Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: sluckey on February 22, 2015, 05:11:04 am

Title: Power cord strain relief
Post by: sluckey on February 22, 2015, 05:11:04 am
This is a nice, easy to use alternative to the more common Heyco style strain relief that requires a "D" shaped hole. I just bought 10 of these and will be using them when I run out of IEC connectors. This guy offers these in 5 or 10 packs also.

http://www.ebay.com/itm/3-8-NPT-Strain-Relief-Cord-Grip-Cable-Gland-w-nut-gasket-NEW/271307829316?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D29310%26meid%3D7fa6bc87287d4308a3f10e3621164e0d%26pid%3D100005%26rk%3D1%26rkt%3D6%26sd%3D271275346009&rt=nc (http://www.ebay.com/itm/3-8-NPT-Strain-Relief-Cord-Grip-Cable-Gland-w-nut-gasket-NEW/271307829316?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D29310%26meid%3D7fa6bc87287d4308a3f10e3621164e0d%26pid%3D100005%26rk%3D1%26rkt%3D6%26sd%3D271275346009&rt=nc)
Title: Re: Power cord strain relief
Post by: blues man on February 22, 2015, 07:30:09 am
When i worked as an electronic assembler we used a Heyco crimping tool especially made for their strain relief and it really made it easier to install one. Ive looked on the net to buy one and I couldn't find any.
Title: Re: Power cord strain relief
Post by: Willabe on February 22, 2015, 09:00:50 am
I think I bought mine from Digi-Key?


             Brad    :icon_biggrin:
Title: Re: Power cord strain relief
Post by: jjasilli on February 22, 2015, 09:09:49 am
@ sluckey:  Great find!


@ blues man & Willabe: I got mine on eBay some time ago.  They work.  http://www.ebay.com/itm/Electrical-Strain-Relief-Bushing-Assembly-Pliers-Tool-/381096012962?pt=LH_DefaultDomain_0&hash=item58bb17aca2 (http://www.ebay.com/itm/Electrical-Strain-Relief-Bushing-Assembly-Pliers-Tool-/381096012962?pt=LH_DefaultDomain_0&hash=item58bb17aca2)
Title: Re: Power cord strain relief
Post by: Willabe on February 22, 2015, 09:24:50 am
Oh man.......  $4.99?     :BangHead:       :cussing:

That's not what I paid.


            Brad    :sad2:
Title: Re: Power cord strain relief
Post by: Fresh_Start on February 22, 2015, 02:14:30 pm
Oh man.......  $4.99?     :BangHead:       :cussing:

That's not what I paid.


            Brad    :sad2:

Don't worry Brad - it would've been worth a lot more than $4.99 not to go through the Rube Goldberg process I've used with those old strain relief parts and the D-shaped hole.

Cheers,

Chip
Title: Re: Power cord strain relief
Post by: Willabe on February 22, 2015, 03:12:59 pm
Yeah that's why I bought them, I have 2 different sizes.

They do make taking the strain relief in/out a LOT easer.

           
                      Brad    :icon_biggrin:

Title: Re: Power cord strain relief
Post by: darryl on February 22, 2015, 05:08:16 pm
I always use these thingies:


(http://images.altronics.com.au/prod/p/P8324.jpg)

They remove the need for cable clamping, and have the added safety feature that the fuse cannot be accessed until the mains cable is unplugged.

Cutting the chassis hole is a real b*tch though. 
Title: Re: Power cord strain relief
Post by: mresistor on February 22, 2015, 07:00:54 pm
Great find Sluckey - are they made by Heyco.  I like these.
Title: Re: Power cord strain relief
Post by: jjasilli on February 22, 2015, 08:50:45 pm
@ Darryl: Though I like IEC's; I'm always afraid that having an amp separate from its power chord is messing with Murphy's Law.
Title: Re: Power cord strain relief
Post by: Willabe on February 22, 2015, 08:52:34 pm
and have the added safety feature that the fuse cannot be accessed until the mains cable is unplugged.

That's a good point.

I've had good success using a Dremel to cut the chassis for them.   

           Brad    :icon_biggrin:
Title: Re: Power cord strain relief
Post by: Willabe on February 22, 2015, 08:53:30 pm
@ Darryl: Though I like IEC's; I'm always afraid that having an amp separate from its power chord is messing with Murphy's Law.

Why?


                Brad     :dontknow:
Title: Re: Power cord strain relief
Post by: darryl on February 22, 2015, 11:51:56 pm
@ Darryl: Though I like IEC's; I'm always afraid that having an amp separate from its power chord is messing with Murphy's Law.

You can usually find a kettle lead in the venue's kitchen.  (http://www.twoweekwait.com/community/images/smilies/shh.gif)
Title: Re: Power cord strain relief
Post by: kagliostro on February 23, 2015, 12:50:25 am
The strain relief Steve has find is a nice and sturdy one,

but my preference are for IEC connector, when the unit is to be moved, it is always a pain to manage the cable,

no matter the attempt to roll up the cable carefully it always end you goes to stumble on it or it gets stuck somewhere,

not to mention how annoying is an irremovable cable when storing the amp in a flight case

certainly, as Darryl says, drill the hole for the IEC is difficult and Steve's solution is much easier to install

but I prefer to suffer only one time

however, it is possible to solve the problem of a fixed cable in this way

(https://www.gearslutz.com/board/attachments/high-end/52207d1204736390-best-small-tube-guitar-combo-amp-st-6v6se_back_741_1.jpg)

or this way (also if I don't like it much)

(http://c1.zzounds.com/media/fit,2018by3200/quality,85/2313700000v5_hi-dff6c64ba215f1b2124f252f4705f98d.jpg)

Franco
Title: Re: Power cord strain relief
Post by: mresistor on February 23, 2015, 04:52:26 am
When i worked as an electronic assembler we used a Heyco crimping tool especially made for their strain relief and it really made it easier to install one. Ive looked on the net to buy one and I couldn't find any.

I went to Harbor Freight and bought a cheap set of slip-joint pliers  then using a grinder ground the teeth off of the inside of the jaws to smooth and slightly rounded. It makes compressing and installing those strain relief bushings very easy. It's also easier to heat the bushing area of the cord prior to compression. 
Title: Re: Power cord strain relief
Post by: blues man on February 23, 2015, 06:16:14 am
i am currently using a bent nose pliers which does work but not as easy as the Heyco tool. I should have stole them.
Title: Re: Power cord strain relief
Post by: jjasilli on February 23, 2015, 08:08:19 am
@ Darryl: Though I like IEC's; I'm always afraid that having an amp separate from its power chord is messing with Murphy's Law.

Why?
                Brad     :dontknow:


Let's call it the techies version of The Lost Chord!  :icon_biggrin:
Title: Re: Power cord strain relief
Post by: Willabe on February 23, 2015, 12:21:00 pm
Oh.   :laugh:
Title: Re: Power cord strain relief
Post by: floyd on February 23, 2015, 05:44:50 pm
I'll NEVER again use the usual strain relief. This is how I do it.. a tight fitting grommet with a cable clip.. simple.
Title: Re: Power cord strain relief
Post by: tubeswell on February 23, 2015, 07:30:37 pm
I'll NEVER again use the usual strain relief. This is how I do it.. a tight fitting grommet with a cable clip.. simple.


Does it for me too.
Title: Re: Power cord strain relief
Post by: lego4040 on February 25, 2015, 02:27:44 pm
Last night i destroyed a strain relief trying to get the damn thing in. I gave up, stepped back to look at WTF was going on and realized the cord I was using was 16awg not 18awg and thats why it wouldnt go in. Now to find a 16AWG cord, I have another relief
Title: Re: Power cord strain relief
Post by: sgmezei16 on February 25, 2015, 02:42:01 pm
Cool find! I just ran across this working on a Trace Elliot Velocette. First time I ever saw it and dug it alot. Definetly going to get some.

A quick tip though, I use a heat gun to warm up the cable then use a pair of pliers to cramp down the strain relief on the cable. I use a round hole on the chassis and heating up the cable makes it ALOT easier to get it in there.
Title: Re: Power cord strain relief
Post by: lego4040 on February 25, 2015, 03:37:45 pm
Quote
I use a heat gun to warm up the cable then use a pair of pliers to cramp down the strain relief on the cable.
Why didnt I think of that
Title: Re: Power cord strain relief
Post by: mresistor on February 25, 2015, 04:28:22 pm
Gee Lego   I mentioned using heat already in this thread... and Floyd I don't think I would do that. It takes an extra hole to drill in the chassis and takes up more real estate, and still isn't 100% secure. The D hole isn't that hard to do. And compressing the strain relief grommet isn't that hard to do either using the simple tool I made and using heat. When you use 16 ga wire you need to use a grommet that accommodates it. I like Sluckeys strain relief and it isn't very expensive. For that matter cutting a square hole isn't that hard, and I know you guys have a file set or a dremel and some cheap Chinese diamond burrs. Just outline the square hole and drill most out with a drill bit and file the rest. No need for an expensive punch unless you are going to go into production and do many. 

OK sorry if I step on anyones toes.
Title: Re: Power cord strain relief
Post by: G._Hoffman on February 25, 2015, 05:54:29 pm
@ Darryl: Though I like IEC's; I'm always afraid that having an amp separate from its power chord is messing with Murphy's Law.

Why?
                Brad     :dontknow:


Let's call it the techies version of The Lost Chord!  :icon_biggrin:

Yeah, but you can buy perfectly good IEC cables 6 for $20, and you can find one just about anywhere at this point.  Easy to find, cheap to buy.  I have about 30 extra IEC cables just hanging on my wall, and any time I'm putting together a gig kit, I throw a half a dozen extra IEC cables in the box.  Their ubiquity makes them safe from loss.  If you don't have enough, you can always beg one off the lighting guy.


Gabriel
Title: Re: Power cord strain relief
Post by: eleventeen on February 25, 2015, 06:06:27 pm
I agree with the IEC cord approach. I get them for free from the local computer e-scrap guy and 1/4 of the time they are brand new unused. When I had a business selling refurbed terminals I'd just buy 50 of them for a buck each and was done for the year.
Title: Re: Power cord strain relief
Post by: lego4040 on February 25, 2015, 06:07:19 pm
I've used those here at work, the one Sluckey linked. Never thought to use those. I didn't use heat, I just flexed the spot back and forth for a while, put relief on and slapped that bad boy right in. That tool is cool to
Title: Re: Power cord strain relief
Post by: floyd on February 26, 2015, 03:39:51 am
Gee Lego   I mentioned using heat already in this thread... and Floyd I don't think I would do that. It takes an extra hole to drill in the chassis and takes up more real estate, and still isn't 100% secure. The D hole isn't that hard to do. And compressing the strain relief grommet isn't that hard to do either using the simple tool I made and using heat. When you use 16 ga wire you need to use a grommet that accommodates it. I like Sluckeys strain relief and it isn't very expensive. For that matter cutting a square hole isn't that hard, and I know you guys have a file set or a dremel and some cheap Chinese diamond burrs. Just outline the square hole and drill most out with a drill bit and file the rest. No need for an expensive punch unless you are going to go into production and do many. 

OK sorry if I step on anyones toes.      No.. just drilled the usual hole in the back of the chassis for the power cord, then secured the cord to a PT bolt with a cable clip and a keps nut.. very secure with no movement.
Title: Re: Power cord strain relief
Post by: jjasilli on February 26, 2015, 12:14:47 pm
Good thread.  Lot's of info & ideas.  Different solutions will appeal to different builders and end-users.
Title: Re: Power cord strain relief
Post by: sluckey on February 27, 2015, 01:05:08 pm
If you look closely at Steve Luckey's strain relief, you will see the hole in the chassis has a grommet, in it.  I believe it important as it lowers the chaffing on the cord, and subsequent short circuiting when the cord cover and one of the power wires wears through.    (My rickenbacker M8e, came from the factory with its  deadly power cord (two prong), as Sluckey shows.).   
I don't know what you're talking about.
Title: Re: Power cord strain relief
Post by: shooter on February 27, 2015, 03:17:02 pm
He might be talking about post#18, floyd's
Title: Re: Power cord strain relief
Post by: sluckey on March 03, 2015, 05:07:03 pm
Sorry about that Steve and Floyd.
You and Floyd should hook up.
Title: Re: Power cord strain relief
Post by: shooter on March 03, 2015, 07:01:42 pm
 :l2: :m2 :occasion14: