Molex SPOX vs KK

[exlabs]

Hello,

Is anyone interested in wire to board connectors?

I've been looking at the Molex SPOX and KK 396 because I need a connector that can support from 26 to 18 AWG and up to 5A.

I don't understand Molex branding, because this product seems to be in the KK family but also SPOX?


https://www.molex.com/en-us/products/part-detail/09652048
Where as this one seem to be just the KK series


https://www.molex.com/en-us/products/part-detail/26604040
I'm leaning towards the SPOX style because the friction clip seems more sturdy - it runs all the way along the connector's body.

First time looking in to this so I'd rather go with a tried and tested connector to standardise around, curious what people like and use and if it even matters

 

[fallout]

If I'm remembering correctly, the SPOX contacts/housings are different than the KK series.

 

[Newmarket]

Hi. I've used Molex extensively in past designs for industrial and scientific instrumentation designs. Yeah - it's kind of confusing. SPOX is basically a subset of KK. There are various header/housing comparability permutations. IIRC these are normally detailed on the datasheet.
SPOX are superior to standard KK. eg four face crimp contact and higher pull out force. Preferable if cost allows. BUT to get full benefit you need to have the correct crimp tooling - as always £££££s.

 

[exlabs]

If I'm remembering correctly, the SPOX contacts/housings are different than the KK series.

Yeah the connector housing is different.

The KK has two clips

the SPOX is more moulded

SPOX are superior to standard KK. eg four face crimp contact and higher pull out force. Preferable if cost allows. BUT to get full benefit you need to have the correct crimp tooling - as always £££££s.

Thanks for clear advice, I really don't know why Molex don't explain this stuff. I didn't notice the four face crimp that and the housing seem more robust.

I took a look at Digikey for prices, they actually seem comparable for small volumes, however SPOX only supports 18-24 AWG Crimp Terminals, KK supports 18-24 AWG and 22-26 AWG Crimp Terminals with the same housing. So SPOX is a little less versatile but perhaps more robust.

Here are current prices (UK) for SPOX



and for KK with the additional crimp terminal for smaller gauge wire

BUT to get full benefit you need to have the correct crimp tooling - as always £££££s.

Yarp... in both cases the tool is £300+. Two tools needed for KK if you want to support both size crimps.

For these higher power connections I'm going to go with the SPOX and I'll go with KK 254 (smaller pitch) for more standard - lower power - stuff. In either case I will need to buy two crimp tools so it does not really make a difference. Thanks a lot!

PS. Regarding using the actual hand tool. I prefer to spend the money on the correct tool for the job because a few failed crimps at best could waste my (already limited) time and at worst cause failure of the circuit or be dangerous. £300 is not too bad to minimise that risk. Still need to get good at it, I think it takes a bit of practice.

 

[Newmarket]

Yes. That's exactly what I did wrt 3.96mm SPOX and 2.54mm KK.
The board had been made with 'standard' KK 3.96mm. But I was able to change the housing to SPOX as it was compatible with the existing header. Then changed the header to SPOX for new production.
wrt Tooling - I tend to agree and have only made them myself with Molex brand tooling. Although I know others use alternatives and seem to get on fine.
As with anything it's a matter of quantity. Really I would have preferred to have had the assembly done by a local wiring/assembly house where they have automatic tooling - so consistent strip length and calibrated crimping force. But for financial reasons the company wished to use internal resources so it was done (not by me) with Molex brand hand tooling.

 

[exlabs]

Really I would have preferred to have had the assembly done by a local wiring/assembly house where they have automatic tooling - so consistent strip length and calibrated crimping force.

Yeah this would be preferable. From your experience what number of units does it make sense? I’m trying to get a product off the ground, I’m going to do the first run myself and outsource if orders become unmanageable.

designs for industrial and scientific instrumentation

This is really interesting, do you have portfolio online? I have a background in physics and used plenty of instrumentation when in the lab.

 

[Pars]

I use KK 2.54 and SPOX 5.08mm a lot. I bought this crimper online, and it seems to do a good job for not much money. I normally use teflon jacketed wire in 20-22-24ga, and use Ideal T-Strippers for the stripping. This is just hobbyist usage in building audio equipment, and not production use, so YMMV.

 

[MidnightArrakis]

I’m trying to get a product off the ground

do you have portfolio online? used plenty of instrumentation when in the lab.

[do you have portfolio online?] -- I DO!!! I have designed electronic equipment ranging from audio, radio broadcast and video electronics to medical electronics instrumentation to all sorts of -- creepy and spooky -- "covert intelligence-gathering, surveillance and/or tracking operations" projects for U.S. Government agencies. Below is a link to some of my equipment designs, which are mostly "rack-mount" equipment designs:

https://mega.nz/file/J35VGbQS#stq1wr-Vk7oLb4rvlk37rN1o5uzbnVeTJvXq-C9-4Kk
/

 

[Gold]

I really don't know why Molex don't explain this stuff.

I think this is the information I'm missing. I have both SPOX and KK here. I knew they were different but I didn't know they were different. I could never figure out why sometimes the pins would lock and sometimes they wouldn't. Now I think I can go through what I have and figure out what goes with what and how to use them successfully.

 

[radardoug]

Yeah the connector housing is different.

The KK has two clips
View attachment 118020
the SPOX is more moulded
View attachment 118021



Thanks for clear advice, I really don't know why Molex don't explain this stuff. I didn't notice the four face crimp that and the housing seem more robust.

I took a look at Digikey for prices, they actually seem comparable for small volumes, however SPOX only supports 18-24 AWG Crimp Terminals, KK supports 18-24 AWG and 22-26 AWG Crimp Terminals with the same housing. So SPOX is a little less versatile but perhaps more robust.

Here are current prices (UK) for SPOX

View attachment 118023

and for KK with the additional crimp terminal for smaller gauge wire

View attachment 118025




Yarp... in both cases the tool is £300+. Two tools needed for KK if you want to support both size crimps.

For these higher power connections I'm going to go with the SPOX and I'll go with KK 254 (smaller pitch) for more standard - lower power - stuff. In either case I will need to buy two crimp tools so it does not really make a difference. Thanks a lot!

PS. Regarding using the actual hand tool. I prefer to spend the money on the correct tool for the job because a few failed crimps at best could waste my (already limited) time and at worst cause failure of the circuit or be dangerous. £300 is not too bad to minimise that risk. Still need to get good at it, I think it takes a bit of practice.

You dont have to crimp them, you can solder them, and in my opinion that works better. You do have to crimp over the tops a bit to fit them in.

 

[Newmarket]

You dont have to crimp them, you can solder them, and in my opinion that works better. You do have to crimp over the tops a bit to fit them in.

Technically a properly made crimp is better here. The key is "properly made" ie a gas tight connection and properly securing the insulation. Crimping and soldering is poor practice as it introduces a brittle area into the interconnection.

 

[Newmarket]

I think this is the information I'm missing. I have both SPOX and KK here. I knew they were different but I didn't know they were different. I could never figure out why sometimes the pins would lock and sometimes they wouldn't. Now I think I can go through what I have and figure out what goes with what and how to use them successfully.

Well SPOX is sort of a variant / sunset of KK. Data sheets should indicate approved header / housing combinations.

 

[radardoug]

I have done thousands of them with no problems. Crimps on the other hand especially in high current situations can be very bad.

 

[Newmarket]

I have done thousands of them with no problems. Crimps on the other hand especially in high current situations can be very bad.

That simply implies that those crimps were not properly made.

 

[radardoug]

In units such as Eventides H910 and 949, the current drawn through the crimp was enough to heat them, burn the connector, and fail.
Crimps and current do not mix.

 

[Newmarket]

In units such as Eventides H910 and 949, the current drawn through the crimp was enough to heat them, burn the connector, and fail.
Crimps and current do not mix.

No. It just implies that either the crimping was poor or wire/ crimps simply too small. Crimp connections are widely used in high current electrical applications.

 

[exlabs]

I use KK 2.54 and SPOX 5.08mm a lot. I bought this crimper online, and it seems to do a good job for not much money.

Another vote for this combo. Good to know, thanks for the recommendation.

 

[exlabs]

[do you have portfolio online?] -- I DO!!!

How modest of you! Congrats, seems an amazing career.

 

[exlabs]

I'm ready to pick a Molex KK 254 header, housing and crimp combination.

@Pars I'm going to take you advice and get the crimp tool you suggested and @Newmarket I'm following your advice where you mentioned you use the housing with polarising ribs. So far I have decided on these parts

Header

https://www.molex.com/en-us/products/part-detail/22272021

Housing

https://www.molex.com/en-us/products/part-detail/22013027

However for the crimp I see a lot of options, see the "mates with" sections here https://www.molex.com/en-us/products/part-detail/22013027#mates-with-use-with

I think not getting the reel is the best option before I will have to cut each one, but in terms of the other options I really don't have a clue. Can someone recommend a sensible option?

 

[Pars]

I would probably use this style of housing with the ears on it for polarization instead of the ramp, but either will work:
38-00-1422
https://www.mouser.com/ProductDetail/Molex/38-00-1422?qs=vE/395LYEscttR0/2YbCpg==
For the crimp pins, I like these: 0008520123. You are right about the reel mounted ones. They are a pain in the ass to cut off the reel. I only buy bagged items, and usually in qty of 100 or multiples.

If you use the same crimper I have, be careful with how far you insert the pin into the crimper, as too far and you will crush the tension loop on the pin.