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Molex connector crimps.

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Thomas W

Tue Oct 28 2014, 10:19PM

Registered Member #3324 Joined: Sun Oct 17 2010, 06:57PM
Location:
Posts: 1276

A while back brought a load of these:

and a load of these:

For some reason no matter what i do, the pins won't stay in the plastic shell, its likey they won't go far enough in. and im not sure what ones i should be using with them ,even though they look like the right ones. Can anyone help me with this please?
Thanks,
Thomas

P.S. any good crimping tools that don't cost an arm an a leg.... Â£300... SERIOUSLY?

Dr. Slack

Tue Oct 28 2014, 11:25PM

Registered Member #72 Joined: Thu Feb 09 2006, 08:29AM
Location: UK St. Albans
Posts: 1659

They look like they're the matching parts, the 'use with's match, and yes, the correct crimp tools do cost an arm and a leg. However, what I've found with a similar terminal system, and may be your problem with this set, is that if you don't use the right crimp tool, the metal leaves that don't get crunched down the right amount get in the way of the little retention barbs that secure the terminals in the mouldings. That doesn't mean you have to buy the right crimp tool, but it does mean that you have to look at the mechanics very carefully, and figure out what should be where, and what you have to do to make it so. In my case, I found that the crimp leaves could be left in their 'as supplied' position, as long as I didn't use excess solder to attach the wire to where it would normally crimp. With a different system, YMMV.

Thomas W

Tue Oct 28 2014, 11:33PM

Registered Member #3324 Joined: Sun Oct 17 2010, 06:57PM
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Posts: 1276

Hmm, i given it a go, bending them in different ways. However it seems like the pin doesn't go in correctly, like the back tab that holds it in gets bent and does not return. It also looks like the pin won't go as deep into the connector as it should, like it gets stuck. Even if i cut the tabs off it still happens.

Dr. Slack

Tue Oct 28 2014, 11:50PM

Registered Member #72 Joined: Thu Feb 09 2006, 08:29AM
Location: UK St. Albans
Posts: 1659

Yeah, sounds like evidence of not using the right crimp tool. These bent metal systems, it's a wonder they work at all, they truly are a wonder of value engineering. The bending and moulding tolerances mean that a single thou can be the difference between them working and not. The right crimp tool usually has a rachet thing that means they can't be released until the full compression cycle has happened, meaning that the terminal can't be removed until it meets its finished size tolerance. Persist with trying to figure out what is stopping it working. Section a housing with a scalpel so you can see the insides as the terminal goes in. It may help if you can get an already crimped terminal to see what it should look like, and where it catches.

Thomas W

Wed Oct 29 2014, 12:29AM

Registered Member #3324 Joined: Sun Oct 17 2010, 06:57PM
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Posts: 1276

Think i might just go with a different connector. these things are crap. I actually like IDE connectors more. or just buy pre-made wires.

Its stupid how bad these kind of connectors are really.

2Spoons

Wed Oct 29 2014, 01:01AM

Registered Member #2939 Joined: Fri Jun 25 2010, 04:25AM
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Posts: 615

Actually they work really well if you use the proper crimp tool and the correct wire gauge

A properly made crimp should outperform a solder joint. It is gas tight, and has an integral strain relief (crimp on insulation).

Yes the tools are horribly expensive - because the dies are precision engineered to create the right force and shape for a specific crimp pin, and because they don't sell many.

Sometimes i've fixed retention problems by bending the little catch tab out a little further.

Thomas W

Wed Oct 29 2014, 01:14AM

Registered Member #3324 Joined: Sun Oct 17 2010, 06:57PM
Location:
Posts: 1276

Thing is, i have been bending and reforming the metal on the connector. no matter what i do... it doesn't seem to fit :|

I think 6-10 pin IDE connectors are much better. quite cheap too

Dr. Slack

Wed Oct 29 2014, 08:52AM

Registered Member #72 Joined: Thu Feb 09 2006, 08:29AM
Location: UK St. Albans
Posts: 1659

Thomas W wrote ...

Think i might just go with a different connector. these things are crap. I actually like IDE connectors more. or just buy pre-made wires.

Its stupid how bad these kind of connectors are really.

Think very carefully what you are saying. These 'crap' connectors sell billions of units, and they have been value engineered to be made for pennies, but are able to be assembled by unskilled people with a very high success rate, when using the specified tools.

Bear in mind the crimp tool may not just be making the wire crimp portion, but may also be deforming the rest of the terminal into the final shape required for the housing. What you have bought may be raw material to be finished into terminals by the crimp tool.

The connectors aren't stupid. It's stupid how you try to use stuff the way it wasn't intended, and then lash out at the stuff, rather than having the humility to look for and learn the lesson from the experience.

If you have a favourite connector, that you get on with, then I think using that is a good plan.

Sulaiman

Wed Oct 29 2014, 10:20AM

Registered Member #162 Joined: Mon Feb 13 2006, 10:25AM
Location: United Kingdom
Posts: 3140

I can confirm that when used with the correct crimping tool, Molex KK series are ok
(I prefer round pin connectors myself)
you may be flattening the part that crimps the conductors
when flat it will block the pin from entering the housing.

Without the correct crimping tool you will need to solder the wire
. using pliers squeeze the tabs around the conductors, first from both sides then 'wrap' the tabs over the conductors, do not close the part for the insulation
. Solder the wire in place
. when cooler squeeze the back part around the insulation
should be ok.

mbd

Wed Oct 29 2014, 01:05PM

Registered Member #43278 Joined: Sat Feb 22 2014, 09:18AM
Location: Sydney
Posts: 9

Having introduced myself to the 'art' of pinball maintenance in the last couple of years, I have managed to acquire some small skills in crimping various connectors.

I would like to echo the various comments above - a properly crimped KK connector is a fine thing.

My question is: what crimper are you using? Can you please post a photo? If you are using an ultra-cheap crimper, I don't think you have a chance of getting the crimp done correctly. (I know I never could.)

BTW you should be able to get an adequate crimper for less than USD50.

MBD

PS The general consensus among the pinball crowd is that IDC connectors are to be avoided. But then again, the pinball crowd is after longevity and reliability and maybe your application is not nearly so demanding.

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