insulation under the crimp would be significant compared to the actual wire.  But, I know a "good" crimp requires the insulation to be in the crimp.

Found these on Amazon and will give them a try:

https://www.amazon.com/Molex-Micro-Fit-Circuits-receptacle-Terminal/dp/B078PZY6SM/ref=sr_1_2?qid=1681422924&refinements=p_n_feature_four_browse-bin%3A18945778011&s=industrial&sr=1-2

Thanks!



davethomaspilot:
The maximum insulation thickness for the ones in that link is 1.8 mm--same as the SM that I've used.

Outside diameter is 2 mm.

I actually shaved some insulation off the wires and got a pair of wires to fit.  But, that's too much hassle and I still don't think it adds significant mechanical strength compared to something like 20 AWG wire.  But, opinions welcome!

thm_w:
If this is for a high end product, then yeah just get an appropriate connector that is rated for ~19 AWG wire.

Mini fit jr. can be 18-24 AWG
Micro fit contacts you linked are 20-24 AWG so might work.

Probably this https://www.molex.com/pdm_docs/ps/PS-44300-001.pdf
Spec states max outside insulation diameter 1.85mm
Navigation
Message Index
Next page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod