Author Topic: Prevent cable from being pulled through hole  (Read 19474 times)

0 Members and 1 Guest are viewing this topic.

Offline JacksterTopic starter

  • Frequent Contributor
  • **
  • Posts: 549
  • Country: gb
    • PCBA.UK
Prevent cable from being pulled through hole
« on: May 14, 2018, 09:17:30 am »
Hi all.

Having to have a cable go through the side of a electronics housing.
Would love a socket for the cable to connect into but there is not enough room internally for it so having to drill a hole for the cable to come through.
Obviously need something to clamp it to prevent it being pulled out.

I know there is a name for this product, but I don't know what it is.
Yes I zip tie would work but looking for something better..

Thanks
Jack

Offline Zero999

  • Super Contributor
  • ***
  • Posts: 21886
  • Country: gb
  • 0999
Re: Prevent cable from being pulled through hole
« Reply #1 on: May 14, 2018, 09:37:35 am »
Tie a knot in the cable, then it can't slip through the hole.
 


Offline Messtechniker

  • Frequent Contributor
  • **
  • Posts: 888
  • Country: de
  • Old analog audio hand - No voodoo.
Re: Prevent cable from being pulled through hole
« Reply #3 on: May 14, 2018, 09:43:05 am »
Tie a knot in the cable, then it can't slip through the hole.

Never ever do this. It's unprofessional and the housing edges may
cut into the cable insulation and the is no strain relief.
Use a cable gland instead.
Agilent 34465A, Siglent SDG 2042X, Hameg HMO1022, R&S HMC 8043, Peaktech 2025A, Voltcraft VC 940, M-Audio Audiophile 192, R&S Psophometer UPGR, 3 Transistor Testers, DL4JAL Transistor Curve Tracer, UT622E LCR meter, UT216C AC/DC Clamp Meter
 

Offline Richard Crowley

  • Super Contributor
  • ***
  • Posts: 4319
  • Country: us
  • KJ7YLK
Re: Prevent cable from being pulled through hole
« Reply #4 on: May 14, 2018, 09:47:04 am »
The most common solution is a strain-relief bushing, and the prominent brand is Heyco.
When you use the proper size, they grip the cable so well that the cable will break before they let go.
But they need exactly the right size hole and they are tricky to install/remove with ordinary pliers.



https://www.heyco.com/Strain_Relief_Bushings/product.cfm?product=Original-Strain-Relief-Round-1

 
The following users thanked this post: Jackster, Connoiseur, Electro Detective

Offline Zero999

  • Super Contributor
  • ***
  • Posts: 21886
  • Country: gb
  • 0999
Re: Prevent cable from being pulled through hole
« Reply #5 on: May 14, 2018, 09:49:52 am »
Tie a knot in the cable, then it can't slip through the hole.

Never ever do this. It's unprofessional and the housing edges may
cut into the cable insulation and the is no strain relief.
Use a cable gland instead.
I agree it's not ideal, but wouldn't say never. I've done it plenty of times, without any issues.
 

Offline Brumby

  • Supporter
  • ****
  • Posts: 12521
  • Country: au
Re: Prevent cable from being pulled through hole
« Reply #6 on: May 14, 2018, 10:02:30 am »
Knot tying isn't my first choice - but it can be effective enough if the likelihood of the cable being tugged is low.  What is most important is that the hole itself must not offer any risk to the integrity and safety to the cable.

Strain relief bushings and cable glands of the correct size are much better solutions.
Why Clippy?  --> https://www.youtube.com/watch?v=2_Dtmpe9qaQ
 

Offline JacksterTopic starter

  • Frequent Contributor
  • **
  • Posts: 549
  • Country: gb
    • PCBA.UK
Re: Prevent cable from being pulled through hole
« Reply #7 on: May 14, 2018, 10:18:11 am »
The most common solution is a strain-relief bushing, and the prominent brand is Heyco.
When you use the proper size, they grip the cable so well that the cable will break before they let go.
But they need exactly the right size hole and they are tricky to install/remove with ordinary pliers.



https://www.heyco.com/Strain_Relief_Bushings/product.cfm?product=Original-Strain-Relief-Round-1

That's the one! Could not think of what it was called.

Ill try and find if they do the size I need.

Online Gyro

  • Super Contributor
  • ***
  • Posts: 10766
  • Country: gb
Re: Prevent cable from being pulled through hole
« Reply #8 on: May 14, 2018, 10:22:41 am »
Nobody asked if it was a mains cable?  ???  If it is, then no way should you ever tie a knot in it! Mains cables require proper strain relief to prevent tugging or chafing on the sides of the hole. That's a safety issue. [Edit: Another vital function of a strain relief is rotation prevention - that can tear internal mains wiring loose.]
« Last Edit: May 14, 2018, 10:30:36 am by Gyro »
Best Regards, Chris
 

Online jpanhalt

  • Super Contributor
  • ***
  • Posts: 4744
  • Country: us
Re: Prevent cable from being pulled through hole
« Reply #9 on: May 14, 2018, 10:26:52 am »
I have just used a zip tie (nylon strap).   You can also wrap tape around it, use heat shrink, or any combination of the three.
 

Offline Mr. Scram

  • Super Contributor
  • ***
  • Posts: 9823
  • Country: 00
  • Display aficionado
Re: Prevent cable from being pulled through hole
« Reply #10 on: May 14, 2018, 10:28:46 am »
I have just used a zip tie (nylon strap).   You can also wrap tape around it, use heat shrink, or any combination of the three.
Even Weller uses zip ties this way in their higher end stuff. If it works, I guess.
 

Offline Richard Crowley

  • Super Contributor
  • ***
  • Posts: 4319
  • Country: us
  • KJ7YLK
Re: Prevent cable from being pulled through hole
« Reply #11 on: May 14, 2018, 10:41:17 am »
Nobody asked if it was a mains cable?  ???  If it is, then no way should you ever tie a knot in it! Mains cables require proper strain relief to prevent tugging or chafing on the sides of the hole. That's a safety issue. [Edit: Another vital function of a strain relief is rotation prevention - that can tear internal mains wiring loose.]
Yes that seems like common sense here in the 21st century.  But back 60-80 years ago, rubber grommets and special knots were quite common with attached zip-cord power entrances.  I remember seeing the special knots where you zip apart the two wires (L & N) and tie a symmetrical knot.  Look at some of those videos showing vintage electronic gear.

I hate attached power cords (including wall-warts and line-lumps).  I take special pleasure in replacing those old crumbly grommets (and even Heyco bushings) with proper IEC 60320 panel-mount connectors. I still have a nice big bag of IEC connectors that I bought at the Tektronix surplus sales.

 

Online Gyro

  • Super Contributor
  • ***
  • Posts: 10766
  • Country: gb
Re: Prevent cable from being pulled through hole
« Reply #12 on: May 14, 2018, 01:29:20 pm »
Me too. You can almost guarantee, the more valuable or irreplaceable the 'treasure' you're carrying, the more likely the cord is to get wrapped around your ankles!
Best Regards, Chris
 

Offline bd139

  • Super Contributor
  • ***
  • Posts: 23102
  • Country: gb
Re: Prevent cable from being pulled through hole
« Reply #13 on: May 14, 2018, 01:33:08 pm »
Captive leads of any kind are evil.

I watched my father stand on an old radio power supply lead when he was carrying it once. Faceplanted and cracked a rib.

Yes I did laugh  >:D
 

Offline Kjelt

  • Super Contributor
  • ***
  • Posts: 6663
  • Country: nl
Re: Prevent cable from being pulled through hole
« Reply #14 on: May 14, 2018, 01:35:06 pm »
Yes also often put a knot in it or used a tiewrap,
it prevents the cable from being pulled out but it does not prevent the cable from being pushed in  :)

Also in dusty environments those holes are dustcollectors.
 

Offline rstofer

  • Super Contributor
  • ***
  • Posts: 10020
  • Country: us
Re: Prevent cable from being pulled through hole
« Reply #15 on: May 14, 2018, 02:59:55 pm »

Yes that seems like common sense here in the 21st century.  But back 60-80 years ago, rubber grommets and special knots were quite common with attached zip-cord power entrances.  I remember seeing the special knots where you zip apart the two wires (L & N) and tie a symmetrical knot.  Look at some of those videos showing vintage electronic gear.


It was done all the time!  I remember seeing knots in the power cords to a lot of appliances, particularly things like table lamps.  I thought the ARRL handbook showed how to tie the knot, many years ago.  In any event, it is known as the Underwriter's Knot and there are a lot of hits on Google:

https://www.google.com/search?q=ul+knot

Done all the time!
« Last Edit: May 14, 2018, 03:35:48 pm by rstofer »
 
The following users thanked this post: Richard Crowley

Offline FriedMule

  • Frequent Contributor
  • **
  • Posts: 807
  • Country: dk
  • Can make even the simplest task look imposible.
Re: Prevent cable from being pulled through hole
« Reply #16 on: May 14, 2018, 03:43:22 pm »
Could you please tell about what material the box are made of, type of cord, main / signal, how secure you want the cord (shall it hold any load, weight, bee trip secure)?
Even if I appear online is it not necessary so, my computer is on 24/7 even if I am not on.
 

Offline Electro Detective

  • Super Contributor
  • ***
  • Posts: 2715
  • Country: au
Re: Prevent cable from being pulled through hole
« Reply #17 on: May 14, 2018, 11:30:30 pm »
The most common solution is a strain-relief bushing, and the prominent brand is Heyco.
When you use the proper size, they grip the cable so well that the cable will break before they let go.
But they need exactly the right size hole and they are tricky to install/remove with ordinary pliers.




https://www.heyco.com/Strain_Relief_Bushings/product.cfm?product=Original-Strain-Relief-Round-1


They were/are called 'Nylon Cable Gland' or 'Nylon Cable Entry Gland' the last time I bought some in a few sizes,
they are very handy quick fixes, and a painless upgrade for stiff or deteriorating rubber grommet 'disater waiting to happen' devices   

and yes they are tricky to remove if fitted securely, unless you have the purpose made tool,
or a customized/butchered  >:D  pair of cheapie pliers or grippers 

FWIW if they are not a perfect fit, or loose/wonky and a suss grip, you can wrap electrical tape around the cable first to beef it up, then press down on the gland and slot it in to the chassis

I have successully used this method for round holes too and it works well enough (an internal silicone gob 'may' be required for zero rotation movement) as these Nylon Cable Entry Glands are designed to stay put in oblong shaped holes


If aesthetics are involved, conceal the black electrical tape under length of the gland,
or just get it sorted and then carefully trim off the excess tape for a pro look


Other cable diameter beef up methods are heatshrink or thin wall rubber tubing, but electrical tape works fine (UL listed preferably) if the cable isn't being removed or replaced.

My personal preference is good quality black or grey duct tape, it's wide, performs well under the pressure, it's one solid adhesive piece that I stretch a bit for extra grip, to ensure it won't budge or go gooey over time and temperature extremes 


Hard to put it in words, hope it made sense  :phew:

 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf