Author Topic: "No-crimp" connector idea  (Read 5290 times)

0 Members and 1 Guest are viewing this topic.

Offline ElectronicSupersonicTopic starter

  • Regular Contributor
  • *
  • Posts: 77
  • Country: lt
"No-crimp" connector idea
« on: September 15, 2019, 05:39:11 am »
While working on a project (one of many which most probably never be finished), I had to design an easy to assemble connector (like IDC type connectors). Here is what I came up with.

Since my goal was to design something which wouldn't require expensive crimping tools, the usual crimp style was not an option. Instead omega shaped contacts are used. Where wire is inserted in to an "eyelet" and affixed in place by the spring action of the contact. Thus special tools are not needed.

Same idea could be used for both round (3.5mm headphone jack style) and the usual rectangular connectors. Bellow are attached screenshots of both types. Note that these are only to illustrate the idea - not the actual working solutions.
 

Offline Dubbie

  • Supporter
  • ****
  • Posts: 1115
  • Country: nz
Re: "No-crimp" connector idea
« Reply #1 on: September 15, 2019, 05:44:33 am »
You should make some and see if they work.
 

Offline T3sl4co1l

  • Super Contributor
  • ***
  • Posts: 22436
  • Country: us
  • Expert, Analog Electronics, PCB Layout, EMC
    • Seven Transistor Labs
Re: "No-crimp" connector idea
« Reply #2 on: September 15, 2019, 06:42:25 am »
Hmmm...

Heh, I can see where you're going with these.  It's nice thinking, but it's missing something.


Have you held a piece of stranded wire in your life?  How the heck are you going to coax every single strand into a just-perfectly-sized space?  (If you have a solution for that, I would honestly like to see it.  Every so often I find myself wrestling very fine strands (might be welding cable, might be litz cable) into a crimp lug.  Such a PITA when they're tight fitting!)

Even if it's solid core wire, how are you going to have adequate retention force, while also being able to push the thing in?

For the phono jack: how are you going to insert the wires, or tension the springs, while also stretching the spring over the connector body?

For the square pin connector: the square pin spreads the terminal frame apart, loosening the wire, doesn't it?

Tim
Seven Transistor Labs, LLC
Electronic design, from concept to prototype.
Bringing a project to life?  Send me a message!
 

Offline Alex Eisenhut

  • Super Contributor
  • ***
  • Posts: 3549
  • Country: ca
  • Place text here.
Re: "No-crimp" connector idea
« Reply #3 on: September 15, 2019, 07:29:52 am »
For solid wire something like that is used on electrical outlets.

Hoarder of 8-bit Commodore relics and 1960s Tektronix 500-series stuff. Unconventional interior decorator.
 

Offline ElectronicSupersonicTopic starter

  • Regular Contributor
  • *
  • Posts: 77
  • Country: lt
Re: "No-crimp" connector idea
« Reply #4 on: September 15, 2019, 07:45:21 am »
Quote
For the square pin connector: the square pin spreads the terminal frame apart, loosening the wire, doesn't it?

The pin is held in place by the housing. Housing has a groove intended to press-fit both the wire (sleeve) and the contact. Thus contact, then inserted, is "squished" by the housing and accordingly provides retention. Since housing is tight, pin insertion shouldn't cause problems, there is simply no place to spread inside the housing.
835752-0

Quote
For the phono jack: how are you going to insert the wires, or tension the springs, while also stretching the spring over the connector body?

Well pre-cut wires would be inserted first (in the correct location leaving striped ends not inserted), then rings are to be mounted then strands go.

Quote
Even if it's solid core wire, how are you going to have adequate retention force, while also being able to push the thing in?

Wires are to be press-fit in to the housing, thus a good amount of retention should be present. That is housing is designed to provide retention via tight fit of grooves where wires would go.
« Last Edit: September 15, 2019, 07:47:06 am by ElectronicSupersonic »
 

Offline tautech

  • Super Contributor
  • ***
  • Posts: 29810
  • Country: nz
  • Taupaki Technologies Ltd. Siglent Distributor NZ.
    • Taupaki Technologies Ltd.
Re: "No-crimp" connector idea
« Reply #5 on: September 15, 2019, 08:15:44 am »
Have you held a piece of stranded wire in your life?  How the heck are you going to coax very single strand into a just-perfectly-sized space?  (If you have a solution for that, I would honestly like to see it.  Every so often I find myself wrestling very fine strands (might be welding cable, might be litz cable) into a crimp lug.  Such a PITA when they're tight fitting!)

Tim
;D
Yep, we've all been tested on that one !
There's a simple trick for fine stranded cables and insertion into crimp lugs, ferrules and the like.

Pull off ~6"or more of insulation tape and spin/twist it loosely into a soft round rope shape and bind the strands not too firmly together starting from the insulation sheath nearly to the tip of the strands and then back towards the insulation a couple of turns. Keep finished end taught.
Insert exposed strand tip into lug and press not too firmly home.
The tape rope slides down the strands and will bunch up at the end of the sheath between it and the lug.
Unwrap tape rope then press cable fully home..... done !
Done properly you'll never miss inserting even a single strand.

This tape rope can be used again and again.

Thanks to my sparky mate Wayne for that one.  :)
« Last Edit: September 16, 2019, 04:13:52 am by tautech »
Avid Rabid Hobbyist.
Some stuff seen @ Siglent HQ cannot be shared.
 

Offline Yansi

  • Super Contributor
  • ***
  • Posts: 3930
  • Country: 00
  • STM32, STM8, AVR, 8051
Re: "No-crimp" connector idea
« Reply #6 on: September 15, 2019, 09:09:49 am »
...and then you reinvent the spring terminals (WAGO).  ;D
 
The following users thanked this post: ElectronicSupersonic

Online Gyro

  • Super Contributor
  • ***
  • Posts: 10173
  • Country: gb
Re: "No-crimp" connector idea
« Reply #7 on: September 15, 2019, 09:12:16 am »
Maybe I'm just not getting it, but I don't understand what stops individual strands from squeezing out into the open side of the 'omega' when compressed?  That would spoil the 'perfect fit'. Wire diameters will be subtly different between types too.

A connection really needs to be 'gas tight' for long term reliability, I'm not sure how/if this achieves that.  :-\
Best Regards, Chris
 

Online 2N3055

  • Super Contributor
  • ***
  • Posts: 7465
  • Country: hr
Re: "No-crimp" connector idea
« Reply #8 on: September 15, 2019, 10:18:23 am »
...and then you reinvent the spring terminals (WAGO).  ;D
This. Spring based terminals are old news.
"Just hard work is not enough - it must be applied sensibly."
Dr. Richard W. Hamming
 

Offline FreddieChopin

  • Regular Contributor
  • *
  • !
  • Posts: 102
  • Country: ua
Re: "No-crimp" connector idea
« Reply #9 on: September 15, 2019, 10:25:10 am »
...and then you reinvent the spring terminals (WAGO).  ;D

Wago connectors are horrible because they are prone to rust, have pretty high contact resistance and when overloaded they melt. I worked on many building sites in Poland and everywhere I worked it was forbidden to use wago because when installation is overloaded with electric oven, kettle or arc welder it can start a fire. Instead we use proven screw terminals that can whitstand high overloads.


In my parents house there is aluminim electric instaltion done by my grandfather, it is soldered instead of any terminals and it works without issues since 1950s and I'll bet it will work great 30-40 years into the future. We don't do much soldered electric installation nowdays unless client is willing to pay more for it because it takes time.
 

Offline Monkeh

  • Super Contributor
  • ***
  • Posts: 8134
  • Country: gb
Re: "No-crimp" connector idea
« Reply #10 on: September 15, 2019, 10:59:08 am »
Wago connectors are horrible because they are prone to rust

Just like anything else with steel in it, like your screw terminals..

Quote
have pretty high contact resistance

[citation needed]

Quote
and when overloaded they melt.

Just like everything else with plastic housings, like your screw terminals..

Quote
I worked on many building sites in Poland and everywhere I worked it was forbidden to use wago because when installation is overloaded with electric oven, kettle or arc welder it can start a fire.

Perhaps Poland should investigate the concept of a circuit breaker.

Quote
Instead we use proven screw terminals that can whitstand high overloads.

Proven to be cheap, awkward, and easily misused, yes.

Quote
In my parents house there is aluminim electric instaltion done by my grandfather, it is soldered instead of any terminals and it works without issues since 1950s and I'll bet it will work great 30-40 years into the future. We don't do much soldered electric installation nowdays unless client is willing to pay more for it because it takes time.

Soldered.. aluminium. Not impossible, also not likely, and of course surely won't melt under overload :-DD
 
The following users thanked this post: Yansi, Ysjoelfir

Offline Yansi

  • Super Contributor
  • ***
  • Posts: 3930
  • Country: 00
  • STM32, STM8, AVR, 8051
Re: "No-crimp" connector idea
« Reply #11 on: September 15, 2019, 11:06:18 am »
...and then you reinvent the spring terminals (WAGO).  ;D

Wago connectors are horrible because they are prone to rust, have pretty high contact resistance and when overloaded they melt. I worked on many building sites in Poland and everywhere I worked it was forbidden to use wago because when installation is overloaded with electric oven, kettle or arc welder it can start a fire. Instead we use proven screw terminals that can whitstand high overloads.


In my parents house there is aluminim electric instaltion done by my grandfather, it is soldered instead of any terminals and it works without issues since 1950s and I'll bet it will work great 30-40 years into the future. We don't do much soldered electric installation nowdays unless client is willing to pay more for it because it takes time.

If something is overloaded, then probably the overloaded components is not at fault, more likely You who put it there incorrectly in the first place.

Spring terminals are currently the go-to in the industry and there are no problems with their reliability. In fact, they have better reliability, than screw-type terminals.  Even installation errors like forgotten screw that was not tightened properly are quite eliminated.

Soldered what?! O_o   
 

Offline FreddieChopin

  • Regular Contributor
  • *
  • !
  • Posts: 102
  • Country: ua
Re: "No-crimp" connector idea
« Reply #12 on: September 15, 2019, 01:44:32 pm »
If something is overloaded, then probably the overloaded components is not at fault, more likely You who put it there incorrectly in the first place.

At work we use YDYp 3x1.5mm cable to wire outlets. Sometimes B16 breaker wont trip with something heavy connected (like dishwasher or kettle) but WAGO will burn  :-- while screw connectors are fine  :-+ It's simple math - more connection area -> less I^2R losses -> less heat.
 

Offline Monkeh

  • Super Contributor
  • ***
  • Posts: 8134
  • Country: gb
Re: "No-crimp" connector idea
« Reply #13 on: September 15, 2019, 01:49:09 pm »
If something is overloaded, then probably the overloaded components is not at fault, more likely You who put it there incorrectly in the first place.

At work we use YDYp 3x1.5mm cable to wire outlets. Sometimes B16 breaker wont trip with something heavy connected (like dishwasher or kettle) but WAGO will burn  :-- while screw connectors are fine  :-+ It's simple math - more connection area -> less I^2R losses -> less heat.

Dishwasher or kettle? You mean a sub-10A load, on a 16A breaker, using a connector generally rated around 32A? Bullshit.

Having watched real Wago connectors take a 3xIn overload for several minutes, I don't believe you.
« Last Edit: September 15, 2019, 01:51:23 pm by Monkeh »
 
The following users thanked this post: dom0

Online langwadt

  • Super Contributor
  • ***
  • Posts: 4857
  • Country: dk
Re: "No-crimp" connector idea
« Reply #14 on: September 15, 2019, 01:54:20 pm »
looks like it would basically be like a incorrectly done crimp
 
The following users thanked this post: tooki

Offline Yansi

  • Super Contributor
  • ***
  • Posts: 3930
  • Country: 00
  • STM32, STM8, AVR, 8051
Re: "No-crimp" connector idea
« Reply #15 on: September 15, 2019, 02:08:23 pm »
If something is overloaded, then probably the overloaded components is not at fault, more likely You who put it there incorrectly in the first place.

At work we use YDYp 3x1.5mm cable to wire outlets. Sometimes B16 breaker wont trip with something heavy connected (like dishwasher or kettle) but WAGO will burn  :-- while screw connectors are fine  :-+ It's simple math - more connection area -> less I^2R losses -> less heat.

If you do that, you should get slapped.  On a 16 Amp circuit, 2.5 mm2 wires shall be used.

YDYp is good at best as a light fixture wiring.
 

Offline Monkeh

  • Super Contributor
  • ***
  • Posts: 8134
  • Country: gb
Re: "No-crimp" connector idea
« Reply #16 on: September 15, 2019, 02:09:52 pm »
If you do that, you should get slapped.  On a 16 Amp circuit, 2.5 mm2 wires shall be used.

Err, that's going to depend on your regulations, so that's a high horse you can abandon rapidly. 1.5mm² is adequate for 16A in many cases.
 

Offline Addicted2AnalogTek

  • Frequent Contributor
  • **
  • Posts: 511
  • Country: us
Re: "No-crimp" connector idea
« Reply #17 on: September 15, 2019, 02:35:49 pm »
For solid wire something like that is used on electrical outlets.



Some info regarding these connections on receptacles and switches:

According to US NEC (National Electric Code), using these push-in connections are not permissible. I've encountered many of these where "do-it-yourselfers" or maintenance people have swapped a receptacle (typically on GFCIs) and installed the new device this way.  This type of connection is notoriously unreliable and many times, regardless of the screw being tightened, the wire slips out when removing the device. The only accepted method is to loop the wire around the screw terminal, pinch the end and the conductor together (so that it holds regardless of whether the screw is tight) then snug the screw and tighten a half turn.
 

Offline madires

  • Super Contributor
  • ***
  • Posts: 8274
  • Country: de
  • A qualified hobbyist ;)
Re: "No-crimp" connector idea
« Reply #18 on: September 15, 2019, 03:01:57 pm »
Wago connectors are horrible because they are prone to rust, have pretty high contact resistance and when overloaded they melt. I worked on many building sites in Poland and everywhere I worked it was forbidden to use wago because when installation is overloaded with electric oven, kettle or arc welder it can start a fire. Instead we use proven screw terminals that can whitstand high overloads.

Genuine Wago or Wago style copies/counterfeits?
 
The following users thanked this post: tooki

Offline Simon

  • Global Moderator
  • *****
  • Posts: 18118
  • Country: gb
  • Did that just blow up? No? might work after all !!
    • Simon's Electronics
Re: "No-crimp" connector idea
« Reply #19 on: September 15, 2019, 03:18:23 pm »
The problem is contact resistance. The key is to just fing a connector that you can use is many applications and stick with it. This is like standards. There are so many crimp tools because companies want to screw you for the tools. TE are the worse because all tooling is made by "the" tooling subsidiary that are expected to turn a profit. with mass produced off the shelf die sets costing £500-1500 for tiny pins it is daylight robery when I can get a custom die made for heavy duty pins for £1000
 
The following users thanked this post: tooki

Online Zero999

  • Super Contributor
  • ***
  • Posts: 20357
  • Country: gb
  • 0999
Re: "No-crimp" connector idea
« Reply #20 on: September 15, 2019, 03:44:10 pm »
What voltage is this connector going to be working at?

If it can be plugged or unplugged, when live, then the earth connection needs to made first and broken last and there shall be no chance of the earth becoming live.

Going from the drawings in the original post,  there's no way it'll meet the above requirements.
 

Offline Simon

  • Global Moderator
  • *****
  • Posts: 18118
  • Country: gb
  • Did that just blow up? No? might work after all !!
    • Simon's Electronics
Re: "No-crimp" connector idea
« Reply #21 on: September 15, 2019, 03:54:51 pm »
It also relies on a specific wire size to work. i like the idea but in all my experionce of using various connectors i can't see it working.
 
The following users thanked this post: Yansi

Offline Yansi

  • Super Contributor
  • ***
  • Posts: 3930
  • Country: 00
  • STM32, STM8, AVR, 8051
Re: "No-crimp" connector idea
« Reply #22 on: September 15, 2019, 04:36:27 pm »
If it can be plugged or unplugged, when live, then the earth connection needs to made first and broken last and there shall be no chance of the earth becoming live.


Tell that to a TRS phone jack.  >:D

//Way to many times I've see 1/4" TRS jacks used for amplifier speaker outputs... stupid design choice//
 

Offline Simon

  • Global Moderator
  • *****
  • Posts: 18118
  • Country: gb
  • Did that just blow up? No? might work after all !!
    • Simon's Electronics
Re: "No-crimp" connector idea
« Reply #23 on: September 15, 2019, 04:41:41 pm »
It's about the voltage level and safety regulations on mains plugs. Plenty of connectors are rated for high voltages and disconnect everything at once. My issue with this design is that in practice it will never work because of real life and contact resistance of the wire with the contact.

If you want a universal connector that is not a pain in the as use Deutsch/TE DT, DTM or DTP connectors and/or the equivalents from Amphenol sine AT, ATM and ATP. The crimp tool for all 3 sizes of pin and all wire sizes costs £500 and lasts forever. Never mind all of the other shitty TE connectors that have a single die for a single size that costs £500.
 

Offline mikerj

  • Super Contributor
  • ***
  • Posts: 3382
  • Country: gb
Re: "No-crimp" connector idea
« Reply #24 on: September 15, 2019, 04:44:25 pm »
It seems extremely unlikely this will achieve a reliable gas tight connection.  Also what mechanically retains the cable, looks like one good pull would see the cable separated for the connector.
 
The following users thanked this post: tooki


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf